Catheter for use in a breathing apparatus

Abstract

A conduit for use in a respiratory device is disclosed. A method of heating breathable gas in a conduit of a respiratory device configured to transport the breathable gas through the conduit is provided, the method comprising: passing a flow of humidified breathable gas through the conduit; heating the conduit by supplying a DC current to a plurality of wires supported by the conduit at a predetermined duty cycle; sensing a temperature in the conduit during an OFF period of the predetermined duty cycle; and controlling the DC current to maintain the temperature in the conduit at a selected temperature. A respiratory device for transporting breathable gas to a patient, a humidifier for a respiratory device, and a method of starting a respiratory device are also disclosed.

Description

[0001] This application is a divisional application of patent application No. 201910397235.1, filed on November 8, 2007, entitled "A catheter used in a respiratory device". Application No. 201910397235.1 is a divisional application of patent application No. 201410069663.9, filed on November 8, 2007, entitled "A catheter used in a respiratory device". Application No. 201410069663.9 is a divisional application of patent application No. 200780044030.0 (international application No. PCT / AU2007 / 001716), filed on November 8, 2007, entitled "A catheter used in a respiratory device".

[0002] Cross-references to related applications

[0003] This invention claims priority to U.S. Application 60 / 955,222, filed August 10, 2007, and Australian Provisional Application 2006906224, filed November 8, 2006, the entire contents of which are incorporated herein by reference. Technical Field

[0004] This invention relates to humidification and heating devices for controlling the humidity of inhalable gases used in ventilation systems of all forms of respiratory devices, including sleep disorder breathing (SDB) for conditions such as obstructive sleep apnea (OSA) and invasive and non-invasive ventilation, continuous positive ventilatory pressure (CPAP), bilevel therapy, and treatment for a variety of other respiratory disorders and diseases. Background Technology

[0005] To reduce airway dryness and the resulting discomfort and related complications, breathing devices typically have the ability to alter the humidity of the inhaled gas. The use of a humidifier between the fluid generator and the patient mask produces humidified gas that minimizes nasal dryness and improves airway comfort. Additionally, in colder climates, occasional leakage can cause warm air to be applied to the facial area around the mask; warm air applied generally inside and around the mask is more comfortable than cold air.

[0006] Many types of humidifiers are available, although the most convenient form is either integrated with or designed to be connected to a respiratory device. While passive humidifiers can provide some relief, heated humidifiers are generally required to provide sufficient humidity and temperature for patient comfort. A typical humidifier includes: a water tank with a capacity of several hundred milliliters, a heating element for heating the water in the tank, a controller for varying the humidification level, a gas inlet for receiving gas from a fluid generator, and a gas outlet suitable for connecting to a patient catheter that delivers humidified pressurized gas to the patient's face mask.

[0007] Typically, the heating element is incorporated into a heating plate located below and in thermal contact with the water tank.

[0008] Humidified air cools along the path from the humidifier to the patient, causing "rain-out" or condensation to form on the inside of the tubing. To address this problem, it is known to insert a heating line into the patient tubing that supplies humidified gas from the humidifier to the patient's mask, thereby providing additional heating to the gas supplied to the patient. This system is described on page 97 of Mosby's Respiratory Therapy Devices (7th Edition).

[0009] Because the heating wire is positioned along the catheter wall rather than within the main airflow, this method of heating the patient's catheter provides only poor heat conduction. Due to the small profile of the heating wire, it also provides only poor vortex mixing. Therefore, heat conduction is poor, and the mixing of water vapor and air is also poor.

[0010] Alternatively, the heating circuitry can be positioned within the wall of the patient's catheter. Such a system is described in U.S. Patent 6,918,389.

[0011] U.S. Patent 6,918,389 describes several humidifier devices for supplying relatively low-humidity, high-temperature humidified gas to patients. Some of these devices include preheating or postheating of the gas to reduce relative humidity.

[0012] None of these existing devices provide a completely satisfactory solution for providing patients with comfortable humidified breathable gas, nor do they provide a solution that simplifies the structure, meets hygiene requirements, and satisfies energy and patient comfort requirements at startup. Summary of the Invention

[0013] The purpose of this invention is to provide an alternative humidifier device that overcomes or improves upon the disadvantages of the prior art, or at least provides a useful alternative.

[0014] In one exemplary embodiment of the invention, the humidifier and / or temperature or other sensing or control device used with the breathing apparatus includes a heating wire in thermal contact with gas and / or water, wherein the wire is in the form of an elongated strip. The strip may be flexible, and in one exemplary embodiment, the strip may pass through a hole in the patient's gas catheter or be incorporated into the catheter wall.

[0015] In another exemplary embodiment, the humidifier used with the breathing device includes a heater that is in contact with water in the humidifier tank, and the heater floats or otherwise rises or falls with changes in the water level in the humidifier tank.

[0016] In another embodiment, the invention provides a humidifier device for a breathing apparatus, comprising an elongated filament heater in contact with an air path located in a region prior to or after a humidification chamber. The filament heater may further contact water within the humidification chamber.

[0017] The heating of the wire can be divided into two or more independently controlled zones.

[0018] Another exemplary embodiment of the present invention provides a method for improving patient comfort during humidification activation, the method comprising providing a heating element for thermal contact with breathable gas supplied to the patient along a gas flow path and with water in a humidifier device; and configuring the heating element to heat the gas in the gas flow path and the water in the humidifier device, thereby initially supplying heated gas to the patient while the temperature of the water in the humidifier device increases to its operating temperature.

[0019] The gas in the heating gas flow path may include a portion of the heating gas flow path located upstream of the humidification chamber, so that the heating gas provides initial humidity through the humidifier device.

[0020] According to an exemplary embodiment of the present invention, a catheter used in a breathing device for delivering breathable gas to a patient includes: a tube; a spiral rib located on the outer surface of the tube; and a plurality of wires supported by the spiral rib and in contact with the outer surface of the tube.

[0021] According to another exemplary embodiment of the invention, the catheter may further include a connector plug block connected to one end of the catheter, wherein the connector plug block is configured to connect to a patient interface of a fluid generator or a breathing device.

[0022] According to another exemplary embodiment of the present invention, a breathing device for delivering breathable gas to a patient includes: a fluid generator that generates a supply of pressurized gas to be delivered to the patient; a humidifier that vaporizes water and delivers water vapor to humidify the gas; a first gas flow path from the fluid generator to the humidifier; and a second gas flow path from the humidifier to a patient interface, wherein the first gas flow path includes a first conduit having a first connector plug block configured to connect to the fluid generator, and the second gas flow path includes a second conduit having a second connector plug block configured to connect to the patient interface.

[0023] According to another exemplary embodiment of the present invention, a method for delivering breathable gas to a patient includes: delivering a humidified breathable gas flow through a conduit to a patient interface; heating the conduit by supplying a DC current to multiple wires supported by the conduit at a predetermined duty cycle; sensing the temperature in the conduit during an OFF cycle of the predetermined duty cycle; and controlling the DC current to maintain the temperature in the conduit at a selected temperature. Attached Figure Description

[0024] Embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

[0025] Figure 1-A This is a schematic side cross-sectional view of a patient catheter with a flexible band heater in an embodiment of the present invention;

[0026] Figure 1-B for Figure 1-A An alternative embodiment in which the flexible belt heater has a spiral structure;

[0027] Figure 1-C for Figure 1-A An alternative embodiment in which the flexible strip heater is wound around its longitudinal axis;

[0028] Figure 2 A schematic perspective view of another embodiment of the flexible belt heater;

[0029] Figure 3 This is a schematic side cross-sectional view of a humidification chamber with an embodiment of a floating heater;

[0030] Figures 4-A to 4-D The illustrations schematically show several embodiments of a floating heater located in a humidification chamber;

[0031] Figure 4-A This is a side perspective view of one embodiment of a floating heater, in which a circular floating plate heater is fixed below a floating plastic support grid.

[0032] Figure 4-B This is a side perspective view of another embodiment of the floating heater;

[0033] Figure 4-C This is a side perspective view of another embodiment of a floating spiral flexible ribbon heater;

[0034] Figure 4-D This is a top view of another embodiment of a flexible strip heater wound into a horizontal spiral shape;

[0035] Figure 5 A humidification heater device comprising multiple zones is illustrated schematically;

[0036] Figure 6-A This is a cross-sectional view of the patient's catheter, showing the soft-band heater connected to the catheter wall;

[0037] Figure 6-B yes Figure 6-A Another view of a connector embodiment, wherein the connector is detached;

[0038] Figure 7 A floating heater plate positioned in a shallow pool is shown, which also floats on the surface of the water.

[0039] Figure 8 A power supply / controller connected to an inlet conduit via a connector is shown according to an exemplary embodiment of the present invention;

[0040] Figure 9 A connection to the fluid generator is shown. Figure 8 Inlet conduit;

[0041] Figure 10 A patient catheter or tubing according to an exemplary embodiment of the present invention is shown connected to a patient interface;

[0042] Figure 11 An inlet conduit connected to a connector is shown according to an exemplary embodiment of the present invention, and a fluid generator connector cuff is also included;

[0043] Figure 12 It shows the separation from the connector. Figure 11 Inlet conduit;

[0044] Figure 13 It shows Figure 11 Cross-sectional view of the inlet conduit and connector;

[0045] Figure 14 A rear perspective view of the inlet conduit and the portion of the fluid generator connector joint connected to the wiring clamp is shown;

[0046] Figure 15 for Figure 14 A frontal perspective view of the inlet conduit, fluid generator connector joint, and wiring clamp;

[0047] Figure 16 Top perspective view of the inlet conduit and the fluid generator connector joint without clamps;

[0048] Figure 17 This is a perspective view of a wiring clamp according to an exemplary embodiment of the present invention;

[0049] Figure 18 A perspective view of the connector plug block of a fluid generator connector according to an exemplary embodiment of the present invention;

[0050] Figure 19 This is a perspective view of a connector according to an exemplary embodiment of the present invention;

[0051] Figure 20 for Figure 19 A 3D view of the connector contacts;

[0052] Figure 21 for Figure 20 Cross-sectional views of the contacts and connectors;

[0053] Figure 22 A perspective view of a patient catheter or tubing and a portion thereof, according to an exemplary embodiment of the present invention;

[0054] Figure 23 After removing part of the connector Figure 22 Cross-sectional view of the patient catheter and mask connector;

[0055] Figure 24 for Figure 10 Cross-sectional view of the patient catheter and mask connector;

[0056] Figure 25 This is a top perspective view of the connector plug block of the mask connector according to an exemplary embodiment of the present invention;

[0057] Figure 26 for Figure 25 Bottom perspective view of the connector plug block;

[0058] Figure 27 This is a top perspective view of a connector plug block of a mask connector according to an exemplary embodiment of the present invention, which is connected to a patient catheter and includes a printed circuit board of the mask connector.

[0059] Figure 28 To remove the patient's catheter Figure 27 A side perspective view of the connector plug block;

[0060] Figure 29 for Figure 27 Cross-sectional view of the patient catheter and connector plug block;

[0061] Figure 30 A perspective view of the connector plug block of a patient catheter and mask connector according to an exemplary embodiment of the present invention;

[0062] Figure 31 A perspective view of a patient catheter and mask connector according to an exemplary embodiment of the present invention;

[0063] Figure 32 for Figure 31 Cross-sectional view of the patient catheter and mask connector;

[0064] Figure 33 A schematic view of the temperature sensor and thermal fuse of the mask connector circuit according to an exemplary embodiment of the present invention;

[0065] Figure 34 The circuitry of the face mask connector is schematically shown on the connector plug block of the face mask connector;

[0066] Figure 35 A power supply / controller according to an exemplary embodiment of the present invention is illustrated schematically;

[0067] Figure 36 The illustration schematically shows three electric heating tubes according to an exemplary embodiment of the present invention;

[0068] Figure 37a An exemplary embodiment of the power supply / controller circuitry is illustrated schematically.

[0069] Figures 37b-1 to 37b-4 Schematic illustration Figure 37a An exemplary embodiment of the circuit;

[0070] Figures 38 to 40 A perspective view of a secondary-formed gripper for use in fluid generator connectors and / or mask connectors;

[0071] Figure 41 A catheter according to an exemplary embodiment of the present invention is shown;

[0072] Figure 42 A catheter according to an exemplary embodiment of the present invention is shown; and

[0073] Figure 43 A patient catheter and mask connector according to an exemplary embodiment of the present invention is shown. Detailed Implementation

[0074] Soft belt heater

[0075] Figures 1-A to 1-CA flexible band heater 3 is shown within a patient tubing 4 of a ventilator. The patient tubing 4 is positioned between a humidification chamber 1 and a patient interface, such as a face mask 5. The patient tubing 4 delivers airflow from the humidification chamber 1 to the patient face mask 5 in the ventilator. The humidification chamber 1 receives airflow from a fluid generator 20 (…). Figure 5 (or pressurized air from a hair dryer.)

[0076] The flexible band heater 3 in the patient catheter 4 is used to heat the airflow in the patient catheter 4. Heating the gas enables the gas delivered by the breathing device to obtain and maintain comfortable temperature and humidity characteristics.

[0077] The flexible band heater 3 is electrically connected to the heater controller 21 via the patient catheter connector end 2. Figure 5 The heater controller 21 can be integrated into the humidifier or fluid generator 20 or the base unit 22, or the heater controller 21 can be a separate unit 21, for example, which is supplied with a DC voltage of, for example, 0.1V-24V.

[0078] The patient catheter connector end 2 can be connected to the heater controller 21 via another flexible band heater (partially shown on the left side of Figure 1), or via... Figure 6-A and Figure 6-B The connectors 23 and 24 shown are connected to the catheter wall 25 of the patient catheter 4. The connectors may include a plug-in connector element 23 and a socket-type connector element 24, which can establish electrical communication and / or mechanical connection between the flexible band heater 3 and the catheter wall 25. The positions of the plug-in connector element 23 and the socket-type connector element 24 are interchangeable. Connectors 23 and 24 lock the flexible band heater 3 in place on the catheter wall 25, but connectors 23 and 24 can also be detached. Connectors 23 and 24 can be used anywhere along or around the catheter wall 25.

[0079] To reduce heat loss and minimize the resulting condensation or "raindrops" in the patient catheter 4, the patient catheter 4 may be an insulated or heated catheter, as is the case in the prior art. The insulation may be an outer sheath or encapsulation surrounding the patient catheter 4. The outer sheath and encapsulation may be foam, fiber fabric, or, in the case of a double-walled catheter, an air gap.

[0080] In another embodiment, the flexible band heater 3 may be combined with the wall of the patient catheter 4 to provide heating to the wall to prevent condensation; alternatively, another flexible band heater 3 in the patient catheter 4 may provide heating to the airflow.

[0081] In yet another embodiment, the patient catheter 4 is formed by making the flexible band heater 3 into a spiral shape and joining the edges of the flexible band heater 3 together to form the patient catheter 4.

[0082] The flexible band heater 3 should be flexible enough to allow unrestricted bending of the patient catheter 4 during use. The flexibility of the flexible band heater 3 should also be sufficient to allow it to be inserted into and removed from the patient catheter 4, while simultaneously being rigid enough to allow it to be inserted into the patient catheter 4 and supported in the desired position without collapsing against the wall or collapsing to one end of the patient catheter 4. Furthermore, its rigidity should be sufficient to prevent the flexible band heater 3 from oscillating in the airflow and generating unwanted noise.

[0083] The thin, flat, and extended characteristics of the flexible band heater 3 improve thermal conductivity with airflow while also providing low resistance to airflow. The flexible band heater 3 can be placed within the patient catheter 4 to create a helical structure. Figure 1-B ), and / or the flexible strip heater 3 may be curled or bent around one or more flexible strip heater 3 axes. Figure 1-C The image shows a longitudinal axis curled structure.

[0084] The optional profile or geometry of the soft heating band may include:

[0085] The cross-section of the flexible belt heater can be rectangular, elliptical, or any shape;

[0086] The surface of the flexible belt heater 3 can be rough, smooth, or recessed; and / or

[0087] One or more surfaces of the flexible belt heater 3 may be corrugated.

[0088] The thickness and width of the flexible band heater can be varied along its length. For example, a thicker portion of the flexible band heater 3 can be provided in the patient catheter 4 to generate a Venturi effect that increases the airflow rate, allowing flow detection via a pressure sensor along the length of the flexible band heater 3.

[0089] The use of these coiled, spiral, and other structures described above increases the length of the flexible band heater 3 in the patient catheter 4, thus increasing the effective surface area for heat conduction between the airflow and the surface of the flexible band heater 3. Additionally, these structures can be used to improve the vortex mixing of water vapor generated in the humidifier 1 with the airflow.

[0090] Various structures can also be used to guide the patient along the catheter 4 or, for example... Figure 5 The overall device shown provides different zones in terms of flow rate, sound transmission, humidity, or temperature characteristics.

[0091] It may be desirable to improve the acoustic impedance characteristics of the patient catheter 4 using the flexible band heater 3. For example:

[0092] The generation or reduction of white noise (wideband noise);

[0093] Attenuation or filtering of specific acoustic noise frequency components, such as structural noise from a fluid generator or airborne noise; and / or

[0094] Enhance the propagation of the patient's respiratory sound signal through the patient catheter 4 and to the base unit 22 ( Figure 5 (For monitoring and diagnosis)

[0095] Improving acoustic impedance characteristics using a flexible band heater 3 can be achieved by selecting the materials constituting the flexible band heater 3 and the aforementioned construction of the flexible band heater 3 in the patient catheter 4, as well as other methods. Figures 1-A to 1-C As shown in the image.

[0096] Figure 2 An embodiment of the flexible strip heater 3 is shown, wherein heating is performed by heating element 6.

[0097] In one embodiment, the heating element 6 heats elements such as... Printed circuit technology is applied to the surface of flexible substrates made of silicone rubber, polyimide, or PTFE. Available printed circuit technologies include etching, printing, and vacuum deposition.

[0098] Then, another layer of substrate material is laid on the base substrate containing the heating element, and the two layers of substrate material are bonded or fused together to encapsulate the heating element. www.minco.com The above description describes a flexible heater type of Thermofoil manufactured by Minco in Minneapolis, USA. TM The series are examples of commercially available strip heaters that can be modified for use in this invention.

[0099] An alternative embodiment for manufacturing the flexible strip heater 3 is to use a laminator, such as a dual-silicon roller laminator, to encapsulate the heating element 6, in the form of a wire or strip, within two polycarbonate films. The resulting strip can be, for example, 1 mm to 10 mm wide and 0.1 mm to 1 mm thick. A size of approximately 0.2 mm to 0.5 mm thick and approximately 5 mm wide can be used in the patient catheter 4.

[0100] The heating element 6, made of metal wire or strip, can have any suitable cross-section, such as circular, elongated, or rectangular. The heating element 6 can, for example, be made of a resistive conductor.

[0101] The arrangement of the heating elements 6 between the laminates can be any ordered or disordered arrangement that improves the thermal conductivity of the flexible strip heater 3 to the surrounding medium (gas or liquid). The heating elements 6 can also have a positive thermal conductivity (PTC) with respect to impedance, thereby reducing heating as the temperature increases toward the desired temperature.

[0102] Alternatively, the heating element 6 may have a negative thermal conductivity (NTC) to allow sensing of the temperature of the heating element 6 or the temperature of the surrounding medium.

[0103] In other embodiments, the flexible belt heater 3 may include multiple heating element circuits. These multiple heating elements may be connected in series or in parallel. Using these multiple heating circuits in the flexible belt heater 3 makes it possible to apply the additional heating required for the operation of the breathing apparatus.

[0104] In other embodiments, the laminated film may be polyester, polypropylene, or any suitable and permissible material suitable for use in respiratory medicine. Alternatively, multiple laminated films may be used to create a composite strip with desired properties while maintaining desired compatibility with the outer membrane for respiratory medicine use. Other conductors may also be present between each of these multiple layers, for example, to form multiple heating circuits, such as allowing multiple heating zones along the length of the strip heater.

[0105] In another embodiment, an air temperature sensor 7, such as a thermocouple, a platinum resistance thermometer, or a thermistor with an accompanying signal line 9, may be included between the two polycarbonate films. The sensor head may be flat, less than about 2 mm thick, and may be less than 1 mm thick. Other circuit components, such as surface-mount circuit components, may be integrated onto the substrate film and then incorporated into the flexible tape for sensing and / or control. Additionally, heating elements 6 and other circuit components may be present in the multilayer separated by the substrate film as described above.

[0106] For the flexible strip heater 3, the other circuit components share a common physical characteristic: they are small enough to be contained within the overall profile of the flexible strip heater 3 and to be matched with the heating element 6.

[0107] In an alternative embodiment, the flexible band may not have a heater element 6, but instead incorporates one or more other circuit elements for sensing and control. Therefore, the breathing device may include two or more flexible bands, with one or more bands performing the heating function and one or more bands performing the sensing and / or control function.

[0108] The range of other circuit components that can be used is shown below by way of example:

[0109] 7a relative and absolute humidity sensor;

[0110] A temperature sensor 7a in the form of a thermistor with a positive thermal conductivity (PTC) or a negative thermal conductivity (NTC), or a temperature sensor 7a with variable PTC characteristics, can be inherent to the heating element 6, thus making the flexible strip heater 3 self-limiting.

[0111] Thermocouples, platinum resistance thermometers, and other similar devices can be used to generate actual temperature signals for control and monitoring.

[0112] Gas flow direction sensing can be achieved by using at least two independently controlled heating sections spaced apart along a flexible strip heater, each heating section including a temperature sensor (e.g., a thermistor). These two or more heating sections are controlled, and the sensed temperature is used to detect the direction of the airflow.

[0113] Hot-wire wind speed measurement for airflow sensing 7a;

[0114] Environmental pressure sensing 7a, such as inspiratory pressure versus expiratory pressure;

[0115] The controller 7b utilizes the output (e.g., temperature output) of the sensor 7a, which controls, for example, a transistor that regulates the current applied to the heating element 6 for heating;

[0116] An identification-communication-storage chip 8 enables the identification and communication of operating parameters from the flexible band heater 3 to the base unit 22, other heaters, and components in the respiratory apparatus. For example, the flexible band heater 3 can communicate with itself and detect and report on other components connected to the respiratory apparatus (e.g., a patient mask type 5, a patient catheter type 4, or an active ventilation system). The information collected by the flexible band heater 3 can then be sent to the base unit 22. The identification-communication-storage system may partially include a radio frequency identification (RFID) chip to store the identification and operating parameters of the heater 6 and sensor 7. The base unit 22 may have the ability to communicate with the RFID chip and adjust its operation accordingly. Such a system has been disclosed in Australian Patent Application No. 2005907200, entitled “Identification System and Method for Masks and Ventilation Components,” the entire contents of which are incorporated herein by reference. Communication can also be used to control the active ventilation system.

[0117] Electromagnetic communication can be implemented using miniature antennas and receivers, such as Bluetooth. For example, the antenna for sending and receiving information could be located in the flexible band heater 3, in the wall of the patient catheter 4, or in an active ventilation system. Figure 5 Among the other components of the breathing apparatus shown. In another embodiment, the antenna may be the size allowed by the length of the flexible band heater 3 or the patient catheter 4.

[0118] The power supply for the flexible strip heater can be achieved using the same method as the electromagnetic communication described above. In this embodiment, the antenna or sensing coil will be suitable for power transmission.

[0119] These components can be positioned along the flexible strip heater 3 wherever appropriate for their function. For example, a thermocouple can be positioned at the end of the flexible strip heater 3 adjacent to the patient mask 5 to enable closed-loop temperature control based on the temperature of the gas delivered to the patient mask 5.

[0120] In an alternative embodiment, the temperature sensor may be located in or near the patient mask 5, but separate from the flexible band heater 3. However, the temperature sensor may be connected to the flexible band heater 3 in one of the ways described above to achieve closed-loop control of the temperature of the gas delivered to the patient.

[0121] The flexible belt heater 3 may also include a microtube 26 ( Figure 2 This allows for remote sensing away from the fluid generator and / or humidification chamber 1. For example, the microtube can provide sensing of pressure, noise / ventilation, and / or cardiac signals. For example, the microtube can be connected to the side of the flexible belt heater 3 and connected back to the fluid generator 20 in one of the ways described above. The use of the microtube 26 provides the benefit of avoiding flow noise in other areas of the patient catheter 4 and the breathing apparatus.

[0122] The sensing and control methods described above allow for the use of closed-loop control to improve gas delivery to the patient mask 5, thereby ensuring the gas is at the desired temperature and humidity. Alternatively, a simple open-loop system can be used, where the excitation voltage or current for the heating element can be, for example, DC from 0.1V to 24V or equivalent AC power from 0.1W to 50W. Sensing and control can also control the level of intentional gas leakage in the active ventilation system based on the magnitude of the supplied pressure. For example, as the ventilator pressure increases, the active ventilation system can be controlled to reduce its intentional leakage level to an acceptable level.

[0123] In addition, sensor 7a can be used for permission or statistical data collection.

[0124] Furthermore, the different components of the heater and / or sensing / control system described herein can be used as independent components in the breathing device without the use of a humidifier, and this arrangement is covered within the scope of the present invention.

[0125] Thus, the described flexible band heater 3 can be easily removed from the patient catheter 4 to enable cleaning, maintenance, or replacement. The flexible band heater 3 also provides efficient heating by simply incorporating the sensing and control components 7 into it.

[0126] Floating heater

[0127] Figure 3The diagram shows a humidifier device utilizing a floating heater 12. The floating heater 12 floats on the water body 13 in the humidification chamber water tank 1, such that the main part of the floating heater 12 is immersed but remains adjacent to the water surface 14 in order to heat a portion of the water near the surface 14.

[0128] The floating heater 12 may include components having the same characteristics as those referenced above. Figures 1-A to 1-C and Figure 2 This describes a section of a flexible belt heater with a similar structure to the described flexible belt heater. One end of the heater, located in the inlet conduit 10 leading from the fluid generator 20, may be equipped with a connector 11. This connector 11 allows connection of the floating heater 12 to the flexible belt heater, which in turn connects to the base unit 22 of the breathing apparatus. Figure 5 The floating heater 12 receives power through the upstream connector 11. It also receives any sensing or control signals transmitted to or from the floating heater 12 through the upstream connector 11.

[0129] The downstream end 2 of the floating heater in the patient catheter 4 leading to the patient interface may have another connector for providing power and any communication with other parts of the flexible band heater located in the patient catheter 4 (see [link to documentation]). Figure 1-A , Figure 1-B , Figure 1-C and Figure 2 ).

[0130] The heater 12 can be adapted to float by the natural buoyancy of the heater itself (through the surface tension effect), or it can be supported in a way that keeps the heater close to the water surface regardless of changes in water level.

[0131] Figures 4-A to 4-D Several embodiments are shown in which floating heaters 3, 12, 16, and 17 may be located in the humidification chamber 1. In each embodiment, the floating heaters 3, 12, 16, and 17 are either formed by the type of flexible strip heater described above, or by a plate-shaped flexible strip heater 3 and a floating plate heater 16.

[0132] The structure and use of the floating ribbon heater 3 and the floating plate heater 16 are the same as those of the ribbon heater 3 described above, except that they are applied to water. This has a significant advantage: the heaters in both applications are robust against gas or water immersion because the floating ribbon heater 3 or the floating plate heater 16 can be partially submerged in water during operation of the breathing device, whether unintentionally increasing or decreasing the water volume by tilting the device or intentionally maintaining the temperature of the water vapor in the gas from the humidifier 1.

[0133] Figure 4-AA circular floating plate heater 16 is shown, which is fixed below a floating support grid or plate 15 made of, for example, a buoyancy plastic material. The support grid 15 provides a floating positioning mechanism for the floating plate heater 16 to space the heater element directly below the water surface 14, thereby ensuring sufficient contact with the water to induce vaporization. Figure 7 In an alternative embodiment shown, the floating heater plate is positioned in a shallow pool and floats on the water surface 14 of the water body 13. In this embodiment, the floating plate heater includes at least one opening to allow water to fill the shallow pool and overflow the heater plate 16. The small volume of water in the shallow pool can be rapidly heated to generate steam.

[0134] Figure 4-B Another embodiment is shown in which the plate structure is wavy or recessed in a regular or irregular manner. The wavy and / or recessed shapes provide recesses that allow water to accumulate on the upper surface of the floating plate 16. In this embodiment, the floating plate heater 16 is inherently buoyant, and therefore it can float without the need for a support grid or other buoyancy device.

[0135] Figure 4-C A flexible ribbon heater 3 wound into a helical structure is shown. In this embodiment, the floating helical flexible ribbon heater 17 can instinctively float so that the main part of the floating helical flexible ribbon heater 17 is immersed in water 13. In another embodiment, the flexible ribbon heater 3 can be wound into a horizontal helix, such as... Figure 4-D .for Figure 4-C and Figure 4-D In the embodiments, it is possible to use Figure 4-A The support grid 15 is used to position the flexible belt heaters 3, 12, and 17.

[0136] The foregoing embodiments of floating heaters 3, 12, 16, and 17 describe several defined structures; however, in use, the floating heaters may employ combinations of defined or undefined structures. For example, combining... Figure 4-C and Figure 4-D It has a continuous long spiral structure in a spiral shape.

[0137] In the embodiments of the floating heaters 3, 12, 16, and 17 described above, the heaters provide effective heat transfer to the water surrounding the heaters. Furthermore, instead of heating the entire water body from the bottom up, the water near the surface is heated to achieve vaporization, whereas when the heaters are positioned at the bottom of the water body 13, the entire water body is heated from the bottom up.

[0138] Furthermore, the flexible belt heater structure can be spiral, or otherwise formed such that it is partially immersed in the water body 13, thereby heating not only the water near the air but also the air near the water to create a stratified heating zone, which in turn enhances water absorption for humidification. Therefore, the floating heaters 3, 12, 16, and 17 are more dynamically efficient in generating water vapor and can more effectively and quickly reach the desired water surface temperature for humidification upon device startup.

[0139] Multi-zone heating

[0140] Figure 5 A breathing apparatus using three heaters is shown. The overall structure and use of these three heaters are the same as those of the soft belt heater 3 and floating plate heaters 12, 16, and 17 described above.

[0141] These heaters may include multiple heating circuits, allowing each of the three heating zones to be operated independently.

[0142] The fluid generator 20 or the blower supplies gas from an ambient temperature supply, which can be indoor air, or a specific gas supply such as oxygen can be added or substituted. A preheater 18 is positioned within a blower connector 10 leading to the humidifier 1. The blower connector can be rigid, flexible, or a conduit required for operation of the blower connector 10 or the preheater 18 positioned within it. The preheater 18 is connected to a controller / power supply 21 of the base unit 22, which supplies power and communicates with any sensing or control components 7 of the preheater 18, as in the embodiment of the flexible strip heater 3. The preheater 18 is connected at the blower conduit connector end 11 to the floating heaters 12, 16, 17 of the humidification chamber 1. The floating heaters 12, 16, 17 receive power from the controller / power supply 21 via the preheater 18 and communicate with any sensing or control components 7 of the floating heaters 12, 16, 17.

[0143] Alternatively, the floating heaters 12, 16, and 17 can also be configured as described above. Figure 6-A and Figure 6-B The patient catheter 4 described herein is connected to the controller / power supply 21 via the wall of the blower connector 10.

[0144] The post-heater 19 is positioned within the patient catheter 4. The patient catheter connector end 2 provides power and communication to the sensing and control components 7 of the post-heater 19 via the controller / power supply 21. The patient catheter connector end 2 can... Figure 5 The floating heaters 12, 16, and 17 shown in the diagram, or via... Figure 6-A and Figure 6-BThe conduit wall 25 shown is connected to the controller / power supply 21, and then connected to the controller / power supply 21 in the base unit 22 through the humidification chamber 1.

[0145] In alternative embodiments, one or more heaters may not be of the type described above, but rather other suitable heating elements. For example, the preheater 18 may be configured as a simple linear heater or other conventional type of heater, rather than a flexible strip heater of the type described herein.

[0146] Using this arrangement offers the following advantages:

[0147] A single interconnected heater system located inside the blower connector 10, the humidification chamber 1, and the patient catheter 4;

[0148] The entire heater, sensor, and control system can be removed for cleaning, maintenance, or replacement only;

[0149] Interconnectivity facilitates highly closed-loop control of the temperature and humidity of the air delivered to the patient;

[0150] The ability to sense temperature and humidity at different parts of the patient catheter 4, so as to control condensation at different parts of the patient catheter 4;

[0151] Different components of the heater and / or sensing / control system can be used in combination or individually in a conventional humidifier. For example, the flexible heating belt 3 can also be used in conjunction with a conventional humidifier having a heating base plate to heat the patient catheter 4. Alternatively, as described above, the floating heater 12, 16, 17 or the flexible belt heater 3 can be used to heat the water body 13 in the humidification chamber 1 and the heating or insulating walls of the patient catheter 4; and / or

[0152] The ability to install multiple heaters in parallel and series at any location on the breathing apparatus. For example, this allows for "overheating" during the initial operation of the breathing apparatus when the water body 13 needs time to reach the desired temperature. Temporary additional heating of the air using multiple heater circuits will enhance the air's ability to draw in cooler water. This can be controlled or profiled in response to the temperature of the water in the water body 14 to provide an appropriate humidity level.

[0153] For breathing apparatus, the placement of the three heaters and the timing and sequence of their use manage gas temperature and humidity comfort characteristics by allowing for independent, staggered operation:

[0154] Heating an ambient gas with low absolute humidity;

[0155] To vaporize water; and / or

[0156] Heating of the gas with increased absolute humidity (after passing through humidification chamber 1).

[0157] The advantages of operating the exemplary embodiments disclosed herein are illustrated using the following examples.

[0158] Patients need to pay attention to the temperature and humidity comfort characteristics of the breathing gas, especially in winter and very cold climates. In this embodiment, the purpose of the system cold start is to initially deliver warm air rapidly, and then increase the humidity over time as the humidifier warms up. This approach allows the patient to receive comfortable warm air before any adverse signs of low humidity breathing assistance occur, followed by an increase in relative humidity.

[0159] For cold starts in cold climates, the three-heater system can therefore operate as follows. First, the cold ambient temperature gas from the fluid generator 20 is warmed by the preheater 18 located in the blower connector 10, possibly with the assistance of the postheater 19 in the patient catheter 4. This initially provides warm, dry air to the patient.

[0160] As the warm airflow begins to absorb a considerable amount of water vapor from the unheated water in the humidification chamber 1, the post-heater 19 in the patient catheter 4 begins or increases its heating to prevent "raindrop" condensation in the patient catheter 4. The initial warming of the air using the preheater 18 has the advantage of immediately initiating a certain degree of humidification as a simple "pass-over" operation, while the floating heaters 12, 16, and 17 continue to warm the water. In this simple "pass-over" operation, the heat used for vaporization is provided by the heated air.

[0161] As the floating heaters 12, 16, and 17 begin to warm the water surface and rapidly increase the absolute humidity of the air passing through the humidification chamber to achieve the desired humidification level, the post-heater 19 in the patient catheter 4 adjusts its heating to maintain absolute humidity by preventing condensation in the patient catheter 4. The post-heater 19 can also be used to maintain the desired gas temperature in the patient catheter 4. The preheater 18 can have a heating profile based on the heating level of the water body 13 in the humidification chamber 1. The heating profile is the heating ratio of the airflow over a period of time and can be provided by changing the power supplied to the preheater 18 or the structural configuration of the preheater 18. It should be believed that more effective humidity control can exist by controlling the air temperature, rather than heating water.

[0162] Another advantage of this exemplary embodiment is that it allows for less power consumption during humidification startup, enabling the breathing device to be operated via DC power or a portable power source. Furthermore, satisfactory operation can still be achieved when two or more heaters are connected in parallel, with one heater operating at a time, but cycling between the two or more heaters.

[0163] Inlet conduit connection

[0164] refer to Figure 8 The power supply / controller 21 can be connected to the inlet conduit / blower connector 10 via connector 52. Connector 52 has a first connector end 52a connected to the power supply / controller 21 and a second connector end 52b connected to the inlet conduit 10. The inlet conduit 10 has a fluid generator fitting or connector 54. The fluid generator fitting 54 has an end 54a configured to connect to the fluid generator 20. The fluid generator fitting 54 also has a secondary-formed gripper or connector 54b that defines a wiring clamp 54c.

[0165] like Figure 9 As shown, the inlet conduit 10 is connected to the fluid generator 20 via the fluid generator connector 54. The connector 52 is connected to the fluid generator connector 54 at the terminal clamp 54c. Although Figure 9 Not shown, but it should be understood that the first end 52a of connector 52 is connected to power supply / controller 21. Power supply / controller 21 provides current and signals to fluid generator connector 54 through connector 52.

[0166] Patient catheter connection

[0167] like Figure 10 As shown, the patient catheter / air delivery hose 4 is connected to the patient interface 5 via a mask connector or fitting 56. The patient catheter 4 includes a tube 4a and a spiral rib 4b, the tube 4a being made of, for example, a thermoplastic elastomer, and the spiral rib 4b being made of very low density polyethylene. Wires 4c, 4d, and 4e are supported in the spiral rib 4b to contact the outer surface of the tube 4a. Wires 4c, 4d, and 4e can be used to heat the tube 4a and transmit signals to and from the power supply / controller 21. It should be understood that the inlet catheter 10 may have a similar structure to the patient catheter 4, including a tube 10a, a spiral rib 10b, and wires 10c-10e supported by the spiral ribs on the tube.

[0168] Inlet conduit and fluid generator connector

[0169] refer to Figure 11 The fluid generator connector 54 includes a connector plug block 54a. A gripper or connector 54b is secondary-formed on the connector plug block 54a to connect the connector plug block 54a to the inlet conduit 10. The secondary-formed gripper or connector 54b includes gripping features 54d, such as grooves for user fingers, located on the outer surface of the secondary-formed gripper or connector 54b to provide better gripping on the connector connector 54.

[0170] like Figure 8 , Figure 12 and Figure 13 As shown, the fluid generator connector 54 includes a terminal clamp 54c that receives the second connector end 52b of the connector 52. Figure 13 As shown, the connector clamp 54c includes a rib 54n, which is received in the inlet portion 52e of the connector 52. The rib 54n engages the inlet portion 52e to secure the connector 52 to the connector clamp 54c.

[0171] The connector 54c also includes teeth 54e for positioning the wires 10c, 10d, and 10e of the inlet conduit 10. The wires 10c, 10d, and 10e are placed on the outer surface of the thermoplastic elastomer tube 10a and held in place on the outer surface by spiral ribs 10b.

[0172] A groove 54j is provided in the connector plug block 54a to allow the secondary molding material 54b to flow and bond to the interior of the tube 10a, thereby establishing a connection between the connector plug block 54a and the inlet conduit 10. The connector plug block 54, the tube 10a, and the secondary molding material 54b can be formed from materials bonded by chemical methods.

[0173] refer to Figure 14 The connector clamp 54c includes a connector clamp pin 54h, which is received in a hinge groove 54g of the connector clamp hinge portion 54f. The connector clamp hinge portion 54f is disposed on the connector plug block 54a. The connector clamp 54c latches into the connector clamp hinge portion 54f to ensure connection between the teeth 54e and the wires 10c, 10d, 10e of the inlet conduit 10. Figure 15 As shown, the wire clamp 54c can be connected to the connector plug block 54a before connecting the inlet conduit 10 to the connector plug block 54a. The wire clamp pin 54h is connected to the hinge slot 54g, and the wire clamp 54c is tilted or rotated forward. Then, the inlet conduit 10 is connected to the connector plug block 54a, and the wire clamp 54c is rotated or pivoted backward so that the teeth 54e contact the wires 10c, 10d, 10e of the inlet conduit 10. Figure 16 and Figure 17 As shown, the connector plug block 54a includes a guide groove 54p for the spiral rib 10b of the inlet conduit 10 to position the wires 10c, 10d and 10e to contact the teeth 54e.

[0174] refer to Figure 17 The connector 54c includes an arched portion 54k. When the connector 54c is inserted into the connector hinge portion 54f, the arched portion 54k engages with the guide groove 54p. Figure 16 A groove is defined. A slot 54i is provided in the connector plug block 54a. Figure 18The groove 54i is designed to receive the spiral rib 10b and the inlet conduit 10 for the wires 10c, 10d, and 10e. The groove 54i has a smooth surface and a wide contact area to prevent or minimize damage to the wires 10c, 10d, and 10e. Also... Figure 18 As shown, a cavity 54m is provided adjacent to the trench 54j to allow some air to pass through during the secondary molding of the gripper or connector 54b into the connector plug block 54a.

[0175] refer to Figures 19 to 21 The second connector end 52b has a gripping feature 52c to allow for easier gripping. A strain relief feature 52d is also formed in the second connector end 52b to increase flexibility. The gripping and strain relief features can also be provided on the first connector end 52a of the connector 52.

[0176] Contacts 52f, 52g, and 52h are provided for sending and receiving signals from wires 10c, 10d, and 10e of the inlet conduit 10. Although the inlet conduit 10 shown includes three wires, and the terminal clamp 54c shown has three terminals for receiving three contacts of the second connector end 52a, it should be understood that any number of wires, terminals, and contacts can be used for transmitting and receiving signals from the power supply / controller 21 to the inlet conduit 10.

[0177] Patient catheter and mask connector

[0178] refer to Figures 22 to 34 A mask connector or fitting 56 is provided for connecting the patient catheter / air delivery tubing 4 to the patient interface 5. The mask connector or fitting 56 includes a connector plug block 56a, which is connected to the patient catheter 4 via a secondary molding gripper or fitting 56b. The connector plug block 56a, tubing 4a, and secondary molding fitting 56b can be formed from materials bonded by chemical methods.

[0179] like Figure 24 As shown, the connector plug block 56a is connected to the inlet 5a of the patient interface 5. This inlet 5a may be, for example, a rotating bend of a face mask.

[0180] A printed circuit board (PCB) 56c is disposed around the outer surface of the connector plug block 56a. The wires 4c, 4d, and 4e of the patient catheter 4 are connected to the PCB 56c. Figure 25 , Figure 27 and Figure 28As shown, the connector plug block 56a includes hooks or pins 56i for engaging holes or openings 56u in the PCB 56c. Thus, the PCB 56c wraps around the outer surface of the connector plug block 56a and is held in place. A thermal fuse 56d and a temperature sensor 56e, such as a thermistor, are disposed on the PCB 56c. Figure 23 and Figure 26 As shown, one or more windows 56j are provided in the outer surface of the connector plug block 56a, and a thermal fuse 56d and a temperature sensor 56e are disposed in the windows 56j. The windows 56j are covered by the PCB 56c, as shown. Figure 24 As shown in the diagram. As detailed below, PCB56c includes a heater track that is cooled by exposing PCB56c to an airflow along window 56j.

[0181] like Figures 22 to 26 As shown, the spiral rib 56f is positioned on the outer surface of the connector plug block 56a to locate the patient catheter 4. Figure 25 As shown, the outer surface of the connector plug block 56a includes a stepped recess 56h to allow secondary molding material to flow and bond to the underside of the flexible PCB 56c. Figure 29 As shown, the connector plug block 56a also includes a groove 56t to allow the secondary molding material to bond with the interior of the tube 4a of the patient catheter 4. (Return to Reference) Figure 25 A cavity 56g is provided adjacent to the groove 56t to allow air to escape during secondary molding. Also, Figure 28 and Figure 29 As shown, the end of the connector plug block 56a includes a profile 56n that minimizes the capacity for residue accumulation and the capacity required to remove residue if accumulation does occur. The end of profile 56n also minimizes the flow resistance of the secondary molding material.

[0182] like Figure 25 and Figure 27 As shown, an injection groove 56m is provided between the spiral rib 56f and the end groove 56t to allow secondary molding material to bond the tube 4a to the connector plug block 56a. Figure 30 As shown, tube 4a is twisted onto connector plug block 56a, and wires 4c, 4d, and 4e of patient catheter 4 are soldered to flexible PCB 56c at point 56p shown.

[0183] refer to Figure 31 The secondary-molded gripper or connector 56b may include molded gripper features 56q to improve the gripping capability of the mask connector or connector 56, such as grooves for accommodating a user's fingers. The connector plug block 56a may be formed of a rigid polymer, while the secondary-molded gripper or connector 56 may be formed of a thermoplastic elastomer. Figure 32As shown, the connector plug block 56a can have a standard 22mm ISO taper for connection to the patient interface. Also as... Figure 32 As shown, the secondary molding material can be cut off at 56s in the area of ​​the thermal fuse 56d.

[0184] refer to Figure 33 and Figure 34 The circuitry on the flexible PCB 56c includes a thermal fuse or switch 56d and a thermal sensor 56e. One of the wires, such as 4c, can be used as a temperature sensing wire to send a temperature signal to the power supply / controller 21. Other wires, such as 4d and 4e, can be used as heater wires to heat the tube 4a of the patient catheter 4. If the temperature exceeds a certain value, the thermal fuse 56d is configured to cut off the current to the heater wires 4d and 4e.

[0185] The flexible PCB 56c, temperature sensor 56e, and thermal fuse 56d should be mounted on the connector plug block 56a, which should be as close as possible to the inlet 5a of the patient interface 5 and the air passage through the patient catheter 4. The mask connector or fitting 56 can also be formed as small as possible to allow its use with existing respiratory devices. The use of a secondary molding gripper or fitting 56b is also useful for securing the patient catheter 4 to the connector plug block 56a and for holding the flexible PCB 56c (including the temperature sensor 56e and thermal fuse 56e) in place. The use of secondary molding material also helps to reduce or eliminate any sites where bacteria may grow.

[0186] The face mask connector or connector 56 described herein is formed of a biocompatible material. The connector plug block 56a also includes an end 56r ( Figure 32 This end includes a standard 22mm socket-type ISO taper for use with existing patient interfaces. The use of secondary molding materials also simplifies manufacturing and improves the reliability of the mask connector or joint.

[0187] Power supply / controller

[0188] refer to Figure 35 The power supply / controller 21 includes a switching power supply 21a, a switch 21b, a control unit 21c, and multiple LEDs 21d. The power supply / controller 21 has an AC power input 21e, a DC power output 21f, and a bypass AC power lead 21g to the fluid generator 20. The AC power input 21e can be, for example, a 110-240V AC universal input. The switch 21b can be a MOSFET switch connected in series with the heater element and controlled by the control unit 21c. The DC power output 21f can be, for example, a 500mA regulated 5VDC output, or a 1.3A, 24V DC output. At 24V output, the power output is 30W.

[0189] Power input 21e is connected to switching power supply 21a, while bypass 21g is connected to the AC power socket of fluid generator 20. Power supply / controller 21 is configured to provide power to inlet catheter 10, adjust preset temperature levels at patient interface 5, and act as ON / OFF control.

[0190] Control unit 21c is a closed-loop temperature control system. Temperature sensor 56e, located in mask connector 56, provides feedback signals to control unit 21c via wire 4c of patient catheter 4. However, it should be understood that control can be independent of temperature signal feedback. Control unit 21c can instead be configured to provide a predetermined amount of power to output 21f without depending on or relying on the temperature sensor signal.

[0191] DC power output 21f supplies power to inlet conduit 10, while switch 21b is connected in series with power output 21f and controlled by control unit 21c. Power regulation is performed based on ON / OFF control technology. Power regulation has a fixed duty cycle of approximately 95%-99%. The OFF cycle is used for temperature sensing, for example, the OFF cycle is approximately 1%-5%.

[0192] LED 21d may include a green LED to indicate that power is on and being supplied to the inlet conduit 10. A yellow LED may be provided to indicate that power output 21f is on but not supplied to the inlet conduit 10. A red LED may be provided to indicate a fault. Other LEDs may also be provided for indicating and / or controlling temperature. The power supply / controller may be equipped with a manual operation button (not shown) to allow temperature control by the patient or clinician in response to temperature indications from the LEDs.

[0193] Control unit 21c is configured to generate a fixed power switching frequency and duty cycle for power output 21f to heat inlet conduit 10. Control unit 21c is also configured to sense temperature via a signal transmitted by temperature sensor 56 through wire 4c. Based on the sensed temperature, control unit 21c is configured to adjust the temperature to a preset temperature when the ambient temperature changes. Control unit 21c is further configured to record the preset temperature when power control / supply 21 is turned off.

[0194] When a fault is detected, the control unit 21c can also latch the fault state and clear the fault by recirculating power. If a fault occurs, the fault detection circuit locks into the fault condition to send a fault signal to the driver block ( Figure 37aThe fault will persist until power is restored and disconnected again. Control unit 21c can be configured to detect faults, including any interruption in wires 4c-4e and 10c-10e, any arcing and / or poor contact in fluid generator connector 54 and / or mask connector 56. Control unit 21c can also detect low voltage.

[0195] When a fault is detected, the control unit 21c keeps the power output 21f in the OFF state, and the power output 21f remains in the OFF state until the power is recirculated and the fault condition is cleared.

[0196] The status of the power supply / controller 21 can be indicated by LED 21d.

[0197] As shown, for example in Figure 5 and Figure 8 In this configuration, the power supply / controller 21 can be separated from the fluid generator 20 and the humidifier. There is no information exchange between the fluid generator 20 and the humidifier, and the closed-loop control does not include control based on, for example, airflow rate, humidity level, and humidifier outlet temperature. However, it should be understood that information can be exchanged, for example, via the sensing wire 4c. The aforementioned control prevents "raindrops" in the patient catheter 4 and delivers humidified air to the patient interface 5.

[0198] It should be understood that the power supply / controller 21 can be integrated with the fluid generator or humidifier control system. Information regarding the operation of the fluid generator, the humidifier, and the ambient air can be provided to the integrated power supply / controller. By integrating the power supply / controller with the fluid generator 20 or the humidifier, the system is better able to control the temperature, humidity levels, and "raindrops" at the patient interface 5 within a wider range of ambient temperature and humidity.

[0199] refer to Figure 36The diagram illustrates three wire heating tubes or conduits according to an exemplary embodiment of the invention. Wires 4d and 4e can be formed, for example, from 25m long wires with a diameter of 0.23mm, and can be made of copper, for example. A sensing wire 4c can be connected to the heating wires 4d and 4e at a connection point 4f, approximately in the middle of the wires forming wires 4d and 4e, dividing the wires into two resistors Ra and Rb. For example, the total resistance Ra+Rb can be approximately 15Ω-20Ω at 20°C-26°C, and approximately 18Ω at approximately 23°C. The total resistance Ra+Rb is approximately 18Ω, while when the wire-wound resistors are heated to approximately 33°C using a 24V DC power supply at a power of approximately 30W, the total resistance Ra+Rb is approximately 21Ω. As described above, for example, a DC voltage V+ can be supplied through J1 and J3 with a duty cycle of approximately 95%-99%. During current flow through wires 4d and 4e, resistors Ra and Rb generate heat to heat conduit 4. During the 1%-5% OFF period, the sensed voltage Vsen can be determined. During the OFF period, the control unit 21c activates switch 21b to switch the system to the sensing state, and the sensed current of J1 flows back to J2 through resistor Ra and the resistor RT1 of temperature sensor 56e. The resistor RT1 of temperature sensor 56e can be approximately 1kΩ-50kΩ, while the resistor Rb can be approximately half of Ra+Rb, or approximately 5Ω-15Ω, for example, approximately 10Ω, so Rb can be ignored.

[0200] Although the sensing wire 4c is disclosed as being connected to the temperature sensor 56e, it should be understood that the sensing wire can be connected to different sensors, such as a pressure sensor, in cases where the control is not based on feedback control performed on the detected temperature.

[0201] The fuse F2 of the thermal circuit 56d is thermally coupled to the heater rail of the PCB 56c. The PCB 56c can be, for example, approximately 0.05mm-0.15mm thick, such as approximately 0.1mm thick, with a resistance of approximately 0.05Ω-0.15Ω, such as approximately 0.1Ω, and a power output of approximately 0.12W-0.24W, such as approximately 0.18W. As described above, one side of the PCB 56c faces the open window 56j, thus exposing the PCB 56c to the air in the patient catheter 4. Therefore, the air flowing in the catheter cools the PCB 56c to just above the temperature of the air in the catheter. If the fluid generator stops, or the airflow through the catheter is blocked, the temperature of the PCB 56c will rise and trip the fuse F2 to protect the patient catheter 4 from damage. Thus, the temperature sensor 56e and the fuse F2 of the thermal circuit 56d provide over-air temperature protection, tube overheat protection, and low airflow protection. The thermal circuit 56d may include a thermostat, for example, a bimetallic strip instead of a fuse. The increased impedance of the thermostat will suppress or stop the increase in current.

[0202] Since the patient catheter 4 delivers humidified air to the patient interface 5, the power supply / controller 21, the mask connector 56 and its components, and the patient catheter 4 should meet safety standards for temperature specifications, such as ISO 8185. Under normal operating conditions, the patient or clinician should be able to set the temperature of the air delivered from the ambient environment to the patient interface 5 to approximately 30°C. If the system is not equipped with an alarm system or indicator, according to ISO 8185, parts 51.61-51.8, under normal and single-fault conditions, the temperature of the air delivered to the patient interface 5 should not exceed approximately 40°C-42°C, for example, approximately 41°C. This maximum temperature (e.g., 41°C) is at the maximum energy level of 43°C at 100% RH. The fuse F2 of the thermal circuit 56d can be selectively tripped at the maximum temperature.

[0203] Refer again Figure 36The three-wire circuit (4c-4e) of the patient catheter 4 includes heating elements Ra and Rb, wire 4c for supplying the sensing voltage Vsen, and a thermal sensor 56e. Heating elements Ra and Rb are connected in series with the heater rail and fuse F2 on PCB 56c. The thermal sensor 56e includes a thermal resistor TR1 connected to the intermediate 4f of the heater wires 4d and 4e. The circuit has two states: ON and OFF. In the ON state, also known as the heating state, wire 4d is connected at J1 to a voltage V+, such as 24V DC output from power supply output 21f. Heating current flows through J3, wires 4d and 4e, J4, and switch 21b, and then to ground GND. In the ON state, the sensing voltage Vsen at J2 does not sense the air temperature, but rather approximately half the voltage V+, such as approximately 12V.

[0204] In the OFF state, switch 21b is turned on, and heating wires 4d and 4e will be pulled up to V+, for example, about 24V, and sensing current flows through J1, Ra, RT1 and then back to J2.

[0205] The power supply / controller 21 may include circuitry for performing a variety of functions. These circuitry may include: 1) a power switch control circuit; 2) a tube interface and gate drive circuit (driver block); 3) a fault detection and latching circuit (fault detection latch); 4) a temperature preset / control circuit; and 5) a start-up and indication circuit.

[0206] Power supply / controller circuit

[0207] Figure 37a An exemplary embodiment of the circuitry for power supply / controller 21 is shown. The circuitry includes temperature control circuitry configured to control the temperature of the heating conduit, a fault detection latch, sensing circuitry, and a driver block. The driver block is connected to switch 21b, which may be a MOSFET.

[0208] refer to Figures 37b-1 to 37b-4 ,For example, Figure 37a An exemplary embodiment of the circuit can be based on the UC2843 control IC purchased from Texas Instruments. It should be understood that other control circuits can be used. The power switch control circuit has overcurrent and overvoltage protection chips that can be used for error handling. The power switch control circuit can also have an RC clock and undervoltage lockout and push-pull output drivers. By setting the oscillating RC clock to R12 = 22,000Ω and C5 = 330nF, the switching frequency can be set to 138Hz. The time period of this frequency can be determined by T = R12 × C15 (22,000 × 0.00000033) = 7.26ms. Through the ratio of R12 and C5, the power switch control circuit provides a 100μS OFF period, thus the duty cycle is 100μS / 7.26ms = 1.38%.

[0209] Under normal heating conditions Figures 37b-1 to 37b-4 The power switch control circuit drives the transistor gate circuit of switch 21b with a duty cycle of approximately 98.62%. The ON state of the circuit is not interrupted by the Vfb signal. At the Vfb critical point, the gate signal can be displayed as a 50% 69Hz output.

[0210] The power switch control circuit receives input via the Vfb pin. When either signal through D3 or D4 goes low, the output of switch 21c is disabled. Since R10 and R20 set the sensing voltage Vsen below 1V, the sensing current Isen cannot be used for this purpose.

[0211] Refer again to 37a and Figures 37b-1 to 37b-4 The sensing voltage Vsen has two functions: 1) When the heater power is ON, Vsen detects the continuity of the heater wires, arcing, or poor contact by sensing the intermediate voltage V+; and 2) When the heater power is OFF, Vsen senses the air temperature through the voltage divider voltage of RT1 and R13. The Q2 and Q3 networks provide the correct logic for the sensing operation, while MOSFET Q3 provides low impedance (Rdson) for temperature sensing. The Q4 MOSFET gate driver network R23 and R25 limit the maximum trigger voltage; R24 and D5, together with R23, control the closing speed of Q4.

[0212] When the heater power is ON, the fault detection circuit operates. The Vsen signal is fed to a window comparator, such as an ultra-power quad comparator, like the LP339AM from National Semiconductor. Voltage dividers U6B, U6D, R31, R36, and R43 provide a + / -2V window voltage at 12V; the output of the window comparator signal is fed to the secondary comparator U6C.

[0213] The second-stage comparator samples the Q4 gate signal as a baseline and detects error signals from the window comparator output. When the system does not detect a fault, the window comparator output is high impedance, the R34 and R40 voltage divider has a higher voltage output, and then the comparator inputs to the R33 and R42 voltage divider network are reversed, causing U6C to output high.

[0214] When the system detects a fault, the window comparator output goes low, the shunts R34 and R40 / / R35 have a low voltage, then the comparator inputs are inverted in the voltage divider network of R33 and R42, and the U6C outputs a low value to the U2A latch CLR pin.

[0215] When latch CLR pin 1 receives a low signal, Q pin 5 will output a latch fault signal, which will attenuate (kill) the U3 output switching signal. For example, the latch can be a 74HCT74DU2A purchased from Fairchild Semiconductor.

[0216] Temperature sensing operation is performed only during power-off periods. Air temperature sensor RT1 and voltage divider base resistor R13 provide temperature information Vsen, which is directly fed to comparator U6A with its input reversed. The potentiometer and its network perform the temperature preset function. The comparator's output drives D4 and controls the U3 switch output.

[0217] When the system starts up, the startup circuit provides a 140ms delay and resets the latch. After the reset, the system will be in the ON state. The startup circuit can be, for example, the IC U4TCM809 purchased from Telcom Semiconductor, Inc.

[0218] The accuracy of temperature measurement is based on two parts: 1) sensing accuracy; and 2) reference accuracy. Sensing accuracy depends on the NTC thermistor RT1 and the series resistor R13. For example, a good NTC sensor RT1 can have an accuracy error of 1%-5%, such as approximately 3%; the series resistor R13 can have an error of 0.5%-1.5%, such as approximately 1%. The accuracy of the temperature preset circuit is determined when the port is at its highest setting (30°C). The port resistance is 0Ω, and accuracy depends on 1% of the resistor network. However, when the port is set to its lowest setting, the port resistance error will increase by 20%.

[0219] When there is no airflow in the pipes, conduits 4 and 10 will overheat. If the pipes are covered, for example, under a blanket, heat will accumulate inside, and the heater element temperature will rise to 120-150°C. Heat will naturally increase when the thermal switch is exposed to cold air and part of the pipe is covered, for example, under a blanket. For this reason, a no-airflow or low-airflow signal from the fluid generator should be able to cut off the power to the heating pipes.

[0220] A tee connector is provided between the thermistor sensor RT1 and the control unit 21c. Any poor contact on the contactor will cause an increase in the impedance of the sensing circuit; for the NTC thermistor RT1, this will reduce the temperature reading, cause the air temperature to rise, and may shut down the thermal switch 21b at the tube.

[0221] There are two methods to resolve fault conditions in temperature sensing. The first is to modify the voltage divider logic, as contact resistance is high when air temperature decreases. Another method to protect the sensing contactor is to bias the sensing line by changing R6 and R31 to 8.2kΩ. This bias reference voltage can detect high-impedance connectors.

[0222] Connector configuration

[0223] like Figures 38 to 40 As shown, the inlet catheter connector and / or patient catheter and mask connector can take many forms. Each mask connector or connector structure shown and illustrated herein may include gripping features and sufficient strain relief features to improve the flexibility of the connector or connector.

[0224] pipe configuration

[0225] refer to Figure 41 The inlet catheter 10 and / or patient catheter 4 may include inner tubes 4a, 10a, spiral ribs 4b, 10b, and outer tubes 4f, 10f. The outer tubes 4f, 10f may be formed of the same material as the inner tubes 4a, 10a. The outer tubes 4f, 10f may also be provided with fleece or flocked material to improve catheter feel and / or grip, and / or enhance thermal insulation and / or visual appeal. If the outer tubes 4f, 10f are not provided, the outer surfaces of the inner tubes 4a, 10a and spiral ribs 4b, 10b may be provided with wool or cotton fleece material for the same reasons.

[0226] refer to Figure 42 The inner catheter 10 and / or the patient catheter 4 may include inner tubes 4a, 10a and outer tubes 4f, 10f separated by pleats 4g, 10g. The pleats 4g, 10g may extend axially along the catheters 4, 10, or may extend spirally along the catheters 4, 10. Electrical wires may be disposed within the pleats 4g, 10g between the inner tubes 4a, 10a and the outer tubes 4f, 10f. The pleats may also be used to provide auxiliary airflow or liquid flow (e.g., water) along the catheters 4, 10 to regulate the temperature of the airflow within the catheters 4, 10. The pleats may also be used to vent gas from the patient interface, such as exhaled air from the patient. The outer tubes 4f, 10f may also be covered with wool or cotton material.

[0227] Patient catheters, mask connectors and flexible circuits

[0228] refer to Figure 43The illustration shows a patient catheter 400, a mask connector 560, and a flexible circuit 570 according to another exemplary embodiment. The patient catheter 400 is connected to the mask connector 560 via a secondary molding material 580 surrounding the flexible circuit 570. The secondary molding material 580 is secondary molded on the patient catheter 400 and the mask connector 560. The flexible circuit 570 may include conduit wires, sensors, fuses, and other components described in the above exemplary embodiments.

[0229] The mask connector 560 can be formed as a separate component, which is connected to the patient catheter 400 via a secondary molding material 580. Alternatively, the mask connector 560 can be formed as an integral component with the secondary molding material 580.

[0230] While the most practical and preferred embodiments have been shown and described herein, it should be acknowledged that deviations can be made within the scope of the invention, which is not limited to the details described herein but includes any and all equivalent components, devices, and apparatuses. For example, the heating wire may be a PTC element with voltage regulation to limit the temperature of the wire and / or air in the conduit. As another example, one or more PTC or NTC wires may be used in conjunction with a resistor to limit the temperature of the wire and air. As a further example, an NTC wire may be used in conjunction with a current regulator or a measuring resistor to limit the temperature of the heating wire. Temperature sensing and heating can also be performed using only two wires.

[0231] In this specification, the word "comprise" should be understood as "open," meaning "containing," and therefore not limited to its "closed" meaning, which is "composed of." The corresponding words "comprise," "comprised," and "comprises" have their respective meanings in their respective contexts.

[0232] It should be further understood that any reference to known prior art herein should not constitute an admission that such prior art is commonly known to those skilled in the art to which this invention relates, unless indicated to the contrary.

Claims

1. A heating conduit configured to be connected to and receive pressurized breathable gas therefrom a breathing unit, the heating conduit comprising: A first connector, configured to be attached to the breathing unit, includes a tubular air inlet connector portion configured to receive the pressurized breathable gas and an electrical connector portion adjacent to the tubular air inlet connector portion and including three electrical terminals configured to engage the breathing unit. The second connector includes a tubular air outlet configured to allow the pressurized breathable gas to flow to the patient interface. The flexible tube portion between the first connector and the second connector includes a central lumen and helical ribs wound around the central lumen, the central lumen forming a continuous airflow path with the tubular air inlet connector portion of the first connector and the tubular air outlet of the second connector. A sensing device, located within the second connector, is configured to output a signal indicating the temperature within the heating conduit; and A set of wires supported within the spiral ribs of the flexible tube portion, the set of wires including a pair of heating wires configured to generate heat and a signal wire configured to carry a signal output by the sensing device, each of the heating wires and the signal wire being connected to a corresponding one of the three electrical terminals of the electrical connector portion of the first connector.

2. The heating conduit according to claim 1, wherein, The three electrical terminals are positioned in a row, with one of the electrical terminals positioned between the other two electrical terminals.

3. The heating conduit according to claim 1, wherein, The first connector includes a finger gripper.

4. The heating conduit according to claim 1, wherein, The first connector and the second connector are formed onto the opposite ends of the flexible tube portion.

5. The heating conduit according to claim 1, wherein, The sensing device is a thermistor.

6. The heating conduit according to claim 5, wherein, The pair of heating wires are connected to one end of the thermistor, and the signal line is connected to the other end of the thermistor.

7. The heating conduit according to claim 1, wherein, The pair of heating wires and the signal wire extend to the second connector.

8. A breathing device configured to generate and deliver pressurized breathable gas to a patient's airway, the breathing device comprising: A breathing unit, which is configured to pressurize breathable gas; According to claim 1, the first connector of the heating conduit is configured to be connected to the air outlet of the breathing unit; and A printed circuit board (PCB) having control circuitry configured to control the heating conduit.

9. The breathing apparatus according to claim 8, wherein, The breathing unit is a fluid generator or a combination of a fluid generator and a humidifier.

10. The breathing apparatus of claim 8, further comprising a thermal fuse configured to terminate the current supply to the pair of heating wires when the temperature in the flexible tube portion exceeds a threshold temperature.

11. The breathing apparatus of claim 8, further comprising a patient interface having an air inlet configured to receive a pressurized flow of breathable gas from the heating conduit, the patient interface being configured to hermetically engage with a patient's face.

12. The breathing apparatus according to claim 11, wherein, The air inlet of the patient interface is a bend.

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