Zoned heating of breathing circuit

Abstract

The invention discloses zoned heating of a breathing circuit. Some embodiments provide an inspiratory branch for a breathing circuit, the inspiratory branch including a first section including a first heater wire circuit and a second section including a second heater wire circuit. The aspiration branch may include an intermediate connector that includes a connection circuit that electrically couples the first heating wire circuit to the second heating wire circuit. The inspiration branch may be configured to operate in two modes, where in a first mode, electrical power provides power to the first heater strip circuit through the first electrical connection without providing power to the second heater strip circuit, and in a second mode, electrical power provides power to the second heater strip circuit through the second electrical connection without providing power to the first heater strip circuit. Electrical power provides power to both the first heating wire circuit and the second heating wire circuit through the first electrical connection.

Description

[0001] This application is a divisional application of an invention patent application with an application date of September 9, 2016, application number 201680065542.4, PCT international application number PCT / NZ2016 / 050144, and invention name “Partitioned heating of a breathing circuit” and an invention patent application with an application date of September 9, 2016, application number 202110156642.0, and invention name “Partitioned heating of a breathing circuit”.

[0002] Incorporation by reference

[0003] The present application is related to the following applications: U.S. Provisional Application No. 61 / 726,532, filed on November 14, 2012, entitled “ZONE HEATING FOR RESPIRATORY CIRCUITS”; U.S. Provisional Application No. 61 / 786,141, filed on March 14, 2013, entitled “ZONE HEATING FOR RESPIRATORY CIRCUITS”; U.S. Provisional Application No. 61 / 877,736, filed on September 13, 2013, entitled “ZONE HEATING FOR RESPIRATORY CIRCUITS”; U.S. Provisional Application No. 61 / 877,784, filed on September 13, 2013, entitled “CONNECTIONS FOR HUMIDICATION SYSTEM”; U.S. Provisional Application No. 61 / 877,784, filed on September 13, 2013, entitled “MEDICAL TUBES AND METHODS OF MANUFACTURING”; U.S. Provisional Application No. 61 / 877,784, filed on September 13, 2013, entitled “CONNECTIONS FOR HUMIDICATION SYSTEM ... and U.S. Provisional Application No. 62 / 380,195, filed on August 26, 2016, entitled “Zoned Heating for Breathing Circuits,” each of which is incorporated herein by reference in its entirety.

[0004] In addition, PCT application number PCT / IB2012 / 001786, entitled “Medical Tubing and Manufacturing Method”, filed on May 30, 2012, PCT application number PCT / NZ2013 / 000222, entitled “Medical Tubing and Manufacturing Method”, filed on December 4, 2013, and PCT application number PCT / NZ 2013 / 000208, entitled “Zoned Heating of Breathing Circuits”, filed on November 14, 2013, are also incorporated herein by reference in their entirety. Technical Field

[0005] The present disclosure relates generally to humidification systems for providing humidified gas to a user, and more particularly to heating gas in a breathing circuit used with a humidification system. Background Art

[0006] Many gas humidification systems provide heated and humidified gas for various medical procedures (including respiratory therapy, laparoscopy, etc.). These systems can be configured to use feedback from sensors to control temperature, humidity, and flow. In order to maintain the desired characteristics when delivered to the user, the breathing circuit can have a heater associated with the gas conduit, wherein these heaters provide heat to the gas when the gas flows to the user and / or flows out from the user. These conduit heaters can be controlled to provide heat to the gas so that the gas arrives at the user with desired characteristics such as temperature and / or humidity. The humidification system can include a temperature sensor that provides feedback to a humidification controller that can adjust and / or modify the power delivered to these conduit heaters to achieve a target temperature at a position along the associated conduit. Summary of the invention

[0007] The systems, methods and devices described herein have innovative aspects, no single one of which is indispensable or solely responsible for achieving their desirable attributes. Without limiting the scope of the claims, some advantageous features will now be summarized.

[0008] Some embodiments provide an inspiratory limb for a breathing circuit. The inspiratory limb described herein is particularly useful in situations where heated and humidified gases must pass through two different environments. This can be a problem in, for example, an infant incubator where the temperature is significantly higher than the surrounding environment, or where a portion of the conduit delivering gases to a patient is located under a blanket. However, the embodiments disclosed herein can be used in any environment where heated and / or humidified gases are delivered to a patient, and are not limited to use where the inspiratory limb passes through two different environments.

[0009] The inspiratory limb may include a first segment of the inspiratory limb, the first segment including a first structure forming a conduit, the conduit being configured for conveying humidified gas, and wherein the first segment of the inspiratory limb includes a first heating wire circuit. The inspiratory limb may include a second segment of the inspiratory limb, the second segment including a second structure forming a conduit, the conduit being configured for conveying humidified gas, wherein the second structure is configured to be mechanically coupled to the first structure of the first segment to form an extended conduit for humidified gas, and wherein the second segment of the inspiratory limb includes a second heating wire circuit. The inspiratory limb may include an intermediate connector, the intermediate connector including a connecting circuit electrically coupling the first heating wire circuit to the second heating wire circuit, the intermediate connector being connectable to a patient end of the first segment of the inspiratory limb and a chamber end of the second segment of the inspiratory limb to form a single conduit for the humidified gas. The intermediate connector may be covered by a portion of the first segment of the suction branch, a portion of the second segment of the suction branch, or a portion of both the first and second segments of the suction branch, such that the intermediate connector is inside the suction branch.

[0010] The suction branch can be configured to operate in two heating modes. In the first heating mode, electric power passes through the intermediate connector to provide power to the first heating wire circuit without providing power to the second heating wire circuit. In the second heating mode, electric power passes through the intermediate connector to provide power to both the first heating wire circuit and the second heating wire circuit. For example, the intermediate connector may include electrical components that are configured to guide electric power along different paths based at least in part on current flow and / or voltage polarity. The intermediate connector may include the following conductive traces that can provide a short circuit (e.g., direct electrical connection without electrical components) between one or more wires in the first heating wire circuit and one or more wires in the second heating wire circuit. The intermediate connector may include the following conductive traces that electrically couple one or more wires in the first heating wire circuit to one or more wires in the second heating wire circuit, wherein these conductive traces include electrical components, such as but not limited to: diodes, transistors, capacitors, resistors, logic gates, integrated circuits, and the like. In some embodiments, the intermediate connector includes a diode electrically coupled to both the first heating wire circuit and the second heating wire circuit. In some embodiments, the inspiratory branch may further include a first sensor circuit having a first sensor positioned at the intermediate connector. In some embodiments, the inspiratory branch further includes a second sensor circuit having a second sensor positioned at a patient-end connector, the patient-end connector being positioned at the patient end of the second segment of the inspiratory branch. The inspiratory branch may be configured to operate in two sensing modes. In the first sensing mode, a signal from the first sensor is received without receiving a signal from the second sensor. In the second sensing mode, a signal from the second sensor is received without receiving a signal from the first sensor. In some embodiments, sensing includes receiving signals from both the first sensor and the second sensor in parallel. In such embodiments, the algorithm may determine the parameter measured by the first sensor based at least in part on the signals received from both the first and second sensors in parallel. In some embodiments, the intermediate connector includes a diode electrically coupled to both the first sensor circuit and the second sensor circuit. The patient-end connector may be configured to provide an electrical connection for the second sensor circuit. Similarly, the patient-end connector may be configured to provide an electrical connection for the second heating wire circuit. The sensors may be temperature sensors, humidity sensors, flow sensors, or the like. The first and second sensors may be sensors configured to measure one or more parameters such as temperature, humidity, flow, oxygen percentage, etc. In some embodiments, the first and second sensors are configured to measure at least one similar parameter (e.g., temperature, humidity, flow, etc.). In some embodiments, more than two sensors may be included and may be positioned at the intermediate connector and / or the patient end connector.

[0011] Some embodiments provide a respiratory humidification system having an inspiratory limb and a controller. The inspiratory limb may include: a first segment having a first heating wire circuit; a second segment having a second heating wire circuit; an intermediate connector having a connector circuit, the connector circuit being configured to electrically connect the first heating wire circuit to the second heating wire circuit; a first sensor positioned at the patient end of the first segment; and a second sensor positioned at the patient end of the second segment. The controller may be adapted to selectively switch between a first mode and a second mode, wherein in the first mode, the controller provides electrical power to the first heating wire circuit through the connector circuit, and in the second mode, the controller provides electrical power to the first and second heating wire circuits. In some embodiments, the respiratory humidification system switches between modes based at least in part on input from one or both sensors. In some embodiments, the switching is performed at least in part on parameters including one or more of temperature, flow, humidity, power, or any combination thereof. These parameters may be derived or directly obtained from the first sensor, the second sensor, or a combination of the two sensors. In some embodiments, the first and second modes are defined by the current flow direction or voltage polarity provided by the power supply. In some embodiments, the respiratory humidification system may include more than two sensors providing inputs for controlling heating of the inspiratory limb.

[0012] Some embodiments provide a dual-branch circuit that may include an inspiratory branch. Such an inspiratory branch may include: a first segment having a first heating wire circuit; a second segment of the inspiratory branch having a second heating wire circuit; an intermediate connector having a connector circuit, the connector circuit being configured to electrically couple the first heating wire circuit to the second heating wire circuit; a first sensor positioned at the patient end of the first segment; and a second sensor positioned at the patient end of the second segment. The dual-branch circuit may also include an expiratory branch having an expiratory heating wire circuit. The dual-branch system may further include an interface connected to the inspiratory branch and the expiratory branch. The dual-branch system may further include a controller adapted to selectively switch between a first mode and a second mode, wherein in the first mode, the controller provides electrical power to the first heating wire circuit through the connector circuit, and in the second mode, the controller provides electrical power to the first and second heating wire circuits. In some embodiments, heating of the expiratory branch is performed using the expiratory heating wire circuit, independent of heating of the inspiratory branch using the first and second heating wire circuits. In some embodiments, the expiratory limb is powered in parallel with the first heating wire circuit in the first segment of the inspiratory limb and / or in parallel with the first and second heating wire circuits. In some embodiments, the expiratory limb can be designed to be powered only in the first mode, only in the second mode, or in both the first mode and the second mode. In some embodiments, the interface is connected via a Y-piece. Any suitable patient interface can be introduced. Patient interface is a broad term and is given its ordinary and customary meaning (that is, it is not limited to a special or customized meaning) by ordinary technicians in the field, and includes but is not limited to masks (such as tracheal masks, face masks and nasal masks), cannulas and nasal pillows.

[0013] In some embodiments, a segmented inspiratory branch is provided, wherein the structure of these segments includes an elongated pipe. These elongated pipes may include a first elongated member having a hollow body, the first elongated member spirally wound to at least partially form a conduit, the conduit having a longitudinal axis, an inner cavity extending along the longitudinal axis, and a hollow wall surrounding the inner cavity. These elongated pipes may include a second elongated member spirally wound and combined between adjacent turns of the first elongated member, the second elongated member forming at least a portion of the inner cavity of the elongated pipe. In some implementations, the first elongated member forms a plurality of bubbles in a longitudinal section, and the bubbles have a flattened surface at the inner cavity. In some implementations, adjacent bubbles are separated by a gap above the second elongated member. In some implementations, adjacent bubbles are not directly connected to each other. In some implementations, the plurality of bubbles have perforations.

[0014] Some embodiments provide a respiratory humidification system with two control loops. The respiratory humidification system may include an inspiratory branch, the inspiratory branch including a first segment with a first heating wire and a second segment with a second heating wire. The respiratory humidification system may also include a sensor, which is positioned at the patient end of the second segment for measuring patient end parameters. The first and second heating wires are electrically connected, the first heating wire forms a first heater circuit, and the first wire and the second wire form a second heater circuit. The respiratory humidification system may include a hardware controller configured to receive the output of the sensor. The hardware controller may be further configured to provide electrical power to the first heater circuit when the difference between the output of the sensor and the patient end parameter set point is less than a predetermined threshold, and to provide electrical power to the second heater circuit when the difference between the output value of the sensor and the patient end parameter set point is equal to or greater than the predetermined threshold. When the hardware controller provides electrical power to the first heater circuit, the hardware controller may be configured to provide maximum power to the first heater circuit. In some embodiments, the respiratory humidification system may further include an intermediate connector having a connector circuit, which is configured to electrically connect the first and second heating wires. In some embodiments, the patient end parameter can be temperature. In some embodiments, the first heating wire and the second heating wire can be exposed to different ambient environments. In some embodiments, the first heating wire and the second heating wire can be exposed to different ambient temperatures. In some embodiments, the power supplied to the first and / or second heater circuit can be determined by a PID control scheme.

[0015] Some embodiments provide a respiratory humidification system with two control loops. The respiratory humidification system may include an inspiratory limb having a first segment of a first heating wire, a second segment of a second heating wire, and a temperature sensor positioned at the patient end of the second segment for measuring a patient end parameter. The first and second heating wires may be electrically connected, the first heating wire forming a first heater circuit, and the first wire and the second wire forming a second heater circuit, the first and second heating wires being configured to heat the respiratory gas passing through the inspiratory limb. The respiratory humidification system may include a flow sensor, the flow sensor being in the flow path of the system and being configured to measure the flow of the respiratory gas. The respiratory humidification system may include a hardware processor, the hardware processor being in electrical communication with the first and second heating wires and the temperature sensor and the flow sensor. The hardware processor may be configured to execute software instructions, the software instructions may cause the processor to control the first and second heater circuits. When the difference between the output of the sensor and the patient end parameter set point is less than a predetermined error threshold, the processor may be configured to use the first heater circuit to heat the respiratory gas until a maximum temperature is reached in the first heating wire. When the difference between the output of the sensor and the patient-end parameter set point is equal to or greater than the predetermined error threshold, the processor can be configured to use the second heater circuit to heat the respiratory gas. The maximum power provided to the first heater circuit can be a first maximum value or a second maximum value based on the flow rate, the first maximum value being greater than the second maximum value.

[0016] In some embodiments, the maximum power can be the first maximum value when the measured flow rate is greater than a flow threshold, and the second maximum value when the measured flow rate is less than the flow threshold. In some embodiments, the flow threshold can be between about 2.4 lpm and about 5 lpm. In some embodiments, the flow threshold can be about 3.5 lpm. In some embodiments, the flow threshold can be about 3 lpm.

[0017] In other embodiments, when the first maximum power is provided to the first heater circuit and the measured flow rate decreases to a threshold value from high flow to low flow, the maximum power provided to the first heater circuit can be switched to the second maximum power. When the second maximum power is provided to the first heater circuit and the flow rate increases to a threshold value from low flow to high flow, the maximum power provided to the first heater circuit can be switched to the first maximum power, and the threshold value from high flow to low flow is less than the threshold value from low flow to high flow. In some embodiments, the threshold value from high flow to low flow can be between about 2.4 lpm and about 5 lpm. In some embodiments, the threshold value from low flow to high flow is about 6.5 lpm.

[0018] In some embodiments with a flow sensor, a portion of the first segment of the inspiratory branch adjacent to the second segment can be exposed to the same ambient environment as the second segment. In some embodiments, the portion of the first segment and the second segment can be located inside an incubator, and the remainder of the first segment can be located outside the incubator. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Reference numerals may be repeated throughout the drawings to indicate general correspondence between reference elements.The drawings are provided to illustrate the exemplary embodiments described herein and are not intended to limit the scope of the present disclosure.

[0020] Figure 1 An exemplary respiratory humidification system for delivering humidified gas to a user is presented, the respiratory humidification system having a breathing circuit including a segmented inspiratory limb with a sensor in each segment.

[0021] Figure 2 A segmented inspiratory branch for a humidification system is presented, the segmented inspiratory branch having an intermediate connector configured for coupling the heating wires and sensors in the two segments.

[0022] Figure 3A and 3B An exemplary circuit diagram is shown, including an active rectifier power supply for providing power to a heater wire in a segmented inspiratory limb of a breathing circuit, wherein the circuit is configured to power the heater wire in a first segment of the inspiratory limb in a first mode and to power the heater wire in both segments in a second mode.

[0023] Figures 4A-4D Exemplary humidification systems having an inspiratory limb and an expiratory limb are shown, wherein the humidification systems are configured to control heating wires in both limbs.

[0024] Figure 5 A block diagram of an exemplary system configured to detect the presence of an extended segment of an inspiratory limb and provide power to a heater wire in the inspiratory limb, the extended end of the inspiratory limb, and the expiratory limb is presented.

[0025] Fig. 6A and 6B An exemplary circuit diagram in a humidification system is shown, where the circuits are configured to read data from two sensors.

[0026] Figure 7 An exemplary circuit diagram in a humidification system is shown, where the circuit is configured to read temperature data using two transistors.

[0027] Fig. 8A and 8BAn exemplary diagram of a hardware configuration for a breathing circuit having an inspiratory limb and an expiratory limb, the inspiratory limb having a first segment and a second segment is presented.

[0028] Fig. 9 An exemplary embodiment of a humidification system is presented that utilizes a microcontroller in an intermediate connector to measure data to control heating and to read sensor values ​​in the inspiratory branch.

[0029] Fig.10 A block diagram of an exemplary intermediate connector for an inhalation branch using a microcontroller is shown.

[0030] Fig.11 Shown Fig.10 A circuit diagram of an exemplary power module and data line converter included in an intermediate connector is shown in FIG.

[0031] Fig.12 Shown with Fig.10 is a circuit diagram of an exemplary dual optocoupler circuit used in conjunction with an intermediate connector shown in to provide bidirectional data communication between the control side and the AC side on a power board.

[0032] Fig.13 A circuit diagram of an exemplary humidification system incorporating a digital temperature sensor for use with a breathing circuit having an inspiratory limb with at least two segments is presented.

[0033] Fig.14A and 14B An exemplary printed circuit board ("PCB") of an intermediate connector is shown.

[0034] Fig. 14C and 14D Exemplary embodiments of intermediate connectors are shown.

[0035] Fig.15A An example PCB showing the patient-side connector.

[0036] Figures 15B-15E An exemplary embodiment of a patient-end connector is shown.

[0037] Figures 16A-16E Exemplary embodiments of an insertion stop for a segmented suction branch are presented.

[0038] Fig.17A A side plan view of a section of an exemplary composite pipe is shown.

[0039] Fig. 17B Shown with Fig.17A An exemplary composite pipe resembles a longitudinal cross-section of a top portion of a pipe.

[0040] Fig. 17C Another longitudinal cross section is shown illustrating a first elongated member in the composite conduit.

[0041] Fig.17D Another longitudinal section of the top portion of the pipe is shown.

[0042] Fig.17E Another longitudinal section of the top portion of the pipe is shown.

[0043] Fig.18A A cross section of a second elongate member in a composite conduit is shown.

[0044] Fig.18B Another cross-section of the second elongate member is shown.

[0045] Fig. 18C Another exemplary second elongated member is shown.

[0046] Fig.18D Another exemplary second elongated member is shown.

[0047] Fig.18E Another exemplary second elongated member is shown.

[0048] Fig.18F Another exemplary second elongated member is shown.

[0049] Figure 18G Another exemplary second elongated member is shown.

[0050] Fig.19A -C shows an example of a first elongated member shape configured to improve thermal efficiency.

[0051] Fig.19D -F shows an example of a filament arrangement configured for improved thermal efficiency.

[0052] Fig. 20A -C shows an example of a first elongated member stack.

[0053] Fig.21A An exemplary circuit diagram configured to independently control two heaters is shown.

[0054] Fig.21B An exemplary circuit diagram configured to provide gated control of two heaters is shown.

[0055] Fig. 21C An exemplary circuit diagram configured to switch between independent control and gated control of two heaters is shown.

[0056] Fig.22AAn exemplary circuit diagram including a logic module and a mode relay configured to implement control of two heaters, or a segmented heater, is shown.

[0057] Fig. 22B A block diagram of a mode relay configured to control two heaters is shown.

[0058] Fig. 22C A block diagram of a mode relay configured to control a segmented heater is shown.

[0059] Fig.23 An exemplary circuit diagram is shown, which is configured to switch between independent control of two heaters or gated control of two heaters and is used to provide information about Fig.22A The functions described are shown in the exemplary circuit diagram.

[0060] Fig.24A An exemplary circuit diagram configured to control two heaters in parallel is shown.

[0061] Fig. 24B Shown Fig.24A An exemplary configuration of a heater module is shown in FIG. , wherein each of the heaters includes a diode to control the flow of current.

[0062] Fig.24C Shown in Fig.24A An exemplary circuit diagram is shown in FIG. , which is configured to control a segmented heater using a heater module.

[0063] Fig.24D Shown Fig.24C An exemplary configuration of a heater module is shown in FIG.

[0064] Figures 25A-25C Another exemplary circuit diagram is shown that is configured to control two heaters in parallel using an active rectification circuit.

[0065] Fig.26 A flow chart of an exemplary method for controlling a segmented heater is presented.

[0066] Fig. 27 An exemplary target temperature profile is shown.

[0067] Fig.28 A functional block diagram is presented to illustrate the relationship between the processing components of the control module, the requirements associated with the heater segments, and the results of the determinations of the application control module.

[0068] Fig.29 A flow chart of an exemplary control algorithm is presented.

[0069] Fig.30A flow chart of an exemplary PID control scheme is shown.

[0070] Fig.31 A flow chart of another exemplary control algorithm is shown.

[0071] Fig.32A -C shows an exemplary intermediate connector.

[0072] Fig.33A -C shows an exemplary cover for an intermediate connector.

[0073] Fig.34 Exemplary embodiments of an air intake branch and an extension branch with a heating wire directly coupled together via a diode are shown.

[0074] Fig.35 A flow chart of another exemplary control algorithm is shown.

[0075] Fig.36 A flow chart of another exemplary control algorithm is shown.

[0076] Fig.37 A flow chart of another exemplary PID control scheme is shown.

[0077] Fig.38 Another exemplary embodiment of an inspiratory catheter for use with a humidification system is presented.

[0078] Fig.39A -B shows an exemplary configuration of the suction branch and the extension branch relative to the incubator.

[0079] Fig.40 A flow chart of another exemplary control algorithm having a low flow control portion is presented.

[0080] Fig.41 Another exemplary low flow control portion flow chart is shown.

[0081] Fig.42 Another exemplary PCB of an intermediate connector is shown.

[0082] Fig.43 Another exemplary PCB showing a patient-side connector.

[0083] Fig.44A -B shows an exemplary PCB of the chamber end connector. DETAILED DESCRIPTION

[0084] Certain embodiments and examples of segmented inspiratory limbs, multi-zone heating, and inspiratory and / or expiratory limb heating are described herein. Those skilled in the art will appreciate that the present disclosure extends beyond these specifically disclosed embodiments and / or uses and their obvious modifications and equivalents. Therefore, it is intended that the scope of the disclosure disclosed herein should not be limited by any specific embodiment described herein.

[0085] Systems and methods for providing heat to a segmented inspiratory limb in a respiratory circuit of a respiratory humidification system, or providing heat to an inspiratory and / or expiratory limb, are described herein. It should be appreciated that while much of the description herein is in the context of a segmented inspiratory and / or expiratory limb in a respiratory circuit, one or more features of the present disclosure may also be implemented in other contexts where it is desirable to provide differential heating in segmented gas delivery conduits or to provide independent heating to separate gas delivery conduits such as in respiratory applications, surgical applications, or other applications.

[0086] The present disclosure relates to heating wires, heating elements, and / or heaters in the context of providing heat to a catheter. For example, a heating wire is a broad term and is given its common and customary meaning (that is, it is not limited to a special or custom meaning) by a person of ordinary skill in the art, and includes but is not limited to a heating strip and / or a conductive element that generates heat when electrical power is provided. Examples of such heating elements include wires made of conductive metals (e.g., copper), conductive polymers, conductive inks printed on the surface of a catheter, conductive materials for creating traces on a catheter, and the like. In addition, the present disclosure relates to catheters, branches, and medical tubing in the context of gas delivery. For example, a pipeline is a broad term and is given its common and customary meaning by a person of ordinary skill in the art, and includes but is not limited to passages (e.g., cylindrical passages and non-cylindrical passages) with a variety of cross-sections. Certain embodiments may introduce a composite pipeline, which may be generally defined as a pipeline comprising two or more parts, or specifically comprising two or more components in some embodiments, as described in more detail below. Segmented branches including the disclosed medical tubing may also be used in a breathing circuit, such as a continuous, variable, or bi-level positive airway pressure (PAP) system or another form of respiratory therapy.The terms "conduit" and "branch" should be interpreted in a manner similar to tubing.

[0087] When a heated and humidified breathing tube is used in an incubator or temperature-controlled environment (or any area where there is temperature variation, such as around a radiant warmer for a burn victim, or under a blanket used by a patient), the breathing tube may pass through at least two different zones: a lower temperature zone (e.g., a zone outside the incubator) and a higher temperature zone (e.g., a zone inside the incubator). If the tube is heated along its entire length by a single heater, one of these zones will tend to be at an undesirable, unsuitable, or non-optimal temperature depending on which zone is sensed (e.g., which zone contains the temperature sensor). If the heater is controlled by a sensor inside the incubator (e.g., a patient-end temperature sensor), the section outside the incubator will tend to be too cold, which may result in condensation. Conversely, if the heater is controlled by a sensor outside the incubator, the section inside the incubator will tend to be too hot, which may result in overheating of the gas provided to the patient. Accordingly, the present disclosure describes systems and methods for providing control of heat in a segmented breathing tube, wherein each segment has an associated sensor that provides feedback to a control module. Although several embodiments are described herein for two zones, such systems may also be expanded to accommodate use with additional zones, segments, or regions. For example, in an embodiment including three temperature zones, a segment of the respiratory duct may be heated based at least in part on three different temperature sensors in the zones. In addition, embodiments disclosed herein may control the heat delivered to the respiratory duct based at least in part on parameters at the patient end, thereby bypassing or ignoring one or more sensors located at intermediate points along the duct. In addition, embodiments disclosed herein may control the heat delivered to the respiratory duct using parameters provided by the following sensors, including, for example, but not limited to: temperature sensors, humidity sensors, flow sensors, oxygen sensors, etc.

[0088] The control module can monitor and control the heating temperature in multiple areas or sections. The control module can be configured to use the connector assembly embodiments described herein to provide heat to the first section of the breathing duct in a first mode and to the entire breathing duct in a second mode. The embodiments described herein can be used without hanging wires, exposed connectors, and / or patient-end electrical connections. Hanging wires as used herein include electrical connections that extend outside the breathing duct, pass inside the breathing duct, and are incorporated, molded, or otherwise formed or included as part of the breathing duct. The control module can be positioned inside or outside the humidifier. In some embodiments, the control module is positioned inside the humidifier for: controlling the first segment of the inspiratory limb, the second segment of the inspiratory limb, and the heating wire associated with the expiratory limb; and reading parameters from sensors associated with the first and second segments of the inspiratory limb and / or the expiratory limb. In some embodiments, the control module is configured to independently control the heating wire associated with the inspiratory limb and the heating wire associated with the expiratory limb.

[0089] The control module may also adaptively change the temperature of the segments. For example, the control module may monitor temperature sensors associated with one or more segments. The monitoring may be continuous, interval-based, or other schemes, such as interrupt or event-based monitoring. For example, monitoring of a temperature sensor may be based on: reading a value from an analog-to-digital converter; determining a voltage or current; sensing a logic condition; reading a thermostat; measuring a thermistor value; measuring a resistance temperature detector; measuring a voltage of a thermocouple; or other methods for sensing temperature, including but not limited to: using a semiconductor junction sensor, an infrared or thermal radiation sensor, a thermometer, an indicator, etc. In some embodiments, the temperature sensor is a thermistor.

[0090] In some embodiments, the ratio of power delivered to the first segment of the inspiratory limb and the second segment of the inspiratory limb can be changed during use at least in part based on feedback from sensors associated with each segment. For example, the ratio of power can be changed so that each segment is heated to a temperature that reduces or eliminates condensation. As another example, the ratio of power can be changed so that overheated gas is not provided to the patient. In some embodiments, the ratio of power can be continuously changed based on feedback from sensors (e.g., temperature sensors, humidity sensors, oxygen sensors, flow sensors, etc.). The ratio of power can be changed in different ways. For example, the ratio of power can be changed by changing the amplitude of the power signal (including but not limited to, voltage and / or current), the duration of the power signal, the duty cycle of the power signal, or other appropriate changes to the power signal. In an embodiment, the ratio of power is changed by changing the amplitude of the current provided. Similarly, in some embodiments, the ratio of power delivered to the inspiratory limb and the expiratory limb can be changed during use at least in part based on feedback from sensors associated with each limb.

[0091] Some embodiments provide an inhalation branch including a heating wire, which is not in the gas path, but is contained in a material that separates the heating wire from the gas path and also isolates the heating wire from the external environment. In some embodiments, the circuit system for providing power to the heating wires in these segments and reading these sensors is inside the inhalation branch so that it is not exposed to the external environment. In some embodiments, the heating wire is molded into the inhalation or exhalation duct so that the heating wire ends in the complementary segments of the duct contact the intermediate connector, so that these heating wires are electrically connected to the intermediate connector, wherein the intermediate connector can be configured to provide a circuit system for heating wire control and / or sensor reading. In some embodiments, the duty cycle of the power supply applied to the heating wire can be modulated, modified, and / or changed to change the amount of heat delivered to the gas when the gas flows through the associated segment or branch.

[0092] Some embodiments described herein provide a respiratory humidification system configured to deliver warm humidified gas to a patient or other user. The gas passes through a liquid chamber filled with a liquid (e.g., water) heated using a heating plate. The liquid evaporates in the chamber and combines with the gas flowing through the chamber, thereby heating and / or humidifying the gas. The humidified gas can be directed to an inhalation branch having one or more heating wires associated therewith. These heating wires can be selectively powered to provide a defined, desired, appropriate, or selected amount of heat to the humidified gas. In some embodiments, the respiratory humidification system can be used in combination with an incubator or a radiant warmer or a temperature-controlled environment. The temperature-controlled environment can be a substantially sealed environment in which the temperature within the environment is strictly controlled within a predefined temperature limit. The temperature-controlled environment mentioned defines a sealed enclosure including strict temperature control. The inhalation branch can be segmented, so that the first segment is outside the incubator and the second segment is inside the incubator. In addition, the first group of heating wires can be associated with the first segment, and the second group of heating wires can be associated with the second segment. The humidification system can be configured to provide power to the first group of heating wires in the first mode and to the first and second groups of heating wires in the second mode. In some embodiments, the humidification system can be configured to provide power to the first group of heating wires in the first mode and to the second group of heating wires in the second mode. In some embodiments, the first section or the first group of heating wires is heated, and only in a temperature-controlled environment or an incubator, for example, due to airflow, or placing a fan or blanket on the sensor of the pipeline in the incubator, there is a sudden change, and both the first and second heating wire groups are heated. The inspiratory branch can include a sensor at one end of each segment to provide feedback to the humidification system, for selecting the power delivered to the heating wire groups in these segments. In some embodiments, the sensor can be positioned only at one end of the entire pipeline, and the sensor can be positioned in a temperature-controlled environment or an incubator or a radiant warmer. In some embodiments, the humidification system can include an expiratory branch with an associated heating wire, and the heating wire is also selectively controlled by the humidification system. In the present disclosure, the segmented limb is described with reference to the inspiratory limb. However, the described features may also be applied to the expiratory limb.

[0093] Respiratory humidification system

[0094] Figure 1An exemplary respiratory humidification system 100 for delivering humidified gas to a user is shown having a respiratory circuit 200 including a segmented inspiratory limb 202 having sensors 204a, 204b in each segment. The segmented inspiratory limb 202 can be used in conjunction with an incubator 208 (as shown) or with another system in which different temperatures exist along different segments of the inspiratory limb 202, such as a radiant warmer or a temperature-controlled environment. The segmented inspiratory limb 202 can be used to provide different levels of heat to different segments 202a, 202b of the inspiratory limb to reduce or prevent condensation, and / or control the temperature of gas delivered to the user.

[0095] The respiratory humidification system 100 shown includes a pressurized gas source 102. In some implementations, the pressurized gas source 102 includes a fan, a blower, etc. In some implementations, the pressurized gas source 102 includes a ventilator, or other positive pressure generating device. In some implementations, the gas source can be a pressurized gas reservoir, and the gas can be supplied through an outlet such as a wall gas source in a hospital. The pressurized gas source 102 includes an inlet 104 and an outlet 106.

[0096] The pressurized gas source 102 provides a fluid flow (e.g., oxygen, anesthesia gas, air, a mixture of air and oxygen, a gas mixture, etc.) to the humidification unit 108. The fluid flow flows from the outlet 106 of the pressurized gas source 102 to the inlet 110 of the humidification unit 108. In the illustrated configuration, the humidification unit 108 is separate from the gas source 102 and removably connectable to the gas source 102. In the illustrated configuration, the humidification unit 108 is shown as being separate from the pressurized gas source 102, wherein the inlet 110 of the humidification unit 108 is connected to the outlet 106 of the pressurized gas source 102 via a conduit 112. In some implementations, the pressurized gas source 102 and the humidification unit 108 can be integrated into a single housing.

[0097] Although other types of humidification units can be used with certain features, aspects, and advantages described in the present disclosure, the humidification unit 108 shown is a pass-over humidifier including a humidification chamber 114 and an inlet 110 leading to the humidification chamber 114. In some implementations, the humidification chamber 114 includes a body 116 having a base 118 attached thereto. A compartment can be defined within the humidification chamber 116, which is adapted to hold a volume of liquid that can be heated by heat conducted or provided through the base 118. In some implementations, the base 118 is adapted to contact a heating plate 120. The heating plate 120 can be controlled by a controller 122 or other suitable component so that the amount of heat transferred to the liquid can be varied and controlled.

[0098] The controller 122 of the humidification unit 108 can control the operation of the various components of the respiratory humidification system 100. Although the system shown is shown as using a single controller 122, multiple controllers can be used in other configurations. These multiple controllers can communicate or can provide separate functions, so these controllers do not need to communicate. In some implementations, the controller 122 may include a microprocessor, a processor, a logic circuit system with an associated memory or storage device containing computer program software code. In such an implementation, the controller 122 can control the operation of the respiratory humidification system 100 according to instructions contained in a computer program, for example, and also in response to internal or external inputs. The controller 122, or at least one of the multiple controllers, can be located together with the breathing circuit, that is, attached to the breathing circuit or integrated as part of the breathing circuit.

[0099] The body 116 of the humidification chamber 114 includes a port 124 defining an inlet 110 of the humidification chamber 114 and a port 126 defining an outlet 128. As the liquid contained within the humidification chamber 114 is heated, the liquid vapor mixes with the gas introduced into the humidification chamber 114 through the inlet port 124. The mixture of gas and vapor exits the humidification chamber 114 through the outlet port 126.

[0100] The respiratory humidification system 100 includes a breathing circuit 200, which includes an inhalation branch 202 connected to an outlet 128, which defines an outlet port 126 of the humidification unit 108. The inhalation branch 202 transmits a mixture of gas and water vapor leaving the humidification chamber 114 toward the user. The inhalation branch 202 may include a heating element 206 positioned along the inhalation branch 202, wherein the heating element 206 is configured to reduce condensation, control the temperature of the gas reaching the user, maintain the humidity of the gas, or any combination of these along the inhalation branch 202. The heating element 206 can increase or maintain the temperature of the gas and water vapor mixture transmitted by the inhalation branch 202. In some implementations, the heating element 206 can be a wire that defines a resistive heater. By increasing or maintaining the temperature of the gas and water vapor mixture leaving the humidification chamber 114, water vapor is less likely to condense out of the mixture.

[0101] The respiratory humidification system 100 can be used in conjunction with an incubator 208. The incubator 208 can be configured to maintain a desired environment, such as a selected, defined, or desired temperature, for a user within the incubator 208. Thus, within the incubator 208, the internal ambient temperature can be different from the temperature outside the incubator 208. Thus, the incubator 208 causes, defines, creates, or maintains different temperature zones along the inspiratory limb 202, wherein the internal temperature is typically hotter than the external temperature. Having at least two different temperature zones along the inspiratory limb 202 may cause problems in delivering gas to the user, such as condensation along the inspiratory limb 202, delivery of gas at too high a temperature, or both.

[0102] The respiratory humidification system 100 may include an expiratory limb 210 associated with a heating element 212. In some embodiments, the expiratory limb 210 and the inspiratory limb 202 may be connected using a suitable assembly (e.g., a Y-piece). In some embodiments, the respiratory humidification system 100 may be used in conjunction with a radiant warmer under a blanket, or in other systems or situations that produce two or more temperature zones. The systems and methods described herein may be used with such systems and are not limited to implementations that incorporate an incubator.

[0103] The inhalation branch 202 can be divided into segments 202a and 202b, wherein the first segment 202a can be a portion of the inhalation branch 202 outside the incubator 208, and the second segment 202b (e.g., an incubator extension) can be a portion of the inhalation branch 202 inside the incubator 208. The first segment 202a and the second segment 202b can have different lengths or the same length. In some embodiments, the second segment 202b can be shorter than the first segment 202a, and in some implementations, the second segment 202b can be about half the length of the first segment 202a. The length of the first segment 202a can be, for example, at least about 0.5m and / or less than or equal to about 2m, at least about 0.7m and / or less than or equal to about 1.8m, at least about 0.9m and / or less than or equal to about 1.5m, or at least about 1m and / or less than or equal to about 1.2m. The second segment 202b may have a length of, for example, at least about 0.2m and / or less than or equal to about 1.5m, at least about 0.3m and / or less than or equal to about 1m, at least about 0.4m and / or less than or equal to about 0.8m, or at least about 0.5m and / or less than or equal to about 0.7m.

[0104] The segments of the inspiratory branches 202a, 202b can be connected to each other to form a single conduit for gas delivery. In some embodiments, the first segment 202a may include one or more first heating wires 206a and one or more first sensors 204a, and can be used without the second segment 202b. The controller 122 can be configured to control the first heating wire 206a and read the first sensor 204a when the second segment 202b is not connected to the first segment 202a. In addition, when the second segment 202b is connected to the first segment 202a, the controller 122 can be configured to control the first heating wire 206a and the second heating wire 206b in its corresponding segment, and read the first sensor 204a and the second sensor 204b. In some embodiments, the controller 122 can be configured to control the corresponding first and second heating wires 206a and 206b when the second segment 202b is attached, and read the corresponding first and second sensors 204a and 204b; and control the first heating wire 206a and read the first sensor 204a when the second segment 202b is not attached, without having to modify the controller 122 or the humidification unit 108. Therefore, whether the inspiratory limb 202 includes both the first segment 202a and the second segment 202b or only the first segment 202a, the same controller 122 and / or the humidification unit 108 can be used. In some embodiments, the controller 122 can be further configured to control the heating wire 212 in the expiratory limb 210, without having to modify the controller 122 or the humidification unit 108. Accordingly, the respiratory humidification system 100 can function with or without the second segment 202b attached, and / or with or without the expiratory limb 210 attached. It should be understood that, without the second segment 202b, the first segment 202a of the inspiratory limb 202 can act as a stand-alone inspiratory limb, just as when a patient interface is attached to one end of the first segment to provide gas to the patient. In some configurations, the controller 122 can control both the first segment 202a and the second segment 202b, or simply the first segment 202a, or simply the second segment 202b.

[0105] In one configuration, the controller 122 is configured to control the first segment 202a and the second segment 202b, or only the first segment 202a, based only on readings from the sensor 204b. In this configuration, the suction duct 202 may include only one sensor 204b positioned at one end of the second segment, without an intermediate sensor 204a.

[0106] In some embodiments, the first segment 202a and the second segment 202b are permanently joined together to form a single conduit for gas delivery. As used herein, permanent joining can refer to that the segments 202a, 202b are joined together in a manner that makes it difficult to separate the segments, such as by using an adhesive, a friction fit, overmolding, a mechanical connector, etc. In some embodiments, the first segment 202a and the second segment 202b are configured to be releasably coupled. For example, the first segment 202a can be used for gas delivery without the second segment 202b, or the first segment 202a and the second segment 202b can be coupled together to form a single conduit for gas delivery. In some embodiments, the first segment 202a and the second segment 202b can be configured so that they can be coupled together in only one configuration. For example, the first segment 202a can have a defined chamber end (e.g., the end closest to the chamber 114 or the humidification unit 108 along the direction of humidified gas flow to the patient), and a defined patient end (e.g., the end closest to the patient along the direction of humidified gas flow to the patient), wherein the chamber end is configured to be coupled to a component at the chamber 114 and / or the humidification unit 108. The second segment 202b can have a defined chamber end and a defined patient end, wherein the chamber end is configured to be coupled only to the patient end of the first segment 202a. The chamber end of the first segment 202a can be configured not to be coupled to either end of the second segment 202b. Similarly, the patient end of the first segment 202a can be configured not to be coupled to the patient end of the second segment 202b. Similarly, the patient end of the second segment 202b can be configured not to be coupled to either end of the first segment 202a. Accordingly, the first section 202a and the second section 202b can be configured to be connected in only one way to form a single conduit for gas delivery. In some embodiments, the first section 202a and the second section 202b can be configured to be connected in a variety of configurations. For example, the first section 202a and the second section 202b can be configured to not include a defined patient end and / or a defined chamber end. As another example, the first section 202a and the second section 202b can be configured so that the patient end and / or the chamber end of the first section 202a can be coupled to the chamber end or the patient end of the second section 202b. Similarly, the first section 202a and the second section 202b can be configured so that the chamber end and / or the patient end of the second section 202a can be coupled to the chamber end or the patient end of the second section 202b.

[0107] The respiratory humidification system 100 may include an intermediate connector 214 that may be configured to electrically connect elements of the first segment 202a and the second segment 202b of the inspiratory limb 202. The intermediate connector 214 may be configured to electrically connect the heating wire 206a in the first segment 202a to the heating wire 206b in the second segment 202b, so that the heating wires 206a, 206b can be controlled using the controller 122. The intermediate connector 214 may be configured to electrically connect the second sensor 204b in the second segment 202b to the first sensor 204a in the first segment, so that the controller 122 can obtain their corresponding outputs. The intermediate connector 214 may include electrical components that enable selective control of the heating wires 206a, 206b and / or selective reading of the sensors 204a, 204b. For example, the intermediate connector 214 may include electrical components that direct power through the first heating wire 206a in the first mode and through the first heating wire 206a and the second heating wire 206b in the second mode. The electrical components included on the intermediate connector 214 may include, for example, but not limited to, resistors, diodes, transistors, relays, rectifiers, switches, capacitors, inductors, integrated circuits, microcontrollers, microprocessors, RFID chips, wireless communication sensors, etc. In some embodiments, the intermediate connector 214 may be configured to be inside the inhalation branch 202 so that it is significantly shielded from external factors (e.g., less than 1% of water, particles, contaminants, etc. from the environment outside the inhalation branch 202 contacts the intermediate connector 214). In some embodiments, some of the electrical components on the intermediate connector 214 may be configured to be physically isolated from the humidified gas within the inhalation branch 202 to reduce or prevent damage that may be caused by exposure to humidity. In some embodiments, the intermediate connector 214 may include relatively inexpensive passive electrical components to reduce cost and / or increase reliability.

[0108] The inspiratory branch 202 may include sensors 204a, 204b in the respective segments of the inspiratory branches 202a, 202b. The first sensor 204a may be positioned near one end of the first segment 202a, close to the incubator 208, so that the parameters derived from the first sensor 204a correspond to the parameters of the humidified gas entering the second segment 202b. The second sensor 204b may be positioned near one end of the second segment 202b, so that the parameters derived from the second sensor 204b correspond to the parameters of the humidified gas delivered to the patient or user. The output of the sensors 204a, 204b may be sent as feedback to the controller 122 for controlling the power of the heating elements 206a, 206b delivered to the segments of the inspiratory branches 202a, 202b. In some embodiments, one or both of the sensors 204a, 204b may be a temperature sensor, a humidity sensor, an oxygen sensor, a flow sensor, etc. The temperature sensor may be any suitable type of temperature sensor, such as but not limited to: a thermistor, a thermocouple, a digital temperature sensor, a transistor, etc. Parameters provided by or derived from the sensors may include, for example but not limited to: temperature, humidity, oxygen content, flow rate, or any combination of these, etc.

[0109] The controller 122 can be configured to: control the heating wires 206a and 206b; receive feedback from the sensors 204a and 204b; provide logic to control the power to the heating wires 206a and 206b; adjust the control of the heating wires 206a and 206b in response to the readings of the sensors 204a and 204b; detect the presence of the second segment 202b of the inspiratory branch 202; derive parameters based on the readings of the sensors 204a and 204b, etc. In some embodiments, the controller 122 includes a power supply configured to deliver electrical power to the heating wires. The power supply can be an AC source or a DC source. In some embodiments, the controller 122 can receive input from the heating plate sensor 130. The heating plate sensor 130 can provide information about the temperature and / or power usage of the heating plate 120 to the controller 122. In some embodiments, the controller 122 can receive input from the flow sensor 132. Any suitable flow sensor 132 may be used and may be positioned between the ambient air and the humidification chamber 114, or between the pressurized gas source 102 and the humidification chamber 114. In the illustrated system, the flow sensor 132 is positioned on the inlet port 124 of the humidification chamber 114.

[0110] Segmented suction branch

[0111] Figure 2A portion of a segmented inspiratory limb 202 for use with a respiratory humidification system 100 is shown, the segmented inspiratory limb 202 comprising a first segment 202a and a second segment 202b, and having an intermediate connector 214 configured to couple a first heating wire 206a in the respective segments 202a and 202b to a second heating wire 206b, and to couple a first sensor 204a to a second sensor 204b. Coupling the two segments 202a and 202b may include mechanically coupling the segments to form a single conduit through which humidified gas may be delivered to a user, wherein mechanically coupling the segments 202a and 202b may allow the respective heating wires 206a, 206b and the respective sensors 204a, 204b to be electrically coupled via the intermediate connector 214.

[0112] The segmented inspiratory branch 202 may include a structure 216 forming an inner cavity through which humidified gas may pass. The structure 216 may include multiple paths formed in the wall of the structure 216, the paths being configured to accommodate the heating wires 206a or 206b, so that the heating wires 206a or 206b are shielded from the humidified gas passing through the inner cavity, and / or covered by the outer surface of the structure 216, so that they are not exposed. For example, the structure 216 may be a spiral bubble tube, in which the heating wire path is a coil molded in the pipe. The structure 216 may include any type of suitable material, and may include an insulating material and / or a flexible material. In some embodiments, the structure 216 and the intermediate connector 214 may be configured so that when the first segment 202a and the second segment 202b are mechanically connected, the heating wires 206a and 206b are wrapped around the intermediate connector 214 in a manner electrically connected to the intermediate connector 214. In some embodiments, the first segment 202a and / or the intermediate connector 214 may eliminate any dangling wires for connecting to the second segment 202b, thereby facilitating the connection of the second segment 202b to the first segment 202a.

[0113] The structure 216 at the complementary ends of the first segment 202a and the second segment 202b can be configured to accommodate the intermediate connector 214. Thus, the intermediate connector 214 can be inside the inspiratory limb 202. In some embodiments, the complementary ends of the first segment 202a and the second segment 202b can be configured to shield the intermediate connector 214 from the humidified gas advancing through the inspiratory limb 202. In some embodiments, the intermediate connector 214 is both inside the inspiratory limb 202 and shielded from the humidified gas in the conduit, thereby reducing or eliminating exposure of electrical connections on the intermediate connector 214. In an exemplary configuration, the intermediate connector, or at least the portion of the intermediate connector 214 that is inside the lumen, is overmolded with a silicone or plastic material to form a protective layer or coating.

[0114] In some embodiments, the first heating wire 206a may include two wires 218 and 220, and the second heating wire 206b may include two wires 222 and 224. The two wires 218 and 220 in the first segment 202a may be electrically coupled to each other via an electrical component 228, wherein the electrical coupling creates an electrical path through the wire 218, at least a portion of the electrical component 228, and the wire 220. Similarly, the two wires 222 and 224 in the second segment 202b may be electrically coupled to each other via the electrical component 228, and / or electrically shorted together at the end of the segment 202b opposite the intermediate connector 202b, for example, via a patient-end connector (not shown), as described herein with reference to Figure 3A , 3B , 8A, 8B, 9, and 13. By coupling the wires 222 and 224 of the second segment 202b at the intermediate connector 214, electrical connections at the patient end of the inspiratory limb 202 are reduced or eliminated, which can reduce cost, system complexity, and / or risk to the patient.

[0115] The intermediate connector 214 may be configured to allow a single controller to control power to the heating wires 206a, 206b, wherein the controller may be a controller as described herein with reference to Figure 1 The humidifier controller 122 described above. In some embodiments, the humidifier controller 122 controls the heating wires without any additional control functions located on the intermediate connector 214. For example, the intermediate connector 214 may include passive components without any logic circuitry, where these passive components direct power to the heating wires 206a and / or 206b selected by the controller 122. This may allow the intermediate connector 214 to be designed using relatively inexpensive components and may reduce the complexity of the design.

[0116] In some embodiments, the heating of the two segments 202a and 202b can be achieved using up to four wires in each segment 202a and 202b. For example, in the first segment 202a, the four wires may include a first heating wire 218, a second heating wire 220, a sensor signal wire 228, and a sensor return wire 230. In the second segment 202b, the four wires may include a first heating wire 222, a second heating wire 224, a sensor signal wire 232, and a sensor return wire 234. By coupling the second heating wires 222, 224 to the first heating wires 218, 220 at the connection point 226, and by coupling the second sensor wires 232, 234 to the first sensor wires 228, 230 at the connection point 226, the controller can be configured to independently provide power to the first heating wire 206a and the second heating wire 206b, and independently read sensor data from the sensors 204a and 204b, in the case where no more than four wires are included in the segment 202a or 202b. In some embodiments, the control of the heating wires 206a and 206b and the reading of the sensors 204a and 204b can be achieved by using less than four wires in each segment (e.g., using 3 wires or using 2 wires), or using more than four wires in each segment (e.g., using 5 wires, using 6 wires, using 7 wires, using 8 wires, or using more than 8 wires).

[0117] The intermediate connector 214 may include an electrical component 228 configured to allow the controller 122 to selectively control the heating wires 206a, 206b. The controller 122 may be configured to control the heating of the inspiratory limb 202 using two modes, wherein the first control mode includes providing power to the heating wire 206a in the first segment, and the second control mode includes providing power to the heating wires 206a and 206b in the first segment 202a and the second segment 202b. Therefore, the controller 122 may be configured to independently control the heating wire segments. This capability allows the controller 122 to control the heating of the inspiratory limb 202 by controlling the heating of the inspiratory limb 202 only according to the first control mode when the second segment 202b is not present, thereby allowing the respiratory humidification system 100 to be used in a variety of situations without having to modify the controller 122 or the humidification unit 108. In some embodiments, these control modes may include the following mode: only the heating wire 206b in the second segment 202b is provided with power. In some embodiments, the controller 122 includes a power supply that provides current. The first and second control modes can be based at least in part on the voltage supplied by the power supply, wherein a positive voltage or positive current can trigger the first control mode, and a negative voltage and negative current can trigger the second control mode. In some embodiments, the power supply provides rectified AC or DC electricity to the heating wires 206a and 206b, and the change of rectification or polarity triggers the change of the control mode. By switching the control mode, the control of heating in the breathing circuit 200 can be achieved with any power supply source that can switch the polarity of the output signal. In some embodiments, the amount of power provided to the heating wires 206a, 206b can be adjusted by adjusting the duty cycle of the power applied to the heating wires 206a, 206b. For example, pulse width modulation (PWM) can be used to power the heating wires 206a, 206b, and the duty cycle of the PWM signal can be adjusted to control the power delivered. In another example, the amount of power provided to the heating wires 206a, 206b can be adjusted by controlling the amplitude of the power signal.

[0118] The intermediate connector 214 may include an electrical component 230 configured to allow the controller 122 to selectively read the sensors 204a, 204b. Selective reading may be accomplished by using a current source, wherein applying a positive current on the wires 228 to 230 may cause the controller 122 to measure a signal from the first sensor 204a, and applying a negative current on the wires 228 and 230 may cause the controller 122 to measure a signal from the second sensor 204b, or from both the first sensor 204a and the second sensor 204b, as described herein with reference to Fig. 6A , 6Band 7. The controller 122 can use the readings from the sensors 204a, 204b to adjust the power to the heating wires 206a, 206b, for example, by using pulse width modulation. The first sensor 204a can be positioned near the connecting portion or intersection of the first segment 202a and the second segment 202b to provide the controller 122 with the parameters of the gas entering the second segment 202b, and entering the second segment can correspond to entering an incubator or other such area with different ambient temperatures. The second sensor 204b can be positioned at the patient end of the second segment 202b to provide the controller 122 with the parameters of the gas delivered to the patient, or the parameters of the gas before the final part (e.g., Y-piece) before the patient. The controller 122 can use these readings to adjust the power to the heating wires 206a, 206b to maintain the gas temperature at the patient end of the inspiratory limb 202 at a target temperature or a suitable temperature. The target temperature or suitable temperature may vary depending at least in part on the application and environment in which it is used, and may be about 37°C, about 40°C, at least about 37°C and / or less than or equal to about 38°C, at least about 36.5°C and / or less than or equal to about 38.5°C, at least about 36°C and / or less than or equal to about 39°C, at least about 35°C and / or less than or equal to about 40°C, at least about 37°C and / or less than or equal to about 41°C, or at least about 39.5°C and / or less than or equal to about 40.5°C. In some embodiments, the second sensor 204b may be positioned inside the incubator but not attached to the breathing circuit. By measuring parameters inside the incubator, for example, the temperature of the second segment 202b may be calculated.

[0119] The controller 122 can independently control the amount of power delivered in the first and second control modes, as described herein. Based at least in part on feedback from the sensors 204a and / or 204b, the controller 122 can independently adjust the power delivered in the first and second control modes, thereby causing the ratio of heater power between the first segment 202a and the second segment 202b to change.

[0120] In some embodiments, the first sensor 204a is positioned within the gas flow within the inhalation branch 202. In some embodiments, the intermediate connector 214 or the first segment 202a may include a mechanical component that reduces turbulence of the gas flow across the first temperature sensor 204a, which may increase the accuracy of the readings of the sensor 204a. For example, the mechanical connector may have an aerodynamic cross section, referring to Figures 15B-15EAn example of this is described for a patient-end connector. In some embodiments, a mechanical component that reduces turbulence (e.g., a cross member feature within the inspiratory duct) also secures the sensor 204a within the gas fluid. In some embodiments, the intermediate connector 214 and the mechanical component are configured to thermally isolate the sensor 204a from electrical components on the intermediate connector 214, which may be advantageous if, for example, the sensor 204a is a temperature sensor.

[0121] In some embodiments, the intermediate connector 214 is not limited to Figure 2 In addition to the connection points 226 shown in FIG. 2 , additional connection points are included. These additional connection points can be used to introduce further functions into the breathing circuit, such as introducing a memory device (PROM) or (EPROM), a microcontroller, additional circuits, etc.

[0122] Intermediate connector circuit

[0123] Figure 3A A circuit diagram of an exemplary intermediate connector 214 is shown, the circuit diagram including an active rectifier power supply for providing power to heating wires in a segmented inspiratory limb of a breathing circuit, wherein the circuit is configured to power the heating wires R1 and R2 in a first segment of the inspiratory limb in a first mode, and to power the heating wires R1, R2, R3, and R4 in both segments in a second mode. By providing diodes D1 and D2 on the intermediate connector 214, and providing switches S1 and S2, power can be alternately applied through the heating wires R1 and R2 (where the resistors represent the heating wires), or through the heating wires R1, R2, R3, and R4.

[0124] The power supply is represented in the figure using VP and VN corresponding to the terminals of the power supply source. In an embodiment, the voltage supply source is an alternating current (AC) power supply source. Alternatively, the power supply can be a direct current (DC) power supply source. Although described as diodes in this embodiment, D1 and D2 can include any of a variety of different types of flow control devices, such as but not limited to: rectifiers, transistors, relays, switches, triacs, metal oxide semiconductor field effect transistors, thyristors (SCRs), thermostats, etc.

[0125] Switches S1 and S2 switch between the VP and VN terminals of the power supply. In an embodiment, switches S1 and S2 are switched every half cycle of the AC power cycle so that approximately equal current is drawn from the power supply during each half cycle. Figure 3AThe circuit shown in can be used to control the heaters R1, R2, R3, and R4 in two control modes, wherein the first control mode corresponds to providing power only to R1 and R2, and the second control mode corresponds to providing power to R1, R2, R3, and R4. To provide power only to the heaters R1 and R2 in the first segment 202a (corresponding to the first control mode), during the positive cycle of the power supply, the switch S1 is connected to VP and the switch S2 is connected to VN, and during the negative cycle of the power supply, the switch S1 is connected to VN and the switch S2 is connected to VP. In the first control mode, current flows through R1, R2, and D1, while D2 prevents current from flowing through R3 and R4. To provide power to the heaters R1, R2, R3, and R4 in the first segment 202a and the second segment 202b (corresponding to the second control mode), during the positive cycle of the power supply, the switch S1 is connected to VN and the switch S2 is connected to VP, and during the negative cycle of the power supply, the switch S1 is connected to VP and the switch S2 is connected to VN. In the second control mode, current flows through R1, R2, R3, R4 and D2, and D1 prevents current from bypassing the heaters R3 and R4 and shorting across these wires. The switching of switches S1 and S2 can be achieved by adding hardware or software logic to the system, as described herein with reference to Figure 5 In some embodiments, the switching of switches S1 and S2 is performed at the zero crossing of the AC power cycle. In some embodiments, the falling edge and rising edge of the zero crossing circuit system are not delayed by the same amount, and the circuit is not effective near the zero crossing. Therefore, the switching of switches S1 and S2 can be performed with or without zero crossing switching detection and / or logic.

[0126] Diodes D1 and D2 can consume power in the circuit and therefore generate heat. In some embodiments, Schottky diodes can be used in situations where it is desirable to reduce power consumption in relatively high temperature environments. Schottky diodes can operate near a maximum junction temperature to reduce or minimize power consumption, which may be desirable in certain implementations of the respiratory humidification system described herein. In some embodiments, the heat generated by the diodes may affect the temperature reading of sensor 204a. To reduce this effect, the diodes can be thermally connected to the airflow path of the loop. To reduce this effect and dissipate the heat generated by the diodes, a heat sink or heat sink thermally connected to the surrounding environment can be included on the intermediate connector 214. To reduce this effect, as well as the effect of other components on the intermediate connector 214, the sensor 204a (e.g., a thermistor or other temperature sensor) can be thermally isolated from these components and physically located relatively far away from the other components, as described with reference to FIG. Fig.14A -B and described in Figure 15.

[0127] Figure 3BAnother circuit diagram of an exemplary intermediate connector 214 is shown, the circuit diagram comprising an active rectifier power supply for providing power to heating wires in a segmented inspiratory limb of a breathing circuit, wherein the circuit is configured to power heating wires R1 and R2 in a first segment of the inspiratory limb in a first mode, and to power heating wires R1, R2, R3, and R4 in both segments in a second mode. Figure 3B As shown, only the diode D1 may be provided, and the path of the power through the heating wires R1 and R2 or through the heating wires R1 to R4 may still be controlled, as previously described with reference to Figure 3A Described. Eliminated Figure 3A D2 is shown in the circuit. Figure 3B The circuit shown with only one diode D1 can achieve less heat generation in the circuit, reduced parts cost, and a smaller circuit board. Figure 3B The rest of the circuit shown is similar to Figure 3A In the embodiment without D2, as Figure 3B As shown, most of the current flows through R1, R2, and D1, with only the remaining current flowing through R3 and R4. The remaining current flowing through R3 and R4 may be negligible, so that it does not affect the performance of the humidification system.

[0128] In addition to reference Figure 3A and 3B In addition to the described AC operation, similar circuits can be operated with a DC supply source. Switches S1 and S2 can be switched based at least in part on, for example, time, output current of the supply source, feedback from a sensor, or other control input. In such an embodiment, Figure 3A The circuit shown in FIG. 3B can also be used to control the heaters R1, R2, R3, and R4 in two control modes, wherein the first control mode corresponds to providing power only to R1 and R2, and the second control mode corresponds to providing power to R1 to R4. In order to provide power only to the heaters R1 and R2 in the first segment 202a (corresponding to the first control mode), the switch S1 is connected to VP and the switch S2 is connected to VN. In the first control mode, current flows through R1, R2, and D1. In Figure 3A In the circuit shown, D2 prevents current from flowing through R3 and R4. However, D2 is an optional component. Figure 3B As shown. To provide power to the heaters R1, R2, R3, and R4 in the first segment 202a and the second segment 202b (corresponding to the second control mode), switch S1 is connected to VN and switch S2 is connected to VP. In the second control mode, current flows through R1, R2, R3, R4, and D1 prevents current from bypassing R3 and R4 and shorting across these wires. As previously described, switching can be achieved by adding hardware or software logic to the system, as described herein with reference to Figure 5Described.

[0129] Control of the inspiratory and expiratory limb heaters

[0130] Figure 1 An exemplary respiratory humidification system 100 having an inspiratory branch 202 and an expiratory branch 210 is also shown, wherein the humidification system 100 is configured to control the heating wires 206, 212 in the two branches. In some embodiments, the expiratory heating wire 212 in the expiratory branch 210 can be electrically connected to the inspiratory heating wire 206 outside the humidification unit 108 and the controller 122, so that the control of the expiratory heating wire 212 can be achieved without affecting other control modes and without the need for additional switching transistors. Similarly, the expiratory heating wire 212 can be electrically connected to the inspiratory heating wire 206 within the humidification unit 108. The connection between the expiratory heating wire 212 and the inspiratory heating wire 206 can be achieved in the humidification system 108, on the intermediate connector 214, in the sensor box at the humidification system 108, or in the like. Therefore, the controller 122 can control the expiratory heating wire 212 without an additional electrical connection at the patient end, the presence of which may increase risk, system complexity, and cost. Figures 4A-4D , Fig. 8A and 8B An example of electrical coupling of the exhalation heating wire 212 and the inhalation heating wire 206 inside the humidification unit 108 is shown.

[0131] Reference Figure 4A , the humidification unit 108 can be combined with switches or relays S3 and S4 to select between independent control and dependent control of the inhalation heating wire and the exhalation heating wire. In some embodiments, these switches or relays are activated when a pipe (e.g., an inhalation branch or an exhalation branch) with appropriate identification (e.g., by an identification resistor detected and / or measured by the humidification unit 108) is connected to the humidification unit 108. For example, when these switches are not activated (e.g., S3, S4 are both disconnected), the heating wire in the inhalation branch and / or the heating wire in the exhalation branch can be controlled individually and / or independently.

[0132] When the appropriate tubing is connected or the system otherwise determines that it is appropriate, switches S3 and S4 can be closed to control both the inspiratory and expiratory branches. The humidification unit 108 can include an inspiratory power supply INSP and an expiratory power supply EXP, wherein the system can implement switching in each power supply, as described herein with reference to Figure 3A and 3B For example, refer to Figure 3A , the suction power supply may have switches S1 and S2 configured to selectively direct positive and negative cycles to the heaters R1 to R4. Figure 4A, the exhalation power supply EXP may include a plurality of switches configured to selectively direct power to the exhalation branch having heaters R5 and R6. In some embodiments, when switches S3 and S4 are closed, the two switches in the exhalation power supply EXP are disconnected, so that power is provided to the inhalation heating wire and the exhalation heating wire by the inhalation power supply INSP. In some embodiments, the humidification unit 108 does not include the exhalation power supply EXP. In such an embodiment, the inhalation power supply INSP is used to provide power to the inhalation heating wire when switches S3 and S4 are disconnected, and to provide power to both the inhalation heating wire and the exhalation heating wire when switches S3 and S4 are closed. Therefore, the inhalation branch heating wire 206 can be controlled in the same manner as before, but now the system can use switches S3, S4 to simultaneously control the power to the exhalation heating wire 212 and the exhalation heating wire 206 by using a unified circuit and / or control system. For example, the humidification unit 108 can operate in two modes with respect to the inspiratory branch 202 (e.g., the first mode is that the humidification unit 108 provides power to the heaters R1 and R2, and the second mode is to provide power to the heaters R1 to R4) while selectively controlling the power of the heaters R5 and R6 in the expiratory branch, so that the humidification unit 108 can not provide power to the heaters R5 and R6, or provide power to the heaters R5 and R6 when operating in the first mode, the second mode, or both modes. As previously described, the connection between the inspiratory branch 202 and the expiratory branch 210 can be made inside or outside the humidification unit 108. In an embodiment, the connection is made in the sensor box, the intermediate connector 214, or another location.

[0133] In some embodiments, the Figure 1 The intermediate connector 214 shown is implemented to be configured to connect the exhalation heating wire 212 to the exhalation circuit on the controller 122. The exhalation circuit can be connected in one or more ways in several ways. For example, the exhalation circuit can be connected in parallel with the heating wire 206a in the first segment 202a or with the heating wire 206b in the second segment 202b. In some embodiments, the intermediate connector 214 may include an internal overhead or suspended wire that makes the exhalation circuit available on the intermediate connector 214. In some embodiments, the intermediate connector 214 can be connected to the third channel added so that there is no overhead wire between the inhalation circuit and the exhalation circuit. A heating wire drive control circuit can be added to the controller 122 to adapt to such embodiments.

[0134] Figure 4BAn exemplary embodiment of a humidification system is shown that incorporates a power supply 405 to provide power to both the inspiratory heating wires R1 to R4 and the expiratory heating wires R5 and R6 through a combination of switches or relays S1 to S6 and a diode D1. In the illustrated embodiment, the humidification system is configured to provide power to the expiratory heating wires when only the inspiratory heating wires R1, R2 in the first segment of the inspiratory branch are receiving power (e.g., in a first operating mode) or when the inspiratory heating wires R1 to R4 in both segments are receiving power (e.g., in a second operating mode). The power supply 405 can be any suitable power supply, including, for example, a power supply that provides alternating current in the form of a sine wave, sawtooth wave, square wave, or other form. In some embodiments, the power supply 405 is a transformer that provides the following voltage for the alternating current signal: at least about 22VAC, at least about 5VAC or less than or equal to about 30VAC, at least about 10VAC or less than or equal to about 25VAC, at least about 12VAC or less than or equal to about 22VAC.

[0135] Continue to refer to Figure 4B , the humidification system can be configured to provide power to the exhalation heating wires R5 and R6 in a first operating mode when the power supply source 405 provides power in a negative cycle. To this end, switches S1, S2, S5, and S6 are closed, and switches S3 and S4 are disconnected. The current flows from the negative terminal of the power supply source 405 through switch S2 and branches out to provide power to the heating wires in both the inhalation branch and the exhalation branch. In the inhalation branch, the current flows to the inhalation heating wire R2, then flows to the inhalation heating wire R1 through the diode D1, and then returns to the positive terminal on the power supply source 405 through switch S1. In the exhalation branch, the current flows to the exhalation heating wire R5 through switch S6, then flows to the exhalation heating wire R6, and then returns to the positive terminal on the power supply source 405 through switches S5 and S1.

[0136] Similarly, continue to refer to Figure 4B , the humidification system can be configured to provide power to the exhalation heating wires R5 and R6 in a first operating mode when the power supply source 405 provides power in a positive cycle. To this end, switches S3, S4, S5, and S6 are closed, and switches S1 and S2 are disconnected. The current flows from the positive terminal of the power supply source 405 through switch S3 and branches out to provide power to the heating wires in both the inhalation branch and the exhalation branch. In the inhalation branch, the current flows to the inhalation heating wire R2 through switch S6, then flows to the inhalation heating wire R1 through diode D1, and then returns to the negative terminal on the power supply source 405 through switches S5 and S4. In the exhalation branch, the current flows to the exhalation heating wire R5, then flows to the exhalation heating wire R6, and then returns to the negative terminal on the power supply source 405 through switch S4.

[0137] Continue to refer to Figure 4B , the humidification system can be configured to provide power to the exhalation heating wires R5 and R6 in a second operating mode when the power supply source 405 provides power in a positive cycle. To this end, switches S1, S2, S5, and S6 are closed, and switches S3 and S4 are disconnected. The current flows from the positive terminal of the power supply source 405 through the switch S1 and branches out to provide power to the heating wires in both the inhalation branch and the exhalation branch. In the inhalation branch, the current flows to the inhalation heating wire R1, then bypasses the diode D1 to flow to the inhalation heating wire R3, then flows to the inhalation heating wire R4, then flows to the inhalation heating wire R2, and then returns to the negative terminal on the power supply source 405 through the switch S2. In the exhalation branch, the current flows to the exhalation heating wire R6 through the switch S5, then flows to the exhalation heating wire R5, and then returns to the negative terminal on the power supply source 405 through the switches S6 and S2.

[0138] Similarly, continue to refer to Figure 4B , the humidification system can be configured to provide power to the exhalation heating wires R5 and R6 in a second operating mode when the power supply source 405 provides power in a negative cycle. To this end, switches S3, S4, S5, and S6 are closed, and switches S1 and S2 are disconnected. The current flows from the negative terminal of the power supply source 405 through switch S4 and branches out to provide power to the heating wires in both the inhalation branch and the exhalation branch. In the inhalation branch, the current flows to the inhalation heating wire R1 through switch S5, then bypasses the diode D1 to flow to the inhalation heating wire R3, then flows to the inhalation heating wire R4, then flows to the inhalation heating wire R2, and then returns to the positive terminal on the power supply source 405 through switches S6 and S3. In the exhalation branch, the current flows to the exhalation heating wire R6, then flows to the exhalation heating wire R5, and then returns to the positive terminal on the power supply source 405 through switch S3.

[0139] Figure 4C An exemplary embodiment of a humidification system is shown that incorporates a power supply 405 to provide power to both the inspiratory heating wires R1 to R4 and the expiratory heating wires R5 and R6 through a combination of switches or relays S1 to S6 and diodes D1, D2. In the illustrated embodiment, the humidification system is configured to provide power to the expiratory heating wires only when the inspiratory heating wires R1, R2 in the first segment of the inspiratory limb are receiving power (e.g., only in the first operating mode).

[0140] Continue to refer to Figure 4C, the humidification system can be configured to provide power to the exhalation heating wires R5 and R6 in a first operating mode when the power supply source 405 provides power in a negative cycle. To this end, switches S1, S2, S5, and S6 are closed, and switches S3 and S4 are disconnected. The current flows from the negative terminal of the power supply source 405 through switch S2 and branches out to provide power to the heating wires in both the inhalation branch and the exhalation branch. In the inhalation branch, the current flows to the inhalation heating wire R2, then flows to the inhalation heating wire R1 through the diode D1, and then returns to the positive terminal on the power supply source 405 through the switch S1. In the exhalation branch, the current flows to the exhalation heating wire R5 through the switch S6 and the diode D2, then flows to the exhalation heating wire R6, and then returns to the positive terminal on the power supply source 405 through the switches S5 and S1.

[0141] Similarly, continue to refer to Figure 4C , the humidification system can be configured to provide power to the exhalation heating wires R5 and R6 in a first operating mode when the power supply source 405 provides power in a positive cycle. To this end, switches S3, S4, S5, and S6 are closed, and switches S1 and S2 are disconnected. The current flows from the positive terminal of the power supply source 405 through switch S3 and branches out to provide power to the heating wires in both the inhalation branch and the exhalation branch. In the inhalation branch, the current flows to the inhalation heating wire R2 through switch S6, then flows to the inhalation heating wire R1 through diode D1, and then returns to the negative terminal on the power supply source 405 through switches S5 and S4. In the exhalation branch, the current flows to the exhalation heating wire R5 through diode D2, then flows to the exhalation heating wire R6, and then returns to the negative terminal on the power supply source 405 through switch S4.

[0142] Continue to refer to Figure 4C , the humidification system can be configured to provide power only to the inhalation heating wires R1 to R4 (and not to the exhalation heating wires R5 and R6) in a second operating mode when the power supply source 405 provides power in a positive cycle. To this end, switches S1, S2, S5, S6 are closed, and switches S3 and S4 are opened. Current flows from the positive terminal of the power supply source 405 through switch S1 to the inhalation heating wire R1, which then bypasses the diode D1 and flows to the inhalation heating wire R3, to the inhalation heating wire R4, to the inhalation heating wire R2, and returns to the negative terminal on the power supply source 405 through switch S2. In the positive cycle when the switch is configured as described, the current does not flow through the exhalation heating wire due to the diode D2, which blocks the current from flowing through the circuit.

[0143] Similarly, continue to refer to Figure 4C, the humidification system can be configured to provide power only to the inhalation heating wires R1 to R4 (and not to the exhalation heating wires R5 and R6) in a second operating mode when the power supply source 405 provides power in a negative cycle. To this end, switches S3, S4, S5, and S6 are closed, and switches S1 and S2 are opened. Current flows from the positive terminal of the power supply source 405 through switches S4 and S5 to the inhalation heating wire R1, which then bypasses the diode D1 and flows to the inhalation heating wire R3, to the inhalation heating wire R4, to the inhalation heating wire R2, and returns to the negative terminal on the power supply source 405 through switches S6 and S3. In the negative cycle when the switches are configured as described, the current does not flow through the exhalation heating wire due to the diode D2, which blocks the current from flowing through the circuit.

[0144] Figure 4D An exemplary embodiment of a humidification system is shown that incorporates a power supply 405 to provide power to both the inspiratory heating wires R1 and R4 and the expiratory heating wires R5 and R6 through a combination of switches or relays S1 to S6 and a diode D1, wherein the expiratory heating wires R5, R6 are electrically coupled to the inspiratory heating wires R1 to R4 on the patient side of the heating wires in the first segment of the inspiratory limb, which can occur at an intermediate connector, such as any of the intermediate connectors described herein. As described with reference to Figure 4D In the embodiment shown, the exhalation heating wires R5 and R6 are connected to the inhalation heating wires R1 to R4 at the intermediate connector, but any suitable position after the inhalation heating wires in the first segment can be used to connect the heating wires in the inhalation branch and the exhalation branch. In the embodiment shown, the humidification system is configured to provide power to the exhalation heating wires only when the inhalation heating wires R1 to R4 in the two segments of the inhalation branch are receiving power (e.g., only in the second operating mode).

[0145] Continue to refer to Figure 4D , the humidification system can be configured to provide power to the inhalation heating wires R1 to R4 and the exhalation heating wires R5 and R6 in a second operating mode when the power supply source 405 provides power in a positive cycle. To this end, switches S1, S2, S5, S6 are closed, and switches S3 and S4 are disconnected. The current flows from the positive terminal of the power supply source 405 through switch S1 to the inhalation heating wire R1, then bypasses the diode D1 and branches out to provide power to the second segment of the inhalation branch and the heating wires in both the exhalation branch. In the second segment of the inhalation branch, the current flows to the inhalation heating wire R3, then flows to the inhalation heating wire R4, and returns to the intermediate connector. In the exhalation branch, the current flows to R5 and then flows to R6, returning to the intermediate connector. The current then flows through the inhalation heating wire R2 and then returns to the negative terminal on the power supply source 405 through switch S2.

[0146] Similarly, continue to refer to Figure 4D , the humidification system can be configured to provide power to the exhalation heating wires R5 and R6 in a second operating mode when the power supply source 405 provides power in a negative cycle. To this end, switches S3, S4, S5, and S6 are closed, and switches S1 and S2 are disconnected. The current flows from the negative terminal of the power supply source 405 through switches S4 and S5 to the inhalation heating wire R1, then bypasses the diode D1 and branches out to provide power to the second section of the inhalation branch and the heating wires in both the exhalation branch. In the second section of the inhalation branch, the current flows to the inhalation heating wire R3, then flows to the inhalation heating wire R4, and returns to the intermediate connector. In the exhalation branch, the current flows to R5 and then flows to R6, returning to the intermediate connector. The current then flows through the inhalation heating wire R2 and then returns to the positive terminal on the power supply source 405 through switches S6 and S3.

[0147] Continue to refer to Figure 4D , the humidification system can be configured to provide power only to the inhalation heating wires R1 and R2 in the first segment of the inhalation branch (but not to the exhalation heating wires R5 and R6) in the first operating mode when the power supply source 405 provides power in a negative cycle. To this end, switches S1, S2, S5, and S6 are closed, and switches S3 and S4 are opened. Current flows from the negative terminal of the power supply source 405 through switch S2 to the inhalation heating wire R2, and the current then flows to the inhalation heating wire R1 through the diode D1, and then returns to the positive terminal on the power supply source 405 through switch S1.

[0148] Similarly, continue to refer to Figure 4D , the humidification system can be configured to provide power only to the inhalation heating wires R1 and R2 in the first segment of the inhalation branch (but not to the exhalation heating wires R5 and R6) in the first operating mode when the power supply source 405 provides power in a positive cycle. To this end, switches S3, S4, S5, and S6 are closed, and switches S1 and S2 are opened. Current flows from the positive terminal of the power supply source 405 through switches S3 and S6 to the inhalation heating wire R2, and the current then flows to the inhalation heating wire R1 through the diode D1, and returns to the negative terminal on the power supply source 405 through switches S5 and S4.

[0149] Other circuit designs and configurations for controlling the inhalation heater, the segmented inhalation heater and / or the exhalation heater are possible. Figure 1The controller 122 described in the embodiment of the present invention is used to control the control of the electric power to each heater. The control module can be configured to coordinate the opening and closing of the switch so as to selectively control the electric power of the one or more heaters. For example, the switch can be opened and closed to control the amount of power delivered to the heater. In some implementations, the power supply provides alternating current, and the switch can be controlled to modulate the amount of electric power to one or more heaters by using, for example, pulse width modulation technology. As another example, the control module can coordinate the operation of the switch to control which heaters or heater segments are delivered with electric power. In some embodiments, each area or heating wire to be heated can include a dedicated power supply. This can make it possible to remove the diode configured to regulate the current flow in the heating wire circuit. In some embodiments, the control algorithm can use flow information to directly control the fixed duty cycle of the first heater segment. In some embodiments, the control algorithm can use ambient temperature readings or measurements to directly control the fixed duty cycle of the first heater segment to a custom value.

[0150] In some embodiments, the control module may use a temperature measurement at a midpoint or between the patient end and the chamber end. For example, the control module may utilize such a midpoint temperature measurement to adapt the duty cycle of the first heater segment to maintain a target midpoint temperature. The duty cycle of the first heater segment may be adapted to maintain a target temperature difference relative to a chamber output dew point (humidity) associated with the chamber output temperature. The duty cycle of the first heater segment may be continuously adapted to maintain a target temperature difference relative to a measured patient end temperature. If the duty cycle remains at 100% for a custom time period and the patient end temperature is below a target set point by a custom amount, and the flow rate has been determined to be non-zero, the chamber output temperature may advantageously be reduced by a calculated target level (defined by the patient end temperature) based at least in part on the duty cycle of the combined first and second heater segments.

[0151] In some embodiments, at least a single measurement point for temperature feedback control in the system may be implemented, and this may be located at the system output. Such a configuration may be sufficient to achieve target gas conditions. In certain implementations, a dual zone system may not include temperature sensors if a priori knowledge of the heat transfer characteristics of each zone is established for known ambient operating conditions. In such a system, separate power levels may be established for each zone so that target gas output conditions may be obtained based on accurate measurements of mass flow through the system and knowledge of the gas conditions entering the gas delivery system.

[0152] Fig.21AAn exemplary circuit diagram 2000a is shown, which is configured to independently control two heaters H1, H2 (e.g., an inhalation heater, an exhalation heater, a segmented heater, etc.). As used herein, independent control can mean that delivering electrical power to one of the two heaters does not determine whether electrical power is delivered to the other heater. For example, switches S1 and S3 can be closed and switches S2 and S4 can be opened to deliver power only to heater H1, switches S1 and S3 can be opened and switches S2 and S4 can be closed to deliver power only to heater H2, or switches S1 to S4 can be closed to deliver power to both heaters H1, H2.

[0153] Circuit 2000a may include a power supply 2002 configured to provide electrical power. Power supply 2002 may be a power supply of alternating current or direct current. Power supply 2002 may be a voltage source or a current source. Circuit 2000a may include a main relay 2004 configured to deliver electrical power to components of circuit 2000a. Main relay 2004 may be disconnected (e.g., enter a state that does not allow current to flow) when the system detects a fault condition or when the system decides to cut off electrical power to the heaters and / or other electrical components of the breathing circuit.

[0154] In some embodiments, the system can be configured to detect when there is a short circuit (e.g., a short circuit between a heating wire and a sensor wire) between a low-power circuit and a high-power circuit. When the high-power circuit and the low-power circuit receive electrical power from a common source and / or receive electrical power from a common circuit, there may be a short circuit. In some implementations, the high-power circuit and the low-power circuit receive electrical power from a transformer, which rectifies the electrical power (e.g., from an AC power source), reduces (or increases) the output voltage (e.g., using a voltage divider) for the high-power circuit, and reduces the output voltage (e.g., using a voltage divider) for the low-power circuit. For example, the high-power circuit can be configured to provide about 22V, and the low-power circuit can be configured to provide about 3.3V. Other voltages are also possible. For example, the voltage provided by the high-power circuit can be at least about 50V, at least about 30V and / or less than about 50V, at least about 20V and / or less than about 30V, or at least about 10V and / or less than about 25V. As another example, the voltage provided by the low power circuit can be at least about 5V, at least about 3V and / or less than about 5V, at least about 2V and / or less than about 3.5V, or at least about 1.5V and / or less than about 2V. The actual voltage on the low power circuit can depend on the temperature measured by one or more temperature sensors connected to the low power circuit. For example, in a low power circuit providing about 3.3V, a thermistor measuring a temperature of about 50°C can output a voltage of about 0V, and a thermistor measuring a temperature of about 20°C can output a voltage of about 1.2V.

[0155] The system may include a first comparator, which is connected to the output of a series of voltage dividers, which are electrically connected to the transformer output configured to provide a voltage for a low-power circuit. The first comparator can provide an out-of-range signal when the voltage exceeds the expected voltage (for example, the voltage that the comparator is configured to detect). For example, in the case where the expected range is between 0 and 1.2V or 1.5V, the comparator can be configured to provide a signal indicating a possible short circuit when the voltage exceeds 1.2V or 1.5V. The system may include a second comparator, which is grounded and configured to provide a signal indicating a possible short circuit when the voltage is negative. The system may be configured to provide a signal indicating a possible short circuit immediately (for example, in real time or almost in real time) when the voltage outside the expected range is detected. In some implementations, the system may include the following logic, which is configured to ignore the short circuit signal, trigger an alarm, and / or turn off or reduce the power to the high-power circuit and / or the low-power circuit. If the system receives an out of range signal, the system can disconnect the main relay 2004 to cut off the electrical power to the electrical components (e.g., heating wires, sensors, etc.). A short circuit may occur in the presence of a voltage leakage from a high power circuit to a low power circuit (which may increase the voltage on the low power circuit to outside the expected range). Similarly, if a negative bias voltage supplied to a high power circuit leaks to a low power circuit, the voltage on the low power circuit may become negative.

[0156] Circuit 2000a may include switches S1 to S4 to control the electrical power of the heaters H1 and H2. As used herein, the term "switch" may be used to indicate an electrical switch and / or any other combination of electrical components and / or electromechanical components configured to control the flow of current. For example, the switch may include a MOSFET, a diode, a transistor, or a combination of these, etc. The heaters H1 and H2 may be any of the heaters described herein.

[0157] Circuit 2000a may include a control module 2006 configured to control switches S1 to S4. Control module 2006 may be configured to provide a signal to the switch to indicate the desired state of the receiving switch. For example, the control module may send a signal (e.g., a voltage exceeding a threshold voltage) to switches S1 and S3 or switches S2 and S4 to control their closure. Control module 2006 may be configured to use one signal to control switches S1 and S3 and another signal to control switches S2 and S4. In this way, a switch pair (e.g., switches S1, S3 and / or switches S2, S4) may synchronize its operation (e.g., opening and closing at or near the same time). Circuit 2000a is configured to independently control heaters H1, H2 by independently controlling the opening and closing of switch pairs S1, S3 and switch pairs S2, S4.

[0158] Fig.21B An exemplary circuit diagram 2000b configured to provide gated control to heaters H1 and H2 is shown. Circuit 2000b is similar to circuit 2000a, but the flow of electric power to the circuit controlled by switches S2 and S4 is controlled by switches S1 and S3, respectively. In this way, control module 2006 can provide gated control to heaters H1 and H2. As used herein, gated control can refer to that the flow of electric power to heater H1 can be controlled by switches S1 and S3, while the flow of electric power to heater H2 can be controlled by switches S1 and S3 at a first level and by switches S2 and S4 at a second level. For example, depending on the state of switches S2 and S4, when switches S1 and S3 are closed, electric power can flow to heater H2. However, if switches S1 and S3 are disconnected, the states of switches S2 and S4 are irrelevant because electric power does not flow to heater H2. In this way, hardware can control the operation of heaters H1 and H2. This enables gated control of heater H2, because the control module 2006 can use switches S1 and S3 to control power to heater H2 (e.g., provide a gate to enable heater H2 to receive electrical power). This may be beneficial in situations where hardware control of heaters H1, H2 is desired to provide an additional control mechanism in addition to software control of the heaters. For example, control software on a humidifying device may request that heater H2 be powered, but this request may be overridden by hardware configuration.

[0159] Fig. 21C An exemplary circuit diagram 2000c configured to switch between independent control and gated control of heaters H1, H2 is shown. The control module 2006 can control switches S5, S6 to selectively arrange the circuit 2000c into an independent control configuration (similar to the circuit diagram of FIG. 2001 ). Fig.21A Circuit 2000a described herein), or a gate control configuration (similar to the circuit 2000a described herein) Fig.21B Circuit 2000c provides the benefits of both circuits 2000a, 2000b and selects a desired, appropriate, and / or suitable configuration with control module 2006.

[0160] Fig.22A An exemplary circuit diagram 2100a is shown, which includes a logic module 2008 and a mode relay 2010, which is configured to enable control of two heaters (e.g., an inspiratory heater and an expiratory heater) or a segmented heater (e.g., a heater in a segmented inspiratory conduit). Circuit diagram 2100a is similar to that described herein with reference to Figures 21A-21CThe circuit diagrams 2000a, 2000b and 2000c described include a power supply 2002, a main relay 2004, and a control module 2006. Switches S1 to S4 are configured in a manner similar to the circuit diagram 2000a. However, a logic module 2008 is interfaced with the control module 2006 to control switches S1 to S4. In addition, a mode relay 2010 provides dynamic configuration for different heater configurations.

[0161] The logic module 2008 receives the control signals SW1, SW2 from the control module 2006 and processes these signals based at least in part on the mode signal MODE from the control module 2006. The mode signal MODE can indicate a predetermined, selected, or desired mode for the circuit 2100a. For example, the mode signal MODE can be used to indicate to the logic module 2008 that the operation of the circuit 2100a should be to independently control the heater or the segmented heater. Based on the control signals SW1, SW2 and the mode signal MODE, the logic module 2008 outputs the switch signals HW1, HW2 to control the switch pairs S1, S3 and S2, S4, respectively.

[0162] In some implementations, the mode signal MODE can be used to indicate the independent heater control mode to the logic module 2008. In this case, the logic module 2008 can be configured to pass the control signals SW1, SW2 to the output switch signals HW1, HW2 with little or no modification. In this way, the control module 2006 can control the two heaters independently. In some embodiments, the operating mode indication received by the mode relay 2010 is similar to the indication provided by the mode signal MODE. In response to the received indication, the mode relay 2010 can provide electrical connections for lines 1-4 (corresponding to the lines controlled by switches S1-S4). For example, as Fig. 22B As shown, the mode relay 2010 can provide electrical paths for lines 1-4 to enable independent control of the heaters H1, H2, similar to the embodiments described herein with reference to Fig.21A The operation of circuit 2000a is described.

[0163] In some implementations, the mode signal MODE can be used to indicate the segmented heater control mode to the logic module 2008. In this case, the logic module 2008 can be configured to output switch control signals HW1, HW2 to selectively control switches S1 to S4 to provide a rectified electrical signal to the segmented heater. In this way, the control module 2006 can control the segmented heater as described elsewhere herein. In some embodiments, the operating mode indication received by the mode relay 2010 is similar to the indication provided by the mode signal MODE. In response to the received indication, the mode relay 2010 can provide an electrical connection for lines 1-4 (corresponding to the lines controlled by switches S1-S4). For example, as Fig. 22C As shown, the mode relay 2010 can electrically connect lines 1 and 4 and electrically connect lines 2 and 3 to enable control of a segmented heater including heater segments H1 and H2, similar to the operation of other circuits configured to control segmented heaters described herein. In this mode, the mode relay 2010 provides the ability to turn on heater segment H1 or both heater segments H1 and H2 based at least in part on the configuration of switches S1 to S4 and the polarity of the voltage / current.

[0164] For example, in the segmented heater mode, the control module 2006 may use the control signal SW1 to indicate a desire or request to provide power to both heater segments H1 and H2. In response, the logic module 2008 may provide a switch control signal HW1 to control switches S1 and S3 to close during periods when the polarity of the signal from the power source 2002 is positive; and a switch control signal HW2 to control switches S2 and S4 to close during periods when the polarity of the signal from the power source 2002 is negative. Similarly, the control module 2006 may use the control signal SW2 to indicate a desire or request to provide power only to the heater segment H1. In response, the logic module 2008 may provide a switch control signal HW2 to control switches S2 and S4 to close during periods when the polarity of the signal from the power source 2002 is positive; and a switch control signal HW1 to control switches S1 and S3 to close during periods when the polarity of the signal from the power source 2002 is negative. In this manner, the logic module 2008 is able to achieve rectification of the voltage / current to the segmented heaters H1 , H2 .

[0165] Logic module 2008 implements a safety latch that can be implemented when operating with segmented heater control. Logic module 2008 can be configured to set the two switch control signals HW1, HW2 to control switches S1 to S4 to disconnect if control signals SW1, SW2 indicate a request to operate in its requested mode. This can be used to reduce or prevent failures associated with providing power to the segmented heater. For example, power supply source 2002 can be used to provide alternating current, or to provide positive and negative biased voltages. These currents and / or bias voltages can be controlled by switches S1 to S4. Closing all switches S1 to S4 may cause currents in two directions or these two positive and negative biased voltages to be provided to heater circuit 2100a at the same time, which may damage the system. The logic module 2008 may include a latch that opens the main relay 2004 when the control module 2006 (eg, by software or hardware failure) activates an incompatible heater driver (eg, when both switch groups S1, S3 and S2, S4 are activated or closed).

[0166] Fig.23 An exemplary circuit diagram 2100b is shown, which is configured to independently control two heaters (e.g., as described herein with reference to Fig.21A Circuit diagram 2000a) or gate control (eg, as described herein with reference to Fig.21B The circuit diagram 2000b) described above switches between the two circuits and provides a circuit diagram with respect to Fig.22A The exemplary circuit diagram 2100a shown in FIG. 2100b provides a schematic diagram of the circuit diagram of FIG. Fig. 21C The switching function of the circuit diagram 2000c described herein and the switching function of the circuit diagram 2000c described herein Fig.22A The circuit diagram 2100a described in the embodiment of the present invention provides the function provided by the circuit diagram 2100a described. To achieve this function, the control module 2006 can provide an additional control signal SW3, which the logic module 2008 can use to provide a switch control signal HW3 to operate switches S5 and S6. Switches S5 and S6 can be configured so that when operating in an independent heater control mode and when operating in a segmented heater control mode, switches S1 and S2 are connected in parallel and switches S3 and S4 are connected in parallel. Switches S5 and S6 can be configured so that when operating in a gated heater control mode, switches S1 and S2 are connected in series and switches S3 and S4 are connected in series. The logic module 2008 can perform additional checks to verify that the control signal SW3 is appropriate based at least in part on a mode signal MODE, wherein the mode signal can be configured to provide the following indication: select, request, or wish to operate in an independent heater control mode, a gated heater control mode, or a segmented heater control mode.

[0167] Fig.24AAn exemplary circuit diagram 2200 configured to control two heaters H1, H2 in parallel is shown. The circuit 2200 can be configured to be coupled to a heater module 2012a, which includes heaters H1, H2. The circuit 2200 can be configured to provide electrical connections for the heater module 2012a, which are similar to the mode relay 2010 (when it is referred to herein). Fig. 22C Circuit 2200 may be configured in other ways relative to circuit 2100a, as described herein. Fig.22A Described.

[0168] Reference Fig.24A , the circuit 2200 can be configured to power the heaters H1 and H2 in the heater module 2012a in parallel. In some embodiments, the heater module 2012a can include one or more diodes to guide or limit the current flow to one or more heaters in the heater module 2012a. For example, Fig. 24B An exemplary configuration of heater module 2012a is shown in which heaters H1, H2 both include diodes to control the flow of electrical current. Diodes D1, D2 can be used to control when electrical power flows through the associated heaters H1, H2 to provide additional control capabilities.

[0169] Fig. 24B A simplified circuit diagram is also shown, illustrating the functionality of the circuit 2200, wherein the heater module 2012a is configured to include diodes D1, D2. When switches S1 and S3 are closed (and switches S2 and S4 are open), a positive current provided by the power supply 2002 flows through the heater H1 but not through the heater H2, and a negative current provided by the power supply 2002 flows through the heater H2 but not through the heater H1. Similarly, when switches S2 and S4 are closed (and switches S1 and S3 are open), a positive current provided by the power supply 2002 flows through the heater H2 but not through the heater H1, and a negative current provided by the power supply 2002 flows through the heater H1 but not through the heater H2. In this way, the control module can coordinate the opening and closing of the switch pairs S1, S3 and S2, S4 and the polarity of the voltage or current provided by the power supply 2002 to selectively energize the heaters H1, H2. In some implementations, diodes D1, D2 can be configured with different biases so that current flows through heaters H1, H2 opposite to that described. In some implementations, either diode D1 or D2 can be removed so that current is limited in one of heaters H1, H2 but not in the other.

[0170] Fig.24CAn exemplary circuit diagram 2200 configured to control a segmented heater by using a heater module 2012b is shown. In this configuration, when the mode relay 2010 in the circuit 2100a is configured to electrically connect lines 1 and 4 and to electrically connect lines 2 and 3 to enable control of a segmented heater including heater segments H1 and H2 (as referred to herein). Fig. 22C ), the circuit 2200 with the heater module 2012b operates in a similar manner to the circuit 2100a. Fig.24D An exemplary configuration of the heater module 2012b and a simplified circuit diagram of the circuit 2200 are shown to illustrate the functionality of the circuit when the switches are in different configurations. As described elsewhere herein, the two heater segments H1, H2 can be powered when the power supply 2002 provides a positive current and the switches S1, S3 are closed, or when the power supply 2002 provides a negative current and the switches S2, S4 are closed. As described elsewhere herein, the heater segment H1 can be powered when the power supply 2002 provides a negative current and the switches S1, S3 are closed, or when the power supply 2002 provides a positive current and the switches S2, S4 are closed.

[0171] Circuit diagram 2200 can advantageously allow connections to different heater modules to be implemented to allow a single circuit design to operate different heater configurations. This can also simplify control system design, software design, and improve interoperability of components for different respiratory devices.

[0172] Figures 25A-25C An exemplary circuit diagram 2500 is shown for controlling a segmented heater by using an active rectification circuit that uses quasi-back-to-back MOSFETs to quickly and finely control the direction of current from an A / C power source 2502. To help describe how the exemplary circuit 2500 controls a segmented heater, Fig.25B and 25C The switches S1-S4 are shown as diodes to make it easier to understand the resulting current flow in the circuit for a particular control mode and for a particular configuration of open and closed switches, as described below. However, it should be understood that the switches S1-S4 are electrical switches, such as MOSFETs, such as Fig.25A Displayed.

[0173] The active rectifier circuit 2500 can function to provide current to the target heater segments H1 and / or H2 by selectively switching MOSFETS1, S2, S3, and S4. For example, Fig.25BA circuit configuration for providing power to heater segments H1 and H2 is shown. When the power source 2502 provides a positive current, MOSFETS1 and S3 can be closed (e.g., turned on) and MOSFETS2 and S4 can be opened (e.g., cut off), and when the power source 2502 provides a negative current, MOSFETS1 and S3 can be opened (e.g., cut off), and MOSFETS2 and S4 can be closed (e.g., turned on). Fig.25C A circuit configuration for providing power to heater segment H1 is shown. When the power source 2502 provides a positive current, MOSFETS1 and S3 can be opened (e.g., cut off) and MOSFETS2 and S4 can be closed (e.g., turned on), and when the power source 2502 provides a negative current, MOSFETS1 and S3 can be closed (e.g., turned on), and MOSFETS2 and S4 can be opened (e.g., cut off).

[0174] In some embodiments, the exhalation heater is electrically coupled to the first heater segment H1 . In such embodiments, the exhalation heater receives power when the first heater segment H1 receives power.

[0175] Circuit diagram 2500 advantageously allows the use of a single power supply and a patient-end temperature sensor (e.g., a thermistor) to control a segmented heater. For example, circuit diagram 2500 can be used in a system that does not include a temperature sensor on the intermediate connector connecting the first heater segment H1 to the second heater segment H2. Circuit diagram 2500 can be implemented using a control system that is configured to change the switching of the MOSFET pair to heat the first heater segment H1 (e.g., the inner loop HW1 of the inspiratory branch) or the first heater segment H1 and the second heater segment H2 (e.g., the outer loop HW2 of the inspiratory branch including the inspiratory branch and the extension branch), which will be described in more detail below. HW2 can include both H1 and H2, that is, the entire heating circuit along the entire pipeline.

[0176] Check the extension of the connection on the suction branch

[0177] Figure 5 A block diagram of an exemplary system 500 is shown, the system being configured to detect the presence of an extension of an inspiratory limb using an extension detection module 502; and to provide power to a heating wire in an inspiratory limb (e.g., a first segment of the inspiratory limb), in an extension of an inspiratory limb (e.g., a second segment of the inspiratory limb), and / or in an expiratory limb. A logic module 504 (which may include hardware, software, or some combination of the two) may be configured to provide logic that enables switching described for different control modes, such as, for example, with reference to Figure 3A , 3B, 4, 8A and 8B. The logic module 504 can receive a signal from an integrated circuit 506, which is part of the respiratory humidification system 100. In some embodiments, the logic module 504 is software embedded in the integrated circuit 506 in whole or in part for converting signals from the integrated circuit 506. The combination of the logic module 504 and the integrated circuit 506 can be configured to detect a zero-crossing level, or a voltage or current that changes from positive to negative or vice versa, and change the state of the switch according to the control mode. The logic module 504 can output PWM signals 508a, 508b according to the desired, selected, and defined power output, wherein the PWM signal is delivered to the inhalation heating wire (INSPHW), the exhalation heating wire (EXPHW), or both.

[0178] In some embodiments, the system 500 may include an extension detection module 502 configured to detect whether the second segment 202b is connected to the breathing circuit 200. If the second segment 202b is connected, the extension detection module 502 may generate a "start signal". The logic module 504 may receive the "start" signal and adjust the switching accordingly. In some embodiments, the "start signal" indicates to the logic module 504 that the system 500 will not independently and simultaneously control the inspiratory circuit and the expiratory circuit.

[0179] In some embodiments, the extended segment detection module 502 can be configured to detect the presence of the second segment 202b by connecting both the inhalation circuit and the expiratory circuit and detecting whether a hardware overcurrent event is detected. If an overcurrent event is not detected when either is independently connected, but is detected when both are connected together, the extended segment detection module 502 can generate a "start signal" indicating that the second segment 202b is connected. In some embodiments, the extended segment detection module 502 can detect the presence of the second segment 202b by using current measurement to detect the resistance of the identification resistor or the heating wire in each segment. Based at least in part on the current detection of these various segments, the extended segment detection module 502 can detect the presence of the second segment 202b when the current is detected as described above with reference to Figure 3A , 3B When different control modes are implemented as described in , 4, 8A and 8B and the current measurement values ​​for different cycles are different, a "start" signal is generated.

[0180] Sensor circuit

[0181] Fig. 6A and 6B FIG. 6 shows an exemplary circuit diagram of a respiratory humidification system 100 , wherein a circuit 600 is configured to read data from two sensors R1 and R2 . Fig. 6A and 6B, sensors R1 and R2 are represented using resistors, but any suitable type of sensor may be used, such as but not limited to: temperature sensors, humidity sensors, flow sensors, oxygen sensors, etc. In some embodiments, the sensor may be a temperature sensor, such as a thermistor. In such an embodiment, sensors R1 and R2 represent a first thermistor at the intermediate connector 214 and a second thermistor at the patient end of the breathing circuit 200 (e.g., on the patient end connector), respectively. The two thermistors R1 and R2 may be measured using two wires in the breathing circuit 200, using circuit 600 in combination with a current source or voltage source and a switch in the humidifier controller 122. Although referring to Fig. 6A and 6B The description relates to thermistors, but this applies to other suitable sensors that affect the voltage and / or current provided to the circuit with which it is associated.

[0182] To selectively read sensors R1 and R2, current is supplied in either polarity through lines 602 and 604. To measure the patient-side sensor R2, the humidifier controller 122 sets the switch to ground the top current supply source. Current then flows from the bottom current supply source through R2 and flows to the ground through the switch. The current is blocked by diode D1 from flowing through R1. The humidifier controller 122 can be configured to measure the voltage drop from the bottom current supply source to the ground, and to derive the resistance of sensor R2 based at least in part on the supplied current and the measured voltage. To measure the sensor R1 positioned at the intermediate connector 214, the humidifier controller 122 can read the patient-side sensor R2 and record the result. The humidifier controller 122 can then set the switch to ground the bottom current supply source. Current then flows from the top current supply source through R1 and R2 and flows to the ground through the switch. The humidifier controller 122 can be configured to measure the voltage drop from the top current supply source to ground and derive the resistance of the sensor R1 based at least in part on the supplied current, the measured voltage, and the recorded result of measuring the resistance of R2. In some embodiments, the voltage drop across D1 is taken into account when deriving the resistance of R1. Fig. 6A In the illustrated embodiment, by placing D1 close to R1 , the temperature of diode D1 can be calculated, which can be used to calculate the voltage drop across D1 . Fig. 6A One potential advantage of the configuration shown in FIG. 1 is that the measurements of sensor R2 at the patient end can be more accurate because these measurements are made without passing through a diode (as in FIG. Figure 6B The above is shown in the embodiments, which may introduce uncertainties or errors).

[0183] In some embodiments, Figure 6BAs shown, an additional diode D2 may be added to the intermediate connector 214. In such an embodiment, the humidifier controller 122 may be configured to communicate with Fig. 6A , and described above. The difference is that when measuring sensor R1, current flows through R1 and D1 and does not flow through R2 because diode D2 blocks current from flowing through R2. In this way, the measurement of sensor R1 can be substantially isolated or separated from the measurement of sensor R2. Similar to deriving the resistance of sensor R1, the voltage drop across diode D2 can be considered when deriving the resistance of sensor R2. By placing D1 and D2 in close proximity to R1, the temperatures of these diodes can be calculated, which can be used to calculate the voltage drops across D1 and D2, respectively.

[0184] In some embodiments, the measurements of sensors R1, R2 are made by connecting to Fig. 6A or 6B. Such software can control the direction and amount of the current supplied to the circuit. By measuring the voltage using, for example, an analog-to-digital converter, an accurate measurement of the resistance of sensors R1 and R2 can be obtained. In order to minimize or eliminate the effect of the changes caused by diodes D1 and / or D2, the software can supply two different currents (I1 and I2) in the same direction. This will produce two different voltage readings (V1 and V2) corresponding to these two different currents (I1 and I2). Using these two voltages and currents, the software can solve the voltage drop of diodes D1 and D2 and the resistance of sensors R1 and R2. For example, for sensor R1, the voltage drop can be solved by the following equation: V drop = ((V1*I2-V2*I1) / ((V1-V2) / R2+I2-I1)). The resistance of sensor R1 can be calculated by the following equation: R1 = (V2-V drop) / (I2-V2 / R2). In an embodiment, the calculated V drop has a constant error relative to the measured V drop, which is corrected in software. In an embodiment, the V drop is increased by about 15% as error compensation.

[0185] In some embodiments, sensors R1 and R2 (e.g., thermistors) may be removed. In such embodiments, more accurate sensors may be included in the system. This may allow the use of a symmetrical intermediate connector (e.g., a mechanically and electrically independent connector). For example, the intermediate connector may be physically connected in two ways and also operate to mechanically couple multiple segments of the suction branch and direct electrical power to a target segment of the segmented heater. In some embodiments described herein, if the connector is inserted backwards, the diodes and other electrical components may be configured such that the control algorithms provide power to undesirable portions of the segmented heater.

[0186] Figure 7 An exemplary circuit diagram of a respiratory humidification system 100 is shown, where the circuit 700 is configured to read temperature data using two transistors Q1 and Q2 acting as temperature sensors. The temperature measurement can be based at least in part on the temperature effect of the pn junction of the base terminal and the emitter terminal of these transistors. The switching of the current in the humidifier controller 122 can be related to the reference Fig. 6A and 6B The same circuit described, or it can be an alternating configuration as shown. For example, the switching configuration shown uses two switches with two power supplies and two ground wires for selectively providing electrical power to these filaments. In a first configuration, the top switch electrically connects the top power supply to filament 702, and the bottom switch electrically connects the ground wire to filament 704. In a second configuration, the top switch electrically connects the ground wire to filament 702, and the bottom switch electrically connects the bottom power supply to filament 704. By using transistors Q1 and Q2 as temperature sensors, these diodes can be removed because these transistors provide the functions of temperature sensors and diodes.

[0187] Breathing circuit hardware configuration

[0188] Fig. 8A An example diagram of a hardware configuration 800 for a breathing circuit 200 is shown, the breathing circuit having a first segment 202a of an inspiratory limb, a second segment 202b of an inspiratory limb, and a respiratory limb 210. The hardware configuration 800 may include a humidifier 108 configured to connect the wiring of the heating wires HW1 and HW2 and the wiring of the sensors 204a, 204b via switches or relays S3 and S4. In some embodiments, the sensor box 802 can be configured to connect the wiring of the heating wires HW1, HW2 and the wiring of the sensors 204a, 204b. Switches S3, S4 can be used to selectively control power to the heating wire HW2 of the expiratory limb 210, as described with reference to Figure 4A described, which has the same Figures 4B-4DSimilar functions described. In some embodiments, switches S3 and S4 are both defaulted to the disconnected position and closed when the appropriate pipeline is connected to the humidifier 108 (for example, the inhalation branch or the exhalation branch with the appropriate identification resistor). In this way, the hardware configuration 800 can be used to provide power to the heating wire HW1 and / or the heating wire HW2. Regardless of whether the heating wire HW2 is receiving electric power, the heating wire HW1 can be controlled with two modes. In the first mode, the first heating wire 206a receives electric power, and the second heating wire 206b does not receive electric power. In the second mode, the first heating wire 206a and the second heating wire 206b receive electric power. In the embodiment shown, when the heating wire HW1 is controlled in one of the first mode or the second mode, the heating wire HW2 can be powered. It should be understood that the heating wire HW2 of the exhalation branch can be selectively controlled, while the heating wire HW1 of the inhalation branch remains in a single mode. For example, when the heating wire HW1 of the inspiratory limb is controlled in the first mode (or the second mode), the heating wire HW2 of the expiratory limb can alternately receive or not receive power based at least in part on the operation of the switches S3 and S4, without any change in the control mode of the heating wire HW1. Similarly, when the heating wire HW1 of the inspiratory limb changes between the first mode and the second mode, the heating wire HW2 of the expiratory limb can continue to receive power.

[0189] The hardware configuration 800 may include an intermediate printed circuit board (PCB) 214 including two diodes, one of which is a power diode D1 and the other is a signal diode D3. The intermediate PCB 214 may include a heat sink for dissipating heat generated by the diodes D1 and D3 to reduce the impact on the sensor 204a. The hardware configuration 800 may include a patient-side PCB 804 having two heating wires and a sensor 204b, wherein the heating wire 206b is directly electrically connected. In a first operating mode, electrical power is provided to HW1 so that current flows through the heating wire 206a and flows through the diode D1, while substantially no current flows through the heating wire 206b (e.g., less than 1% of the current flowing through the heating wire 206a flows through the heating wire 206b). In a second operating mode, electrical power may be provided to HW1 so that current flows through the heating wires 206a and 206b. The first and second operating modes may be at least partially controlled by the direction of the current flowing through the heating wire HW1.

[0190] In some embodiments, diodes D2 and D4 may be added to hardware configuration 800, such as Figure 8BIn such an embodiment, the software for the sensing circuit can be changed to account for the increased heat. In some embodiments, the signal diodes D3, D4 are positioned close to each other so that they experience the same or similar environmental conditions to reduce the differential effects due to different ambient temperatures. Fig. 8A The circuit shown works in a similar manner.

[0191] In some embodiments, Fig. 8A and Figure 8B In comparison, removing diode D4 improves the sensing reliability at the patient end. For example, the diode may fail in the disconnected position. If diode D4 fails when disconnected, reading the patient end temperature may not be possible. Fig. 8A In the circuit shown, if diode D3 fails, the patient-side sensor 204b can still be read. Removing diode D2 can have similar advantages.

[0192] In some embodiments, sensor cartridge 802 may be positioned within humidification system 100 or external to the system.

[0193] Exemplary segmented inhalation branch with connector having microcontroller

[0194] Fig. 9 An exemplary embodiment of a respiratory humidification system 100 is shown that utilizes a microcontroller in an intermediate connector 214 to measure data to control heating and read sensor values ​​in the inspiratory limb 202. In some embodiments, one or more microcontrollers may be introduced in a sensor box, in a humidifier, in an intermediate connector 214, or in any combination thereof. The microcontroller provides similar functionality as described herein when introduced, for example, on a sensor box. The exemplary embodiment shown uses a heating wire as a common reference (the wire connected to VN), and connects the two heating wires HW1, HW2 and the sensor wire to the common reference. The exemplary embodiment also converts the readings of the two sensors 204a, 204b into digital signals in the intermediate connector 214 to be sent to the humidifier controller 122. This can reduce or eliminate isolation issues by connecting the sensors 204a, 204b to a common reference point and sending digital parameter readings, which can be transmitted through an optocoupler on the controller 122, which will isolate the signal, as described herein with reference to Fig.12 Use of this exemplary embodiment may allow for implementation of two independent control paths to heat only the first section 202a or both the first and second sections of the suction branches 202a, 202b to provide desired, selected, or limited heating control.

[0195] Fig.10A block diagram of an intermediate connector 214 for the inhalation branch 202 is shown, wherein the intermediate connector 214 uses a microcontroller. The microcontroller can be used to measure the analog signals from thermistors 204a and 204b and convert the analog signals into digital signals using an analog-to-digital converter (ADC). The converted digital signals can be sent to the humidifier controller 122 via a single data line. The data line can be used to allow communication between the microcontroller and the humidifier controller 122 to provide temperature data. The data line can be used to provide power to the microcontroller by pulling the data line high on the humidifier controller 122 when no data is sent. The power module and the data line converter can include a capacitor and a diode so that when the data line is set high, the capacitor is charged. The charged capacitor can be used to power the microcontroller when the data line is used for communication. Fig.11 Circuit diagrams of exemplary power modules and data line converters are shown.

[0196] Temperature sensing using this configuration can be implemented using a current source or voltage source on the intermediate connector 214, which is used to drive these thermistors so that they can be read by the microcontroller. This can be done, for example, using a transistor or an op-amp. Data line communication can be implemented using a time slot-based scheme, where each logic level is sent and read in a predefined time slot. In this way, two-way communication between the humidifier controller 122 and the microcontroller can be achieved using a single wire.

[0197] The humidifier controller 122 may include a DC power supply source referred to as VN. A capacitor may be included that can be charged when the heating wire is powered on and can provide power to the microcontroller when the heating wire is powered off. The humidifier controller 122 may include a dual optocoupler circuit 1200, such as Fig.12 The dual optocoupler circuit can be used to isolate signals and implement bidirectional data communication between the controller 122 and the power supply source.

[0198] In some embodiments, calibration data may be stored on the microcontroller, which may be read when the breathing circuit is connected. In some embodiments, a component identification number or serial number may be stored to determine the origin of a connected circuit.

[0199] Segmented suction branch with digital temperature sensor

[0200] Fig.13A circuit diagram of an exemplary respiratory humidification system 100 is shown that incorporates digital temperature sensors 204a, 204b for use with a respiratory circuit 200 having a first segment 202a and an intermediate connector 214 that couples a second segment 202b to form an inspiratory limb 202. Fig. 9 With the described design, the digital temperature sensors 204 a , 204 b may utilize a single line for both communication and power, thereby simplifying the circuit design and reducing the amount of wiring used in the system 100 . Fig.13 The design shown may implement the temperature sensor and data communications as a single chip rather than a combination of circuit elements, which may be desirable.

[0201] Intermediate connector board

[0202] Fig.14A and 14B An exemplary intermediate PCB 250 of the intermediate connector 214 is shown, and the corresponding figures show both sides of the intermediate PCB 250. The intermediate PCB 250 includes connection pads 252, 254 for heating wire and sensor connection. The connection pads 252, 254 are configured to be located on opposite sides of the intermediate PCB 250 to facilitate connection with the heating wire spirally wound around the suction branch.

[0203] The intermediate PCB 250 includes a sensor connection pad 256 for the sensor, such as a thermistor or other temperature measuring component, or a humidity sensor, or a flow sensor, etc. The sensor can be connected to a diode (e.g., see FIG. 1 ) via a signal connection pad 258 on the intermediate PCB 250. Figure 8B As shown, the intermediate PCB 250 includes a gap 262 configured to thermally isolate the sensor from other electrical components and traces. In some embodiments, the gap 262 can be filled with an insulating material to further thermally isolate the sensor connected to the sensor connection pad 256. In addition, the intermediate PCB 250 can be configured to space the sensor from other active and / or passive electrical components, such as by protruding features 257.

[0204] The intermediate PCB 250 includes power connection pads 260 to electrically couple the diode to the heating wire via electrical traces on the intermediate PCB 250. The diode may be a reference Figure 3B , 6B , or diode D1 as described in 8B. Power connection pad 260 may be electrically and thermally coupled to heat sink 264 to assist in dissipating heat, thereby reducing or minimizing the impact on the accuracy of parameter readings of sensors coupled to sensor connection pad 256.

[0205] Fig. 14Cand 14D An exemplary embodiment of an intermediate connector 214 is shown, which includes an intermediate PCB 250 and an intermediate connecting element 263. The intermediate connecting element 263 can be configured to guide a portion of the humidified gas flowing through the inspiratory branch through a conduit formed by the intermediate connecting element 263. The sensor on the intermediate PCB 250 can then provide a signal corresponding to a parameter of the gas flowing through the intermediate connecting element 263, which represents at least one characteristic of the humidified gas at this point in the inspiratory branch (e.g., temperature, humidity, flow, oxygen percentage, etc.). In some embodiments, the intermediate connecting element 263 is configured to provide mechanical support to the intermediate PCB 250 to position it in the inspiratory branch. In some embodiments, the intermediate connecting element 263 is configured to provide mechanical support to combine two segments of the inspiratory branch together at or near the intermediate connector 214.

[0206] The intermediate connector 214 includes a first connection pad 252 on a first side of the intermediate PCB 250 and a second connection pad 254 on a second side of the intermediate PCB 250, and the second side is located on the opposite side of the intermediate PCB 250. The first connection pad 252 and the second connection pad 254 can be configured to provide electrical contacts to the heating wires in the corresponding first and second sections of the segmented suction branch, as described herein. In some embodiments, the heating wires in the sections of the suction branch are spirally wound. The intermediate PCB 250 is configured to electrically connect the spirally wound heating wires and / or signal wires (e.g., temperature sensor wires) in the first section to the spirally wound heating wires and / or signal wires in the second section.

[0207] In some embodiments, the intermediate PCB 250 includes a first portion that extends along a diameter or chord across the inner cavity formed by the intermediate connecting element 263, so that a portion of the intermediate PCB 250 divides at least a portion of the flow path of the gas into two parts in general. The first portion of the intermediate PCB 250 can be overmolded by an overmolding composition. The intermediate PCB 250 can include a second portion 251 that is adjacent to the first portion and extends outward from the outside of the intermediate connecting element 263 in a direction away from the inner cavity. The second portion 251 of the intermediate PCB 250 includes one or more connection pads 252, which are configured to receive one or more wires from the first segment of the inhalation branch. The intermediate PCB 250 can include a third portion 253 that is adjacent to the first portion and extends outward from the outside of the intermediate connecting element 263 in a direction away from the inner cavity and in a direction opposite to the second portion 251. The third part 253 may include one or more connection pads 254 located on the intermediate PCB 250, and the connection pads are configured to receive one or more wires from the second segment of the suction branch. The intermediate PCB 250 may include one or more conductive traces, which are configured to electrically connect the one or more connection pads 252 of the second part 251 to the one or more connection pads 254 of the third part 253, and are configured to provide electrical connection between the wires in the first segment of the suction branch and the wires in the second segment.

[0208] In some embodiments, the number of contact pads for the wires can be limited to four by the intermediate PCB 250. In such embodiments, the wires can overlap and maintain the continuity of the conduit. In such embodiments, it may be advantageous to maintain the orientation and / or order of the wires.

[0209] Fig.34 An exemplary embodiment of an air intake branch 3405 and an extension branch 3410 is shown, and the heating wires 3402, 3404 of these branches are directly connected together through a diode 3420. In some embodiments, the intermediate connector 214 can be configured to include a diode to directly connect the wires 3402, 3404. For example, the wires 3402, 3404 can be laser ablated so that they are exposed. The diode 3420 can be configured to contact these wires across the heating wires 3402, 3404 without the sensor and the intermediate PCB as described herein. In such a configuration, the air intake branch and the extension branch can be advantageously configured so that there is no unheated section. Similarly, this configuration can reduce or eliminate condensation, dendrite growth, heating wire or sensing wire electrical short circuit, printed circuit board in the intermediate connector, circuit break and / or flow resistance.

[0210] Patient side connector board

[0211] Fig.15A An exemplary patient-side PCB 270 is shown with a patient-side connector 804. The patient-side PCB 270 includes connection pads 272 for connection of heating wires and sensors. The connection pads 272 are configured on only one side of the patient-side PCB 270 to connect to the spirally wound heating wires and signal wires from the inspiratory limb. Two of the connection pads 272 can be directly electrically connected to each other as an electrical pathway. The heating wire can be connected to the connection pads 272, which are directly electrically connected. The remaining two connection pads 272 can be electrically connected to the sensor connection pads 274. The electrical traces 278 to and from the sensor connection pads 274 can be configured to reduce or minimize the width of the traces and increase or maximize the length of the traces to thermally isolate the sensors connected to the sensor connection pads 274. The patient-side PCB 270 may include similar protruding features 276, as described with respect to Fig.14A and 14B The protruding features 276 can be configured to thermally isolate the sensor from the influence of current flow and components on the patient-side PCB 270 .

[0212] Figures 15B-15E An exemplary embodiment of a patient-end connector 804 is shown. Fig. 15B and 15D An exemplary embodiment of a patient-side PCB 270 overmolded as part of the inspiratory limb 202 is shown. Fig. 15C and 15E The cross-section of the patient-end PCB 270 shown in FIG. 2 can be configured to be aerodynamic to reduce or minimize turbulence of the gas delivered to the patient.

[0213] Insert limiter for segmented suction branch

[0214] Figures 16A-16E An exemplary embodiment of an insertion stop 280 for a segmented suction branch 202 is shown. Fig.16AAn exemplary insertion stop 280 is shown, configured with a larger chamber end 282 (e.g., the end closer to the gas supply source), a smaller patient end 284, and a sharp corner 286 with a groove 288 into which a grommet 294 can be placed. The insertion stop 280 can be configured to prevent or reduce the entry of the intermediate connector or segment connection point of the inhalation limb 202 (e.g., where the intermediate PCB 250 is located) through the opening 292 into the incubator 290. The smaller end 284 can be configured to enter the incubator 290, while the larger end 282 can be configured to prevent or block entry into the incubator opening 292 by contacting the grommet 294. In some embodiments, the insertion stop 280 is configured to substantially fix the position of the intermediate PCB 250 within a target or desired distance from the incubator or other such point defining a different temperature environment. The target or desired distance may be less than or equal to approximately 20 cm, less than or equal to 10 cm, less than or equal to approximately 5 cm, or approximately 0 cm. Fig. 16B An exemplary insertion stop 280 is shown for use with the bubble tube 202 , wherein the insertion stop is positioned a distance d1 from the inlet 292 of the incubator 290 .

[0215] Fig. 16C An exemplary embodiment of an insertion stopper 280 is shown, which is configured to be clamped or fixed to an object, such as clothing, a blanket, or another object separate from the patient. The insertion stopper 280 is fixed to the inspiratory limb 202 and is configured to be movable along the inspiratory limb 202 to adjust the arrangement of the inspiratory limb 202. Fig.16D The suction branch 202 is shown with an insertion stopper 280 when used with an incubator 290 , which is used to block or prevent the intermediate PCB connector 250 from entering the incubator 290 . Fig.16E The inspiratory limb 202 is shown with an insertion stopper 280 when used with a patient, wherein the insertion stopper 280 is secured to the patient's blanket to block or prevent movement of the inspiratory limb 202 relative to the patient and / or the blanket. The insertion stopper 280 can also be used with an expiratory limb or other medical tubing used in conjunction with a gas delivery system. Segmented medical tubing for use with respiratory humidification systems

[0216] Fig.17A A side plan view of a section of an exemplary composite pipe 1201 is shown, which may be similar to the reference Figure 1The composite pipe 1201 can be used as an inspiratory branch 202 and can be configured to provide thermally beneficial properties that assist in preventing gas condensation along the pipe as described herein. The composite pipe 1201 includes a plurality of elongated members that are wrapped and combined to form a passage, wherein the plurality of elongated members may include one or more of the heating wires described herein. Based at least in part on embedding the heating wires in the wall of the composite pipe 1201, using the composite pipe 1201 as an inspiratory branch 202 can reduce condensation and condensation precipitation (rainout), and maintain a more desirable or target temperature curve along the length of the inspiratory branch 202. The wall of the composite pipe can provide greater thermal mass to resist temperature changes and increase the thermal insulation effect of the wall relative to the ambient temperature outside the branch 202. Therefore, the temperature along the length of the branch 202 (including passing through any number of different temperature environments) can be more accurately controlled, and less power or energy can be spent to control the temperature of the gas delivered to the patient. In some embodiments, composite conduit 1201 may be used as expiratory limb 210 .

[0217] In general, composite pipe 1201 includes first elongated member 1203 and second elongated member 1205. Member is a broad term and is given its ordinary and customary meaning by those of ordinary skill in the art (that is, it is not limited to a special or customary meaning) and includes, but is not limited to: an integral part, an integral component, and a distinct component. Therefore, although Fig.17A An embodiment made of two different parts is shown, but it should be understood that in other embodiments, the first elongated member 1203 and the second elongated member 1205 can also represent areas in a pipe formed of a single material. Thus, the first elongated member 1203 can represent a hollow portion of the pipe, while the second elongated member 1205 represents a structural support or reinforcement portion of the pipe that adds structural support to the hollow portion. The hollow portion and the structural support portion can have a spiral configuration, as described herein. The composite pipe 1201 can be used to form the inspiratory limb 202 and / or the expiratory limb 210 as described herein, a coaxial pipe as described below, and any other pipe as described elsewhere in this disclosure.

[0218] In this example, the first elongated member 1203 comprises a hollow body, which is spirally wound and at least partially formed into an elongated pipe having a longitudinal axis LA-LA and an inner cavity 1207 extending along the longitudinal axis LA-LA. In at least one embodiment, the first elongated member 1203 is a pipe. Preferably, the first elongated member 1203 is flexible. In addition, the first elongated member 1203 is preferably transparent or at least translucent or semi-opaque. Optical transparency allows a caregiver or user to check the blockage or contaminants of the inner cavity 1207 or to confirm the presence of moisture. A variety of plastics (including medical grade plastics) are suitable for the body of the first elongated member 1203. Examples of suitable materials include polyolefin elastomers, polyether block amides, thermoplastic copolyester elastomers, EPDM-polypropylene blends, and thermoplastic polyurethanes.

[0219] The hollow body structure of the first elongated member 1203 contributes to the insulating properties of the composite tubing 1201. Isolating the tubing 1201 is desirable because it prevents or reduces heat loss as explained herein. This can allow the tubing 1201 to deliver gas from the heater / humidifier to the patient while substantially maintaining the conditioned state of the gas with reduced or minimized energy consumption.

[0220] In at least one embodiment, the hollow portion of the first elongated member 1203 is filled with a gas. The gas may be air, which has a low thermal conductivity (2.62 x 10 -2 W / m·K) and very low cost. It is also advantageous to use gases that are more viscous than air, since the higher viscosity reduces convective heat transfer. Thus, for example, argon (17.72x10 at 300K) -3 W / m·K), krypton (9.43x10 at 300K) -3 W / m·K), and xenon (5.65x10 -3W / m·K) and other gases can improve the isolation performance. Each of these gases is non-toxic, chemically inert, flame retardant, and commercially available. The hollow portion of the first elongated member 1203 can be sealed at both ends of the pipeline, so that the gas therein is basically stagnant. Alternatively, the hollow portion can be a secondary pneumatic connector, such as a pressure sampling line, for transmitting pressure feedback from the patient end of the pipeline to the controller. The first elongated member 1203 can be optionally perforated. For example, the surface of the first elongated member 1203 is perforated on the outward-facing surface (opposite to the inner cavity 1207). In another embodiment, the hollow portion of the first elongated member 1203 is filled with a liquid. Examples of liquids can include water or other biocompatible liquids with high heat capacity. For example, nanofluids can be used. Exemplary nanofluids with suitable heat capacity include water and nanoparticles of substances such as aluminum.

[0221] The second elongated member 1205 is also helically wound and joined to the first elongated member 1203 between adjacent turns of the first elongated member 1203. The second elongated member 1205 forms at least a portion of the lumen 1207 of the elongated tube. The second elongated member 1205 acts as a structural support for the first elongated member 1203.

[0222] In at least one embodiment, the second elongated member 1205 is wider at the base (close to the inner cavity 1207) and narrower at the top. For example, the shape of the second elongated member can be generally triangular, generally T-shaped, or generally Y-shaped. However, any shape that meets the profile of the corresponding first elongated member 1203 is suitable.

[0223] Preferably, the second elongated member 1205 is flexible to facilitate bending of the pipe. Desirably, the flexibility of the second elongated member 1205 is less than that of the first elongated member 1203. This improves the ability of the second elongated member 1205 to structurally support the first elongated member 1203. For example, the modulus of the second elongated member 1205 is preferably 30-50 MPa (or about 30-50 MPa). The modulus of the first elongated member 1203 is less than the modulus of the second elongated member 1205. The second elongated member 1205 can be solid or mostly solid. In addition, the second elongated member 1205 can encapsulate or contain conductive materials, such as filaments and specifically heating filaments or sensors (not shown). The heating filaments can minimize the cold surface on which humid air can form condensation. The heating filaments can also be used to change the temperature profile of the gas in the inner cavity 1207 of the composite pipe 1201. A wide variety of polymers and plastics, including medical grade plastics, are suitable for the body of the second elongated member 1205. Examples of suitable materials include polyolefin elastomers, polyether block amides, thermoplastic copolyester elastomers, EPDM-polypropylene blends, and thermoplastic polyurethanes. In certain embodiments, the first elongated member 1203 and the second elongated member 1205 can be made of the same material. The second elongated member 1205 can also be made of a different color material than the first elongated member 1203 and can be transparent, translucent, or opaque. For example, in one embodiment, the first elongated member 1203 can be made of a transparent plastic and the second elongated member 1205 can be made of an opaque blue (or other color) plastic.

[0224] This spiral winding structure including a flexible hollow body and an integral support can provide crush resistance while making the pipe wall flexible enough to allow short radius bending without kinking, occlusion or collapse. Preferably, the pipe can be bent around a 25 mm diameter metal cylinder without kinking, occlusion or collapse, as defined in the test of increasing flow resistance with bending according to ISO5367:2000 (E). This structure can also provide a smooth inner cavity 1207 surface (pipeline hole), which helps keep the pipe from deposits and improves gas flow. It has been found that the hollow body improves the isolation characteristics of the pipe while allowing the pipe to remain lightweight.

[0225] As explained above, the composite tube 1201 can be used as an exhalation tube and / or an inhalation tube in a breathing circuit, or as a part of a breathing circuit. Preferably, the composite tube 1201 is used at least as an inhalation tube.

[0226] Fig. 17B Shows Fig.17A A longitudinal cross-section of a top portion of exemplary composite pipe 1201. Fig. 17B With Fig.17ASame orientation. This example further illustrates the hollow body shape of the first elongated member 1203. As seen in this example, the first elongated member 1203 forms a plurality of hollow bubbles in longitudinal section. A portion 1209 of the first elongated member 1203 overlaps an adjacent wrap of the second elongated member 1205. A portion 1211 of the first elongated member 1203 forms a wall of the lumen (tube hole).

[0227] It has been discovered that having voids 1213 between adjacent turns of the first elongated member 1203, i.e., between adjacent bulbs, unexpectedly improves the overall insulation properties of the composite pipe 1201. Thus, in certain embodiments, adjacent bulbs are separated by voids 1213. In addition, certain embodiments include the realization that providing voids 1213 between adjacent bulbs increases the heat transfer resistivity (R-value) and correspondingly reduces the heat transfer conductivity of the composite pipe 1201. It has also been discovered that this void configuration improves the flexibility of the composite pipe 1201 by permitting shorter radius bends. The T-shaped second elongated member 1205 (e.g., Fig. 17B 1213 between adjacent bulbs. However, in some embodiments, adjacent bulbs are in contact. For example, adjacent bulbs may be bonded together.

[0228] One or more conductive materials may be arranged in the second elongated member 1205 to heat or sense the gas flow. In this example, two heating filaments 1215 are enclosed in the second elongated member 1205, one on each side of the vertical portion of the "T". The heating filaments 1215 include a conductive material, such as an alloy of aluminum (Al) and / or copper (Cu), or a conductive polymer. Preferably, the material forming the second elongated member 1205 is selected to not react with the metal in the heating filaments 1215 when the heating filaments 1215 reach their operating temperature. The filaments 1215 may be spaced apart from the lumen 1207 so that the filaments are not exposed to the lumen 1207. At one end of the composite pipe, multiple filament pairs may form a connecting loop.

[0229] In at least one embodiment, multiple filaments are arranged in the second elongated member 1205. These filaments can be electrically connected together to share a common track. For example, a first filament, such as a heating filament, can be arranged on a first side of the second elongated member 1205. A second filament, such as a sensing filament, can be arranged on a second side of the second elongated member 1205. A third filament, such as a grounding filament, can be arranged between the first filament and the second filament. The first, second and / or third filament can be connected together at one end of the second elongated member 1205.

[0230] Fig. 17C Shows Fig. 17B12. A longitudinal cross-section of a bubble in FIG. 12. As shown, the portion 1209 of the first elongated member 1203 that overlaps the adjacent cladding of the second elongated member 1205 is characterized by a degree of bonding area 1217. A larger bonding area improves the resistance of the pipe to delamination at the junction of the first and second elongated members. Additionally or alternatively, the shape of the bead and / or bubble can be adapted to increase the bonding area 1217. For example, Fig.17D A relatively small bonding area is shown on the left. Fig.19B Smaller bonding areas are also illustrated. Fig.17E Because of the size and shape of the beads, Fig.17D Much larger bonding area shown. Fig.19A and 19C A larger bonding area is also shown. Each of these figures is discussed in more detail below. It should be understood that although in some embodiments, Fig.17E , 19A The configurations in 19C and 19D may be preferred, but other configurations (including Fig.17D , 19B and other variations included).

[0231] Fig.17D A longitudinal section of the top portion of another composite pipe is shown. Fig.17D With Fig. 17B This example further demonstrates the hollow body shape of the first elongated member 1203 and illustrates how the first elongated member 1203 forms a plurality of hollow bubbles in a longitudinal cross-section. In this example, the bubbles are completely separated from each other by gaps 1213. The generally triangular second elongated member 1205 supports the first elongated member 1203.

[0232] Fig.17E A longitudinal section of the top portion of another composite pipe is shown. Fig.17E With Fig. 17B Same orientation. Fig.17E In the example, the heating filament 1215 is Fig. 17B The filaments 1215 in the pipe are further apart from each other. It has been found that increasing the space between the heating filaments can improve the heating efficiency, and certain embodiments include such an implementation. The heating efficiency refers to the ratio of the amount of heat input to the pipe to the amount of energy output from the pipe or recoverable from the pipe. In general, the more energy (or heat) dissipated from the pipe, the lower the heating efficiency. In order to obtain improved heating performance, the heating filaments 1215 can be spaced equidistantly (or approximately equidistantly) along the hole of the pipe. Alternatively, the filaments 1215 can be positioned at the extremes of the second elongated member 1205, which can provide simpler manufacturing.

[0233] Next, refer to Figures 18A to 18G , the accompanying drawings illustrate an exemplary configuration of the second elongated member 1205. Fig.18A shows a shape similar to Fig. 17B A cross section of a T-shaped second elongated member 1205 is shown. In this exemplary embodiment, the second elongated member 1205 does not have a heating filament. Other shapes may also be utilized for the second elongated member 1205, including a T-shape as described below, and triangular variations.

[0234] Fig.18B Another exemplary second elongated member 1205 having a T-shaped cross-section is shown. In this example, a heating filament 1215 is embedded in a cutout 1301 on either side of the vertical portion of the "T" in the second elongated member 1205. In some embodiments, the cutout 1301 can be formed in the second elongated member 1205 during the extrusion process. Alternatively, the cutout 1301 can be formed in the second elongated member 1205 after extrusion. For example, a cutting tool can form the cutout in the second elongated member 1205. Preferably, the cutout is formed by the heating filament as the heating filament 1215 is squeezed or pulled (mechanically fixed) into the second elongated member 1205 shortly after extrusion, while the second elongated member 1205 is relatively soft. Alternatively, one or more heating filaments can be mounted (e.g., adhered, bonded, or partially embedded) on the base of the elongated member so that the filaments are exposed to the lumen of the conduit. In such embodiments, it may be desirable to contain the filaments in an isolated manner to reduce the risk of fire if a flammable gas (eg, oxygen) passes through the lumen of the conduit.

[0235] Fig. 18C A cross section of yet another second elongated member 1205 is shown. The second elongated member 1205 has a generally triangular shape. In this example, heating filaments 1215 are embedded on opposite sides of the triangle.

[0236] Fig.18DA cross section of another second elongated member 1205 is shown. The second elongated member 1205 includes four grooves 1303. In this cross-sectional profile, these grooves 1303 are pits or notches. In some embodiments, grooves 1303 can help form cutouts (not shown) to embed filaments (not shown). In some embodiments, grooves 1303 help position filaments (not shown), which are squeezed or pulled in and thus embedded in the second elongated member 1205. In this example, these four initial grooves 1303 help place up to four filaments, such as four heating filaments, four sensing filaments, two heating filaments and two sensing filaments, three heating filaments and one sensing filament, or one heating filament and three sensing filaments. In some embodiments, the heating filament can be located on the outside of the second elongated member 1205. The sensing filament can be located on the inside.

[0237] Fig.18E Shown is a cross section of yet another second elongated member 1205. The second elongated member 1205 has a T-shaped profile and a plurality of grooves 1303 for placing heating filaments.

[0238] Fig.18F A cross section of yet another second elongated member 1205 is shown. Four heating filaments 1215 are enclosed in the second elongated member 1205, two on each side of the vertical portion of the "T". As explained in more detail below, these filaments are enclosed in the second elongated member 1205 because the second elongated member 1205 is extruded around the filaments. No cuts are formed for embedding the heating filaments 1215. In this example, the second elongated member 1205 also includes a plurality of grooves 1303. Since the heating filaments 1215 are enclosed in the second elongated member 1205, the grooves 1303 are not used to facilitate the formation of cuts to embed the heating filaments. In this example, the grooves 1303 can facilitate the separation of the embedded heating filaments, which makes it easier to peel off the individual cores when, for example, terminating the heating filaments.

[0239] Figure 18G FIG. 10 shows a cross section of yet another second elongated member 1205. The second elongated member 1205 has a generally triangular shape. In this example, the shape of the second elongated member 1205 is similar to Fig. 18C , however, second elongated member 1205 encloses four filaments 1215, all of which are centered in the bottom third of second elongated member 1205 and arranged along a generally horizontal axis.

[0240] As explained above, it may be desirable to increase the distance between the filaments to improve heating efficiency. However, in some embodiments, when the heating filament 1215 is introduced in the composite pipe 1201, the filament 1215 can be positioned relatively centered in the second elongated member 1205. The centered positioning promotes the robustness of the composite pipe for reuse, in part because the position reduces the likelihood of the filament breaking after repeated flexing of the composite pipe 1201. Centering the filament 1215 can also reduce the risk of ignition hazards caused by the filament 1215 being coated with an insulating layer and removed from the gas path.

[0241] As explained above, some of these examples demonstrate suitable placement of filament 1215 in second elongated member 1205. In the above-mentioned examples including more than one filament 1215, filament 1215 is generally aligned along a horizontal axis. Alternative configurations are also suitable. For example, two filaments can be aligned along a vertical axis or along a diagonal. Four filaments can be aligned along a vertical axis or along a diagonal. Four filaments can be aligned in a cross configuration, with one filament arranged at the top of the second elongated member, one filament arranged at the bottom (near the pipeline lumen) of the second elongated member, and two filaments arranged on the opposite arms of "T", "Y" or on the base of a triangle.

[0242] Tables 1A and 1B show some preferred sizes of medical tubing described herein and some preferred ranges of these sizes. These sizes refer to the cross section of the tubing. In these tables, the lumen diameter represents the inner diameter of the tubing. Spacing represents the distance between two repeated points measured along the axial direction of the tubing, i.e., the distance between the tips of the vertical parts of the adjacent "T" of the second elongated member. Bubble width represents the width (maximum outer diameter) of the bubble. Bubble height represents the height of the bubble from the lumen of the tubing. Bead bubble height represents the maximum height of the second elongated member from the lumen of the tubing (e.g., the height of the vertical part of the "T"). Bead bubble width represents the maximum width of the second elongated member (e.g., the width of the horizontal part of the "T"). Bubble thickness represents the thickness of the bubble wall.

[0243] Table 1A

[0244]

[0245]

[0246] Table 1B

[0247]

[0248] Tables 2A and 2B provide exemplary ratios between the dimensions of the conduit features of the conduits described in Tables 1A and 1B, respectively.

[0249] Table 2A

[0250] ratio baby aldult Inner cavity diameter: spacing 2.3:1 2.4:1 Spacing: Bulb width 1.1:1 1.1:1 Spacing: Bubble Width 2.2:1 3.1:1 Bubble width: Bubble width 2.0:1 2.9:1 Inner cavity diameter: Bulb height 3.9:1 5.1:1 Inner cavity diameter: Bubble height 12.2:1 12.0:1 Bubble height: Bubble height 3.1:1 2.3:1 Inner cavity diameter: Bulb thickness 27.5:1 90.0:1

[0251] Table 2B

[0252]

[0253]

[0254] The table below shows some exemplary properties of a composite tubing (labeled "A") having a heating filament integrated within the second elongated member as described herein. For comparison, the properties of a Fisher & Paykel Model RT100 disposable bellows (labeled "B") having a heating filament helically wound within the bore of the tubing are also shown.

[0255] The resistance to flow (RTF) measurements were performed according to Annex A of ISO 5367:2000 (E). The results are shown below in Table 3. As seen below, the RTF of the composite pipe is less than that of the model RT100 pipe.

[0256] Table 3

[0257]

[0258] The condensate or "condensation precipitation" in the pipe refers to the weight of condensate collected every day when the gas flow rate is 20L / min and the room temperature is 18°C. Humidified air flows continuously from the chamber through the pipe. The weight of the pipe before and after each test is recorded. Three consecutive tests were performed, in which the pipe was dried between each test. The results are shown in Table 4 below. The results show that the condensation precipitation in the composite pipe is significantly less than the condensation precipitation in the model RT100 pipe.

[0259] Table 4

[0260]

[0261]

[0262] Power demand refers to the power consumed during the condensate test. In this test, the ambient air was maintained at 18°C. The humidified chamber (see e.g. Figure 1The humidification chamber 114 in the pipe is powered by an MR850 heater base. The heating filaments in these pipes are independently powered by a DC power supply. Different flow rates are set, and the chamber is left to stand until it is 37°C at the chamber output. Next, the DC voltage to the circuit is changed to produce a temperature of 40°C at the output of the circuit. The voltage required to maintain the output temperature is recorded and the generated power is calculated. The results are shown in Table 5. The results show that composite pipe A uses significantly more power than pipe B. This is because pipe B uses a spiral heating filament in the pipe hole to heat the gas from 37°C to 40°C. The composite pipe does not tend to heat the gas quickly because the heating filament is located in the wall of the pipe (embedded in the second elongated member). Alternatively, the composite pipe is designed to maintain the gas temperature and prevent condensation precipitation by maintaining the pipe hole at a temperature higher than the dew point of the humidified gas.

[0263] Table 5

[0264] Flow rate (L / min) 40 30 20 Pipe A, requested power (W) 46.8 38.5 37.8 Pipe B, requested power (W) 28.0 27.5 26.8

[0265] The pipe flexibility was tested by using a three-point bend test. The pipe was placed in a three-point bend test fixture and used with an Instron 5560 test instrument to measure load and extension. Each pipe sample was tested three times: the extension of the pipe under the applied load was measured to obtain the corresponding average stiffness constant. The average stiffness constants of pipe A and pipe B are reproduced in Table 6.

[0266] Table 6

[0267] pipeline Stiffness(N / mm) A 0.028 B 0.088

[0268] As described above, heating wire 206 may be placed within inspiratory limb 202 and / or expiratory limb 210 to reduce the risk of condensation settling in the conduits by maintaining the conduit wall temperature above the dew point temperature.

[0269] Thermal properties

[0270] In embodiments of composite tubing 1201 incorporating heating filaments 1215, heat may be lost through the walls of first elongated member 1203, resulting in uneven heating. As explained above, one way to compensate for such heat loss is to apply an external heating source at the walls of first elongated member 1203, which helps regulate the temperature and counteract the heat loss. However, other methods for optimizing thermal properties may also be used.

[0271] Next, refer to Figures 19A to 19C , which illustrates an exemplary configuration of bulb height for improving thermal properties (ie, the cross-sectional height of the first elongated member 1203 measured from the surface facing the lumen to the surface forming the largest outer diameter).

[0272] The size of the bulb can be selected to reduce heat loss from the composite duct 1201. In general, increasing the height of the bulb increases the effective thermal resistance of the duct 1201 because a larger bulb height permits the first elongated member 1203 to contain more insulating air. However, it has been found that at a certain bulb height, changes in air density cause convection to occur within the duct 1201, thereby increasing heat loss. Also, at a certain bulb height, the surface area becomes so large that the heat lost through the surface outweighs the benefits of the increased bulb height. Certain embodiments include these results.

[0273] The radius of curvature and curvature of the bubble can be useful in determining the desired bubble height. The curvature of an object is defined as the inverse of the radius of curvature of the object. Thus, the larger the radius of curvature an object has, the less curved the object is. For example, a flat surface would have an infinite radius of curvature and therefore a curvature of 0.

[0274] Fig.19A A longitudinal section of the top portion of the composite pipe is shown. Fig.19A An embodiment of a composite pipe 1201 is shown in which the bubble has a greater height. In this example, the bubble has a relatively small radius of curvature and thus has a large curvature. Also, the height of the bubble is approximately three to four times greater than the height of the second elongated member 1205.

[0275] Fig.19B A longitudinal section of the top portion of another composite pipe is shown. Fig.19B An embodiment of a composite pipe 1201 is shown in which the top of the bubble is flattened. In this example, the bubble has a very large radius of curvature, but a small curvature. Also, the height of the bubble is approximately the same as the second elongated member 1205.

[0276] Fig.19C A longitudinal section of the top portion of another composite pipe is shown. Fig.19C An embodiment of a composite pipe 1201 is shown in which the width of the bubble is greater than the height of the bubble. In this example, the bubble has Fig.19A and Fig.19B The radius of curvature and the curvature between, and the center of the radius of the upper part of the bubble is outside the bubble (with Fig.19A The turning points on the left and right sides of the bubble are approximately in the middle of the bubble (in the height direction) (compare with Fig.19A In the lower part of the bubble). Also, the height of the bubble is approximately twice that of the second elongated member 1205, thereby obtaining Fig.19A and Fig.19B The height of the bubbles between.

[0277] Fig.19AThe configuration of 19B minimizes the heat loss of the pipeline. The configuration of 19B maximizes the heat loss of the pipeline. Fig.19C The configuration has Fig.19A and 19B Moderate heat loss between configurations. However, Fig.19A The large surface area and convective heat transfer in the configuration lead to inefficient heating. Figures 19A-19C In the three bubble arrangements, Fig.19C was determined to have the best overall thermal characteristics. When the same amount of heat energy is input to these three pipes, Fig.19C The configuration produces the greatest temperature rise along the length of the pipe. Fig.19C The bubbles are large enough to increase the insulating air volume, but not large enough to cause significant convective heat losses. Fig.19B The configuration of was determined to have the worst thermal characteristics, i.e., Fig.19B The configuration produces a minimum temperature rise along the length of the pipe. Fig.19A The configuration has moderate thermal characteristics and allows for less than Fig.19C The temperature of the configuration increases.

[0278] It should be understood that although in some embodiments Fig.19C The configuration may be preferred, but in other embodiments other configurations (including Fig.19A , 19B configuration and other variations).

[0279] Table 7 shows Fig.19A , 19B and 19C respectively show the bubble height, tube outer diameter, and radius of curvature of the configuration.

[0280] Table 7

[0281] Pipeline (picture) 19A 19B 19C Bulb height (mm) 3.5 5.25 1.75 Outer diameter(mm) 21.5 23.25 19.75 Curvature radius (mm) 5.4 3.3 24.3

[0282] Next, refer to Figures 19C to 19F , the figure illustrates an exemplary positioning of heating element 1215, which is shaped like a bubble to improve thermal characteristics. The location of heating element 1215 can change the thermal characteristics within composite pipe 1201.

[0283] Fig.19C A longitudinal section of the top portion of another composite pipe is shown. Fig.19C An embodiment of the composite tubing 1201 is shown in which the heating element 1215 is centrally located in the second elongated member 1205. This example shows the heating elements 1215 close to each other but not close to the bubble walls.

[0284] Fig.19DA longitudinal section of the top portion of another composite pipe is shown. Fig.19D An embodiment of a composite pipe 1201 is shown in which a heating element 1215 is disposed within the second elongated member 1205 and within the second elongated member 1205. Fig.19C These heating elements are closer to the bubble wall and provide better regulation of the heat within composite tubing 1201 than being further apart.

[0285] Fig.19E A longitudinal section of the top portion of another composite pipe is shown. Fig.19E An embodiment of the composite pipe 1201 is shown in which the heating elements 1215 are spaced apart up and down along the vertical axis of the second elongated member 1205. In this example, the heating elements 1215 are equidistantly adjacent each bubble wall.

[0286] Fig.19F A longitudinal section of the top portion of another composite pipe is shown. Fig.19F An embodiment of the composite pipe 201 is shown in which the heating element 1215 is spaced apart at opposite ends of the second elongated member 1205. Figures 19C-19E In contrast, heating element 1215 is closer to the bubble wall.

[0287] exist Figures 19C-19F Among the four filament arrangements, Fig.19F was determined to have the best thermal characteristics. Due to their similar bulb shapes, all of these configurations experience similar pipe heat losses. However, when the same heat energy is input to the pipe, Fig.19F The filament configuration produces the greatest temperature increase along the length of the pipe. Fig.19D The configuration was determined to have the second best thermal characteristics and produce the second largest temperature rise along the length of the pipe. Fig.19C The configuration performed second best. Fig.19E The configuration has the worst performance and produces the smallest temperature rise along the length of the pipe when the same amount of heat is input.

[0288] It should be understood that although in some embodiments Fig.19F The configuration may be preferred, but in other embodiments other configurations (including Fig.19C , 19D , 19E configuration and other variants).

[0289] Next, refer to Figures 20A to 20C , which illustrates an exemplary configuration for stacking the first elongated member 1203. It has been found that heat distribution can be improved by stacking multiple bulbs in certain embodiments. These embodiments can be more beneficial when using internal heating filaments 1215. Fig. 20A A longitudinal section of the top portion of another composite pipe is shown. Fig. 20A A cross section of composite pipe 1201 is shown without any stacking.

[0290] Fig. 20B A longitudinal section of the top portion of another composite pipe is shown. Fig. 20B Another exemplary composite pipe 1201 having stacked bubbles is shown. In this example, two bubbles are stacked one above the other to form a first elongated member 1203. Fig. 20A Compared with the conventional method, the total bubble height is maintained, but the bubble spacing is Fig. 20A And, Fig. 20B The embodiment has only slightly reduced air volume. The stacking of the bulbs reduces natural convection and heat transfer in the gaps between the bulbs 1213 and reduces the overall thermal resistance. The heat flow path in the stacked bulbs is increased, allowing heat to be more easily distributed through the composite pipe 1201.

[0291] Fig. 20C A longitudinal section of the top portion of another composite pipe is shown. Fig. 20C Another example of a composite pipe 1201 having stacked bubbles is shown. In this example, three bubbles are stacked one above the other to form a first elongated member 1203. Fig. 20A Compared with the conventional method, the total bubble height is maintained, but the bubble spacing is Fig. 20A And, Fig. 20B The embodiment has only slightly reduced air volume. The stacking of the bulbs reduces natural convection and heat transfer in the gaps between the bulbs 1213.

[0292] Additional Exemplary Intermediate Connectors

[0293] Fig.32A -C shows other examples of intermediate connector 3200, which includes intermediate PCB 3205 and intermediate connecting element 3210. Intermediate PCB 3205 may include a conformal coating configured to protect it from water immersion. For example, water may follow the contour of intermediate PCB 3205. Intermediate connector 3200 may include multiple features, which are configured to position the bead bubble in a position suitable for attaching a wire (e.g., a heating or sensing element for a circuit described herein). Intermediate PCB 3205 may partially extend through intermediate connecting element 3210. For example, a portion of intermediate PCB 3205 may extend outside the conduit of intermediate connecting element 3210, and a portion may partially extend through the inner cavity portion of intermediate connecting element 3210. In some implementations, the portion of intermediate PCB 3205 extending into the inner cavity is about one-third of the way through the inner cavity. This can provide relatively less flow resistance relative to an intermediate PCB extending all the way through the inner cavity.

[0294] In some embodiments, the intermediate PCB 3205 generates heat during operation at least in part due to diodes on the intermediate PCB 3205. The heat generated by the intermediate PCB 3205 can help evaporate excess condensation.

[0295] The intermediate connector 3200 may be overmolded to secure the components in place and seal the portion. In some embodiments, a clamshell may be applied that may provide increased isolation from the intermediate connector 3200 .

[0296] The intermediate connector 3200 may include a pipe stopper 3220 configured to prevent the pipe from rotating too far because it may be configured to get stuck between the bubble tube and the bead bubble. The pipe stopper 3220 may be configured to be positioned 180 degrees and / or 270 degrees from the PCB to correctly position the correct alignment of the pipe. The pipe stopper 3220 may be configured to provide an attachment point for the pipe. The intermediate connector 3200 may include one or more bridges 3222 configured to raise the bead bubble to allow the polymer to flow below it to reduce waterlogging. In some embodiments, the one or more bridges 3222 may be positioned on each side of the intermediate connector 3200. The intermediate connector 3200 may include a slot 3224 configured to hold a wire (e.g., a heating wire) in place in the slot. The intermediate connector 3200 may include an indicator, such as an arrow 3226, configured to indicate the orientation of the intermediate connector 3200 to ensure that the diode faces the correct path. Arrow 3226 can also help reduce or prevent water ingress. Intermediate connector 3200 can include a water ingress ring 3228 that forms a complete loop around intermediate connector 3200. Water ingress ring 3228 can be configured to limit or eliminate water ingress to exposed areas of PCB 3205.

[0297] In some embodiments, the intermediate connecting element 3210 can have a wall of about 1-2 mm thick and can have a diameter between 4 mm and 15 mm. In some implementations, the inner diameter of the intermediate connecting element 3210 can be about 8 mm-9 mm, and the outer diameter can be about 11.5 mm. The outer diameter of the intermediate connecting element 3210 can be configured to be large enough to reduce flow resistance. A smaller passage in the intermediate connecting element 3210 can mean that gas passes through it faster, which can reduce condensation.

[0298] The intermediate connector 3200 may include a process aid 3230 configured to properly align the connected pipe so that the bubble engages the pipe and holds it in place. The intermediate connector 3200 may include a pin 3232 configured to position the cover (e.g., the clamshell 3300 described herein with reference to FIG. 33) and to retain it in place by friction fit (e.g., it may engage with a matching recess in the cover). In some implementations, the intermediate connector 3200 includes 3 or 4 pins. These pins 3232 may be configured to have sufficient length so that they protrude through the overmolding to achieve the purpose of alignment and / or positioning. These pins 3232 may be positioned on either side of the intermediate connector 3200 so that they are positioned at, for example, 90 degrees to the displayed position. In some embodiments, the intermediate connector 3200 includes a slot 3234 that acts as a keying mechanism for processing to reduce the possibility of incorrect orientation.

[0299] Fig.33A -C shows an example of a clamshell 3300 that can be applied to an intermediate connector, such as the intermediate connector 3200 described herein with reference to FIG 32. The clamshell 3300 can be configured to provide an aesthetic cover to an overmolded intermediate connector, such as the intermediate connector 3200. The clamshell 3300 can also be configured to protect the PCB from damage.

[0300] The clamshell 3300 includes two halves 3305a, 3305b coupled together. In some embodiments, the two halves 3305a, 3305b are permanently coupled together (e.g., decoupling the two halves involves at least partially damaging or destroying the clamshell 3300; or a force of at least about 30N is required to separate the two halves 3305a, 3305b of the clamshell 3300). Each half 3305a, 3305b can be formed from the same one-piece tool and can be symmetrical so that one half can be rotated and still mate with the other half. The clamshell 3300 can include a snap-fit ​​connection including a clip 3309a and a clip receiving mechanism 3309b. The clip 3309a can be a pair of protruding clips extending from two diagonally opposed cover pieces of the clamshell 3300. The clip 3309a can be configured to interact with the complementary clip receiving mechanism 3309b and form the main connection feature of the clamshell 3300 to reduce the gap between the half pieces 3305a, 3305b, thereby keeping the gap closed and keeping the two ends closed. The clamshell 3300 can include a concave locating slot 3307a, which is configured to engage with the convex locating pin 3307b. In some implementations, the concave locating slot 3307a can include a slight inward taper, which requires force to insert the convex locating pin 3307b. The convex locating pin 3307b can be configured to be press-fit into the corresponding concave locating slot 3307a on the other half of the clamshell 3300. This can serve as a backup connection if the snap-fit ​​connection fails.

[0301] The clamshell 3300 includes a plurality of features, such as ribs 3310a, 3310b, to ensure that the clamshell is assembled correctly. This may occur at least in part because the two halves 3305a, 3305b are configured so that they cannot fully engage each other when not assembled correctly. The cover 3300 may include horizontal ribs 3310a to reduce the vertical movement of the intermediate connector and vertical ribs 3310b to reduce the horizontal movement of the intermediate connector. The vertical ribs 3310b can be configured so that the central rib is longer, so that it is closer to the overmolding and can reduce the rotation of the overmolding. The ribs 3310a, 3310b can be generally configured to receive the pins of the overmolded intermediate connector and position it. For example, the ribs 3310a, 3310b can be configured to prevent or hinder improper positioning by pushing an overmolded intermediate connector (e.g., pin 3232 of intermediate connector 3200 described herein with reference to FIG. 32) off-center, which can also prevent or hinder engagement of a second pin.

[0302] The clamshell 3300 may include a coupling region 3315 including a protruding section and a cut-out region. The coupling region 3315 may be configured to interact with a corresponding region on the other half of the clamshell 3300. The coupling region 3315 may be configured to prevent the formation of a rough edge between the two halves 3305a, 3305b, thereby obtaining a better overall finish and may help guide the proper alignment of the two halves. The coupling region 3315 may be configured to be symmetrical with a corresponding coupling region on the other half of the clamshell. The clamshell 3300 may include an internal cut-out region 3320 configured to allow space to be obtained so that a protruding overmolded PCB fits within the region 3320.

[0303] In some embodiments, the overmolded intermediate connector 3200 can be configured to fit within the clamshell 3300 in at least four different positions. The intermediate connector 3200 can include, for example, three pins that are not centered relative to the intermediate connector 3200. In some embodiments, the central pin can be centered relative to the other pins and not the intermediate connector 3200.

[0304] In some embodiments, the overmolded intermediate connector 3200 includes three or more pins 3220 for fixedly securing the overmolded intermediate connector 3200 to the clamshell 3300. These pins 3220 can be configured to reduce horizontal and / or vertical translation and / or rotation about a horizontal axis, as described herein with reference to Fig.32A -C described. In some embodiments, four pins 3220 can be used to effectively place and position the overmolded intermediate connector 3200 in the clam shell 3300. In such an embodiment, the two half pieces 3305a, 3305b of the clam shell 3300 may not be symmetrical. In addition, the fourth pin can push the wire outward, thereby potentially increasing the chance of exposing these wires due to the reduction in the amount of overmolding material covering these wires. These pins 3220 can be configured to be long enough so that they engage with ribs 3310a, 3310b, thereby reducing or preventing the rotation of the overmolded intermediate connector 3200. In some embodiments, the central pin can be longer than other pins. In addition, these pins 3320 can be configured to be thick enough to obtain mechanical robustness.

[0305] The clamshell 3300 and the overmolded intermediate connector may include features that reduce or prevent misalignment of the overmolded intermediate connector within the clamshell 3300 during installation or manufacturing. In some embodiments, when the overmolded intermediate connector is incorrectly placed within the clamshell 3300, the overmolded intermediate connector may move within the clamshell 3300, thereby preventing the two halves 3305a, 3305b from properly coupling. This may cause the two halves 3305a, 3305b to become disconnected and decouple the clamshell 3300 from the overmolded intermediate connector.

[0306] The size of the clamshell 3300 can be determined based on the intended use. For example, the size of the clamshell 3300 can be determined based on the size of the opening in one side of the incubator. The clamshell 3300 can be configured to fit within the opening of the incubator to allow the pipe to be placed within the incubator. However, if the clamshell 3300 is too small, the material strength may be reduced to below an acceptable level. This may be particularly true with respect to the clamping mechanism. In some embodiments, the clamshell 3300 is configured to fit snugly without contacting the overmolded intermediate connector. Therefore, it may be difficult to include additional structure or features within the clamshell 3300.

[0307] During manufacturing, tubing may be wrapped onto either end of the intermediate connector prior to overmolding. The clamshell 3300 may be configured to be close to the tubing but with little or no contact, as this may put stress on the clamshell 3300. The clamshell 3300 may be made of materials including polypropylene, acetyl, or other materials having similar properties.

[0308] In some embodiments, the cover (e.g., clamshell 3300) can include a living hinge that can be used to connect the two halves of the cover. This living hinge can provide a simple mechanism to assemble the cover. In some embodiments, an internal hinge is integrated into the cover, which can be combined with a clip to provide an effective connection mechanism.

[0309] In some embodiments, the cover can include a plurality of pins that are used in place of the horizontal and vertical ribs of the clamshell 3300. The pins can be configured to provide the same locating function as the ribs 3310a, 3310b of the clamshell 3300. In some implementations, the cover can use fewer pins or no pins. This can allow the intermediate connector to rotate and can prevent the intermediate connector from sliding. In some implementations, the ends of the locating pins can be flattened so that the insert forms a locating point.

[0310] In some embodiments, the overmolding on the intermediate connector can form an outer cover. In some embodiments, the cover can be shaped so that it matches the shape of the overmolded intermediate connector. In such a configuration, the cover can be an asymmetric part. The shape can be configured to reduce the contact between the cover and the intermediate connector.

[0311] In some embodiments, the cover halves may be joined using ultraviolet (UV) glue, adhesive, or using male and female locating pins on the cover to form a press fit connection.

[0312] Control of segmented heaters

[0313] Fig.26 A flow chart of an exemplary method for controlling a segmented heater in, for example, an inlet branch having a heater coupled to an extension branch also having a heater is shown. The control method may be implemented by a humidification system (as described herein) or other control module. As such, and for ease of description, the following method is described as being performed by a control module, but one or more steps of the method or a portion of a single step of the method may be performed by any combination of components in the humidification system. In some embodiments, the method 2600 may be run at least once per second to provide substantially continuous and fine control of the humidification system.

[0314] In step 2605, the control module determines the power requirement of the first heater segment (e.g., the heater in the inspiratory branch). This can be done, for example, using open loop control. A default duty cycle can be determined as the power requirement of the first heater segment determined at least in part based on the gas flow through the humidification system. In some embodiments, this default duty cycle can be used to control the first heater segment and is determined using a model that is configured to be applicable to most situations. Advantageously, this can allow the control module to apply the same control parameters during most situations. For example, this can mean that the control module does not change its control parameters for different environmental conditions.

[0315] The power demand may be configured such that the control module maintains a target temperature profile, Fig. 27 Examples are shown. In some embodiments, the target temperature profile utilizes a greater amount of heating in the first heater segment to reduce condensation (e.g., relative to the second heater segment of the extension leg). For example, the first heater segment can be controlled to heat the inspiratory leg above the set point to give the gas a relatively low humidity. This can effectively control the cooling of the gas as it reaches the patient after flowing through the extension leg, thereby allowing the gas to maintain a high absolute humidity.

[0316] In step 2610, the control module determines the temperature at the patient end of the combined inspiratory limb and extension limb, which is determined using a patient end temperature sensor. The control module can be configured to monitor this temperature sensor frequently (e.g., once per second, twice per second, etc.). In response to the determined temperature, the control module can change the duty cycle to achieve a target temperature profile, a target absolute or relative humidity of the gas at the patient end, and / or a target temperature of the gas at the patient end.

[0317] In step 2615, the control module determines the difference between the set point temperature and the measured temperature at the patient end. For ease of reference, the value of this difference is referred to as the error, but it should not be inferred or understood that this value represents an error or other unintended result.

[0318] In step 2620, the control module determines the power requirement of the combination of the first heater segment and the second heater segment (e.g., the suction branch and the extension branch connected to the suction branch). The power requirement can be proportional to the length of the branch relative to the flow rate. For example, the control module can determine the power requirement as power per unit length.

[0319] The power demand may be expressed as: DC_12 = Kp*e+Ki*∫edt, where DC_12 is the output of the control module (e.g., power, duty cycle, etc.) for the combination of the first and second heater segments, Kp is a proportional coefficient in a proportional-integral-derivative (PID) control scheme, Ki is an integral coefficient in the PID scheme, and e is the error (i.e., the current difference between the set point temperature and the measured temperature as determined in step 2615). The control module may be configured to reduce or eliminate the error. For example, the control module may be configured to control the power to the heater segments to bring the current temperature to the set point, taking into account the short-term and long-term effects on the temperature in response to the power delivered to the respective heater segments.

[0320] In a PID control scheme, the value of Kp can be related to the rate of temperature change within the system. Changing Kp can achieve a target or appropriate rate of temperature change within the system to reach the set point temperature, taking into account short-term and long-term effects. The product of Kp and e in the above equation can be called the proportional term in the PID scheme.

[0321] In a PID control scheme, the value of Ki can be related to how quickly the system achieves a target set point when the system is close to steady-state operation. Ki can also be related to how fast the system heats up. The integral value of the error (e.g., ∫ede) represents the error accumulated over the time the system has been running. The product of Ki and the accumulated error in the above equation can be called the integral term in the PID scheme.

[0322] In some embodiments, there is no derivative term in the PID control scheme.

[0323] In step 2625, the control module selectively heats the first and second heater segments to meet the respective power requirements. In some embodiments, the power requirement of the first heater segment can be exceeded. In some implementations, the control module can implement an algorithm that allows the power requirement of the first heater segment to be exceeded depending on other control parameters, as described herein with reference to Fig.29 Described.

[0324] The control module can be configured to consider a first heater segment power demand to be met, where at least one of the following conditions applies: (1) the power demand of the first heater segment is met by heating of the first heater segment; (2) the power demand of the first heater segment is met in part by heating of the first heater segment and in part by heating of the second heater segment, where the combined duty cycle of the first and second heater segments contributes to the total demand and any shortfall is met by heating of the first heater segment (see Fig.28 Examples of which are described); or (3) the demand of the first heater segment is met by combined heating of the first and second heater segments.

[0325] Fig.28 A functional block diagram 2800 is shown to illustrate the relationship between the processing components of the control module, the requirements associated with the heater segments, and the application of the resulting duty cycle determination results. For example, the control module may be as described herein with reference to Fig.26 PID controller 2802 may be implemented as described in the embodiments of the present invention and / or 30. PID controller 2802 may be configured to control a combination of first and second heater segments 2806 (e.g., an outer loop of an air intake branch coupled to an extension of the air intake branch) based at least in part on a demand determined by a control module, as described herein with reference to Fig.26 The control module can be as described herein. Fig.26 , 29and / or 31 to implement the control algorithm 2804. The control algorithm 2804 can control the first heater segment 2808 based at least in part on the demand determined by the control module. The control module can use the PID controller 2802 to apply power to the first and second heater segments based on the determined duty cycle 2810 to meet the demand of the first and second heater segments 2806. Similarly, the control module can use the control algorithm 2804 to apply power to the first heater segment based on the determined duty cycle 2812 to meet the demand of the first heater segment 2808. In some embodiments, the control algorithm can determine the duty cycle 2812 of the first heater segment based at least in part on the demand of the combination of the first and second heater segments, because the power applied to the combination of the heater segments affects the temperature and humidity of the gas in the first segment. For example, as described herein with reference to Fig.26 As described, the demand of the first heater segment can be partially or completely met by the demand of the combination of the first and second heater segments. In certain implementations, the PID controller 2802 can be configured as the primary means for controlling heating in the combined induction leg and extension (e.g., the first and second heater segments), and the control algorithm 2804 for the induction leg (e.g., the first heater segment) can serve as a means of providing supplemental heating that can be particularly appropriate during specific operating phases (e.g., during startup, a warm-up period, during changing temperatures, etc.).

[0326] Fig.29 A flow chart of an exemplary control algorithm 2900 implemented by a control module for controlling a segmented heater is shown. In step 2902, the control module operates in an open loop control mode by setting the demand for the first heater segment to a fixed duty cycle value. In some implementations, the fixed duty cycle may be initially set to 80%. The duty cycle value may be incremented or decremented as determined by the steps in the control algorithm.

[0327] In step 2904, the control module determines whether the humidification system is in standby mode. In some embodiments, the control module can determine that the humidification system is in standby mode by checking the value stored in the local variable. If the humidification system is in standby mode, the control module goes to step 2906 to determine whether the patient end temperature (Tpe) has increased by more than the change threshold Tth (e.g., about 2°C) within the time window (e.g., about 1 minute). This can effectively determine whether flow has been added to the humidification system. If it is determined in step 2906 that flow has been added, the control module exits the standby mode in step 2908.

[0328] When the unit is not in standby (as determined in step 2904) or after exiting step 2908, in step 2910, the control module determines whether the heating plate temperature exceeds the heating plate temperature threshold Tth_hp (e.g., about 50°C). This can correspond to the warm-up period. If the control unit determines that the heating plate temperature exceeds the heating plate temperature threshold, then in step 2912, the control module determines whether the duty cycle DC_12 of the combination of the first and second heater segments (e.g., the outer segment) is greater than about 99%, and whether the patient end temperature Tpe is less than the set point temperature minus the temperature value Tnear, which is configured to determine when the patient end temperature is close to the set point temperature. In some embodiments, the value of Tnear can be about 2°C. If the control module determines that the combination of the first and second heater segments is greater than about 99% and the patient end temperature is less than the set point temperature minus Tnear, it is possible that there is no flow condition in the humidification system. For example, in the case where the humidification system is applying about 100% duty cycle, but the patient end temperature is not close enough to the set point, there may be no flow condition. If this is true, the control module goes to step 2914 to account for potential disturbances in the system (e.g., placing a cold item on the system) and waits a custom amount of time t_wait (e.g., about 5 minutes). If it has been longer than the time t_wait, the control module goes to step 2916 and enters a standby state until flow is applied or reapplied to the humidification system. In the standby state, the control mode sets the duty cycle of the first heater segment to 0% and sets the duty cycle of the combination of the first and second heater segments to about 40%.

[0329] If the result of the determination in any of steps 2910, 2912, or 2914 is negative, the control module proceeds to step 2918 to control the combination of the first and second heater segments to achieve the target set point at the patient end using a PID control scheme. In some embodiments, the PID control scheme is described herein with reference to Fig.30The method described in step 2920. For example, the control module may control the combined first and second heater segments to achieve a target set point based on the difference between the current measured temperature at the patient end and the set point. In some implementations, the control is proportional to the difference between the measured temperature and the temperature set point. In step 2920, the control module may monitor a timer to determine when a customized time threshold (e.g., 30 seconds) expires. This customized time threshold may be set to allow sufficient time for the PID controller to take effect. The control module implements a PID control scheme to achieve the following duty cycle: the duty cycle meets the relevant requirements, namely the requirements determined in step 2922. For example, the PID control scheme may be implemented to achieve a duty cycle DC_12 for the combination of the first and second heater segments, and / or a duty cycle DC_1 for the first heater segment, wherein the duty cycle of the first heater segment takes into account the requirements of the combination of the first and second heater segments.

[0330] After the custom time threshold has expired, the control module may proceed to step 2924 to determine whether (a) the duty cycle of the combined first and second heater segments is equal to 0%, (b) the patient end temperature exceeds a set point (e.g., approximately 39° C.), and (c) the duty cycle of the first heater segment is greater than a duty cycle threshold (e.g., approximately 40%). This test may be true in the event that the combined first and second heater segments cease heating the gas, thereby indicating that it is appropriate to reduce the temperature profile of the inspiratory limb. For example, this may be accomplished by reducing the duty cycle of the first heater segment. Accordingly, if this is true, then in step 2926, the control module decrements the duty cycle of the heater cycle by the decrement value (e.g., 2%). If not true, the control module proceeds to step 2928 to determine whether (a) the duty cycle of the combined first and second heater segments is greater than the duty cycle of the first heater segment plus a constant c (e.g., testing whether DC_12>DC_1+c is satisfied, where c may be approximately 20%), and (b) the duty cycle of the first heater segment is less than an inner segment threshold DC_1th (e.g., approximately 80%). The constant may be customized so that the initial duty cycle value plus the constant is 100% (e.g., the initial duty cycle value may be 80%, so the constant may be 20%). This test is true in situations where increasing the duty cycle of the first heater segment to maintain the temperature profile of the suction leg may be appropriate. Therefore, if this test is true, the control module proceeds to step 2930 to increase the duty cycle of the first heater segment by an incremental value (e.g., approximately 2%). If not true, the control module returns to step 2922 described above. In step 2932 , if the control module increments or decrements the duty cycle of the first heater segment, the control module resets the timer. Control may then return to step 2922 .

[0331] Fig.30 FIG. 1 shows a flow chart of an exemplary PID control scheme 3000 configured to provide closed-loop control using a combined first and second heater segment to achieve a target temperature set point at the patient side. The PID control scheme can be used to determine the duty cycle of the combined first and second heater segments.

[0332] In step 3002, the control module initializes the PID parameters by determining the difference between the measured temperature Tpe and the temperature set point Tset, which is referred to as the error e: e = Tset - Tpe. In step 3004, the control module sets the proportional term of the PID control scheme to the product of a constant Kp and the error e: P = Kp * e. In some implementations, the constant Kp is set to approximately 10. In step 3006, the control module sets the derivative term D of the PID control scheme to 0. Other values can also be used.

[0333] In step 3008, the control module determines whether the error is less than or equal to a temperature difference threshold Tdiff (e.g., approximately 100). This can be used to determine when it is appropriate to set the integral term I of the PID control scheme to 0, as shown in step 3010. If the current temperature is within the temperature difference threshold of the temperature set point, the control module can proceed to step 3011 to assign the integral term I of the PID control scheme as the previous or prior integral term plus a fraction Ki of the error e: I = I prev + Ki * e. In some implementations, the fraction Ki can be approximately 0.05. In step 3012, the control module can further check that the integral term I is within an acceptable or suitable boundary (e.g., -2 < I < 100), and if it is outside this suitable range, the control module can set the integral term to the boundary value.

[0334] In step 3014, the control module determines the duty cycle as the sum of the proportional term P, the integral term I, and the derivative term D: DC = P + I + D. As determined by the control module in step 3015, if the duty cycle is greater than 100% and the integral term is greater than the previous integral term (e.g., I > I prev ), then in step 3016, the control module resets the integral term to its previous value and recalculates the duty cycle in step 3018. In step 3020, the control module bounds the value of the duty cycle between 0 and 100 (e.g., if it is less than 0, the control module sets the duty cycle to 0, and if the duty cycle is greater than 100, the control module sets the duty cycle to 100).

[0335] Fig.31A flow chart of another exemplary control algorithm 3100 that can be implemented by a control module in a humidification system is shown. In step 3102, the control module determines the flow range of the humidification system. In step 3104, the control module determines the demand for the first heater segment based on the determined flow range. In some embodiments, the flow range can be a level of flow and corresponding demand. For example, the flow range can be divided into a low flow range, a medium flow range, or a high flow range, and a low flow demand can be determined for the low flow range, a medium flow demand can be determined for the medium flow range, and a high flow demand can be determined for the high flow range. In some embodiments, the flow ranges can overlap. In certain implementations, the control module determines the flow range to determine the initial demand of the first heater segment only at startup. In such cases, the control module can use the combined demand of the first and second heater segments to achieve most of the control of the humidification system. After this initial setting, the rest of the control algorithm 3100 can adjust the demand for the first heater segment.

[0336] In step 3106, the control module determines whether the humidification system is in standby mode. For example, the control module can determine that the humidification system is in standby mode by checking the value stored in a local variable. If the humidification system is in standby mode, the control module proceeds to step 3108 to determine whether the patient end temperature (Tpe) has increased by more than 2°C in about 1 minute. This can effectively determine whether flow has been added to the humidification system. If it is determined in step 3108 that flow has been added, the control module exits the standby mode in step 3110.

[0337] When the unit is not in the standby state (as determined in step 3106), in step 3112, the control module determines whether the heating plate temperature exceeds about 50°C. This can correspond to the warm-up period. If the control unit determines that the heating plate temperature exceeds about 50°C, then in step 3114, the control module determines whether the duty cycle of the combination of the first and second heater segments (e.g., the outer segment) is greater than about 99%, and whether the patient end temperature Tpe is less than the set point temperature minus the temperature value Tnear (e.g., about 2°C). If the control module determines that this is true, it is possible that there is no flow condition in the humidification system. For example, in the case where the humidification system is applying about 100% duty cycle, but the patient end temperature is not close enough to the set point, there may be no flow condition. If this is true, the control module goes to step 3116 to account for potential disturbances in the system (e.g., placing a cold item on the system) and waits about 5 minutes. If it has been more than about 5 minutes, the control module goes to step 3118 and enters the standby state until flow is applied or reapplied to the humidification system. In the standby state, the control mode sets the duty cycle of the first heater segment to 0% and sets the duty cycle of the combination of the first and second heater segments to approximately 40%.

[0338] If the result of the determination in any of steps 3112, 3114, or 3116 is negative, the control module proceeds to step 3120 to control the combination of the first and second heater segments to achieve the target set point at the patient end using a PID control scheme. In some embodiments, the PID control scheme is described herein with reference to Fig.30 The method described. For example, the control module can control the combined first and second heater segments to achieve a target set point based on the difference between the current measured temperature at the patient end and the set point. In some implementations, the control is proportional to the difference between the measured temperature and the temperature set point. The control module implements a PID control scheme to achieve the following duty cycle: the duty cycle meets the relevant requirements, namely the requirements determined in step 3122. For example, the PID control scheme can be implemented to achieve a duty cycle DC_12 for the combination of the first and second heater segments, and / or a duty cycle DC_1 for the first heater segment, wherein the duty cycle of the first heater segment takes into account the requirements of the combination of the first and second heater segments.

[0339] The control module proceeds to step 3124 to determine whether (a) the duty cycle of the combined first and second heater segments is equal to 0%, (b) the patient end temperature exceeds a set point (e.g., approximately 39° C.), and (c) the duty cycle of the first heater segment is greater than a duty cycle threshold (e.g., approximately 40%). This test may be true in the event that the combined first and second heater segments cease heating the gas, thereby indicating that it is appropriate to reduce the temperature profile of the inspiratory limb. For example, this may be accomplished by reducing the duty cycle of the first heater segment. Therefore, if this is true, then in step 3126, the control module decrements the duty cycle of the heater cycle by a decrement value (e.g., 2%) every 30 seconds while this is true. If not true, the control module proceeds to step 3128 to determine whether (a) the duty cycle of the combined first and second heater segments is greater than the duty cycle of the first heater segment plus a constant (e.g., testing whether DC_12>DC_1+c is satisfied, where the constant may be approximately 20%), and (b) the duty cycle of the first heater segment is less than an internal segment threshold (e.g., approximately 80%). The constant may be customized so that the initial duty cycle value plus the constant is 100% (e.g., the initial duty cycle value may be 80%, so the constant may be 20%). This test may be true in situations where increasing the duty cycle of the first heater segment to maintain the temperature profile of the suction leg may be appropriate. Therefore, if this test is true, the control module proceeds to step 3130 to increase the first heater segment duty cycle by an incremental value (e.g., approximately 2%). If not true, the control module may return to step 3122 or step 3106 described above. If the control module increments or decrements the duty cycle of the first heater segment, the control module may return to step 3122 or step 3106 .

[0340] Additional control systems

[0341] Next, we describe the Fig.25A -C is another exemplary control system of the circuit diagram 2500. As described above, the circuit diagram 2500 can be used in a system where the intermediate connector that connects the first heater segment H1 in the suction branch to the second heater segment H2 in the extension branch does not include a temperature sensor. The circuit diagram 2500 can be implemented using a control system that is configured to change the switching of the MOSFET pair to heat in the inner loop HW1 or the outer loop HW2. Loop HW1 ( Fig.25C The loop HW2 (shown) may include a first heater segment H1 of the suction segment. Fig.25BThe circuit 100 may include a first heater segment H1 and a second heater segment H2. Power may be supplied to loop HW1 to heat H1, or to HW2 to heat both H1 and H2, depending on the polarity of the voltage. In the present application, power may include electrical power, voltage, and / or current. Fig.25C The switching arrangement shown is used to switch the MOSFETS on / off to activate loop HW1. The diodes / switches may be MOSFETS. The polarity of the supplied power may be switched to activate only loop HW2, as shown. Fig.25B The controller can be configured to operate the MOSFETS to switch polarity as required and provide an appropriate duty cycle to the heating wire.

[0342] Fig.35 An exemplary control algorithm 3500 for controlling these loops HW1 and HW2 is shown. In the embodiment shown, loops HW1 and HW2 can be controlled sequentially, thereby allowing the algorithm 3500 to proceed smoothly. The controller can continue to repeat all steps to determine whether the output of the HW1 or HW2 duty cycle needs to be controlled and at what level. The controller can determine at step 3502 whether the patient-side sensor (e.g., Fig.13 The error between the patient end temperature measured by the sensor 204b) and the patient end temperature set point is determined. The output of each of the HW1 and HW2 duty cycles can be controlled based on the error using a PID controller known in the art. The controller can optionally undergo one or more initial system readiness checks in step 3510. If the system is not ready, a system reset 3505 can be performed. If the system is ready, then at step 3515, the output of the HW1 duty cycle can be determined based on the error between the measured patient end temperature and the patient end temperature set point. The output of the HW1 duty cycle can optionally be based on a standard PID controller with a set of constants. In some embodiments, the PID controller can be implemented as follows Fig.37 PID control scheme 3700 is shown, which is described in more detail below. The controller can determine the output of each term (e.g., proportional term, integral term, and differential term) based on the error and the set of constants. The constants can be predetermined for the system and stored in a memory or a lookup table or any other suitable format. The constants can be changed depending on the changing conditions because the system can store multiple constants that can be related to a variety of environments. A non-limiting example is that a portion of the catheter is or is not inside the incubator.

[0343] In one embodiment, the entire inspiratory catheter including the inspiratory limb and the extension limb is exposed to the same ambient environment along its length. In this embodiment, the controller can be used as a normal PID controller to control the output of the HW2 duty cycle (at step 3515). Since the error between the measured patient end temperature and the patient end temperature set point may be large, a set of constants can be used to heat the loop HW2. The error may be large because the patient end of the inspiratory catheter is exposed to ambient temperature, which may be much lower than the patient end temperature set point. In this embodiment, at step 3520, the algorithm 3500 can output a large HW2 duty cycle. Then at step 3625, the algorithm 3500 can determine the output of the HW1 duty cycle. In this embodiment, since the output of the HW1 duty cycle can be inversely related to the output of the HW2 duty cycle, the HW1 duty cycle can be set to 0%. If the output of the HW2 duty cycle is large enough, the output of the HW1 duty cycle can be set to 0%. This may occur when there is a large error value between the patient end temperature and the patient end set point.

[0344] As the heating wires H1 and H2 are heated by the power provided to the loop HW2, the error can be reduced to within an appropriate error threshold. As described above, the controller can continuously run the algorithm 3500 to continuously monitor the error. In this embodiment, when the error is within an appropriate error threshold, the loop HW1 can be activated to achieve temperature control. The activated loop HW1 will be described in more detail below with reference to another embodiment.

[0345] In another embodiment, the inspiratory branch and the extension branch can be exposed to different ambient environments. For example, the extension segment can be placed in a controlled environment such as an incubator, or other suitable device (closed system). The controlled environment can control at least the temperature and / or humidity within the environment. When the extension branch is inserted into the incubator, the patient-end sensor can read a higher temperature value that is closer to the set point value because the temperature inside the incubator rises to above the ambient temperature. Therefore, the error can be smaller than when the extension branch is exposed to the ambient temperature. When the error is within a predetermined threshold (this is typically the case when the extension branch is placed inside the incubator), loop HW1 can be activated. In a non-limiting example, the error threshold can be equal to or less than 2.5°C. At step 3525, the controller can determine the output of the HW1 duty cycle. In some embodiments, the controller can provide PID control 3700 of the output of the HW1 duty cycle, such as Fig.37 As shown. Since the error is further reduced by the heating of H1, the output of the HW1 duty cycle can be further increased because the output of the HW2 duty cycle determined in step 3515 is further reduced.

[0346] Continuing with reference to the incubator environment, the controller is configured to control the power supplied to loop HW1 to energize H1 to maximum capacity until H1 reaches a predetermined surface temperature threshold. The surface temperature threshold may prevent the inhalation branch from becoming too hot and making the humidification system unsafe to operate or use. In some embodiments, the surface temperature threshold may be specified by a regulatory standard. The predetermined surface temperature threshold may be related to the maximum power / voltage supplied to loop HW1. The maximum power / voltage may be set based on empirical data.

[0347] Additionally, since H2 is not powered and therefore not heated when the controller supplies power to loop HW1 (at step 3530), there may be a temperature drop across the extension leg from the intermediate connector to the patient end. This temperature drop may occur at a known decay rate due to the well-known cooling characteristics within the incubator. The power supplied to loop HW1 may be controlled to achieve a certain temperature at the beginning of the extension leg so that the temperature drop across the extension leg may produce the desired patient end temperature. Fig. 27 An exemplary heating curve for the inhalation catheter in this incubator environment is shown. At the end of the inhalation catheter where the humidification chamber is connected, the temperature can be higher or lower than the patient end temperature, depending on the chamber outlet temperature set point. The controller can determine the difference between the chamber outlet temperature and the measured patient end temperature and can adjust the output of the HW1 duty cycle accordingly. The temperature of the inhalation branch can increase along the length of the inhalation branch (which can end at the intermediate connector) and can gradually decrease from the intermediate connector to the patient end along the extension branch, which is not heated when loop HW1 is activated.

[0348] In control algorithm 3500, loop HW1 can perform most of the heating of the humidification system. If the error exceeds a threshold, loop HW2 can take over. In addition, the controller can maintain the output of the HW2 duty cycle at a low value. On the one hand, the low output of the HW2 duty cycle can advantageously reduce the possibility of overheating of the extension branch inside the incubator, thereby increasing the safety of the humidification system. For example, the low output of the HW2 duty cycle can prevent burns to an infant in the incubator or a caregiver operating the inhalation catheter. At the same time, H1 can be heated to a surface temperature threshold to advantageously prevent condensation from occurring in the inhalation branch. On the other hand, the low output of the HW2 duty cycle can advantageously allow loop HW2 to respond quickly to environmental changes and maintain such. Fig. 27The heating curve shown. Sudden changes in the environment may include, but are not limited to: temperature changes inside the incubator, airflow, cold ambient temperature, etc. In addition, supplying power to loop HW2 can further advantageously provide a more stable heating curve. The more stable heating curve can be achieved by reducing or eliminating oscillations when loop HW2 is activated. When only loop HW1 is activated, oscillations may occur due to the time required for heat to be transferred by the heated gas from the inspiratory branch to the patient end and detected at the patient end sensor. Since the patient end sensor can detect a faster temperature change response when both heater segments H1 and H2 are activated than when only loop HW1 is activated, oscillations can be reduced.

[0349] In some embodiments, since the PID control scheme is configured to reduce the error, the output of the HW2 duty cycle can reach a steady state of 0%, and the loop HW2 is only activated to react to the sudden change in the environment, as described above. The steady state can be achieved due to the proportional and differential terms of the loop HW2 being reduced to substantially 0 when the error is within the threshold. In other embodiments, the output of the HW2 duty cycle may not achieve a steady state, but has a low value. For example, but not limited to, when the inspiratory catheter is in cold ambient conditions, the cooling of the gas in the inspiratory branch outside the incubator may increase. This rapid cooling may be due to a lower ambient temperature, which may cause a greater rate of heat dissipation from the heated humidified gas in the pipeline to the surrounding environment. Supplying power to both H1 and H2 in the activated loop HW2 (at 3530) can compensate for the increased cooling of the gas in the inspiratory branch and achieve the desired patient end temperature.

[0350] Fig.36 Another exemplary control algorithm 3600 for controlling the output of the duty cycle of HW1 and HW2 is shown. Control algorithm 3600 may have the same features as control algorithm 3500, except as described below. Accordingly, features of control algorithm 3600 may be incorporated into features of control algorithm 3500, and features of control algorithm 3500 may be incorporated into features of control algorithm 3600.

[0351] The controller may continuously run the algorithm 3600. Continuous operation of the algorithm 3600 may provide substantially continuous and fine control of the humidification system. The controller may start 3602 by determining the error between the measured patient end temperature and the patient end set point. In some embodiments, the patient end set point may be independent of the gas flow in the inspiratory conduit. The set point may be a function of the chamber outlet temperature set point. For example, the patient end temperature set point may be set higher or lower than the chamber outlet temperature set point. If the humidification system is in a very cold ambient environment, the patient end set point may change. In addition, continuous operation of the algorithm 3600 may allow the system to be reset 3605 at any time when there is significant overheating. In the illustrated embodiment, the reset 3605 may reset the error term used in the PID control algorithm to 0 and reset the output of the HW1 and HW2 duty cycles to 0%.

[0352] like Fig.36 As shown, the controller can start the algorithm 3600 through a series of checks 3610, 3615, 3620, 3625 to ensure that all sensors are working, all alarms are working, and the system is in operating condition. These checks may be optional. Specifically, the controller may check (3610) whether a reset needs to be performed. In some embodiments, the controller may be programmed to determine whether a reset needs to be performed based on a predetermined algorithm. In other embodiments, the system may have a user interface to allow a user or caregiver to manually reset the system. For example, when the required conditions are met, the reset can be completed automatically by using an on / off button to turn the device off and on, unplugging the device, or using software. If a reset is not required at step 3610, the controller may determine at step 3615 whether the system is ready to run the algorithm 3600. If the system is not ready, a reset 3605 may be performed. If the system is ready, the controller may determine the state of the patient-side sensor and the state of the sensor at the outlet of the humidification chamber 3620. If the sensor is not responding or is not operating as designed, the system can be reset 3605. If the status of the sensor is satisfactory, in step 3625, the controller can determine whether the high temperature control or high temperature alarm is active. If the measured temperature is above the overheat temperature threshold, the reset 3605 can be activated to prevent overheating of the inspiratory catheter. In some embodiments, if the patient end temperature exceeds the overheat temperature threshold, a separate software module configured to control overheat can take over. This overheat module can set the output of both HW1 and HW2 duty cycles to 0. Reset 3605 can be performed to prevent the integral error term of the PID control scheme 3630, 3680 from accumulating.

[0353] Continue to refer to Fig.36, after determining that the patient end temperature is below the set point and after this series of optional checks, the controller can determine the output of the HW2 duty cycle to bring the system to the patient end set point temperature. At step 3630, the controller can implement a PID control scheme to obtain the output of the HW2 duty cycle. In the illustrated embodiment, the PID control step 3630 can be performed by a PID control scheme known in the art. In general, the output of the controller for HW1 or HW2 in the PID control scheme can be expressed by the following equation: DC = Kp*e+Ki*∫edt+Kd*de / dt, where DC is the output of the HW1 or HW2 duty cycle, Kp is the proportional coefficient, Ki is the integral system, and Kd is the differential coefficient. In addition, e is the error as determined in step 3602. In addition, ∫ede is the error integral, that is, the integral of the past error from time 0 to the current time t, and de / dt is the rate of change of the current error (i.e., the differential term). The PID control scheme can be configured to reduce or eliminate the error.

[0354] Fig.37 An exemplary PID control scheme 3700 is shown. PID coefficients 3705, PID limits 3710, and error terms 3715 may be input into the PID control scheme 3700. As described above, the PID coefficients 3705 may include a proportional coefficient Kp, an integral coefficient Ki, a differential coefficient Kd, and an error introduced into the integral term. In some embodiments, the proportional coefficient may be a system-based term determined by testing. In some embodiments, the differential coefficient Kd may be determined for a heating plate (not shown) of the system, and / or loops HW1 and HW2. For example, Kd may be determined empirically. The PID control scheme 3700 including the differential coefficient Kd may increase the stability of the system and reduce overshoot when correcting errors. In some embodiments, a PI control scheme may be used instead of the PID control scheme 3700, thereby eliminating the differential term. In the PI control scheme, the output of the controller may be expressed as: DC=Kp*e+Ki*∫edt. The PID limits 3710 may include the minimum and maximum integral terms of the duty cycles of HW1 and HW2, and the minimum and maximum output limits. The error term 3715 may include the current error, the error integral, and the previous error.

[0355] Based on the inputs described above, the controller can calculate the proportional term 3720, which is the product of the system's proportional coefficient Kp and the current error in the equation described above. The controller can also calculate the differential term 3725, which is the product of the differential coefficient Kd and the rate of change of the current error de / dt in the equation described above. In step 3735, the controller can calculate the error integral. Then at step 3740, the controller can perform an error term check. For example, the controller can check the error term of any PID variable.

[0356] After the error term check 3740, then at step 3780, the output of the controller may be calculated as follows: DC = proportional term + Ki* error integral + derivative term. At step 3795, the controller may limit the output calculated from step 3780 to the maximum and minimum output limits of the controller. The controller may provide the resulting output 3795 of the controller to Fig.37 Step 3630, or step 3680, which will be described below.

[0357] return Fig.36 At step 3635, the controller may output a HW2 duty cycle defined between 0% and 100% based on the PID control in step 3630. Algorithm 3600 may use the output of the HW2 duty cycle to control the patient end temperature to maintain the patient end temperature as follows: Fig. 27 As described above, the output of HW2 can be low, allowing loop HW2 to respond quickly to sudden changes, while also increasing patient and caregiver safety by preventing overheating of the extension leg.

[0358] The algorithm 3600 may also use the output of the HW2 duty cycle to control the output of the HW1 duty cycle. Before providing the output of the HW2 duty cycle to step 3640 to calculate the PID limit value of the output of the HW1 duty cycle, at step 3645, the controller may filter the raw output of the HW2 duty cycle. This filtering may attenuate the output of the HW1 duty cycle. The filter may allow for the elimination of noise from the heated loop HW2, which in turn may allow for the attenuation of the output of the HW1 duty cycle. Fig.36 As shown, the controller can control the output of the HW2 and HW1 duty cycles in sequence, which can advantageously provide a simple allocation of available electrical power, voltage or current. Next, the PID control of the output of the HW2 duty cycle at step 3630 and the PID control of the output of the HW1 duty cycle at step 3680 can work together to provide more stable control of the system. If the output of the HW1 duty cycle causes the patient end temperature to become too hot or too cold, the output of the HW2 duty cycle can compensate for overheating or underheating. In some embodiments, the output of the HW2 duty cycle can be a negative value to quickly change the integral term of the PID control algorithm. When the output of the HW2 duty cycle is a negative value at step 3630, the controller can define the output of the HW2 duty cycle to be 0 at step 3635. The controller can also quickly reduce the output of the HW1 duty cycle under overheating conditions.

[0359] Continue to refer to Fig.36, in step 3640, the controller may determine a PID limit value for the output of the HW1 duty cycle. Specifically, at step 3650, the controller may calculate the maximum output of the HW1 duty cycle. Also as described above, the maximum output of the HW1 duty cycle may be set to a threshold value to prevent the suction branch from exceeding a surface temperature threshold that would make it unsafe to operate or use. In some embodiments, the maximum output of the HW1 duty cycle may be calculated using a function that includes the maximum threshold output of the HW1 duty cycle and the bounded output of the HW2 duty cycle. In one embodiment, determining the output of the HW1 duty cycle may also include a term that compensates for the difference in resistance of the two heater segments H1 and H2.

[0360] Next, the controller may determine whether the maximum output of the HW1 duty cycle calculated according to step 3650 is a negative value. If the calculated maximum output of the HW1 duty cycle is a negative value, the controller may set the maximum output of the HW1 duty cycle to 0% in step 3660. If the calculated maximum output of the HW1 duty cycle is not a negative value, the controller may limit the output of the HW1 duty cycle to between 0% and the maximum output limit value of the HW1 duty cycle (including the endpoints) at step 3675. In some embodiments, the maximum output limit value of the HW1 duty cycle may be calculated by subtracting the output of the HW2 duty cycle from 100%.

[0361] Based on the PID limit value calculated in step 3640, the controller may perform PID control on the output of the HW1 duty cycle at step 3680. At step 3685, the controller may output the HW1 duty cycle. In one embodiment, the controller may use Fig.37 The controller may also reset the system 3605 after performing PID control on the output of the HW1 duty cycle (at step 3680).

[0362] Fig.38 Another exemplary embodiment of a suction catheter 3802 is shown that may be controlled using algorithms 3500 , 3600 . Fig.35 The suction catheter 3802 may have Figure 1 The features of the suction catheter 3802 may be incorporated into the features of the suction catheter 202, and the features of the suction catheter 202 may be incorporated into the features of the suction catheter 202. Fig.38 In the suction catheter 3802.

[0363] like Fig.38As shown, the suction duct 3802 can be used in conjunction with an incubator 3808 (as shown) or with another system in which different temperatures exist along different sections of the suction branch 3802, such as in conjunction with a radiant warmer. The suction duct 3802 may include two sections. The first section or suction branch 3802a may be outside the incubator 3808, and the second section or extension branch 3802b may be inside the incubator 3808. The first section 3802a may include one or more first internal heating wires 3806a, and the second section 3802b may include one or more second internal heating wires 3806b. The first internal heating wire 3806a and the second internal heating wire 3806b may have the same Figure 2 The first heating wire 206a and the second heating wire 206b have the same features. The suction conduit 3802 may have a gas lumen 3803. The first inner heating wire 3806a and the second inner heating wire 3806b may be wound around the gas lumen 3802.

[0364] Continue to refer to Fig.38 , the inhalation branch 3802 may include an intermediate connector 3814 having an intermediate circuit configured to connect elements of the first segment 3802a and the second segment 3802b of the inhalation duct 3802. In some embodiments, the intermediate connector 3814 may be configured to physically and electrically connect the first inner heating wire 3806a to the second inner heating wire 3806b. In addition, the inhalation duct 3802 may include one or more outer heating wires 3807. The outer heating wire 3807 may have the same or different features as the first inner heating wire 3806a and the second inner heating wire 3806b. In some embodiments, the outer heating wire 3807 may be wound around the inhalation duct 3802. In other embodiments, the outer heating wire 3807 may be positioned inside the gas lumen 3803. In the embodiment shown, the outer heating wire 3807 may be in a spiral configuration. However, it should be understood by those of ordinary skill in the art that the number or configuration of the outer heating wire 3807 is not limited.

[0365] Controller( Fig. 9 The controller may be configured to control the first inner heating wire 3806a forming the inner control loop (loop HW1). The controller may also be configured to control the outer heating wire 3807 forming the outer control loop (loop HW2). Fig.25A -C shows the circuit diagram 2500 of the suction conduit 3802, where H1 corresponds to the first inner heating wire 3806a and H2 corresponds to the outer heating wire 3807.

[0366] The inspiratory branch 3802 may include one or more sensors, and the controller may be configured to receive outputs of the one or more sensors. Fig.38As shown, sensor 3804b can be positioned near the patient end of second segment 3802b so that the parameter (patient end temperature) obtained from sensor 3804b can correspond to the parameter of the humidified gas delivered to the patient or user. In some embodiments, sensor 3804b can function in the same manner as sensors 204a, 204b described above. The output of sensor 3804b can be sent as feedback to the controller for controlling the power, voltage, and / or current delivered to the HW2 loop and the HW1 loop. Additional control system for low flow conditions

[0367] As described herein, in combination with Fig.25A The humidification system of circuit diagram 2500 of -C can be used with an incubator. A non-limiting example of use with an incubator can be when the humidification system is operated in a neonatal therapy mode and connected to an infant patient in an incubator. Fig.39A An exemplary established configuration of the inhalation conduit 3902 and the incubator 3908 of the humidification system is shown. The inhalation branch 3902a with the heating wire segment H1 3906a can be kept outside the incubator 3908 and exposed to the surrounding environment. The extension branch 3902b with the heating wire segment H2 3906b can be placed inside the incubator 3908 and is typically exposed to an elevated temperature compared to the surrounding environment. In the example Fig.39A In the intended configuration shown, the intermediate connector 3914 can be located at the interface between the incubator 3908 and the surrounding environment.

[0368] However, the inspiratory catheter 3902 may be susceptible to movement. For example, the incubator 3908 may move while the inspiratory catheter 3902 is still connected to the patient in the incubator 3908. In another example, an infant patient in the incubator 3908 and connected to the humidification system may move around. As a result, the segment 3902c of the inspiratory branch 3902a may erroneously deviate into the incubator 3908, as caused by Fig.39B The length of segment 3902c may vary.

[0369] exist Fig.39A and 39B middle, Figure 35-36The control algorithms 3500, 3600 may cause loop HW1 (including H1 3906a) to be heated to a surface temperature threshold when the error is less than a predetermined threshold. The control algorithms 3500, 3600 may cause loop HW2 (including H1 3906a and H2 3906b) to be heated to maintain a patient end set point when the error is greater than a predetermined threshold. The increased temperature inside the incubator 3908 may reduce the need to increase the duty cycle of HW2 and may allow loop HW1 to have a high duty cycle to do most of the heating. Since segment 3902c is part of loop HW1, segment 3902c may have a higher surface temperature than extension branch 3902b because HW1 is primarily heated in the primary control scheme.

[0370] However, when the humidification system is in a low flow condition and segment 3902c is located inside the incubator (e.g. Fig.39B When the temperature difference between the segment 3902c and the extension branch 3902b is greater than that between the segment 3902c and the extension branch 3902b, the surface temperature difference between the segment 3902c and the extension branch 3902b may be greater than that between the segment 3902c and the extension branch 3902b. Fig.39A 3902). Low flow conditions may occur more often in neonatal treatment mode because gas may be delivered to infants at a lower flow rate than adults. It should be understood by those of ordinary skill in the art that gas may also be delivered at a low flow rate for other patients. In some embodiments, low flow may occur when the flow rate is below a predetermined value. In some embodiments, low flow may occur when the flow rate is below about 2.4 liters per minute (lpm) to about 5 lpm. In some embodiments, low flow may occur when the flow rate is below about 5 lpm. In some embodiments, low flow may occur when the flow rate is below about 3.5 lpm. In some embodiments, low flow may occur when the flow rate is below about 3 lpm. The definition of low flow conditions is not limited. Low flow conditions can increase the heat loss of gas because it takes longer for the gas to pass through the inspiratory catheter 3902. It may also take longer for the patient-end sensor 3904b to sense the heated gas. Larger heat loss, and / or delays in detecting increased patient-end temperature may result in a large error between the measured patient-end temperature and the patient-end set point. This large error may in turn cause the controller to output a higher duty cycle for HW2 than in normal or high flow conditions until the suction branch 3902a (including segment 3902c inside the incubator 3908) reaches a surface temperature threshold.

[0371] One problem with the segment 3902c inside the incubator 3908 when the system is in low flow conditions may be that the segment 3902c overheats. The overheating may be due to the difficulty in dissipating the heat inside the incubator 3908. The heat loss inside the incubator is proportional to the difference between the incubator temperature and the surface temperature of the segment 3902c. The increased temperature inside the incubator results in a small difference between the incubator temperature and the surface temperature of the segment 3902c. Therefore, the little heat generated by this part of the loop HW1 in the segment 3902c (due to the higher HW1 duty cycle under low flow conditions) can be transferred to the inside of the incubator. Alternatively, heat can accumulate on the surface of the segment 3902c. The heat accumulation on the surface of the segment 3902c may be significant because the heating wires 3906a, 3906b are embedded in the wall 3916 of the suction duct 3902. The accumulated heat can cause the surface temperature of the segment 3902c inside the incubator to exceed the surface temperature threshold.

[0372] Overheating of segment 3902c may endanger the patient within the incubator 3908 because segment 3902c is now closer to the patient than when it was outside the incubator 3908. Overheating of segment 3902c may also result in non-compliance with regulations or temperature standards set by regulatory agencies when the surface temperature threshold is dictated by such regulations or temperature standards. Accordingly, it is important to prevent segment 3902c from exceeding the surface temperature threshold when segment 3902c is expelled into the incubator 3908 under low flow conditions.

[0373] Fig.40 A control algorithm 4000 is shown for addressing overheating of segment 3902c under low flow conditions. The control algorithm 4000 can reduce the likelihood that the surface temperature of segment 3902c will exceed the surface temperature threshold even if segment 3902c is moved inside the incubator 3908. The control algorithm 4000 can have Fig.36 The control algorithm 3600 has the same features as described below. Accordingly, Fig.40 The control algorithm 4000 features can be introduced Fig.36 The control algorithm 3600 is characterized by, and Fig.36 The control algorithm 3600 features can be introduced Fig.40 In the features of the control algorithm 4000. Based on the control algorithm 4000, the duty cycle or power setting end value provided to HW1 and / or HW2 is determined using a suitable end value or limit value that prevents the surface temperature from exceeding a predefined threshold. The duty cycle end value or limit value is predefined in the control algorithm 4000. The duty cycle end value or limit value can be defined as a percentage or a specific value. The limit value or end value can be defined based on system parameters or based on a system model. Fig.40In the example of , the end value or limit value can be hard-coded or predefined. In an alternative configuration, the system can include a temperature sensor, which is positioned on a portion of the pipe or on an intermediate connector. The system can include a first temperature sensor and a second temperature sensor, the first temperature sensor is positioned on a portion of the first segment to determine the surface temperature of the first segment, and the second temperature sensor is positioned on the second segment to determine the surface temperature of the second segment. The control algorithm 4000 can be modified to determine the duty cycle end value or limit value based on the measured surface temperature value.

[0374] like Fig.40 As shown, at step 4002, a controller of the humidification system, such as Figure 1 The controller 122 shown may determine the error between the measured patient end temperature and the patient end set point and perform a series of checks in steps 4010, 4015, 4020, 4025. This series of checks may ensure that all sensors and alarms are working and that the system is in operating condition. These checks may be optional. If the controller detects any problems in any of steps 4010, 4015, 4020, 4025, a reset 4005 may be performed to clear the error integral and the output of the HW1 and HW2 duty cycles.

[0375] Continue to refer to Fig.40 After determining that the patient end temperature is below the set point and after this series of optional checks, the controller can determine the output of the HW2 duty cycle required to bring the system to the patient end set point temperature. At step 4030, the controller can implement a PID control scheme to obtain the output of the HW2 duty cycle. In the illustrated embodiment, the PID control step 4030 can be performed as described herein and Fig.37 Based on the PID control in step 4030, at step 4035, the controller may output a duty cycle of HW2 defined between 0% and 100%. In one non-limiting example, the duty cycle of HW2 may be defined as an upper limit value of 70%, i.e., 70% of the maximum power that can be delivered by the drive circuit. The end value or limit value of 70% is set to ensure that the surface temperature of the pipe (i.e., the two sections of the pipe) does not exceed the surface temperature threshold.

[0376] The algorithm 4000 may also use the output of the HW2 duty cycle to control the output of the HW1 duty cycle after filtering the raw output of the HW2 duty cycle at step 4045 as described above. In step 4040, the controller may determine a PID limit value for the output of the HW1 duty cycle. In the illustrated embodiment, the control algorithm 4000 may have a flow control portion including steps 4050, 4050H, 4050L. Specifically, the controller may first determine at step 4050 whether the flow of the system is above a predetermined threshold. In some embodiments, the flow rate may be measured using an integrated flow sensor disposed on the humidifier housing. In some embodiments, the flow sensor may be positioned at the outlet and / or inlet of the humidifier.

[0377] The controller can divide the calculation of the maximum output of the HW1 duty cycle based on comparing the measured flow rate with a predetermined threshold. The maximum output of the HW1 duty cycle can be calculated using a function including the high flow or low flow maximum terminal output of the HW1 duty cycle and the defined output of the HW2 duty cycle. The low flow maximum terminal output of the HW1 duty cycle ("low flow terminal") can be less than the high flow maximum terminal output of the HW1 duty cycle ("high flow terminal"). If the measured flow rate is higher than the predetermined threshold, then at step 4050H, the controller can calculate the maximum output of the HW1 duty cycle based on the high flow terminal. If the measured flow rate is equal to or less than the predetermined threshold, then at step 4050L, the controller can calculate the maximum output of the HW1 duty cycle based on the low flow terminal. In one embodiment, determining the output of the HW1 duty cycle can also include a term that compensates for the difference in resistance of the two heating wire segments H1 and H2. In one non-limiting example, the low flow end value of the HW1 duty cycle is determined to be 37% of the possible maximum available power output from the drive circuit.

[0378] In some embodiments, the low flow end value may not affect the output of the HW2 duty cycle. The output of the HW2 duty cycle can be as high as 100%, despite the low flow end value. In one embodiment, if the output of the HW2 duty cycle is between 0% and the low flow end value, the output of the HW1 duty cycle can be the difference between the low flow end value and the output of the HW2 duty cycle; if the output of the HW2 duty cycle is equal to or greater than the low flow end value, the output of the HW1 duty cycle can be 0%. The low flow end value may not need to affect the output of the HW2 duty cycle because the output of the HW2 duty cycle can be controlled by the patient end temperature, which is much lower than the surface temperature threshold. In addition, the increased temperature within the incubator 3908 can reduce the need for a very high HW2 duty cycle to maintain the patient end temperature.

[0379] In some embodiments, the amount of condensate generated in the inspiratory duct can be kept low because a smaller amount of gas flows through the inspiratory duct at a low flow rate, although the low flow rate end value may result in less heat available to minimize condensate. In addition, better insulation can be provided to the inspiratory branch to compensate for the less heat generated due to the low flow rate end value.

[0380] The division in steps 4050H and 4050L can ensure that loop HW1 is still heated to the surface temperature threshold under high flow conditions, but is heated to a lesser extent than determined by the low flow end value under low flow conditions. In a non-limiting example, loop HW1 is heated to the surface temperature threshold based on the duty cycle provided to the output provided to HW1. The division is advantageous because the offset of segment 3902c into the incubator 3908 may not cause segment 3902c to overheat under high flow regulation. However, the low flow end value is required to reduce the maximum HW1 duty cycle under low flow conditions so that the surface temperature of segment 3902c does not exceed the surface temperature threshold, even if segment 3902c is moved into the incubator 3908.

[0381] After calculating the maximum output of the HW1 duty cycle according to step 4050H or 4050L, the controller may determine at step 4055 that the calculated maximum output of the HW1 duty cycle is a negative value. If the calculated maximum output of the HW1 duty cycle is a negative value, the controller may set the maximum output of the HW1 duty cycle to 0% at step 4060. If the calculated maximum output of the HW1 duty cycle is not a negative value, the controller may define the output of the HW1 duty cycle between 0% and the maximum output limit value of the HW1 duty cycle (including the endpoints) at step 4075. In some embodiments, the maximum output limit value of the HW1 duty cycle may be calculated by subtracting the output of the HW2 duty cycle from 100%.

[0382] Based on the PID limit value calculated in step 4040, the controller may perform PID control on the output of the HW1 duty cycle at step 4080. Then, at step 4085, the controller may output the HW1 duty cycle. In one embodiment, the controller may use Fig.37 The controller may reset the system 4005 after performing PID control on the output of the HW1 duty cycle (at step 4080).

[0383] Steering Fig.41, another exemplary flow control portion 4150 may be implemented in the control algorithm described herein. The flow control portion 4150 may be implemented as part of step 3525 in the control algorithm 3500, or as part of step 3650 in the control algorithm 3600. The flow control portion 4150 may also replace steps 4045, 4050H, 4050L of the control algorithm 4000.

[0384] In the flow control section 4150, the controller can use different thresholds to determine whether the high flow end value or the low flow end value should be used to calculate the maximum output of the HW1 duty cycle. At step 4152, the controller can first determine whether the system is currently at the high flow end value or the low flow end value to calculate the maximum output of the HW1 duty cycle.

[0385] If the system is currently at the high flow endpoint, the controller may determine whether the measured flow is above a predetermined low flow threshold at step 4154. If the measured flow is above the predetermined low flow threshold, the controller may continue to use the high flow endpoint to calculate the maximum output of the HW1 duty cycle at step 4150H. If the measured flow drops to equal or below the predetermined low flow threshold, the controller may switch to step 4150L to use the low flow endpoint to calculate the maximum output of the HW1 duty cycle.

[0386] If the system is currently at the low flow endpoint, the controller may determine whether the measured flow is below a predetermined high flow threshold. If the measured flow is less than the predetermined high flow threshold, then at step 4150L, ​​the controller may continue to use the low flow endpoint to calculate the maximum output of the HW1 duty cycle. If the measured flow reaches or exceeds the predetermined high flow threshold, then the controller may switch to step 4150H to use the high flow endpoint to calculate the maximum output of the HW1 duty cycle.

[0387] In some embodiments, the high flow threshold can be higher than the low flow threshold. The low flow threshold and the high flow threshold can be determined empirically. In some embodiments, these thresholds can be device or sensor specific. In some embodiments, the low flow threshold can be about 2.4lpm to about 5lpm. In some embodiments, the low flow threshold can be about 3.5lpm. In some embodiments, the low flow threshold can be about 5lpm. In some embodiments, the low flow threshold can be about 6.5lpm. When the system moves from a low flow condition to a high flow condition, switching the duty cycle with different flow thresholds can reduce the oscillation at the low flow / high flow boundary.

[0388] Additional Examples of Midpoint / Intermediate PCB Designs

[0389] Fig.42Another exemplary intermediate PCB 4250 of the intermediate connector 214, 3514 is shown. Fig.32A -C describes a detailed description of how the intermediate PCB can be assembled in the suction branch. The intermediate PCB 4250 may include a diode 4265. The diode 4265 may allow control of HW1 or HW2 (eg, Fig.25A -C). Fig.14A Unlike PCB 250 of -B, intermediate PCB 4250 may not have a thermistor. The absence of a thermistor may advantageously allow the controller to function more efficiently.

[0390] like Fig.42 As shown, the intermediate PCB 4250 can have a generally rectangular shape having two long sides 4254, 4256 and two short sides 4258, 4260. The diode 4265 can be positioned near one of the long sides 4256 and near the midpoint of the long side 4256. The intermediate PCB 4250 can include a connection pad 4252 for connection of a heating wire and / or a sensor. The connection pad 4252 can be configured to be located on the same side of the intermediate PCB 4250 and on the front side ( Fig.42 As shown) and the rear side (not shown). Fig.42 As shown, the middle PCB 4250 can have two groups of four connection pads 4252 along the long side 4254, wherein two connection pads are provided on each side of the diode 4265. The middle PCB 4250 can further have positioning slots 4264 on each side of the short sides 4258, 4260. These positioning slots can assist in aligning the PCB during the molding process. Having two positioning slots can reduce the swing or movement of the PCB during the molding process. These slots, the shape of the middle PCB 4250, and the arrangement of the connection pads 4252 can advantageously allow for easier manufacture and assembly of the middle PCB 4250. The shape of the middle PCB 4250 and the arrangement of the connection pads 4252 can also reduce the possibility of short circuits and noise. The short sides 4258, 4260 of the middle PCB 4250 can each have a diagonal edge 4262 where the short sides 4258, 4260 meet the long sides 4256. The diagonal edge 4262 can help maintain a good flow curve for the gas. Furthermore, the intermediate PCB 4250 does not extend across the entire diameter of the suction branch, but may extend approximately 1 / 3 of the diameter due to the reduced length of the short sides. The short sides 4258, 4260 may advantageously reduce the flow resistance within the suction branch (described above).

[0391] Additional Examples of Patient-End Connector PCB Design

[0392] Fig.43Another exemplary patient end PCB 4370 of the patient end connector is shown. The patient end PCB 4370 can be connected with Fig.15A The patient-side PCB 270 functions in the same manner as the patient-side PCB 270. However, the patient-side PCB 4370 may be Fig.15A The patient-side PCB 270 is longer and easier to mold. The patient-side PCB 4370 may also have a positioning slot so that the PCB 4370 can only be installed on the assembly tool in one orientation for easier assembly. Fig.43 As shown, the patient end PCB 4370 can have a plurality of upper locating slots 4373 and a lower locating slot 4375. These locating slots can assist in aligning the PCB during the molding process. Once the PCB 4370 is assembled, the portion of the PCB 4370 located below the upper locating slots 4373 or below the lower locating slots 4375 can be broken off.

[0393] The patient end PCB 4370 may also include connection pads 4372 for connection of heating wires and / or sensors. The connection pads 4372 may be configured to be located on either end of the patient end PCB 4370. In the illustrated embodiment, the patient end PCB 4370 may have two connection pads 4372 on the front side of the slot 4373. Although Fig.43 4373, but the patient end PCB 4370 may also have two connection pads 4372 on the back side of the slot 4373. Having connection pads 4372 on either end of the PCB 4370 may advantageously prevent or reduce water ingress. The patient end PCB 4370 may also have a thermistor 4374. Fig.15A Unlike the patient-side PCB 270 of the embodiment of the present invention, the thermistor 4374 on the patient-side PCB 4370 can be positioned near the center of the patient-side PCB 4370. In some embodiments, the patient-side PCB 4370 can have a substantially straight trace from the connection pad 4372 to the thermistor 4374. It should be understood by those of ordinary skill in the art that any suitable trace arrangement can be arranged on the patient-side PCB 4370. The location of the thermistor 4374 can also allow for easier manufacturing of the PCB 4370.

[0394] In some embodiments, there may be no lower detent slot 4375. In other embodiments, the patient end PCB 4370 may not include a portion located below the upper detent slot 4373. In one embodiment, the patient end PCB 4370 may not be molded and may terminate below the upper detent slot 4373.

[0395] Example of chamber end PCB design

[0396] Fig.44A -B shows the device for connecting to the box (such as Fig. 8A An exemplary chamber end PCB 4490 that may include electrical connection pads on a complementary connector on a humidification system (as shown). A detailed description of the shape and function of the chamber end PCB is described in U.S. Patent Application No. 15 / 105,531, entitled "HUMIDIFICATION SYSTEM CONNECTIONS," filed on June 16, 2016, and U.S. Patent Application No. 15 / 021,673, entitled "CONNECTIONS FOR HUMIDIFICATION SYSTEM," filed on March 11, 2016, the entire contents of each of which are incorporated herein by reference. Fig.44B , showing a detailed view of the upper portion of a chamber end PCB 4490, the chamber end PCB 4490 may have multiple connection pads 4492 located on the same side. Fig.44A In the non-limiting example shown in FIG. 44-B, the chamber end PCB 4490 can have four connection pads 4492 positioned on the right side of the PCB 4490. In other embodiments, these connection pads can all be positioned on the left side of the PCB 4490 or on any other suitable side. The PCB 4490 is plasma treated to reduce water ingress.

[0397] As in Fig.44B 4492 can be angled. The chamber end PCB 4490 can also have a deep slot 4494 that is deeper than that described in the above-mentioned U.S. Patent Application Nos. 15 / 021,673 and 15 / 105,531. The deep slot 4494 and the angled connection pad 4492 can advantageously allow for correct and uniform wire stretching and reduce the risk of wire tumbling. The chamber end PCB 4490 can accommodate a flattened label that rises at an angle and is positioned straight onto the chamber end PCB 4490.

[0398] Exemplary Embodiments

[0399] The following is a numbered list of exemplary embodiments within the scope of the present disclosure. The listed exemplary embodiments should not be construed in any way as limiting the scope of these embodiments. Different features of the listed exemplary embodiments may be deleted, added, or combined to form additional embodiments, which are part of the present disclosure:

[0400] 1. A medical pipeline, comprising:

[0401] The first section of the medical tubing comprises:

[0402] a first structure forming a conduit configured for conveying humidified gas; and

[0403] a first heating wire circuit;

[0404] The second section of the medical tubing comprises:

[0405] a second structure forming a conduit configured for conveying the humidified gas; and

[0406] a second heating wire circuit; and

[0407] an intermediate connector including a connecting circuit electrically coupling the first heating wire circuit to the second heating wire circuit, the intermediate connector being coupled to the patient end of the first section of medical tubing and the chamber end of the second section of medical tubing to form a single conduit for the humidified gas,

[0408] wherein at least a portion of the intermediate connector is covered by a portion of the first segment of the medical tubing and / or a portion of the second segment of the medical tubing, so that the intermediate connector is inside the medical tubing,

[0409] In which, in the first mode, electric power passes through the connecting circuit to provide power to the first heating wire circuit but not to the second heating wire circuit, and in the second mode, electric power passes through the connecting circuit to provide power to both the first heating wire circuit and the second heating wire circuit.

[0410] 2. The medical tubing as described in Example 1, wherein the connecting circuit includes a diode.

[0411] 3. The medical tubing of any one of embodiments 1 to 2, further comprising a first sensor positioned at the patient end of the first segment.

[0412] 4. The medical tubing as described in Example 3, wherein the first sensor is a temperature sensor or a humidity sensor.

[0413] 5. The medical tubing of any one of Examples 1 to 4, further comprising a second sensor positioned at the patient end of the second section of the medical tubing.

[0414] 6. The medical tubing as described in Example 5, wherein the second sensor is a temperature sensor or a humidity sensor.

[0415] 7. The medical conduit of any one of embodiments 1 to 6, wherein the first structure comprises an elongated conduit, the elongated conduit comprising:

[0416] a first elongated member including a hollow body, the first elongated member being helically wound to at least partially form the conduit having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall surrounding the lumen;

[0417] A second elongate member is helically wound and bonded between adjacent turns of the first elongate member, the second elongate member forming at least a portion of the lumen of the elongate conduit.

[0418] 8. The medical tubing of embodiment 7, wherein the first elongated member forms a plurality of bubbles in a longitudinal section, the bubbles having a flattened surface at the inner cavity.

[0419] 9. The medical tubing of embodiment 8, wherein adjacent bubbles are separated by a gap above the second elongated member.

[0420] 10. The medical tubing of Example 8, wherein adjacent bubbles are not directly connected to each other.

[0421] 11. The medical tubing of Example 8, wherein the plurality of bubbles have perforations.

[0422] 12. A respiratory humidification system, comprising:

[0423] An inspiratory limb comprising: a first segment of the inspiratory limb having a first heater wire circuit; a second segment of the inspiratory limb having a second heater wire circuit; an intermediate connector having a connector circuit, the connector circuit being configured to electrically couple the first heater wire circuit to the second heater wire circuit; a first sensor positioned at a patient end of the first segment; and a second sensor positioned at a patient end of the second segment; and

[0424] Controller;

[0425] The controller is adapted to selectively switch between a first mode and a second mode, wherein in the first mode, the controller provides electrical power to the first heating wire circuit through the connector circuit, and in the second mode, the controller provides electrical power to the first and second heating wire circuits.

[0426] 13. The system of embodiment 12, wherein the switching is performed based on input from one or both sensors.

[0427] 14. The system of embodiment 13, wherein the input from one or both sensors includes one or more of temperature, flow, humidity, and power.

[0428] 15. The system of any one of embodiments 12 to 14, wherein the first and second modes are defined by the direction of current provided by the power source.

[0429] 16. A system as described in any of Examples 12 to 15, wherein the controller is adapted to selectively switch between a first sensor reading mode and a second sensor reading mode, wherein in the first sensor reading mode, the controller reads a signal from the second sensor, and in the second sensor reading mode, the controller reads signals from both the first sensor and the second sensor.

[0430] 17. The system of any one of embodiments 12 to 16, wherein the first sensor and the second sensor are temperature sensors.

[0431] 18. A dual-branch circuit, comprising:

[0432] An inspiratory limb, the inspiratory limb comprising: a first segment of the inspiratory limb having a first heating wire circuit; a second segment of the inspiratory limb having a second heating wire circuit; an intermediate connector having a connector circuit, the connector circuit being configured to electrically couple the first heating wire circuit to the second heating wire circuit; a first sensor positioned at a patient end of the first segment; and a second sensor positioned at a patient end of the second segment;

[0433] expiratory branch;

[0434] an interface connected to the inspiratory limb and the expiratory limb; and

[0435] Controller;

[0436] The controller is adapted to selectively switch between a first mode and a second mode, wherein in the first mode, the controller provides electrical power to the first heating wire circuit through the connector circuit, and in the second mode, the controller provides electrical power to the first and second heating wire circuits.

[0437] 19. A dual-branch circuit as described in Example XXX, wherein the exhalation branch includes an exhalation heating wire circuit.

[0438] 20. The dual-branch circuit of embodiment XXX, wherein the expiratory branch is heated using an expiratory heating wire circuit.

[0439] 21. The dual-branch circuit of embodiment XXX, wherein the exhalation heater wire circuit is powered in parallel with the first heater wire circuit in the first segment of the inhalation branch.

[0440] 22. The dual-branch circuit of embodiment XXX, wherein the exhaled breath heater wire circuit can be configured to be powered only in the first mode, only in the second mode, or in both the first mode and the second mode.

[0441] 23. A dual-branch circuit as described in any one of Examples 18 to 22, wherein the interface is connected via a Y-piece.

[0442] 24. A segmented air intake branch configured to be heated along at least two segments, each segment of the air intake branch comprising:

[0443] a first elongated member including a hollow body, the first elongated member being helically wound to at least partially form an elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall surrounding the lumen;

[0444] A second elongate member is helically wound and bonded between adjacent turns of the first elongate member, the second elongate member forming at least a portion of the lumen of the elongate conduit.

[0445] 25. A medical pipeline comprising:

[0446] Two sections, each section includes:

[0447] an elongated hollow body spirally wound to form an elongated conduit having a longitudinal axis, an inner cavity extending along the longitudinal axis, and a hollow wall surrounding the inner cavity, wherein the elongated hollow body has a wall defining at least a portion of the hollow body in cross-section;

[0448] a reinforcement portion extending along the length of the elongated hollow body, helically disposed between adjacent turns of the elongated hollow body, wherein the reinforcement portion forms a portion of the lumen of the elongated conduit;

[0449] one or more conductive filaments embedded or wrapped in the reinforcement portion;

[0450] wherein the reinforcement portion is relatively thicker or more rigid than the wall of the elongated hollow body;

[0451] a segment connector attached to the first segment, the segment connector comprising:

[0452] a plurality of connection pads configured to electrically couple the conductive filaments of the first segment to the conductive filaments of the second segment when the first segment is physically coupled to the second segment; and

[0453] a power diode electrically coupled to the conductive filament of the first segment,

[0454] wherein the power diode allows electrical power to be delivered to the conductive filaments of the first segment and prevents electrical power from being delivered to the conductive filaments of the second segment when provided with an electrical signal having a first polarity, and

[0455] The power diode allows electrical power to be provided to the conductive filaments of the first segment and the conductive filaments of the second segment when provided with an electrical signal having a second polarity.

[0456] 26. A connector, comprising:

[0457] a first heating wire lead-in connection portion configured to be electrically coupled to a first lead-in heating wire;

[0458] a second heating wire lead-in connection portion configured to be electrically coupled to a second lead-in heating wire;

[0459] A first heating wire lead-out connection portion, the first heating wire lead-out connection portion being configured to be electrically connected to the first lead-out heating wire and to the first heating wire lead-in connection portion;

[0460] A second heating wire lead-out connection portion, the second heating wire lead-out connection portion being configured to be electrically connected to the second lead-out heating wire and to the second heating wire lead-in connection portion;

[0461] a first signal line lead-in connection portion configured to be electrically coupled to a first lead-in signal line;

[0462] a second signal line lead-in connection portion configured to be electrically coupled to a second lead-in signal line;

[0463] A first signal line lead-out connection portion, the first signal line lead-out connection portion being configured to be electrically connected to the first lead-out signal line and to the first signal line lead-in connection portion;

[0464] a second signal line lead-out connection portion configured to be electrically coupled to the second incoming signal line and to the second signal line incoming connection portion;

[0465] A power diode electrically coupled to the first and second lead-in heating wire connections, the power diode being configured to allow current to flow from the second lead-in heating wire to the first lead-in heating wire and to prevent current from flowing from the first lead-in heating wire to the second lead-in heating wire;

[0466] a sensor electrically coupled to the first signal line lead-in connection; and

[0467] A signal diode is electrically coupled to the sensor and the second signal line lead-in connection, the signal diode being configured to allow current to flow from the second lead-in signal line through the sensor to the first lead-in signal line and to prevent current from flowing from the first lead-in signal line through the sensor to the second lead-in signal line.

[0468] 27. A respiratory humidification system comprising:

[0469] An inspiratory limb comprising: a first segment having a first heating wire; a second segment having a second heating wire; and a sensor positioned at a patient end of the second segment to measure a patient end parameter, wherein the first heating wire and the second heating wire are electrically coupled, the first heating wire forming a first heater circuit, and the first wire and the second wire forming a second heater circuit; and

[0470] a hardware controller, wherein the hardware controller is configured to receive the output of the sensor, the hardware controller is further configured to provide electrical power to the first heater circuit when the difference between the output of the sensor and the patient-end parameter set point is less than a predetermined threshold, and to provide electrical power to the second heater circuit when the difference between the output of the sensor and the patient-end parameter set point is equal to or greater than the predetermined threshold,

[0471] Wherein when the hardware controller provides electrical power to the first heater circuit, the hardware controller is configured to provide maximum power to the first heater circuit.

[0472] 28. A respiratory humidification system comprising:

[0473] An inspiratory limb comprising: a first segment having a first heating wire; a second segment having a second heating wire; and a sensor positioned at a patient end of the second segment to measure a patient end parameter, wherein the first heating wire and the second heating wire are electrically coupled, the first heating wire forming a first heater circuit, and the first wire and the second wire forming a second heater circuit, the first heating wire and the second heating wire being configured to heat respiratory gas passing through the inspiratory limb;

[0474] Wherein the first heating wire and the second heating wire are configured to be electrically connected to a hardware processor, and the hardware processor is configured to execute software instructions, wherein the software instructions cause the processor to control the first heater circuit and the second heater circuit, wherein when the difference between the output of the sensor and the patient-end parameter setting point is less than a predetermined threshold, the processor is configured to use the first heater circuit to heat the respiratory gas until a maximum temperature is reached in the first heating wire, and when the difference between the output of the sensor and the patient-end parameter setting point is equal to or greater than the predetermined threshold, the processor is configured to use the second heater circuit to heat the respiratory gas.

[0475] 29. A respiratory humidification system comprising:

[0476] a hardware processor configured to communicate with a first heater wire circuit in a first segment of the inspiratory limb and a second heater wire circuit in a second segment of the inspiratory limb, the hardware processor further configured to communicate with a connector circuit in an intermediate connector configured to electrically couple the first heater wire circuit to the second heater wire circuit, the hardware processor further configured to communicate with a first sensor positioned at a patient end of the first segment and a second sensor positioned at a patient end of the second segment;

[0477] The hardware processor is configured to execute software instructions, which cause the processor to selectively switch between a first mode and a second mode, wherein in the first mode, the processor provides electrical power to the first heating wire circuit through the connector circuit, and in the second mode, the processor provides electrical power to the first and second heating wire circuits.

[0478] 30. A respiratory humidification system comprising:

[0479] An inspiratory limb, the inspiratory limb comprising: a first segment of the inspiratory limb having a first heating wire circuit; a second segment of the inspiratory limb having a second heating wire circuit; an intermediate connector having a connector circuit, the connector circuit being configured to electricall...

Claims

1. A medical pipeline, comprising: a first segment having a first heating wire, a second segment having a second heating wire, and a temperature sensor located at a patient end of the second segment and used to measure a patient end parameter, wherein the first heating wire and the second heating wire are electrically coupled, the first heating wire forming a first heater circuit, the first heating wire and the second heating wire forming a second heater circuit, the first heating wire and the second heating wire being configured to heat respiratory gas passing through the medical tubing; and wherein the first heating wire, the second heating wire and the temperature sensor are configured to be electrically connected to a hardware processor, and the hardware processor is configured to execute software instructions, and the software instructions enable the processor to control the first heater circuit and the second heater circuit; and Wherein, the medical tubing is configured to operate as a single tube when the first segment and the second segment of the medical tubing are exposed to the same ambient environment, and to operate as segmented tubes when the first segment and the second segment of the medical tubing are exposed to different ambient environments, and the processor is configured to control the first heater circuit and the second heater circuit differently based on whether the medical tubing is operated as a single tube or a segmented tube.

2. The medical tube according to claim 1, wherein: The processor is configured to at least: controlling a duty cycle of the second heater circuit to achieve a desired temperature set point at the patient end of the second segment when the medical tubing is operated as a single tube; and The duty cycle of the first heater circuit is controlled to achieve a desired temperature at the chamber end of the second segment when the medical tubing is operated as segmented tubing.

3. The medical tube according to claim 1, wherein: The processor is configured to: determining an error between the patient end temperature measured by the temperature sensor and a desired patient end temperature set point; and The output of the duty cycle of the first heater circuit and the second heater circuit is determined and controlled using PID based on the error.

4. The medical tube according to claim 1, wherein: When the medical tubing is operated as a single tube, the processor is configured to control the output of the second heater circuit duty cycle until the error is within an appropriate error threshold.

5. The medical tube according to claim 4, wherein: The processor is configured to use the second heater circuit as a primary means of controlling heating in the medical tubing.

6. The medical tube according to claim 4 or 5, wherein: The output of the first heater circuit duty cycle is inversely related to the output of the second heater circuit duty cycle.

7. The medical tube according to claim 6, wherein: The first heater circuit duty cycle output is set to 0%.

8. The medical tube according to claim 4, wherein: When the error is within the appropriate error threshold, the controller is configured to control the output of the first heater circuit to achieve temperature control.

9. The medical tube according to claim 1, wherein: When the medical tubing is operated as segmented tubing, the processor is configured to control the output of the first heater circuit duty cycle due to the error being within an appropriate error threshold.

10. The medical tube according to claim 9, wherein: The error threshold is equal to or less than 2.5°C.

11. The medical tube according to claim 9 or 10, wherein: The processor is configured to use the first heater circuit as a primary means of controlling heating in the medical tubing.

12. The medical tube according to claim 11, wherein The output of the second heater circuit duty cycle is set to 0%.

13. The medical tubing according to claim 11, wherein: When the error is greater than the appropriate error threshold, the controller is configured to control the output of the second heater circuit.

14. The medical tubing according to claim 9, wherein: The processor is configured to control the output of the first heater circuit to energize the first heating wire to maximum capacity until a predetermined surface temperature threshold is reached.

15. The medical tubing according to claim 9, wherein: The processor is configured to control the output of the first heater duty cycle to achieve a temperature at the chamber end of the second segment such that a temperature drop across the second segment produces a desired temperature set point at the patient end of the second segment.

16. The medical tubing according to claim 15, wherein: The processor is configured to control an output of the first heater circuit duty cycle based on a difference between a chamber outlet temperature at the chamber end of the first segment and the patient end temperature measured by the temperature sensor.

17. The medical tubing of claim 1, configured to operate as a segmented tube, and wherein: The second section of the medical tubing is placed within a controlled environment.

18. The medical tubing according to claim 17, wherein: The controlled environment may include an incubator or other suitable device as a closed system.

19. A respiratory humidification system comprising: an inspiratory limb comprising: a first segment having a first heating wire, a second segment having a second heating wire, and a temperature sensor located at or near a patient end of the second segment, the first heating wire and the second heating wire being configured to heat respiratory gas flowing through the inspiratory limb, wherein the first heating wire and the second heating wire are electrically coupled, the first heating wire forming a first heater circuit, and the first heating wire and the second heating wire together forming a second heater circuit; and a control module comprising a hardware processor configured to be in electrical communication with the temperature sensor, the first heater wire, and the second heater wire, the hardware sensor configured to execute software instructions that cause the processor to selectively control power provided to the first heater circuit and the second heater circuit, wherein the processor is configured to: Determine the flow range of the respiratory humidification system; and A power requirement of the first heater circuit is determined based on the determined flow range.

20. The respiratory humidification system of claim 19, wherein: The processor is also configured to: Determine whether the respiratory humidification system is in standby mode; upon determining that the respiratory humidification system is not in the standby state, controlling the second heater circuit using a PID control scheme configured to achieve a duty cycle that satisfies a power demand of the second heater circuit required to bring the patient end temperature measured by the temperature sensor to a temperature set point; and The duty cycle of the first heater circuit is reduced to lower the temperature profile of the air intake branch or the duty cycle of the first heater circuit is increased to maintain the temperature profile of the air intake branch.

21. A respiratory humidification system according to claim 19 or 20, wherein: The flow range corresponds to flow levels with corresponding power requirements.

22. The respiratory humidification system of claim 21, wherein: The determined flow range is in a low flow range, a medium flow range, or a high flow range, and a low flow power requirement is determined for the low flow range, a medium flow power requirement is determined for the medium flow range, and a high flow power requirement is determined for the high flow range.

23. The respiratory humidification system of claim 21, wherein: The flow ranges overlap.

24. The respiratory humidification system of claim 19, wherein: The processor is configured to determine the flow range to determine an initial power requirement of the first heater circuit upon startup.

25. The respiratory humidification system of claim 24, wherein: The processor is configured to use the second heater circuit as a primary means of controlling heating in the suction branch.

26. The respiratory humidification system of claim 19, wherein: Upon determining that the respiratory humidification system is in the standby state, the processor is configured to exit the system from the standby state upon determining that flow has been added to the system.

27. The respiratory humidification system of claim 26, wherein: The processor is configured to determine that flow has been added to the system when the patient end temperature has increased by more than a temperature threshold within a time window.

28. The respiratory humidification system of claim 27, wherein: The temperature threshold is approximately 2°C, and the time window is approximately 1 minute.

29. The respiratory humidification system of claim 20, wherein: Prior to controlling the second heater circuit, the processor is further configured to: determine whether the system is in a warm-up period; determine whether a flow condition exists in the system; and consider potential disturbances in the system.

30. The respiratory humidification system of claim 29, wherein: The processor is configured to determine that the system is in a warm-up period when a temperature of a heater plate of the system exceeds a heater plate temperature threshold.

31. The respiratory humidification system of claim 30, wherein: The heating plate temperature threshold is approximately 50°C.

32. A respiratory humidification system according to claim 30 or 31, wherein: The processor is configured to determine whether a flow condition does not exist in the system when the duty cycle of the second heater circuit is greater than approximately 99% and the patient end temperature is less than the set point temperature minus a temperature value.

33. A respiratory humidification system as claimed in claim 32, wherein: This temperature value is about 2°C.

34. The respiratory humidification system of claim 32, wherein: The processor is configured to account for potential interference in the system by waiting a customized amount of time.

35. A respiratory humidification system as claimed in claim 34, wherein: The amount of time for this customization is approximately 5 minutes.

36. A respiratory humidification system as claimed in claim 34 or 35, wherein: The processor is configured to place the system into a standby state until flow is applied or reapplied to the system.

37. A respiratory humidification system as claimed in claim 36, wherein: In the standby state, the processor is configured to set the duty cycle of the first heater circuit to 0% and the duty cycle of the second heater circuit to approximately 40%.

38. The respiratory humidification system of claim 20, wherein: The processor is configured to control the second heater circuit to achieve a target temperature set point based on a difference between a currently measured temperature at the patient end and the temperature set point.

39. A respiratory humidification system as claimed in claim 38, wherein: The processor is configured to determine: whether the duty cycle of the second heater circuit is equal to 0%; whether the patient end temperature exceeds the temperature set point; and Whether the duty cycle of the first heater circuit is greater than a duty cycle threshold.

40. The respiratory humidification system of claim 35, wherein: The duty cycle threshold is approximately 40%.

41. A respiratory humidification system as claimed in claim 39 or 40, wherein: The processor is configured to decrease the duty cycle of the first heater circuit by a decrement value if the condition is met.

42. A respiratory humidification system as claimed in claim 41, wherein: The reduction value is 2%.

43. A respiratory humidification system as claimed in claim 39 or 40, wherein: If the condition is not met, the processor is further configured to determine: whether the duty cycle of the second heater circuit is greater than the duty cycle of the first heater circuit plus a constant; and Whether the duty cycle of the first heater circuit is less than the internal zone threshold.

44. A respiratory humidification system as claimed in claim 43, wherein: This constant is approximately 20%.

45. The respiratory humidification system of claim 43, wherein: The inner segment threshold is approximately 80%.

46. ​​The respiratory humidification system of claim 43, wherein: The processor is configured to increase the duty cycle of the first heater circuit by an incremental value if the condition is met.

47. A respiratory humidification system as claimed in claim 46, wherein: The incremental value is approximately 2%.

48. A respiratory humidification system comprising: a hardware controller configured to communicate with a first heating wire in a first segment of an inspiratory limb and a second heating wire in a second segment of the inspiratory limb, wherein the first heating wire and the second heating wire are electrically coupled and configured to heat respiratory gas passing through the inspiratory limb, the first heating wire forming a first heater circuit, and the first heating wire and the second heating wire forming a second heater circuit; The hardware controller is further configured to communicate with at least one sensor for measuring a surface temperature of the suction branch.

49. A respiratory humidification system as claimed in claim 48, wherein: The at least one sensor includes a surface temperature sensor positioned on a portion of the suction branch or on an intermediate connector configured to couple the first segment and the second segment of the suction branch.

50. The respiratory humidification system of claim 48, wherein: The at least one sensor includes a first temperature sensor positioned on a portion of the first segment to determine a surface temperature of the first segment and / or a second temperature sensor positioned on the second segment to determine a surface temperature of the second segment.

51. A respiratory humidification system as claimed in any one of claims 48 to 50, wherein: The surface temperature value measured by the at least one sensor is used to determine a duty cycle of the first heater circuit and / or the second heater circuit or an end value or limit value of power supplied to the first heater circuit and / or the second heater circuit.

52. The respiratory humidification system of claim 48, wherein: The first heating wire and the second heating wire are exposed to different ambient environments.

53. A respiratory humidification system as claimed in claim 52, wherein: The first heating wire and the second heating wire are exposed to different ambient temperatures.

54. The respiratory humidification system of claim 48, wherein: The power supplied to the first heater circuit and / or the power supplied to the second heater circuit is determined by a PID control scheme.

55. The respiratory humidification system of claim 48, comprising an intermediate connector configured to couple the first segment and the second segment of the inspiratory limb, the intermediate connector having a connector circuit configured to electrically connect the first heater wire and the second heater wire.

56. The respiratory humidification system of claim 48, wherein: The at least one sensor includes a patient-end sensor located at a patient end of the second segment of the inspiratory limb and configured to measure a patient-end parameter, and the hardware controller is configured to communicate with the patient-end sensor.

57. A respiratory humidification system as claimed in claim 56, wherein: The hardware controller is also configured to activate only the first heater circuit when the difference between the output of the patient-end sensor and the patient-end parameter set point is less than a predetermined threshold, and to activate only the second heater circuit when the difference between the output of the patient-end sensor and the patient-end parameter set point is equal to or greater than the predetermined threshold.

58. A respiratory humidification system as claimed in claim 56 or 57, wherein: The patient-side parameter is temperature.

59. The respiratory humidification system of claim 57, wherein: When only the first heater circuit is activated, the hardware controller is configured to heat the first heating wire to a maximum surface temperature.

60. The respiratory humidification system of claim 48, wherein: A duty cycle output of the first heater circuit and / or the second heater circuit or a terminal value of the power output supplied to the first heater circuit and / or the second heater circuit is set to prevent the surface temperature from exceeding a predetermined threshold.

61. A respiratory humidification system as claimed in claim 60, wherein: The duty cycle output of the second heater circuit, or the power output supplied to the second heater circuit, is set to a terminal value of 70% of the maximum power deliverable by the drive circuit.

62. A respiratory humidification system as claimed in claim 60 or 61, wherein: A maximum duty cycle output of the first heater circuit or a maximum power output supplied to the first heater circuit is calculated using a function including a duty cycle terminal value output of the first heater circuit or a power terminal value output supplied to the first heater circuit.

63. A respiratory humidification system as claimed in claim 62, wherein: The duty cycle output of the first heater circuit, or the power output supplied to the first heater circuit, is inversely related to the duty cycle output of the second heater circuit, or the power output supplied to the second heater circuit.

64. The respiratory humidification system of claim 62, wherein: A duty cycle endpoint output of the first heater circuit or a power endpoint output supplied to the first heater circuit is calculated using the high flow or low flow endpoint or limit value.

65. A respiratory humidification system as claimed in claim 64, wherein: The low flow end value or limit of the first heater circuit is set to 37% of the maximum power deliverable by the drive circuit.

66. The respiratory humidification system of claim 64, wherein: When the duty cycle output of the second heater circuit or the power output supplied to the second heater circuit is less than the low flow end value or the limit value, the duty cycle output of the first heater circuit or the power output supplied to the first heater circuit is the difference between the low flow end value or the limit value and the duty cycle output of the second heater circuit or the power output supplied to the second heater circuit.

67. The respiratory humidification system of claim 48, wherein: The hardware controller is configured to control power delivered to the first heater circuit and the second heater circuit.

68. A respiratory humidification system as claimed in claim 67, comprising a first switch pair and a second switch pair, wherein: The hardware controller is configured to independently control power delivered to the first heating wire and the second heating wire by selectively opening and closing the first switch pair and the second switch pair.

69. A respiratory humidification system as claimed in claim 67 or 68, comprising a first switch pair and a second switch pair, wherein: The hardware controller is configured to provide gating control of the first heating wire and the second heating wire by selectively opening and closing the first switch pair and the second switch pair.

70. The respiratory humidification system of claim 69, wherein: The combination of the first switch pair and the second switch pair is configured to selectively control the flow of electrical power provided to the second heating wire.

71. The respiratory humidification system of claim 68, wherein: The hardware controller is configured to selectively open and close the first switch pair and the second switch pair based on a change in voltage polarity.

72. The respiratory humidification system of claim 68, wherein: The first switch pair and the second switch pair include metal oxide semiconductor field effect transistors MOSFETs.

73. A connector for a medical tube, the medical tube having a first section and a second section, each of the first section and the second section comprising a heating wire and a signal wire, the connector comprising: a connecting element configured to provide a pneumatic connection between the first segment and the second segment of the medical tubing; as well as a printed circuit board PCB, the printed circuit board being configured to provide an electrical connection between the first segment and the second segment of the medical tubing, so that the heating wire and the signal wire of the first segment can be electrically coupled to the heating wire and the signal wire of the second segment; wherein the connecting element forms an inner cavity, and a portion of the PCB partially extends into the inner cavity; and Wherein, the PCB includes a coating configured to protect the PCB from water immersion.

74. The connector of claim 73, wherein: The coating is one of a conformal coating or an overmold.

75. A connector as claimed in claim 73 or 74, wherein: The portion of the PCB that extends into the inner cavity extends approximately one-third of the way through the inner cavity.

76. The connector of claim 73, wherein: The PCB generates heat during operation to help evaporate excess condensation.

77. The connector of claim 76, wherein: Heat is generated during operation at least in part due to diodes disposed on the PCB.

78. The connector of claim 73, comprising a diode that allows current to flow in one direction and blocks current from flowing in another direction.

79. The connector of claim 78, wherein: The diode allows the medical tube to operate in two modes, wherein in a first mode the first section of the tubing is heated and in a second mode the first section and the second section of the tubing are heated.

80. The connector of claim 78 or 79, wherein: The PCB has a generally rectangular shape having two long sides and two short sides.

81. The connector of claim 80, wherein: The diode is positioned near or within the cavity near and at the midpoint of the long side.

82. The connector of claim 80, wherein: The short side has a diagonal edge where the short side meets the long side located near or within the lumen to maintain a good curve for the gas.

83. The connector of claim 80, wherein: The PCB includes connection pads for signal wires and / or heating wires of the first segment and the second segment, and the connection pads are located on the long side located away from the inner cavity.

84. The connector of claim 83, wherein: The PCB includes at least two groups of four connection pads.

85. The connector of claim 83, wherein: Two connection pads are provided on each side of the diode.

86. The connector of claim 83, wherein: The connecting element defines a path through which gas can flow between the first section and the second section of the medical tubing.

87. The connector of claim 86, wherein: The path defined by the connecting element is configured to form a passage that is smaller than a flow path defined by the first segment and the second segment, thereby allowing gas to pass through the connecting element more quickly and reducing condensation.

88. The connector of claim 73, comprising an outer cover and / or being overmolded.

89. The connector of claim 88, wherein: The connector is overmolded to secure and seal the first segment and the second segment to the connecting element.

90. The connector of claim 88 or 89, wherein: The cover is a clamshell that can be applied to the connector.

91. The connector of claim 90, wherein: The clamshell is configured to protect the PCB from damage.

92. The connector of claim 90, wherein: The clamshell includes two halves that are coupled together.

93. The connector of claim 92, wherein: The two halves are snap-fit ​​or press-fit together.

94. The connector of claim 92, wherein: The clamshell includes a hinge configured to connect the two halves.

95. The connector of claim 90, wherein: The connecting element is configured to fit within the clamshell in at least four positions.

96. The connector of claim 73, comprising one or more tube stops configured to position the first section of the medical tube on the connecting element when the first section of the medical tube is connected to one end of the connector, and / or to position the second section of the medical tube on the connecting element when the second section of the medical tube is connected to the other end of the connector.

97. The connector of claim 96, wherein: The one or more conduit stops are configured to be positioned 180 degrees and / or 270 degrees from the PCB.

98. The connector of claim 96 or 97, wherein: The one or more tubing stops are configured to provide attachment points for the first segment and / or the second segment of the medical tubing.

99. The connector of claim 73, comprising one or more bridges configured to raise the first segment of the medical tubing from the connecting element when the first segment of the medical tubing is connected to one end of the connector, and / or to raise the second segment of the medical tubing from the connecting element when the second segment of the medical tubing is connected to the other end of the connector.

100. The connector as described in claim 73 comprises one or more card slots, which are configured to hold the heating wire and / or signal wire of the first section of the medical tube when the first section of the medical tube is connected to one end of the connector, and / or hold the heating wire and / or signal wire of the second section of the medical tube when the second section of the medical tube is connected to the other end of the connector.

101. The connector of claim 73, comprising an indicator configured to indicate an orientation of the connector to ensure proper positioning of the diode on the PCB.

102. The connector of claim 73, comprising one or more immersion rings configured to limit or eliminate water intrusion into an exposed area of ​​the PCB when the first section of the medical tubing is connected to one end of the connector, and / or to remove the second section of the medical tubing from the connecting element when the second section of the medical tubing is connected to the other end of the connector.

103. The connector of claim 102, wherein: The one or more immersion rings form a complete loop around the connecting element.

104. The connector of claim 103, comprising a slot configured to act as a keying mechanism to ensure proper orientation of the first segment and / or the second segment on the connector.

105. The connector of claim 73, wherein: Each of the first and second segments of the medical tubing includes a helically wound hollow body joined by a helically wound bead member.

106. The connector of claim 105, wherein: The heating wires and / or signal wires of the first segment and the second segment are embedded in or wrapped in the respective bead bulb components of the first segment and the second segment.

107. The connector of claim 106, wherein: The heating wires are spaced apart from each other in the bead member.

108. The connector of any one of claims 105 to 107, wherein: The bead member provides support for the hollow body.

109. The connector of any one of claims 105 to 107, wherein: The thread-wound hollow body is at least partially formed into an elongated tube having a longitudinal axis, an inner cavity extending along the longitudinal axis, and the bead member forming at least a portion of the inner cavity.

110. The connector of claim 109, wherein: The lumen is configured to deliver gas in a breathing circuit.

111. The connector of claim 105, wherein: The signal wire is configured to be connected to one of a temperature sensor, a flow sensor, an oxygen concentration sensor, or a humidity sensor.

112. The connector of claim 105, wherein: The length of the first segment is different from the length of the second segment.

113. The connector of claim 105, wherein: The medical tubing is used in conjunction with an incubator, wherein a portion of the medical tubing is inserted into the incubator.

114. The connector of claim 113, wherein: The first section is located outside the incubator, and the second section corresponds to the portion of the medical tube inserted into the incubator.

115. The connector of claim 105, wherein: The hollow body is filled with a gas.

116. The connector of claim 105, wherein: The hollow body is flexible.

117. The connector of claim 105, wherein: The hollow body is perforated.

118. The connector of claim 105, wherein: The bubble bead member is coupled between adjacent turns of the spirally wound hollow body and forms a plurality of bubbles in a longitudinal cross section.

119. The connector of claim 118, wherein: The width of the bubble is greater than the height of the bubble.

120. The connector of claim 118 or 119, wherein: The bubbles are separated in longitudinal cross-section by gaps between adjacent turns of the hollow body.

121. The connector of claim 118, wherein: The hollow body comprises more than two parts so that more than two bubbles are formed in a longitudinal cross section.

122. A respiratory humidification system, comprising: an inspiratory limb comprising: a first segment having a first heating wire, a second segment having a second heating wire, and a temperature sensor located at or near a patient end of the second segment, the first heating wire and the second heating wire being configured to heat respiratory gas flowing through the inspiratory limb, wherein the first heating wire and the second heating wire are electrically coupled, the first heating wire forming a first heater circuit, and the first heating wire and the second heating wire together forming a second heater circuit; and a control module comprising a hardware processor configured to be in electrical communication with the temperature sensor, the first heater wire, and the second heater wire, the hardware sensor configured to execute software instructions that cause the processor to selectively control power provided to the first heater circuit and the second heater circuit, wherein the processor is configured to: setting the power demand of the first heater circuit to a fixed duty cycle; Determine whether the respiratory humidification system is in standby mode; and Upon determining that the respiratory humidification system is not in the standby state, the second heater circuit is controlled using a PID control scheme configured to achieve a duty cycle that meets the power demand of the second heater circuit required to bring the patient end temperature measured by the temperature sensor to the temperature set point.

123. A respiratory humidification system as claimed in claim 122, wherein: The control module is configured to operate in an open loop control mode by setting a power demand of the first heater circuit to a fixed duty cycle.

124. A respiratory humidification system as claimed in claim 122 or 123, wherein: The fixed duty cycle of the first heater circuit is initially set to 80%.

125. The respiratory humidification system of claim 122, wherein: The processor is further configured to reduce a duty cycle of the first heater circuit to reduce a temperature profile of the induction branch or to increase a duty cycle of the first heater circuit to maintain the temperature profile of the induction branch.

126. The respiratory humidification system of claim 122, wherein: Upon determining that the respiratory humidification system is in the standby state, the processor is configured to exit the system from the standby state upon determining that flow has been added to the system.

127. A respiratory humidification system as claimed in claim 126, wherein: The processor is configured to determine that flow has been added to the system when the patient end temperature has increased by more than a temperature threshold within a time window.

128. A respiratory humidification system as claimed in claim 127, wherein: The temperature threshold is approximately 2°C, and the time window is approximately 1 minute.

129. The respiratory humidification system of claim 122, wherein: Prior to controlling the second heater circuit, the processor is further configured to: determine whether the system is in a warm-up period; determine whether a flow condition exists in the system; and consider potential disturbances in the system.

130. The respiratory humidification system of claim 129, wherein: The processor is configured to determine that the system is in a warm-up period when a temperature of a heater plate of the system exceeds a heater plate temperature threshold.

131. A respiratory humidification system as claimed in claim 130, wherein: The heating plate temperature threshold is approximately 50°C.

132. A respiratory humidification system as claimed in claim 130 or 131, wherein: The processor is configured to determine whether a flow condition does not exist in the system when the duty cycle of the second heater circuit is greater than approximately 99% and the patient end temperature is less than the set point temperature minus a temperature value.

133. A respiratory humidification system as claimed in claim 132, wherein: This temperature value is about 2°C.

134. A respiratory humidification system as claimed in claim 132, wherein: The processor is configured to account for potential interference in the system by waiting a customized amount of time.

135. A respiratory humidification system as claimed in claim 134, wherein: The amount of time for this customization is approximately 5 minutes.

136. A respiratory humidification system as claimed in claim 134, wherein: The processor is configured to place the system into a standby state until flow is applied or reapplied to the system.

137. A respiratory humidification system as claimed in claim 136, wherein: In the standby state, the processor is configured to set the duty cycle of the first heater circuit to 0% and the duty cycle of the second heater circuit to approximately 40%.

138. The respiratory humidification system of claim 122, wherein: The processor is configured to control the second heater circuit to achieve a target temperature set point based on a difference between a currently measured temperature at the patient end and the temperature set point.

139. The respiratory humidification system of claim 122, wherein: The PID control scheme is used to control the second heater circuit for a customized time threshold.

140. The respiratory humidification system of claim 139, wherein: The customized time threshold is 30 seconds.

141. A respiratory humidification system as claimed in claim 139 or 140, wherein: After the customized time threshold has passed, the processor is configured to determine: whether the duty cycle of the second heater circuit is equal to 0%; whether the patient end temperature exceeds the temperature set point; and Whether the duty cycle of the first heater circuit is greater than a duty cycle threshold.

142. A respiratory humidification system as claimed in claim 141, wherein: The duty cycle threshold is approximately 40%.

143. The respiratory humidification system of claim 141, wherein: The processor is configured to decrease the duty cycle of the first heater circuit by a decrement value if the condition is met.

144. A respiratory humidification system as claimed in claim 143, wherein: The reduction value is 2%.

145. The respiratory humidification system of claim 141, wherein: If the condition is not met, the processor is further configured to determine: whether the duty cycle of the second heater circuit is greater than the duty cycle of the first heater circuit plus a constant; and Whether the duty cycle of the first heater circuit is less than the internal zone threshold.

146. A respiratory humidification system as claimed in claim 145, wherein: This constant is approximately 20%.

147. A respiratory humidification system as claimed in claim 145, wherein: The inner segment threshold is approximately 80%.

148. A respiratory humidification system as claimed in claim 145, wherein: The processor is configured to increase the duty cycle of the first heater circuit by an incremental value if the condition is met.

149. A respiratory humidification system as claimed in claim 148, wherein: The incremental value is approximately 2%.

Images