Moisture detection and management in gas distribution systems

Abstract

Moisture conditions in conduits, particularly gas delivery system conduits for delivering respiratory or surgical gases, can be detected using electrical characteristics of the conduit. Moisture conditions can also be detected in other components of the gas delivery system. The detected moisture conditions can be managed to reduce and / or remove excess moisture in the system.

Description

[Technical Field]

[0001] The present disclosure relates to detecting moisture in conduits. More particularly, the present disclosure describes a respiratory or surgical gas delivery system capable of detecting the presence, amount, and / or location of one or more of condensed water, humidity, and / or bodily fluids. [Background technology]

[0002] Respiratory support devices and surgical inhalers provide a flow of gas or pressurized gas to a patient through a conduit system. In a range of applications using these and similar devices, it is beneficial to humidify the delivered gas. These applications include when gas is insufflated and / or delivered to a patient's surgical site during surgery. A drawback of providing humidified gas through a conduit is the potential for condensed water to form within the conduit. In addition to condensed water, other types of moisture may be introduced into the conduit from the patient, any heat and moisture exchanger (HME), any inhaler, and / or the environment (e.g., via a room intake ventilation system or through a conduit wall that is permeable to liquid or water vapor). Moisture may include bodily fluids such as saliva, blood, mucus, etc. While water may be mentioned as an example in this application, it will be understood that water may be replaced with moisture more generally or other liquids. Summary of the Invention [Problem to be solved by the invention]

[0003] Humidified gas may cool as it passes through the conduit system between the gas source and the gas destination. As a result, moisture (or liquid), such as condensed water, may form in the conduit as the gas cools. In addition to condensed water, moisture can refer to bodily fluids, such as water, saliva, blood, mucus, or the presence of liquid in the conduit. Moisture formation is typically undesirable in respiratory support devices and surgical insufflators. For example, condensed water in the conduit can result in a condition known as "rainout." Rainout occurs when moisture forms and can run down the walls of the conduit system. Moisture may collect at the bottom of the conduit system, or it may escape the conduit system and flow into the patient's respiratory system, body, back to the gas source, back to the ventilator, or into other devices connected to the conduit of the respiratory support device or surgical insufflator. All of these rainout effects are undesirable and can cause numerous complications. Similarly, fluids from other sources (including the patient, other equipment, and / or the environment) may be undesirable and / or should be monitored for other reasons. [Means for solving the problem]

[0004] As used herein, the phrase "conduit system" encompasses any conduits (also referred to herein as tubing), connectors, or patient interfaces that carry gas between a gas source and a patient and / or carry exhaled gas from a patient to another component of a respiratory assistance device or surgical insufflator. For example, as described in further detail below, the conduit system can include one or more of an inspiratory tube, a dry line, a gas delivery tube, an exhalation tube, a gas insufflation tube, a connector, a Y-piece, a patient tube, and / or a patient interface (including a mask, nasal cannula, nasal pillows, an endotracheal tube, a tracheostomy tube, a surgical cannula, etc.). Furthermore, moisture, condensate, condensed water, and liquid are generally used synonymously in this disclosure, as can be understood by those skilled in the art from the contextual usage of these terms herein. Those skilled in the art should understand that the term dry line does not necessarily carry dry gas (e.g., when an air-intake ventilator or air-intake blower system is used, or in the case of backflow through the system, etc.).

[0005] Respiratory assistance devices and surgical inhalers (collectively referred to herein as gas delivery systems) may utilize one or more heating wires within the conduit system, e.g., within the walls of some or all components of the conduit system, to provide a heat source. The heating wire or wires allow the conduits to control the temperature and / or relative humidity of the gas to a desired value or range as the gas passes through the conduit system, reducing the likelihood of condensation. One or more sensor wires may also be included within the lumen of the conduit system or within the walls of the conduit system. The sensor wire or wires are typically used to carry temperature measurement information from one or more temperature sensors to the humidified gas flowing through the conduits and / or patient interface and back to a controller for the gas delivery system. The gas delivery system may use the temperature measurement information in a feedback control system to adjust the amount of heat provided by one or more heating wires or other components of the gas delivery system.

[0006] Even with a heated wire, condensation and rainout still occur, and fluids from other sources may still be introduced into the circuit system. The present disclosure provides for detecting moisture in a circuit system. Moisture can be detected by measuring or estimating the capacitance, inductive resistance, and / or electrical resistance, or changes in capacitance, inductive resistance, and / or electrical resistance, of two or more spaced conductors embedded within the conduit system or in the walls of the conduit system. These conductors can be one or more conductive wires, such as one or more heated wires and / or one or more sensor wires. Alternatively or additionally, dedicated conductors may be provided or embedded within the conduit system, including the lumen of the conduit or its walls. The capacitance can be intrinsic / parasitic capacitance. Measurements can use the time response and / or frequency response of the wire. Moisture can also be detected by measuring changes in resistance as disclosed herein and / or changes to a wireless signal, such as an RF signal.

[0007] The present disclosure provides a humidification system that can be used in a gas supply system, the humidification system including a humidifier, a conduit, the conduit including a first conductive element and a second conductive element, and a controller configured to monitor a signal using one or more of the first conductive element and the second conductive element to determine a value indicative of moisture in the conduit based at least in part on the signal.

[0008] In some configurations, the signal may be indicative of a capacitance between the first conductive element and the second conductive element.

[0009] In some configurations, the signal may be indicative of a change in capacitance between the first conductive element and the second conductive element.

[0010] In some configurations, the controller may include a signal generator.

[0011] In some configurations, the controller may include one or more hardware and / or software processors.

[0012] In some configurations, the first conductive element and the second conductive element can be separated by a distance configured to allow sensing of a capacitive charge between the first conductive element and the second conductive element.

[0013] In some configurations, the humidification system may also include a dielectric material disposed between the first conductive element and the second conductive element.

[0014] In some configurations, the dielectric material may be water vapor permeable or liquid permeable.

[0015] In some configurations, the water vapor permeable dielectric material can allow evaporation of water into the ambient air while inhibiting the passage of liquid water and breathing gases into the ambient air.

[0016] In some configurations, the controller may be configured to determine a value indicative of moisture in a comparison of the measurements of the first conductive element and / or the second conductive element.

[0017] In some configurations, the value indicative of moisture may include a time constant of a circuit including the first conductive element or the second conductive element connected in series with a reference resistor.

[0018] In some configurations, the signal may be indicative of a time constant or a resonant frequency of a circuit including the first conductive element and / or the second conductive element.

[0019] In some configurations, the signal may indicate a change in a time constant or a change in a resonant frequency of a circuit including the first conductive element and / or the second conductive element.

[0020] In some configurations, the inductive value of the moisture in the conduit may correspond to the inductance of the conduit.

[0021] In some configurations, the inductive value of the moisture in the conduit may correspond to a change in the inductance of the conduit.

[0022] In some configurations, the humidification system may also include a resonant circuit in which an inductor is placed in parallel with a capacitor.

[0023] In some configurations, the resonant circuit can be electrically connected in parallel with the first conductive element, the second conductive element, or both the first conductive element and the second conductive element.

[0024] In some configurations, the resonant circuit can be tuned to exhibit resonant behavior when sufficiently excited by a signal.

[0025] In some configurations, the resonant circuit can be tuned to exhibit resonant behavior when excited by a signal, the signal being selected to excite the resonant circuit.

[0026] In some configurations, the controller can be configured to apply additional power to the first conductive element in combination with the normal control power.

[0027] In some configurations, the humidification system may also include an AC power source.

[0028] In some configurations, the humidification system may also include a DC power supply.

[0029] In some configurations, the signal may be indicative of the temperature of the first conductive element or the second conductive element.

[0030] In some configurations, the signal may indicate a change in temperature of the first conductive element or the second conductive element.

[0031] In some configurations, the signal can be indicative of the thermal conductivity of a medium between the first conductive element and the second conductive element, or the signal can be indicative of the thermal conductivity of a medium proximate the first conductive element or the second conductive element.

[0032] In some configurations, the signal may be indicative of a change in thermal conductivity of a medium between the first conductive element and the second conductive element, or the signal may be indicative of a change in thermal conductivity of a medium proximate to the first conductive element or the second conductive element.

[0033] In some configurations, the change in temperature of the first conductive element or the second conductive element may be substantially linear.

[0034] In some configurations, the signal may be indicative of a temperature difference between the first conductive element and the second conductive element.

[0035] In some configurations, the second conductive element is capable of measuring a signal.

[0036] In some configurations, the signal may correspond to a resistance of the second conductive element, the resistance of the second conductive element varying with the temperature of the second conductive element.

[0037] In some configurations, the first conductive element or the second conductive element may further include a thermistor.

[0038] In some configurations, the first conductive element or the second conductive element may further include a diode.

[0039] In some configurations, the diode may be electrically connected in parallel with the thermistor.

[0040] In some configurations, the diode may be electrically connected in parallel with the thermistor and positioned substantially adjacent to the thermistor.

[0041] In some configurations, the first conductive element and the second conductive element may be adjacent to one another.

[0042] In some configurations, the first conductive element and the second conductive element may not be adjacent to one another.

[0043] In some configurations, the first conductive element and the second conductive element can be within a bead of the conduit.

[0044] In some configurations, the first conductive element is capable of measuring a signal.

[0045] In some configurations, the signal may be indicative of the resistance of the first conductive element or the second conductive element.

[0046] In some configurations, the signal may be indicative of the resistance of the medium between the first conductive element and the second conductive element.

[0047] In some configurations, the first conductive element or the second conductive element can include at least two portions that are electrically isolated from one another.

[0048] In some configurations, the first conductive element and the second conductive element can be electrically isolated from the other conductive element for a portion of the length of the first conductive element and a portion of the length of the second conductive element.

[0049] In some configurations, the at least two portions can protrude into the lumen of the conduit. The at least two portions can be flush with the inner wall of the conduit.

[0050] In some configurations, the at least two portions can be disposed within the tube wall and pneumatically coupled to the lumen of the conduit.

[0051] In some configurations, at least two portions that can be electrically decoupled from one another can be in series with one another.

[0052] In some configurations, at least two portions that can be electrically decoupled from one another can be in parallel with one another.

[0053] In some configurations, the controller may determine a value indicative of moisture in the conduit based at least in part on the magnitude and / or phase of the signal.

[0054] In some configurations, the humidification system may also include a signal generator.

[0055] In some configurations, the signal can have a frequency between 30 Hz and 300 GHz.

[0056] In some configurations, the signal may have a frequency between 1 MHz and 100 MHz.

[0057] In some configurations, the signal may have a frequency of about 10 MHz.

[0058] In some configurations, the first conductive element and / or the second conductive element may be a quarter wavelength of the signal.

[0059] In some configurations, the wavelength of the signal may be four times longer than the length of the first conductive element and / or the second conductive element.

[0060] In some configurations, the signal generator can inject a signal into the first conductive element.

[0061] In some configurations, the first conductive element can be configured to be a transmitter.

[0062] In some configurations, the second conductive element can be configured to be a receiver that receives a signal transmitted by the first conductive element.

[0063] In some configurations, the magnitude and / or phase of the signal can be measured by a radio frequency converter.

[0064] In some configurations, the radio frequency converter can be an AM receiver, an RF sampling ADC, or an RF rectifier.

[0065] In some configurations, the humidification system may also include a filter to filter the signal.

[0066] In some configurations, the filter may include a high-pass or band-pass filter.

[0067] In some configurations, the filter may be configured to filter out mains frequencies.

[0068] In some configurations, the filter may be configured to filter out frequencies between 50 and 60 Hz.

[0069] In some configurations, the transmitter may include a loop antenna.

[0070] In some configurations, the receiver may include a loop antenna.

[0071] In some configurations, the transmitter may include a monopole antenna.

[0072] In some configurations, the transmitter may include a monopole antenna.

[0073] In some configurations, the first conductive element can be electrically connected to a first switch.

[0074] In some configurations, the second conductive element can be electrically connected to a second switch.

[0075] In some configurations, the first switch can be configured to electrically disconnect one end of the first conductive element.

[0076] In some configurations, the second switch can be configured to electrically disconnect one end of the second conductive element.

[0077] In some configurations, the first switch and / or the second switch may be located in any one of the heater base, the sensor cartridge, the conduit, the external component, or the intermediate connector.

[0078] In some configurations, the controller may be configured to output an alarm if the value indicative of moisture is below a first threshold.

[0079] In some configurations, the controller may be configured to output an alarm if the value indicative of condensation exceeds a second threshold.

[0080] In some configurations, the alarm indicates an unacceptable level of moisture.

[0081] In some configurations, the controller may be configured to automatically reduce humidification of the respiratory or inhaled gas in response to a value indicative of moisture and / or humidity within the conduit.

[0082] In some configurations, a reduction in humidity delivered to the patient can be achieved by reducing heater plate power.

[0083] In some configurations, the conduit may be a composite conduit.

[0084] In some configurations, the conduit may include water vapor and / or liquid permeable beads.

[0085] In some configurations, the permeable beads allow evaporation of water into the ambient air while inhibiting the passage of liquid water and breathing gases into the ambient air.

[0086] In some configurations, the permeable beads can be one or more of an activated perfluoropolymer material with superhydrophilic properties, a hydrophilic thermoplastic resin, a breathable thermoplastic copolyester, a woven treated fabric exhibiting breathable properties, or a hydrophilic polyester block copolymer.

[0087] In some configurations, the first conductive element and the second conductive element may be spirally wound around at least the length of the conduit.

[0088] In some configurations, the first and second conductive elements may be spirally wound within, through, or around the conduit.

[0089] In some configurations, the first conductive element and the second conductive element may form part of the conduit wall.

[0090] In some configurations, the first conductive element can be a sensing wire.

[0091] In some configurations, the first conductive element can be a heater wire.

[0092] In some configurations, the second conductive element can be a sensing wire.

[0093] In some configurations, the second conductive element can be a heater wire.

[0094] The present disclosure provides a method for detecting an indication of moisture in a conduit of a gas delivery system used to deliver respiratory or surgical gases, the method including determining the presence and / or level of moisture based at least in part on a characteristic of the conduit.

[0095] In some configurations, the determination of the presence or level of moisture can be inferred from the dielectric properties of the conduit.

[0096] In some configurations, determining the characteristic may include applying a signal to a first conductive element within the conduit.

[0097] In some configurations, determining the characteristic may include measuring a capacitance between the first conductive element and the second conductive element.

[0098] In some configurations, determining the characteristic may include measuring a capacitance between the first conductive element and the second conductive element based on the applied signal.

[0099] In some configurations, determining the characteristic includes measuring an indication of a time constant or resonant frequency of a circuit including the first conductive element.

[0100] In some configurations, determining the characteristic may include processing a value indicative of the inductance.

[0101] In some configurations, determining the characteristic may further include measuring an indication of the resistance of the first conductive element.

[0102] In some configurations, determining the characteristic may further include measuring an indication of temperature.

[0103] In some configurations, determining the property can further include measuring an indication of thermal conductivity.

[0104] In some configurations, determining the characteristic may further include measuring the magnitude and / or phase of the signal.

[0105] In some configurations, the conduit can be any of the conduit embodiments disclosed herein.

[0106] In some configurations, the method uses a humidification system of any of the humidification systems disclosed herein.

[0107] The present disclosure provides a method for detecting moisture in a conduit utilized to transport humidified gas, the method including providing two conductive elements separated by a dielectric and placed in, around or on the conduit, and measuring capacitance or a change in capacitance to indicate a measurement of moisture or condensation in the conduit.

[0108] The present disclosure provides a method for detecting moisture in a conduit utilized to transport humidified gas, the method including providing two conductive elements placed in, around or on the conduit and measuring resistance or a change in resistance to indicate a measurement of moisture or condensation in the conduit.

[0109] In some configurations, the method uses a conduit according to any of the conduit embodiments disclosed herein.

[0110] In some configurations, the method uses a humidification system of any of the humidification systems disclosed herein.

[0111] The present disclosure provides a method for detecting moisture in a conduit utilized to transport humidified gas, the method including providing two conductive elements placed in, around or on the conduit and measuring a time constant, a resonant frequency, a change in the time constant, or a change in the resonant frequency to indicate a measurement of moisture or condensation in the conduit.

[0112] In some configurations, the method uses a conduit according to any of the conduit embodiments disclosed herein.

[0113] In some configurations, the method uses a humidification system of any of the humidification systems disclosed herein.

[0114] The present disclosure provides a method for detecting moisture in a conduit utilized to transport humidified gas, the method comprising providing two conductive elements placed in, around or on the conduit and measuring resistance or a change in resistance to indicate a measurement of moisture or condensation in the conduit.

[0115] In some configurations, the method uses a conduit according to any of the conduit embodiments disclosed herein.

[0116] In some configurations, the method uses a humidification system of any of the humidification systems disclosed herein.

[0117] The present disclosure provides a method for detecting moisture in a conduit utilized to transport humidified gas, the method including providing two conductive elements placed in, around or on the conduit, and measuring the temperature or change in temperature to indicate a measurement of moisture or condensation in the conduit.

[0118] In some configurations, the method uses a conduit according to any of the conduit embodiments disclosed herein.

[0119] In some configurations, the method uses a humidification system of any of the humidification systems disclosed herein.

[0120] The present disclosure provides a method for detecting moisture in a conduit utilized to transport humidified gas, the method including providing two conductive elements placed in, around or on the conduit and measuring the thermal conductivity or change in thermal conductivity to indicate a measurement of moisture or condensation in the conduit.

[0121] In some configurations, the method uses a conduit according to any of the conduit embodiments disclosed herein.

[0122] In some configurations, the method uses a humidification system of any of the humidification systems disclosed herein.

[0123] The present disclosure provides a method for detecting moisture in a conduit utilized to transport humidified gas, the method including providing two conductive elements placed in, around or on the conduit, and measuring the magnitude and / or phase of a signal, or a change in the magnitude and / or phase of the signal, to indicate a measurement of moisture or condensation in the conduit.

[0124] In some configurations, the method uses a conduit according to any of the conduit embodiments disclosed herein.

[0125] In some configurations, the method uses a humidification system of any of the humidification systems disclosed herein.

[0126] The present disclosure provides an external accessory, an example of which is a cartridge for use with a humidifier in a respiratory or surgical humidification system.

[0127] The present disclosure provides a cartridge for use with a humidifier in a respiratory or surgical humidification system, the cartridge including one or more sensors for sensing characteristics of gas flow in a removable humidification chamber of the humidifier, a first electrical connector configured to electrically connect with a corresponding electrical connector on the humidifier, a second electrical connector configured to electrically connect with a corresponding electrical connector on an inspiratory conduit removably engageable with the cartridge, the second electrical connector may include at least a first electrical terminal or pad and a second electrical terminal or pad configured to electrically connect with first and second conductive elements extending along at least a portion of the length of the inspiratory conduit, and a control device communicatively connected to the one or more sensors and the first conductive element and second electrical connector.

[0128] In some configurations, the cartridge may be removably attachable to the humidifier, and the controller may be configured to measure, in use, a signal indicative of a capacitance between the first conductive element and the second conductive element of the removable inspiratory conduit.

[0129] The present disclosure provides a cartridge for use with a humidifier in a respiratory or surgical humidification system, the cartridge including one or more sensors for sensing characteristics of gas flow in a removable humidification chamber of the humidifier, a first electrical connector configured to electrically connect with a corresponding electrical connector of the humidifier, a second electrical connector configured to electrically connect with a corresponding electrical connector of an inspiratory conduit removably engageable with the cartridge, the second electrical connector may include at least a first electrical terminal or pad and a second electrical terminal or pad configured to electrically couple with a first conductive element and a second conductive element extending along at least a portion of the length of the inspiratory conduit, and a control device communicatively connected to the one or more sensors and the first conductive element and second electrical connector.

[0130] In some configurations, the cartridge may be removably attachable to the humidifier, and the controller may be configured to measure, in use, a signal indicative of a time constant or resonant frequency of a circuit including the first conductive element and the second conductive element of the removable inspiratory conduit.

[0131] The present disclosure provides a cartridge for use with a humidifier in a respiratory or surgical humidification system, the cartridge including one or more sensors for sensing characteristics of gas flow in a removable humidification chamber of the humidifier, a first electrical connector configured to electrically connect with a corresponding electrical connector on the humidifier, a second electrical connector configured to electrically connect with a corresponding electrical connector on an inspiratory conduit removably engageable with the cartridge, the second electrical connector may include at least a first electrical terminal or pad and a second electrical terminal or pad configured to electrically connect with first and second conductive elements extending along at least a portion of the length of the inspiratory conduit, and a control device communicatively connected to the one or more sensors and the first conductive element and second electrical connector.

[0132] In some configurations, the cartridge may be removably attachable to the humidifier, and the controller may be configured to measure, in use, a signal indicative of the resistance of the first conductive element or the second conductive element of the removable inspiratory conduit.

[0133] The present disclosure provides a cartridge for use with a humidifier in a respiratory or surgical humidification system, the cartridge including one or more sensors for sensing characteristics of gas flow in a removable humidification chamber of the humidifier, a first electrical connector configured to electrically connect with a corresponding electrical connector on the humidifier, a second electrical connector configured to electrically connect with a corresponding electrical connector on an inspiratory conduit removably engageable with the cartridge, the second electrical connector may include at least a first electrical terminal or pad and a second electrical terminal or pad configured to electrically connect with first and second conductive elements extending along at least a portion of the length of the inspiratory conduit, and a control device communicatively connected to the one or more sensors and the first conductive element and second electrical connector.

[0134] In some configurations, the cartridge may be removably attachable to the humidifier, and the controller may be configured to measure a signal indicative of the temperature of the first conductive element or the second conductive element of the removable inspiratory conduit during use.

[0135] The present disclosure provides a cartridge for use with a humidifier in a respiratory or surgical humidification system, the cartridge including one or more sensors for sensing characteristics of gas flow in a removable humidification chamber of the humidifier, a first electrical connector configured to electrically connect with a corresponding electrical connector of the humidifier, a second electrical connector configured to electrically connect with a corresponding electrical connector of an inspiratory conduit removably engageable with the cartridge, the second electrical connector may include at least a first electrical terminal or pad and a second electrical terminal or pad configured to electrically couple with a first conductive element and a second conductive element extending along at least a portion of the length of the inspiratory conduit, and a control device communicatively connected to the one or more sensors and the first conductive element and second electrical connector.

[0136] In some configurations, the cartridge may be removably attachable to the humidifier, and the controller may be configured to measure, in use, a signal indicative of the thermal conductivity of a medium between the first conductive element and the second conductive element of the removable inlet conduit.

[0137] The present disclosure provides a cartridge for use with a humidifier in a respiratory or surgical humidification system, the cartridge including one or more sensors for sensing characteristics of gas flow in a removable humidification chamber of the humidifier, a first electrical connector configured to electrically connect with a corresponding electrical connector on the humidifier, a second electrical connector configured to electrically connect with a corresponding electrical connector on an inspiratory conduit removably engageable with the cartridge, the second electrical connector may include at least a first electrical terminal or pad and a second electrical terminal or pad configured to electrically connect with first and second conductive elements extending along at least a portion of the length of the inspiratory conduit, and a control device communicatively connected to the one or more sensors and the first conductive element and second electrical connector.

[0138] In some configurations, the cartridge may be removably attachable to the humidifier, and the controller may be configured to measure, in use, the magnitude and / or phase of a signal, or a change in the magnitude and / or phase of the signal, between the first and second conductive elements of the removable inspiratory conduit.

[0139] The present disclosure provides a humidifier usable in a gas supply system, the humidifier including: a humidification chamber configured to humidify a gas supply; an inlet conduit connector configured to couple to an inlet conduit including a first conductive element and a second conductive element; and a controller configured to monitor a signal using one or more of the first conductive element and the second conductive element to determine a value indicative of moisture in the conduit based at least in part on the signal.

[0140] In some configurations, the controller may be further configured to monitor the signal.

[0141] In some configurations, the signal may be indicative of a capacitance between the first conductive element and the second conductive element.

[0142] In some configurations, the signal may be indicative of a change in capacitance between the first conductive element and the second conductive element.

[0143] In some configurations, the signal may be indicative of a time constant or a resonant frequency of the first conductive element or the second conductive element.

[0144] In some configurations, the signal may be indicative of the temperature of the first conductive element or the second conductive element.

[0145] In some configurations, the signal may indicate a change in temperature of the first conductive element or the second conductive element.

[0146] In some configurations, the signal may be indicative of the thermal conductivity of a medium between the first conductive element or the second conductive element, or the signal or signals are indicative of the thermal conductivity of a medium proximate to the first conductive element or the second conductive element.

[0147] In some configurations, the signal may be indicative of a change in thermal conductivity of a medium between the first conductive element or the second conductive element, or the signal or signals are indicative of a change in thermal conductivity of a medium proximate to the first conductive element or the second conductive element.

[0148] In some configurations, the signal may be indicative of a temperature difference between the first conductive element and the second conductive element.

[0149] In some configurations, the value indicative of moisture may be the magnitude and / or phase of the signal, or a change in the magnitude and / or phase of the signal.

[0150] In some configurations, the controller may include a signal generator.

[0151] In some configurations, the controller may include one or more hardware and / or software processors.

[0152] In some configurations, the humidifier may further include a conduit according to any of the conduit embodiments disclosed herein.

[0153] The present disclosure provides a conduit for use with a respiratory or surgical gas delivery system, the conduit including a first conductive element, a second conductive element spaced apart from the first conductive element by a distance configured to allow a capacitive effect to exist between the first and second conductive elements such that the capacitive effect alters the presence of moisture, and a material separating the first conductive element from the second conductive element.

[0154] In some configurations, at least one of the conductive elements can be one or more of a heater wire or a sensor wire.

[0155] In some configurations, the conduit may further include a controller configured to determine a presence and / or indication of moisture in the conduit by determining a capacitance or a change in capacitance between the first conductive element and the second conductive element.

[0156] In some configurations, the controller may be one or more microprocessors.

[0157] In some configurations, the controller can use the first conductive element and the second conductive element to determine the presence or indication of moisture in the conduit by measuring the capacitive reactance and / or inductance present between the first conductive element and the second conductive element.

[0158] In some configurations, the first conductive element and the second conductive element can be placed close enough to measure capacitance, but far enough apart to measure a change in capacitance due to the presence of moisture.

[0159] The present disclosure provides a conduit for use with a respiratory or surgical gas delivery system, the conduit including a first conductive element and a second conductive element, one or more of the first conductive element and the second conductive element can be configured to provide a time constant or resonant frequency measurement indicative of the presence or amount of moisture within the conduit.

[0160] In some configurations, the conduit may further include a resonant circuit, wherein the inductive element is electrically connected in parallel with the capacitive element.

[0161] In some configurations, one or more of the first conductive element and the second conductive element can be configured to electrically connect in parallel with the resonant circuit, and the inductive element is electrically connected in parallel with the capacitive element.

[0162] In some configurations, the resonant circuit may be external to the conduit.

[0163] In some configurations, the resonant circuit can be tuned to exhibit resonant behavior when excited by a signal.

[0164] In some configurations, one or more of the first conductive element and the second conductive element can be configured to electrically connect in parallel with the signal generator.

[0165] In some configurations, the conduit may include a controller configured to determine the presence and / or indication of moisture in the conduit by determining a time constant, a resonant frequency, a change in the time constant, or a change in the resonant frequency.

[0166] In some configurations, one or more of the first conductive element and the second conductive element can be configured to electrically connect in parallel with the controller.

[0167] In some configurations, the controller may include a signal generator.

[0168] In some configurations, the controller may be one or more microprocessors.

[0169] The present disclosure provides a conduit for use with a respiratory or surgical gas delivery system, the conduit including a first conductive element and a second conductive element, one or more of the first conductive element and the second conductive element configured to provide a measurement of a resistive characteristic indicative of the presence or amount of moisture within the conduit.

[0170] In some configurations, the first conductive element or the second conductive element can include at least two portions that are electrically isolated from one another.

[0171] In some configurations, at least two portions can protrude into the lumen of the conduit.

[0172] In some configurations, at least two portions may be flush with the inner wall of the conduit.

[0173] In some configurations, the at least two portions can be disposed within the tube wall and can be pneumatically coupled to the lumen of the conduit.

[0174] In some configurations, at least two portions that can be electrically decoupled from one another can be in series with one another.

[0175] In some configurations, at least two portions that can be electrically decoupled from one another can be in parallel with one another.

[0176] In some configurations, the conduit may further include a controller configured to determine the presence and / or indication of moisture in the conduit by determining resistance or a change in resistance.

[0177] In some configurations, the controller may be one or more microprocessors.

[0178] The present disclosure provides a conduit for use with a respiratory or surgical gas delivery system, the conduit including a first conductive element and a second conductive element, one or more of the first conductive element and the second conductive element configured to provide a measurement of temperature or heat transfer properties indicative of the presence or amount of moisture within the conduit.

[0179] In some configurations, the first conductive element or the second conductive element may further include a thermistor.

[0180] In some configurations, the first conductive element or the second conductive element may further include a diode.

[0181] In some configurations, the diode may be electrically connected in parallel with the thermistor.

[0182] In some configurations, the diode may be electrically connected in parallel with the thermistor and positioned substantially adjacent to the thermistor.

[0183] In some configurations, the first conductive element and the second conductive element can be adjacent to one another.

[0184] In some configurations, the first conductive element and the second conductive element may not be adjacent to one another.

[0185] In some configurations, the first conductive element and the second conductive element can be within a bead of the conduit.

[0186] In some configurations, the conduit may further include a controller configured to determine the presence of and / or an indication of moisture in the conduit by determining a temperature, a thermal conductivity, a change in temperature, or a change in thermal conductivity of the first conductive element or the second conductive element.

[0187] In some configurations, the controller can be configured to apply additional power to the first conductive element in conjunction with the rated control power.

[0188] In some configurations, the controller may be one or more microprocessors.

[0189] The present disclosure provides a conduit for use with a respiratory or surgical gas delivery system, the conduit including a first conductive element and a second conductive element, one or more of the first conductive element and the second conductive element configured to measure a magnitude and / or phase of a signal, or a change in magnitude and / or phase of a signal, indicative of the presence or amount of moisture in the conduit.

[0190] In some configurations, the first conductive element can be configured to be a transmitter.

[0191] In some configurations, the second conductive element can be configured to be a receiver for receiving a signal transmitted by the first conductive element.

[0192] In some configurations, the transmitter may include a loop antenna.

[0193] In some configurations, the receiver may include a loop antenna.

[0194] In some configurations, the transmitter may include a monopole antenna.

[0195] In some configurations, the receiver may include a monopole antenna.

[0196] In some configurations, the first conductive element can be electrically connected to a first switch.

[0197] In some configurations, the second conductive element can be electrically connected to a second switch.

[0198] In some configurations, the first switch can be configured to electrically decouple one end of the first conductive element, and the second switch can be configured to electrically decouple one end of the second conductive element.

[0199] In some configurations, the conduit may further include a controller configured to determine the presence and / or indication of moisture in the conduit by determining a magnitude and / or phase of a signal, or a change in magnitude and / or phase of a signal, in the first conductive element or the second conductive element.

[0200] In some configurations, the controller may be one or more microprocessors.

[0201] In some configurations, the material can be a fluid permeable material.

[0202] Throughout this disclosure, "liquid" and "fluid" are used interchangeably.

[0203] In some configurations, the first conductive element and the second conductive element can be elongated filaments.

[0204] In some configurations, the elongated filaments can be surrounded by an electrically insulating jacket.

[0205] In some configurations, the first conductive element and the second conductive element may be spirally wound around at least a portion of the length of the conduit.

[0206] In some configurations, the first conductive element and the second conductive element extend from one end of the conduit to the other end of the conduit.

[0207] In some configurations, the first conductive element and the second conductive element extend at least a portion of the length from one end of the conduit to the other end of the conduit.

[0208] In some configurations, the conduit may include and / or be in communication with a controller configured to determine the presence and / or indication of moisture in the conduit by determining a capacitance or a change in capacitance between the first conductive element and the second conductive element.

[0209] In some configurations, the conduit may be a composite conduit.

[0210] In some configurations, the first conductive element and the second conductive element form part of a wall of the conduit.

[0211] In some configurations, the first conductive element and the second conductive element may form part of a bead arranged within the composite conduit.

[0212] In some configurations, the first conductive element and the second conductive element can be arranged within the conduit such that the first conductive element and the second conductive element can move freely within the conduit.

[0213] In some configurations, the material can be a water vapor and / or liquid permeable material.

[0214] In some configurations, the material allows evaporation of water into the ambient air while inhibiting the passage of liquid water and breathing gases into the ambient air.

[0215] In some configurations, the material can be one or more of an activated perfluoropolymer material with superhydrophilic properties, a hydrophilic thermoplastic resin, a breathable thermoplastic copolyester, a woven treated fabric exhibiting breathable properties, or a hydrophilic polyester block copolymer.

[0216] In some configurations, the conduit may further include microstructures configured to use capillary action to move moisture.

[0217] In some configurations, the water vapor and / or liquid permeable material can be a dielectric material.

[0218] In some configurations, the conduit may include a microstructure configured to wick moisture across a portion of the first conductive element and / or the second conductive element.

[0219] In some configurations, the conduit may further include an opening configured to transport moisture by capillary action between the first conductive element and the second conductive element.

[0220] In some configurations, the conduit can include a wicking material configured to transport moisture between the first and second conductive elements.

[0221] In some configurations, the first conductive element and the second conductive element can be ribbon wires.

[0222] In some configurations, the first conductive element and the second conductive element can be contained within a transparent, non-transparent, or partially transparent and non-transparent bead.

[0223] In some configurations, the first and second conductive elements and the beads can be extruded.

[0224] In some configurations, the conduit may further include a conductive mesh.

[0225] In some configurations, the spacing between the first and second conductive elements can vary depending on the presence and / or amount of moisture present within the conduit.

[0226] In some configurations, the material can cause the first conductive element and the second conductive element to contact or separate based on the presence of moisture.

[0227] In some configurations, the material can include openings, keyways, depressions, channels, and / or gaps configured to admit moisture between the first conductive element and the second conductive element and affect a capacitive effect between the first conductive element and the second conductive element.

[0228] In some configurations, the first conductive element and the second conductive element may be sensitive to contact with the conduit.

[0229] In some configurations, the material may include an accordion shape that expands or contracts in the presence of moisture, causing the first conductive element and the second conductive element to move further apart or closer together.

[0230] In some configurations, the material can cause the first conductive element and the second conductive element to contact or separate based on the presence of moisture.

[0231] The present disclosure provides a humidification system usable in a gas supply system, the humidification system including a humidifier, a conduit including a conductive element, and a controller configured to monitor the signal using the conductive element to determine a value indicative of moisture in the conduit based at least in part on the signal.

[0232] In some configurations, the signal may be indicative of a time constant or resonant frequency of the conductive element.

[0233] In some configurations, the signal may indicate a change in the time constant or a change in the resonant frequency of the conductive element.

[0234] In some configurations, the value may indicate moisture in the conduit, which corresponds to the inductance of the conduit.

[0235] In some configurations, the value indicative of moisture in the conduit may correspond to a change in inductance of the conduit.

[0236] In some configurations, the humidification system may further include a resonant circuit, wherein the inductive element is electrically connected in parallel with the capacitive element.

[0237] In some configurations, the resonant circuit can be electrically connected in parallel with the conductive element.

[0238] In some configurations, the humidification system may further include a signal generator.

[0239] In some configurations, the controller may include a signal generator.

[0240] In some configurations, the controller may include one or more hardware and / or software processors.

[0241] In some configurations, the resonant circuit can be tuned to exhibit resonant behavior when sufficiently excited by a signal.

[0242] In some configurations, the resonant circuit can be tuned to exhibit resonant behavior when excited by a signal, the signal being selected to excite the resonant circuit.

[0243] In some configurations, the controller can be configured to apply additional power to the conductive element in conjunction with the rated control power.

[0244] In some configurations, the humidification system may further include an AC power source.

[0245] In some configurations, the humidification system may further include a DC power supply.

[0246] In some configurations, the signal may be indicative of the temperature of the conductive element.

[0247] In some configurations, the signal may indicate a change in temperature of the conductive element.

[0248] In some configurations, the signal may be indicative of the thermal conductivity of a medium proximate to the conductive element.

[0249] In some configurations, the signal may indicate a change in the thermal conductivity of a medium proximate to the conductive element.

[0250] In some configurations, the change in temperature of the conductive element can be substantially linear.

[0251] In some configurations, the conductive element may further include a thermistor.

[0252] In some configurations, the conductive element may further include a diode.

[0253] In some configurations, the diode may be electrically connected in parallel with the thermistor.

[0254] In some configurations, the diode is electrically connected in parallel with the thermistor and may be positioned substantially adjacent to the thermistor.

[0255] In some configurations, the conductive element may be within a bead of the conduit.

[0256] In some configurations, the conductive element is capable of measuring a signal.

[0257] In some configurations, the controller may be configured to output an alarm if the value indicative of moisture is below a first threshold.

[0258] In some configurations, the controller may be configured to output an alarm if the value indicative of moisture exceeds a second threshold.

[0259] In some configurations, the alarm indicates an unacceptable level of moisture.

[0260] In some configurations, the alarm indicates an unacceptable level of moisture.

[0261] In some configurations, the controller may be configured to automatically reduce humidification of the breathing or insufflation gas in response to a value indicative of moisture and / or humidity within the conduit.

[0262] In some configurations, a reduction in the humidity delivered to the conduit can be achieved by reducing the heater plate power.

[0263] In some configurations, the conduit may be a composite conduit.

[0264] In some configurations, the conduit may include water vapor and / or liquid permeable beads.

[0265] In some configurations, the permeable beads allow evaporation of water into the ambient air while inhibiting the passage of liquid water and breathing gases into the ambient air.

[0266] In some configurations, the permeable beads can be one or more of an activated perfluoropolymer material with superhydrophilic properties, a hydrophilic thermoplastic resin, a breathable thermoplastic copolyester, a woven treated fabric exhibiting breathable properties, or a hydrophilic polyester block copolymer.

[0267] In some configurations, the conductive element may be spirally wrapped around at least the length of the conduit.

[0268] In some configurations, the conductive element may be spirally wound within, through, or around the conduit.

[0269] In some configurations, the conductive element may form part of the conduit wall.

[0270] In some configurations, the conductive element can be a sense wire. The conductive element can be a heater wire.

[0271] The present disclosure provides a method for detecting moisture in a conduit utilized to transport humidified gas, the method including providing a conductive element placed in, around or on the conduit and measuring a time constant, a resonant frequency, a change in the time constant, or a change in the resonant frequency to indicate a measurement of moisture or condensation in the conduit.

[0272] In some configurations, the method uses a conduit according to any of the conduit embodiments disclosed herein.

[0273] In some configurations, the method uses a humidification system of any of the humidification systems disclosed herein.

[0274] The present disclosure provides a method for detecting moisture in a conduit utilized to transport humidified gas, the method including providing a conductive element placed in, around or on the conduit and measuring the temperature or change in temperature to indicate a measurement of moisture or condensation in the conduit.

[0275] In some configurations, the method uses a conduit according to any of the conduit embodiments disclosed herein.

[0276] In some configurations, the method uses a humidification system of any of the humidification systems disclosed herein.

[0277] The present disclosure provides a method for detecting moisture in a conduit utilized to transport humidified gas, the method including providing a conductive element placed in, around or on the conduit and measuring thermal conductivity or a change in thermal conductivity to indicate a measurement of moisture or condensation within the conduit.

[0278] In some configurations, the method uses a conduit according to any of the conduit embodiments disclosed herein.

[0279] In some configurations, the method uses a humidification system of any of the humidification systems disclosed herein.

[0280] The present disclosure provides a cartridge for use with a humidifier in a respiratory or surgical humidification system, the cartridge including one or more sensors for sensing characteristics of gas flow in a removable humidification chamber of the humidifier, a first electrical connector configured to electrically connect with a corresponding electrical connector on the humidifier, a second electrical connector configured to electrically connect with a corresponding electrical connector on an inspiratory conduit removably engageable with the cartridge, the second electrical connector may include at least a first electrical terminal or pad configured to electrically connect with a conductive element extending along at least a portion of the length of the inspiratory conduit, and a control device communicatively connected to the one or more sensors and the first and second electrical connectors.

[0281] In some configurations, the cartridge may be removably attachable to the humidifier and the controller may be configured to measure, in use, a signal indicative of a time constant or resonant frequency of a circuit including the conductive elements of the removable breathing conduit.

[0282] The present disclosure provides a cartridge for use with a humidifier in a respiratory or surgical humidification system, the cartridge including one or more sensors for sensing characteristics of gas flow in a removable humidification chamber of the humidifier, a first electrical connector configured to electrically connect with a corresponding electrical connector on the humidifier, a second electrical connector configured to electrically connect with a corresponding electrical connector on an inspiratory conduit removably engageable with the cartridge, the second electrical connector may include at least a first electrical terminal or pad configured to electrically connect with a conductive element extending along at least a portion of the length of the inspiratory conduit, and a control device communicatively connected to the one or more sensors and the first and second electrical connectors.

[0283] In some configurations, the cartridge may be removably attachable to the humidifier and the controller may be configured to measure a signal indicative of the temperature of the conductive element of the removable breathing conduit in use.

[0284] The present disclosure provides a cartridge for use with a humidifier in a respiratory or surgical humidification system, the cartridge including one or more sensors for sensing characteristics of gas flow in a removable humidification chamber of the humidifier, a first electrical connector configured to electrically connect with a corresponding electrical connector of the humidifier, a second electrical connector configured to electrically connect with a corresponding electrical connector of an inspiratory conduit removably engageable with the cartridge, the second electrical connector may include at least a first electrical terminal or pad configured to electrically couple with a conductive element extending along at least a portion of the length of the inspiratory conduit, and a control device communicatively connected with the one or more sensors and the first and second electrical connectors.

[0285] In some configurations, the cartridge may be removably attachable to the humidifier, and the controller may be configured to measure, in use, a signal indicative of the thermal conductivity of a medium adjacent to the conductive element of the removable breathing conduit.

[0286] The present disclosure provides a humidifier usable in a gas supply system, the humidifier including a humidification chamber configured to humidify the gas supply, an inlet conduit connector configured to couple to an inlet conduit including a conductive element, and a controller configured to monitor the signal using the conductive element to determine a value indicative of moisture in the conduit based at least in part on the signal.

[0287] In some configurations, the signal may be indicative of a time constant or resonant frequency of the conductive element.

[0288] In some configurations, the signal may be indicative of the temperature of the conductive element.

[0289] In some configurations, the signal may be indicative of the thermal conductivity of a medium proximate to the conductive element.

[0290] In some configurations, the controller may include a signal generator.

[0291] In some configurations, the controller may include one or more hardware and / or software processors.

[0292] In some configurations, the humidifier may further include a conduit according to any of the conduit embodiments disclosed herein.

[0293] The present disclosure provides a conduit for use with a respiratory or surgical gas delivery system, the conduit including a conductive element, the conductive element configured to provide a measurement of a time constant or resonant frequency indicative of the presence or amount of moisture within the conduit.

[0294] In some configurations, the conduit may further include a resonant circuit, wherein the inductive element is electrically connected in parallel with the electrostatic element.

[0295] In some configurations, the resonant circuit may be external to the conduit.

[0296] In some configurations, the resonant circuit can be tuned to exhibit resonant behavior when sufficiently excited by a signal.

[0297] In some configurations, the resonant circuit can be tuned to exhibit resonant behavior when excited by a signal, the signal being selected to excite the resonant circuit.

[0298] In some configurations, the conductive element can be configured to electrically connect in parallel with the signal generator.

[0299] In some configurations, the conduit may further include a controller configured to determine a presence and / or indication of moisture in the conduit by determining a time constant, a resonant frequency, a change in the time constant, or a change in the resonant frequency.

[0300] In some configurations, the conductive element can be configured to electrically connect in parallel with the controller.

[0301] In some configurations, the controller may include a signal generator.

[0302] In some configurations, the controller may include one or more microprocessors.

[0303] The present disclosure provides a conduit for use with a respiratory or surgical gas delivery system, the conduit including a conductive element configured to provide a temperature or thermal conductivity measurement that is suitably indicative of the presence or amount of moisture within the conduit.

[0304] In some configurations, the conductive element may further include a thermistor.

[0305] In some configurations, the conductive element may further include a diode.

[0306] In some configurations, the diode may be electrically connected in parallel with the thermistor.

[0307] In some configurations, the diode is electrically connected in parallel with the thermistor and may be positioned substantially adjacent to the thermistor.

[0308] In some configurations, the conductive element may be within a bead of the conduit.

[0309] In some configurations, the conduit may further include a controller configured to determine the presence and / or indication of moisture within the conduit by determining the temperature and / or change in temperature of the electrically conductive element and / or by determining the thermal conductivity of a medium adjacent to the electrically conductive element and / or change in the thermal conductivity of a medium adjacent to the electrically conductive element.

[0310] In some configurations, the controller can be configured to apply additional power to the conductive element in conjunction with the rated control power.

[0311] In some configurations, the controller may be one or more microprocessors.

[0312] The present disclosure is applicable to any known conduit with two conductive elements.

[0313] In some configurations, the material can be a fluid permeable material.

[0314] In some configurations, the conductive elements can be elongated filaments.

[0315] In some configurations, the elongated filaments can be surrounded by an electrically insulating jacket.

[0316] In some configurations, the conductive element may be spirally wound around at least a portion of the length of the conduit.

[0317] In some configurations, the conductive element may extend from one end of the conduit to the other end of the conduit.

[0318] In some configurations, the conductive element may extend only part of the length from one end of the conduit to the other end of the conduit.

[0319] In some configurations, the conduit may be a composite conduit.

[0320] In some configurations, the conductive element may form part of the wall of the conduit.

[0321] In some configurations, the conductive elements may form part of beads arranged within the composite conduit. Alternatively, the first and second conductive elements may be arranged within the conduit such that the first and second conductive elements are free to move within the conduit.

[0322] In some configurations, the material can be a water vapor and / or liquid permeable material.

[0323] In some configurations, the material allows evaporation of water into the ambient air while inhibiting the passage of liquid water and breathing gases into the ambient air.

[0324] In some configurations, the material can be one or more of an activated perfluoropolymer material with superhydrophilic properties, a hydrophilic thermoplastic resin, a breathable thermoplastic copolyester, a woven treated fabric exhibiting breathable properties, or a hydrophilic polyester block copolymer.

[0325] In some configurations, the conduit may further include microstructures configured to use capillary action to move moisture.

[0326] In some configurations, the water vapor and / or liquid permeable material can be a dielectric material.

[0327] In some configurations, the conduit may include a microstructure configured to wick moisture across a portion of the conductive element.

[0328] In some configurations, the conduit may further include an opening configured to transport moisture by capillary action. The conduit may further include a wicking material configured to transport moisture.

[0329] In some configurations, the conductive element can be a ribbon wire.

[0330] In some configurations, the conductive elements can be contained within transparent, non-transparent, or partially transparent and non-transparent beads.

[0331] In some configurations, the conductive elements and beads can be co-extruded.

[0332] In some configurations, the conduit may further include a conductive mesh.

[0333] In some configurations, the conductive element may be sensitive to contact with the conduit.

[0334] A humidification system according to the present disclosure may deliver a flow of gas to a user. The humidifier may provide a humidifier capable of heating and humidifying the gas, a conduit for transporting the gas from the humidifier to the user, at least one sensor capable of outputting at least one sensor signal based on the amount of moisture present in a component of the system, and a controller for controlling operation of the humidifier. The controller may determine at least one value indicative of the amount of moisture present in the component based at least in part on the at least one sensor signal, and may implement one or more moisture management responses based on the at least one value indicative of the amount of moisture present in the component.

[0335] In some configurations, the one or more moisture management may include one or more of generating at least one notification and / or alert, altering the power supplied to a humidifier heater, altering the power supplied to at least one conduit heater, changing the mode of a humidifier, and / or altering parameters of a ventilator that may be part of the humidification system.

[0336] In some configurations, the component may include a conduit, a portion of a conduit, a connector, a portion of a chamber that may be exposed to gas flow, and / or a patient interface.

[0337] In some configurations, moisture present within the system components may include condensed water and / or water in the water vapor permeable and / or liquid permeable materials of the system components.

[0338] In some configurations, the moisture vapor permeable material may be a breathable material.

[0339] In some configurations, the at least one value indicative of the amount of moisture present in the component may include at least one of a value indicative of the amount of condensed water in the component of the system and / or a value indicative of the amount of water in the water vapor permeable material and / or liquid permeable material of the component of the system. The value indicative of the amount of moisture present in the component may be the sum of the value indicative of the amount of condensed water in the component of the system and the value indicative of the amount of water in the water vapor permeable material and / or liquid permeable material of the component of the system.

[0340] In some configurations, the controller may determine at least one value indicative of the amount of moisture present in the component based on the humidity output of the humidifier.

[0341] In some configurations, the controller may determine that a predetermined level of moisture is likely to be present in the component based on at least one value indicative of the amount of moisture present in the component.

[0342] In some configurations, the controller may determine that a predetermined level of moisture is likely present in the component based on comparing at least one value indicative of the amount of moisture present in the component to at least one threshold value.

[0343] In some configurations, a predetermined level of moisture may be determined to be present in response to at least one value exceeding at least one threshold.

[0344] In some configurations, a predetermined level of moisture may be determined to be present in response to at least one value being less than at least one threshold value.

[0345] In some configurations, the at least one threshold may include an absolute value threshold, a value change threshold, a percentage of maximum sensor output threshold, a percentage change threshold, a percentage change over time threshold, a slope threshold, and / or a crossing threshold.

[0346] In some configurations, the maximum sensor output may provide an output that indicates that the water vapor and / or liquid material in the conduit may be saturated with moisture.

[0347] In some configurations, the maximum sensor output may provide an output that indicates that a predetermined or acceptable amount of moisture may be present.

[0348] In some configurations, the percentage threshold may be 80%.

[0349] In some configurations, the percentage threshold may be 90%.

[0350] In some configurations, the percentage threshold may be 100%.

[0351] In some configurations, a threshold crossing may occur when the output exceeds a particular threshold a number of times, which may optionally be over a predetermined period of time.

[0352] In some configurations, the system may generate at least one notification and / or alarm in response to a predetermined level of moisture determined to be present in the component.

[0353] In some configurations, the controller may determine the presence of condensed water in the component based on a comparison between at least one value indicative of the amount of moisture present in the component and at least one condensed water threshold value.

[0354] In some configurations, the controller may determine the presence of a predetermined amount of water within the water vapor permeable and / or liquid permeable material of the component of the system based on a comparison between at least one value indicative of the amount of moisture present within the component and at least one water amount threshold. The predetermined amount of water may optionally indicate saturation of the water vapor permeable and / or liquid permeable material.

[0355] In some configurations, the controller may control the humidifier heater and / or the conduit heater to achieve a humidity target.

[0356] In some configurations, the humidity target may include a dew point target, an absolute target, and / or a relative humidity target.

[0357] In some configurations, the controller may reduce the humidity target, and optionally the absolute humidity and / or relative humidity target, of the gas stream in response to a predetermined amount of moisture determined to be present in the component.

[0358] In some configurations, the humidifier may include a heater configured to heat the humidification liquid.

[0359] In some configurations, the heater may include a heater plate.

[0360] In some configurations, the conduit may include at least one heater wire for heating the gas flow within the conduit.

[0361] In some configurations, the controller may reduce the absolute humidity of the gas stream by altering at least one operating parameter of a heater of the humidifier.

[0362] In some configurations, the controller may reduce the relative humidity of the gas stream by altering at least one operating parameter of a heater of the humidifier.

[0363] In some configurations, the modifying includes reducing, limiting, or negating the relative humidity of the gas stream.

[0364] In some configurations, the at least one operating parameter may include a heater temperature setpoint and / or power to the heater.

[0365] In some configurations, the controller may lower the relative humidity target of the gas stream by modifying at least one operating parameter of the heater of the conduit, hi some configurations, the modification may include increasing the operating parameter.

[0366] In some configurations, the operating parameters of the at least one heater in the conduit may be a patient-end temperature setpoint and / or power to the at least one heater in the conduit.

[0367] In some configurations, operating parameters of the humidifier heater and / or the conduit heater may be altered based on at least one value indicative of the amount of moisture present in the component.

[0368] In some configurations, the controller may further reduce the absolute humidity target and / or the relative humidity target in response to determining that a predetermined level of moisture is still likely to be present in the component after a predetermined period of time after initially determining that a predetermined level of moisture is likely to be present.

[0369] In some configurations, the controller may return to normal operation and / or return to the original absolute humidity and / or relative humidity target for the gas flow in response to determining that the predetermined level of moisture may no longer be present in the component after initially determining that a predetermined level of moisture may be present.

[0370] In some configurations, the controller may return to normal operation and / or return to the original absolute humidity and / or relative humidity target for the gas flow in response to determining that the predetermined level of moisture may no longer be present in the component after initially determining that a predetermined level of moisture may be present.

[0371] In some configurations, the controller may determine that a predetermined level of moisture may no longer be present in the component in response to detecting that no moisture or a small amount of moisture is present in the component.

[0372] In some configurations, the controller may determine that a predetermined level of moisture may no longer be present in the component in response to detecting the absence of condensed water or the presence of a small amount of condensed water in the component.

[0373] In some configurations, at least a portion of the conduit or another component of the system may include a water vapor permeable material and / or a liquid permeable material.

[0374] In some configurations, the conduit may include at least a first conductive element and a second conductive element, and the at least one sensor signal includes a signal generated using one or more of the at least first and second conductive elements.

[0375] In some configurations, the first conductive element and the second conductive element may be spirally wound around at least the length of the conduit.

[0376] In some configurations, the first and second conductive elements are spirally wound within, through, or around the conduit.

[0377] In some configurations, the first conductive element and the second conductive element form part of the conduit wall.

[0378] In some configurations, the first conductive element may be a sensing wire.

[0379] In some configurations, the first conductive element may be at least one heater wire.

[0380] In some configurations, the second conductive element may be at least one heater wire.

[0381] In some configurations, the water vapor permeable material and / or the liquid permeable material may be a dielectric material.

[0382] In some configurations, the dielectric material may be water vapor permeable or liquid permeable.

[0383] In some configurations, the water vapor permeable dielectric material may allow evaporation of water into the ambient air while inhibiting the passage of liquid water and breathing gases into the ambient air.

[0384] In some configurations, the other components may include a patient interface.

[0385] In some configurations, the other components may include connectors and / or adapters.

[0386] In some configurations, the conduit may include a composite conduit.

[0387] In some configurations, the conduit may include water vapor and / or liquid permeable beads.

[0388] In some configurations, the water vapor permeable beads allow water to evaporate into the ambient air while inhibiting the passage of liquid water and breathing gases into the ambient air.

[0389] In some configurations, the water vapor permeable beads can be activated perfluoropolymer materials with superhydrophilic properties, hydrophilic thermoplastics, breathable thermoplastic copolyesters, woven treated fabrics exhibiting breathable properties, and / or hydrophilic polyester block copolymers.

[0390] In some configurations, the signal may be indicative of a capacitance between the first conductive element and the second conductive element.

[0391] In some configurations, the signal may be indicative of a change in capacitance between the first conductive element and the second conductive element.

[0392] In some configurations, the first conductive element and the second conductive element are separated by a distance configured to allow sensing of a capacitive charge between the first conductive element and the second conductive element.

[0393] In some configurations, the humidification system may further include a dielectric material disposed between the first conductive element and the second conductive element.

[0394] In some configurations, the controller may determine at least one value indicative of moisture based on a comparison of the measurements of the first conductive element and / or the second conductive element.

[0395] In some configurations, the signal may be indicative of the temperature of the first conductive element or the second conductive element.

[0396] In some configurations, the signal may be indicative of a change in temperature of the first conductive element or the second conductive element.

[0397] In some configurations, the signals may be indicative of the thermal conductivity of a medium between the first conductive element and the second conductive element, or at least one signal may be indicative of the thermal conductivity of a medium proximate the first conductive element or the second conductive element.

[0398] In some configurations, the signal may be indicative of the resistance of the first conductive element or the second conductive element.

[0399] In some configurations, the first conductive element or the second conductive element includes at least two portions that are electrically isolated from one another.

[0400] In some configurations, the two sections may be in series with each other.

[0401] In some configurations, the humidification system may further include a signal generator, and the controller may determine at least one value indicative of the amount of moisture in the conduit based at least in part on the magnitude and / or phase of the at least one signal.

[0402] In some configurations, the at least one value indicative of the amount of moisture in the conduit may correspond to the inductance of the conduit.

[0403] In some configurations, the at least one value indicative of the amount of moisture in the conduit corresponds to a change in inductance of the conduit.

[0404] In some configurations, a predetermined level of moisture present in a component may indicate a predetermined amount of water within the water vapor permeable and / or liquid permeable materials of the component of the system.

[0405] In some configurations, the controller may initially modify an operating parameter of at least one heater wire of the conduit in response to determining that a predetermined level of moisture is present in the component. In some configurations, the modifying may include reducing, limiting, or disabling the operating parameter. In some configurations, the reducing or limiting includes reducing or limiting power to the at least one heater wire to a range of 3.0 W / m to 7.0 W / m.

[0406] In some configurations, the controller may maintain the initially altered operating parameters of the heater wire in the conduit.

[0407] In some configurations, maintaining the initially altered operating parameters of the at least one heater wire of the conduit may increase the saturation moisture content of the water vapor permeable material and / or the liquid permeable material, which change may optionally be an increase relative to a predetermined saturation moisture content.

[0408] In some configurations, the controller may further vary operating parameters of at least one heater wire in the conduit.

[0409] In some configurations, the controller may maintain the initially altered operating parameters and then, after a predetermined time, further alter the operating parameters of the heater wire in the conduit.

[0410] In some configurations, a further change may be an increase in an operating parameter.

[0411] In some configurations, the controller may alter operating parameters of the heater of the conduit in response to determining that a predetermined level of moisture is present in the component.

[0412] In some configurations, the predetermined level may be a percentage threshold of maximum sensor output. In some configurations, the percentage threshold may be 80%. In some configurations, the percentage threshold may be 90%. In some configurations, the percentage threshold may be 100%. A fully saturated permeable material may be 100%.

[0413] In some configurations, the maximum sensor output may be an output that indicates that the beads in the conduit may be saturated with moisture.

[0414] In some configurations, the maximum sensor output may be an output that indicates that a predetermined or acceptable amount of moisture may be present.

[0415] In some configurations, the controller may maintain altered operating parameters of at least one heater wire of the conduit to allow drying of the water vapor permeable material and / or the liquid permeable material via evaporation to the atmosphere.

[0416] In some configurations, the humidification system may maintain altered operating parameters to increase the rate at which moisture can be transferred across the water vapor permeable material to the atmosphere.

[0417] In some configurations, the altered operating parameters may include increased power to at least one heater wire from 10 W / m to 14 W / m.

[0418] In some configurations, the controller may maintain the altered operating parameters and then return to normal or original operating parameters of the at least one heater in the conduit after a predetermined time.

[0419] In some configurations, the controller may increase and maintain the operating parameter, then decrease and maintain the operating parameter multiple times before returning to the normal or original operating parameter.

[0420] In some configurations, the controller may return to normal or original operating parameters of at least one heater in the conduit in response to determining that the predetermined level of moisture in the component is below a threshold. In some configurations, the threshold may be a percentage threshold. In some configurations, the percentage threshold may be 20%. In some configurations, the percentage threshold may be 15%. In some configurations, the percentage threshold may be 0%.

[0421] In some configurations, the controller may return to normal or original operating parameters of at least one heater wire of the conduit in response to determining that a predetermined amount of water molecules in the water vapor permeable material and / or liquid permeable material falls below a water molecule threshold.

[0422] In some configurations, the controller may return to normal or original operating parameters of at least one heater wire of the conduit in response to determining that the predetermined level of condensation in the component is below a condensation threshold.

[0423] In some configurations, the operating parameters of the at least one heater wire of the conduit may include a patient end temperature set point and / or power to the at least one heater wire.

[0424] In some configurations, the controller may increase the temperature of the water vapor permeable material via a heater in the conduit to increase the rate at which water passes from one side of the material to the other side of the material.

[0425] In some configurations, the controller may increase the temperature of the liquid permeable material via a heater in the conduit to increase the rate at which liquid water within the liquid permeable material evaporates into the atmosphere.

[0426] In some configurations, the control device may control the relative humidity gradient between the water vapor permeable and / or liquid permeable material and the atmosphere to be greater than the relative humidity gradient between the water vapor permeable and / or liquid permeable material and the lumen of the conduit.

[0427] In some configurations, the humidification system may include a moisture exhaust assembly configured to collect condensed water and / or return the condensed water to the humidification chamber.

[0428] In some configurations, the moisture drainage assembly may include a water trap configured to collect condensed water.

[0429] In some configurations, the moisture evacuation assembly includes at least one valve electronically coupled to a controller that can actuate the at least one valve based on the at least one sensor signal.

[0430] In some configurations, the controller may actuate at least one valve to an open position in response to determining that a predetermined level of moisture is present in the component.

[0431] In some configurations, the controller may actuate at least one valve to an open position in response to determining that a predetermined level of condensed water is present in the component.

[0432] In some configurations, the moisture evacuation assembly may include a moisture transport assembly configured to return moisture collected in the water trap or conduit to the humidification chamber.

[0433] In some configurations, the moisture evacuation assembly may further include a conveying conduit and / or a pump, hi some configurations, the pump may be a peristaltic pump.

[0434] In some configurations, the controller may determine a chamber flood event based on at least one value indicative of the amount of moisture present in the component.

[0435] In some configurations, the component may be located near the outlet of the humidification chamber of the humidifier.

[0436] In some configurations, the sensor may include a temperature sensor located near the distal end of the conduit.

[0437] In some configurations, the controller may, in response to determining the presence of a predetermined amount of moisture, determine a dew point temperature of the gas stream or a value indicative thereof based on the temperature of the gas stream sensed by the temperature sensor.

[0438] In some configurations, the controller may, in response to determining the presence of a predetermined amount of condensed water, determine a dew point temperature or a value indicative thereof based on the temperature of the gas flow sensed by the temperature sensor.

[0439] In some configurations, the dew point temperature or a value indicative thereof may be the temperature of the gas flow as sensed by a temperature sensor.

[0440] In some configurations, the controller may control a humidifier heater or a conduit heater based on the determined dew point temperature or a value indicative thereof.

[0441] In some configurations, the controller may decrease the operating parameters of the heater in the conduit to increase the relative humidity in the conduit and induce the formation of condensation.

[0442] In some configurations, the controller may control the gas exiting the humidifier to reach a dew point temperature setpoint.

[0443] In some configurations, the controller, in response to determining that the patient-end temperature may be above the dew point temperature setpoint and that a predetermined level of moisture may be present, may determine that the source of gas for the humidifier may be ambient air or may come from a room-loaded ventilator.

[0444] In some configurations, once the controller determines that the source of gas for the humidifier is ambient air or from a room-loaded ventilator, the controller may control the temperature setpoint of the humidifier to a constant value.

[0445] In some configurations, the temperature setpoint can be the chamber exit setpoint.

[0446] In some configurations, the chamber outlet set point may correspond to the dew point of the gas.

[0447] In some configurations, the controller may determine the presence of a predetermined level of moisture in the conduit based on at least one value indicative of the amount of moisture in the conduit in response to the conduit being connected to the humidifier and / or prior to operation of the humidifier.

[0448] In some configurations, the controller may determine the presence of a predetermined level of moisture in the conduit based on a comparison between a threshold value and at least one value indicative of the amount of moisture in the conduit.

[0449] In some configurations, the controller may determine the presence of a predetermined level of moisture in the conduit when the conduit may first be connected to the humidifier.

[0450] In some configurations, the predetermined level of moisture present in the conduit may be a level at which a new, unused conduit may be needed, or a level at which the conduit needs to be checked for defects or further dried.

[0451] In some configurations, the controller may generate an alarm in response to determining the presence of a predetermined level of moisture in the conduit.

[0452] In some configurations, the alert may include a visual and / or audio indication.

[0453] In some configurations, the controller may, in response to determining the presence of a predetermined level of moisture in the conduit, prevent the conduit from being used with a humidifier by preventing power to the heater of the conduit and / or preventing use of the humidifier while connected to the conduit.

[0454] In some configurations, the conduit may not include a patient-end sensor.

[0455] In some configurations, the at least one sensor signal based on the amount of moisture present in the component may further include a signal related to the humidity of gas within the component.

[0456] In some configurations, a signal relating to a humidifier of gas within the component may be filtered from the at least one signal or ignored by the controller.

[0457] In some configurations, the controller may determine at least one value indicative of the amount of moisture present in the component based on the at least one sensor signal, and control the function of the gas source to reduce the moisture in response to a predetermined amount of moisture determined to be present in the component based on the value.

[0458] In some configurations, functions may include decreasing tidal volume, increasing inspiratory rise time, decreasing inhalation-to-exhalation ratio, increasing inlet gas temperature, and / or decreasing intake air volume, and / or switching to a wall or bottled gas source.

[0459] In some configurations, the gas source may include a ventilator.

[0460] In some configurations, the gas source may include a glow generator.

[0461] In some configurations, the controller may determine at least one value indicative of the amount of moisture present in the component based on the at least one sensor signal, and may determine a depletion state of the humidification chamber based on the at least one value indicative of the amount of moisture present in the component.

[0462] In some configurations, a non-out-of-water condition may be determined in response to detecting an increase in the amount of moisture and / or humidity within the component.

[0463] In some configurations, a non-out-of-water condition may be determined in response to an increase in the amount of moisture and / or humidity within the component exceeding a threshold value.

[0464] In some configurations, a dehydrated condition may be determined in response to not detecting an increase in the amount of moisture and / or humidity within the component.

[0465] In some configurations, a dehydration condition may be determined in response to an increase in the amount of moisture and / or humidity within the component being below a threshold value.

[0466] In some configurations, the dehydrated condition includes the absence of water or the presence of a predetermined level of moisture.

[0467] In some configurations, the controller may increase power to a heater plate of the humidifier and / or decrease power to at least one heater wire in a conduit configured to provide gas from the humidifier to a user to increase humidity and / or increase moisture.

[0468] In some configurations, the increased moisture may be condensation or water in a water vapor permeable and / or liquid permeable material.

[0469] In some configurations, the controller may determine a water-out condition following increasing power to the heater plate and / or decreasing power to at least one heater wire in response to determining that the predetermined amount of moisture and / or humidity is below a threshold.

[0470] A humidification system may deliver a flow of gas to a user. The humidification system may include a humidifier that heats and humidifies the gas, at least one sensor that outputs at least one sensor signal based on the amount of moisture and / or humidity present in a component of the system, and a controller that controls operation of the humidifier, wherein the controller may determine at least one value indicative of the amount of moisture and / or humidity present in the component based on the at least one sensor signal, and may determine a humidity of the flow of gas based on the at least one value indicative of the amount of moisture and / or humidity present in the component.

[0471] In some configurations, the controller may assume the relative humidity to be 100% if it detects the presence of moisture based on the value.

[0472] In some configurations, a temperature sensor located near the distal end of the conduit may transport gas from the humidifier to a user. The controller may determine the presence of a predetermined level of moisture based on at least one value indicative of the amount of water and / or humidity present in the component. The controller may determine a dew point of the gas stream as the humidity of the gas stream.

[0473] In some configurations, the humidity may be a dew point temperature, a relative humidity value, or an absolute humidity value.

[0474] In some configurations, the controller may control a humidifier and / or a heater in the conduit based on the humidity to control the target humidity.

[0475] In some configurations, the controller may determine the presence of a predetermined level of moisture based on at least one value indicative of the amount of moisture and / or humidity present within the component.

[0476] In some configurations, the controller may control at least one operating parameter of the humidification system based on the determined dew point temperature or a value indicative thereof.

[0477] In some configurations, the controller may control the humidifier heater and the conduit heater based on the determined dew point temperature or a value indicative thereof.

[0478] In some configurations, the operating parameters of the humidifier heater may include at least one of a heater plate temperature set point and power to the heater plate.

[0479] In some configurations, the operating parameters of the heater in the conduit may include at least one of a patient end temperature setpoint and power to at least one heater wire.

[0480] In some configurations, the determined dew point temperature or a value indicative thereof may be the temperature of the gas flow as sensed by a temperature sensor.

[0481] In some configurations, the controller may decrease the operating parameters of the heater in the conduit to increase the relative humidity in the conduit and induce the formation of condensation.

[0482] In some configurations, the controller may control the heater in the conduit to reach a patient-end temperature setpoint.

[0483] In some configurations, the target patient end temperature may be greater than the determined dew point temperature or a value indicative thereof.

[0484] In some configurations, the determined humidity of the gas stream may be relative humidity or absolute humidity.

[0485] In some configurations, the output of the at least one sensor may be filtered to obtain at least one portion of the signal that may be related to humidity within the component.

[0486] In some configurations, the humidifier may not include a patient-end sensor.

[0487] In some configurations, the humidification system may include a flow generator.

[0488] In some configurations, the flow generator and humidifier may be in a single housing.

[0489] In some configurations, the conduit may include at least a first conductive element and a second conductive element, and the at least one sensor signal may include a signal generated using one or more of the at least first and second conductive elements.

[0490] In some configurations, the first conductive element and the second conductive element may be spirally wound around at least the length of the conduit.

[0491] In some configurations, the first and second conductive elements may be spirally wound within, through, or around the conduit.

[0492] In some configurations, the first conductive element and the second conductive element form part of the conduit wall.

[0493] In some configurations, the first conductive element may be a sensing wire.

[0494] In some configurations, the first conductive element may be at least one heater wire.

[0495] In some configurations, the second conductive element may be a sensing wire.

[0496] In some configurations, the second conductive element may be at least one heater wire.

[0497] In some configurations, the at least one signal may be indicative of a capacitance between the first conductive element and the second conductive element.

[0498] In some configurations, the at least one signal may be indicative of a change in capacitance between the first conductive element and the second conductive element.

[0499] In some configurations, the first conductive element and the second conductive element may be separated by a distance that may allow for sensing a capacitive charge between the first conductive element and the second conductive element.

[0500] In some configurations, the humidification system may include a dielectric material disposed between the first conductive element and the second conductive element.

[0501] In some configurations, the dielectric material may be water vapor permeable or liquid permeable.

[0502] In some configurations, the water vapor permeable dielectric material may allow evaporation of water into the ambient air while inhibiting the passage of liquid water and breathing gases into the ambient air.

[0503] In some configurations, the controller may determine at least one value indicative of moisture based on a comparison of the measurements of the first conductive element and / or the second conductive element.

[0504] In some configurations, the at least one signal may be indicative of a temperature of the first conductive element or the second conductive element.

[0505] In some configurations, the at least one signal may be indicative of a change in temperature of the first conductive element or the second conductive element.

[0506] In some configurations, the at least one signal may be indicative of the thermal conductivity of a medium between the first conductive element and the second conductive element, or the at least one signal may be indicative of the thermal conductivity of a medium proximate the first conductive element or the second conductive element.

[0507] In some configurations, the at least one signal may be indicative of a resistance of the first conductive element or the second conductive element.

[0508] In some configurations, the first conductive element or the second conductive element may include at least two portions that are electrically isolated from one another.

[0509] In some configurations, at least two portions may be in series with one another.

[0510] In some configurations, at least two portions may be parallel to one another.

[0511] In some configurations, the humidification system may further include a signal generator, and the controller may determine at least one value indicative of the amount of moisture in the conduit based at least in part on the magnitude and / or phase of the at least one signal.

[0512] In some configurations, the at least one value indicative of the amount of moisture in the conduit corresponds to an inductance of the conduit.

[0513] In some configurations, at least one value indicative of the amount of moisture in the conduit may correspond to a change in inductance of the conduit.

[0514] The humidification system may deliver a flow of gas to a user. The humidification system may include a humidifier that heats and humidifies the gas, a first sensor associated with a first location, a second sensor associated with a second location, and a controller that controls operation of the humidifier. The first sensor may output at least one first sensor signal based on an amount of moisture present at the first location. The second sensor may output at least one second sensor signal based on an amount of moisture present at the second location. The controller may determine a first value indicative of the amount of humidity and / or moisture present at the first location based on the first sensor signal, and a second value indicative of the amount of humidity and / or moisture present at the second location based on the second sensor.

[0515] In some configurations, the first location may be associated with a first component of the system.

[0516] In some configurations, the second location may be associated with a second component of the system.

[0517] In some configurations, the first and / or second components may include a conduit, a portion of a conduit, a connector, a portion of a chamber that may be exposed to a flow of gas, and / or a patient interface.

[0518] In some configurations, the connector may include one or more adapters.

[0519] In some configurations, during normal operation of the system, the first location may be upstream of the second location.

[0520] In some configurations, the controller may determine that there may be no flow in the system and / or a flow rate below a threshold by detecting a first predetermined amount of moisture at a first location and determining that a second predetermined amount of moisture may not be detected at a second location a predetermined time period after detecting the predetermined amount of moisture at the first location.

[0521] In some configurations, the controller may determine that the gas flow rate is likely to be within a range based on readings from a first temperature sensor at the first location and a second temperature sensor at the second location in response to detecting a first predetermined amount of moisture at the first location and not detecting a second predetermined amount of moisture at the second location a predetermined period after detecting the predetermined amount of moisture at the first location.

[0522] In some configurations, the first temperature sensor may be located at the chamber outlet of the humidifier.

[0523] In some configurations, the second temperature sensor may be located at or near the patient end of the inhalation conduit or the distal end of the patient delivery conduit configured to carry gases from the humidifier to the user.

[0524] In some configurations, the controller may determine that the flow direction is likely correct in response to the moisture at the upstream location exceeding the moisture at the downstream location.

[0525] In some configurations, the intake conduit may include an upstream location.

[0526] In some configurations, a conduit positioned between the gas source and the humidifier may include a downstream location.

[0527] In some configurations, the humidification system may include a third sensor associated with a third location of the system, the third sensor may output at least one third sensor signal based on the amount of moisture present at the third location.

[0528] In some configurations, the third location can be upstream of the first location and the second location.

[0529] In some configurations, the first location may be in the intake conduit.

[0530] In some configurations, the third location may be in the expiratory conduit.

[0531] In some configurations, the second location may be at the chamber inlet of the humidification chamber.

[0532] In some configurations, the controller may be configured to determine the flow direction based on the direction of moisture detected from the humidifier. The controller may be configured to detect a backflow condition in response to moisture being detected in a component upstream of the humidifier when properly connected.

[0533] A humidification system according to the present disclosure may deliver a flow of gas to a user. The humidifier may include a humidifier capable of heating and humidifying the gas, a conduit for transporting the gas from the humidifier to the user, at least one sensor capable of outputting at least one sensor signal based on the amount of moisture present in a component of the system, and a controller for controlling operation of the humidifier. The controller may determine a value indicative of the amount of moisture present in the component based on the at least one sensor signal, and control function of the gas source to reduce moisture in response to a predetermined amount of moisture determined to be present in the component based on the value.

[0534] In some configurations, functions may include decreasing tidal volume, increasing inspiratory rise time, decreasing the inhalation-to-exhalation ratio, increasing inlet gas temperature, and / or decreasing the amount of air entrained, and / or switching to a wall or bottled gas source.

[0535] In some configurations, the gas source may include a ventilator.

[0536] In some configurations, the gas source may include a glow generator.

[0537] In some configurations, the conduit may include at least a first conductive element and a second conductive element, and the at least one sensor signal may include a signal generated using one or more of the at least first and second conductive elements.

[0538] In some configurations, the first conductive element and the second conductive element may be spirally wound around at least the length of the conduit.

[0539] In some configurations, the first and second conductive elements may be spirally wound within, through, or around the conduit.

[0540] In some configurations, the first conductive element and the second conductive element form part of a wall of the conduit.

[0541] In some configurations, the first conductive element may be a sensing wire.

[0542] In some configurations, the first conductive element may be at least one heater wire.

[0543] In some configurations, the second conductive element may be a sensing wire.

[0544] In some configurations, the second conductive element may be at least one heater wire.

[0545] In some configurations, the at least one signal may be indicative of a capacitance between the first conductive element and the second conductive element.

[0546] In some configurations, the at least one signal may be indicative of a change in capacitance between the first conductive element and the second conductive element.

[0547] In some configurations, the first conductive element and the second conductive element may be separated by a distance that may allow for sensing a capacitive charge between the first conductive element and the second conductive element.

[0548] In some configurations, the humidification system may include a dielectric material disposed between the first conductive element and the second conductive element.

[0549] In some configurations, the dielectric material may be water vapor permeable or liquid permeable.

[0550] In some configurations, the water vapor permeable dielectric material may inhibit the passage of liquid water and breathing gases into the ambient air, while allowing water to evaporate into the ambient air.

[0551] In some configurations, the controller may determine at least one value indicative of moisture based on a comparison of the measurements of the first conductive element and / or the second conductive element.

[0552] In some configurations, the at least one signal may be indicative of a temperature of the first conductive element or the second conductive element.

[0553] In some configurations, the at least one signal may be indicative of a change in temperature of the first conductive element or the second conductive element.

[0554] In some configurations, the at least one signal may be indicative of the thermal conductivity of a medium between the first conductive element and the second conductive element, or the at least one signal may be indicative of the thermal conductivity of a medium proximate the first conductive element or the second conductive element.

[0555] In some configurations, the at least one signal may be indicative of a resistance of the first conductive element or the second conductive element.

[0556] In some configurations, the first conductive element or the second conductive element includes at least two portions that are electrically isolated from one another.

[0557] In some configurations, at least two portions may be in series with one another.

[0558] In some configurations, at least two portions may be parallel to one another.

[0559] In some configurations, the humidification system may further include a signal generator, and the controller may determine at least one value indicative of the amount of moisture in the conduit based at least in part on the magnitude and / or phase of the at least one signal.

[0560] In some configurations, the at least one value indicative of the amount of moisture in the conduit corresponds to an inductance of the conduit.

[0561] In some configurations, the at least one value indicative of the amount of moisture in the conduit may correspond to a change in inductance of the conduit.

[0562] A humidification system according to the present disclosure may deliver a flow of gas to a user. The humidifier may include a humidifier capable of heating and humidifying the gas, a conduit for transporting the gas from the humidifier to the user, at least one sensor capable of outputting at least one sensor signal based on the amount of moisture present in a component of the system, and a controller for controlling operation of the humidifier. The controller may determine at least one value indicative of the amount of moisture present in the component based on the at least one sensor signal, and may determine a depletion condition of the humidification chamber based on the at least one value indicative of the amount of moisture present in the component.

[0563] In some configurations, a non-out-of-water condition may be determined in response to detecting an increased amount of moisture and / or humidity within the component.

[0564] In some configurations, a non-out-of-water condition may be determined in response to an increase in the amount of moisture and / or humidity within the component exceeding a threshold value.

[0565] In some configurations, a dehydrated condition may be determined in response to not detecting an increase in the amount of moisture and / or humidity within the component.

[0566] In some configurations, a dehydration condition may be determined in response to an increase in the amount of moisture and / or humidity within the component being below a threshold value.

[0567] In some configurations, the dehydrated condition includes the absence of water or the presence of a predetermined level of moisture.

[0568] In some configurations, the controller may increase power to a heater plate of the humidifier and / or decrease power to at least one heater wire in a conduit configured to provide gas from the humidifier to a user to increase humidity and / or increase moisture.

[0569] In some configurations, the increased moisture may be condensation or water in a water vapor permeable and / or liquid permeable material.

[0570] In some configurations, the controller may determine a water-out condition following increasing power to the heater plate and / or decreasing power to at least one heater wire in response to determining that the predetermined amount of moisture and / or humidity is below a threshold.

[0571] In some configurations, the conduit may include at least a first conductive element and a second conductive element, and the at least one sensor signal may include a signal generated using one or more of the at least first and second conductive elements.

[0572] In some configurations, the first conductive element and the second conductive element may be spirally wound around at least the length of the conduit.

[0573] In some configurations, the first and second conductive elements may be spirally wound within, through, or around the conduit.

[0574] In some configurations, the first conductive element and the second conductive element form part of the conduit wall.

[0575] In some configurations, the first conductive element may be a sensing wire.

[0576] In some configurations, the first conductive element may be at least one heater wire.

[0577] In some configurations, the second conductive element may be a sensing wire.

[0578] In some configurations, the second conductive element may be at least one heater wire.

[0579] In some configurations, the at least one signal may be indicative of a capacitance between the first conductive element and the second conductive element.

[0580] In some configurations, the at least one signal may be indicative of a change in capacitance between the first conductive element and the second conductive element.

[0581] In some configurations, the first conductive element and the second conductive element may be separated by a distance that may allow for sensing a capacitive charge between the first conductive element and the second conductive element.

[0582] In some configurations, the humidification system may include a dielectric material disposed between the first conductive element and the second conductive element.

[0583] In some configurations, the dielectric material may be water vapor permeable or liquid permeable.

[0584] In some configurations, the water vapor permeable dielectric material may allow evaporation of water into the ambient air while inhibiting the passage of liquid water and breathing gases into the ambient air.

[0585] In some configurations, the controller may determine at least one value indicative of moisture based on a comparison of the measurements of the first conductive element and / or the second conductive element.

[0586] In some configurations, the at least one signal may be indicative of a temperature of the first conductive element or the second conductive element.

[0587] In some configurations, the at least one signal may be indicative of a change in temperature of the first conductive element or the second conductive element.

[0588] In some configurations, the at least one signal may be indicative of the thermal conductivity of a medium between the first conductive element and the second conductive element, or the at least one signal may be indicative of the thermal conductivity of a medium proximate the first conductive element or the second conductive element.

[0589] In some configurations, the at least one signal may be indicative of a resistance of the first conductive element or the second conductive element.

[0590] In some configurations, the first conductive element or the second conductive element may include at least two portions that are electrically isolated from one another.

[0591] In some configurations, at least two portions may be in series with one another.

[0592] In some configurations, at least two portions may be parallel to one another.

[0593] In some configurations, the humidification system may further include a signal generator, and the controller may determine at least one value indicative of the amount of moisture in the conduit based at least in part on the magnitude and / or phase of the at least one signal.

[0594] In some configurations, the at least one value indicative of the amount of moisture in the conduit corresponds to an inductance of the conduit.

[0595] In some configurations, the at least one value indicative of the amount of moisture in the conduit may correspond to a change in inductance of the conduit.

[0596] The humidification system may be used in a gas delivery system. The humidification system may include a humidifier that heats and humidifies gas and a conduit that transports the gas from the humidifier to a user. The conduit may include a first conductive element, a second conductive element, and a controller configured to monitor capacitance and / or a change in capacitance of a capacitor formed between the first conductive element and the second conductive element to detect the presence of skin in proximity to or in contact with the conduit.

[0597] In some configurations, the capacitance and / or change in capacitance includes measuring a time constant, a resonant frequency, a change in the time constant, or a change in the resonant frequency of a capacitor formed between the first conductive element and the second conductive element.

[0598] In some configurations, the controller may detect a change in the dielectric constant of the capacitor based on the monitored capacitance and / or change in capacitance.

[0599] In some configurations, the controller may compare the detected change in permittivity to one or more permittivity threshold values.

[0600] In some configurations, the controller may detect the presence of skin adjacent to or in contact with the conduit in response to a detected change in dielectric constant exceeding one or more thresholds.

[0601] In some configurations, the controller may output an alarm in response to detecting the presence of skin in proximity to or in contact with the conduit.

[0602] In some configurations, the controller may output an alarm in response to detecting the presence of skin in close proximity to or in contact with the conduit, either continuously or intermittently, for a predefined duration.

[0603] In some configurations, the predefined duration may be variable based on the expected conduit surface temperature.

[0604] In some configurations, the conduit may include a dielectric material between the first and second conductive elements.

[0605] In some configurations, the first conductive element and the second conductive element are spirally wound around at least the length of the conduit.

[0606] In some configurations, the first and second conductive elements are spirally wound within, through, or around the conduit.

[0607] In some configurations, the first conductive element and the second conductive element form part of the conduit wall.

[0608] In some configurations, the first conductive element may be a sensing wire.

[0609] In some configurations, the first conductive element may be a heater wire.

[0610] In some configurations, the second conductive element may be a sensing wire.

[0611] In some configurations, the second conductive element may be a heater wire.

[0612] In some configurations, the first conductive element and the second conductive element can be separated by a distance that allows a capacitive charge to be sensed between the first conductive element and the second conductive element.

[0613] In some configurations, the first conductive element or the second conductive element may include at least two portions that are electrically isolated from one another.

[0614] In some configurations, at least two portions may be in series with one another.

[0615] In some configurations, at least two portions may be parallel to one another.

[0616] A method of delivering a flow of gas to a user according to the present disclosure may use a humidifier controller that may be part of a humidification system. The humidifier may include a humidifier that can heat and humidify gas, a conduit that transports the gas from the humidifier to a user, at least one sensor that can output at least one sensor signal based on the amount of moisture present in a component of the system, and a controller that controls operation of the humidifier. The method includes determining at least one value indicative of the amount of moisture present in the component based at least in part on the at least one sensor signal, and implementing one or more moisture management responses based on the at least one value indicative of the amount of moisture present in the component.

[0617] In some configurations, the one or more moisture management may include one or more of generating at least one notification and / or alarm, altering the power supplied to a humidifier heater, altering the power supplied to at least one conduit heater, changing the mode of a humidifier, and / or altering parameters of a ventilator that may be part of the humidification system.

[0618] In some configurations, the component may include a conduit, a portion of a conduit, a connector, a portion of a chamber that may be exposed to gas flow, and / or a patient interface.

[0619] In some configurations, moisture present within the system components may include condensed water and / or water in the water vapor permeable and / or liquid permeable materials of the system components.

[0620] In some configurations, the moisture vapor permeable material may be a breathable material.

[0621] In some configurations, the at least one value indicative of the amount of moisture present in the component may include at least one of a value indicative of the amount of condensed water in the component of the system and / or a value indicative of the amount of water in the water vapor permeable material and / or liquid permeable material of the component of the system. The value indicative of the amount of moisture present in the component may be the sum of the value indicative of the amount of condensed water in the component of the system and the value indicative of the amount of water in the water vapor permeable material and / or liquid permeable material of the component of the system.

[0622] In some configurations, the method may further include determining at least one value indicative of an amount of moisture present in the component based on the humidity output of the humidifier.

[0623] In some configurations, the method may further include determining that a predetermined amount of moisture may be present in the component based on at least one value indicative of an amount of moisture present in the component.

[0624] In some configurations, the method may further include determining that a predetermined level of moisture may be present in the component based on comparing at least one value indicative of the amount of moisture present in the component to at least one threshold value.

[0625] In some configurations, the predetermined level of moisture may be determined to be present in response to at least one value exceeding at least one threshold.

[0626] In some configurations, the predetermined level of moisture may be determined to be present in response to at least one value being less than at least one threshold value.

[0627] In some configurations, the at least one threshold may include an absolute value threshold, a value change threshold, a percentage of maximum sensor output threshold, a percentage change threshold, a percentage change over time threshold, a slope threshold, and / or a crossing threshold.

[0628] In some configurations, the maximum sensor output may provide an output that indicates that the water vapor and / or liquid material in the conduit may be saturated with moisture.

[0629] In some configurations, the maximum sensor output may provide an output that indicates that a predetermined or acceptable amount of moisture may be present.

[0630] In some configurations, the percentage threshold may be 80%.

[0631] In some configurations, the percentage threshold may be 90%.

[0632] In some configurations, the percentage threshold may be 100%.

[0633] In some configurations, a threshold crossing may occur when the output exceeds a particular threshold a number of times, which may optionally be over a predetermined period of time.

[0634] In some configurations, the method may further include generating at least one notification and / or alarm in response to the predetermined level of moisture determined to be present in the component.

[0635] In some configurations, the method may further include determining the presence of condensed water in the component based on a comparison between at least one value indicative of the amount of moisture present in the component and at least one condensed water threshold value.

[0636] In some configurations, the method may further include determining the presence of a predetermined amount of water within the water vapor permeable and / or liquid permeable material of the component of the system based on a comparison between at least one value indicative of the amount of moisture present within the component and at least one water amount threshold. The predetermined amount of water may optionally indicate saturation of the water vapor permeable and / or liquid permeable material.

[0637] In some configurations, the method may further include controlling a heater in the humidifier and / or a heater in the conduit to achieve the humidity target.

[0638] In some configurations, the humidity target may include a dew point target, an absolute humidity target, and / or a relative humidity target.

[0639] In some configurations, the method may further include decreasing the humidity target, and optionally the absolute humidity and / or relative humidity target, of the gas flow in response to the predetermined amount of moisture determined to be present in the component.

[0640] In some configurations, the humidifier may include a heater configured to heat the humidification liquid.

[0641] In some configurations, the heater may include a heater plate.

[0642] In some configurations, the conduit may include at least one heater wire for heating the gas flow within the conduit.

[0643] In some configurations, the method may further include decreasing the absolute humidity of the gas stream by altering at least one operating parameter of a heater of the humidifier.

[0644] In some configurations, the method may further include decreasing the relative humidity of the gas stream by altering at least one operating parameter of a heater of the humidifier.

[0645] In some configurations, the modifying includes reducing, restricting, or negating the relative humidity of the gas stream.

[0646] In some configurations, the at least one operating parameter may include a heater temperature setpoint and / or power to the heater.

[0647] In some configurations, the method may further include lowering the relative humidity target of the gas flow by modifying at least one operating parameter of the heater of the conduit, hi some configurations, the modifying may include increasing the operating parameter.

[0648] In some configurations, the operating parameters of the at least one heater in the conduit may be a patient-end temperature setpoint and / or power to the at least one heater in the conduit.

[0649] In some configurations, operating parameters of the humidifier heater and / or the conduit heater may be altered based on at least one value indicative of the amount of moisture present in the component.

[0650] In some configurations, the method may further include decreasing the absolute humidity target and / or the relative humidity target in response to determining that the predetermined level of moisture may still be present in the component a predetermined time after initially determining that the predetermined level of moisture may be present.

[0651] In some configurations, the method may further include, after initially determining that a predetermined level of moisture may be present, returning to normal operation and / or returning to an original absolute humidity and / or relative humidity target for the gas flow in response to determining that the predetermined level of moisture may no longer be present in the component.

[0652] In some configurations, the method may further include, after initially determining that a predetermined level of moisture may be present, returning to normal operation and / or returning to an original absolute humidity and / or relative humidity target for the gas flow in response to determining that the predetermined level of moisture may no longer be present in the component.

[0653] In some configurations, the method may further include, in response to detecting the absence of moisture or the presence of a small amount of moisture in the component, determining that a predetermined level of moisture may no longer be present in the component.

[0654] In some configurations, the method may further include, in response to detecting the absence of condensed water or the presence of a small amount of condensed water in the component, determining that a predetermined level of moisture may no longer be present in the component.

[0655] In some configurations, at least a portion of the conduit or another component of the system may include a water vapor permeable material and / or a liquid permeable material.

[0656] In some configurations, the conduit may include at least a first conductive element and a second conductive element, and the at least one sensor signal includes a signal generated using one or more of the at least first and second conductive elements.

[0657] In some configurations, the first conductive element and the second conductive element may be spirally wound around at least the length of the conduit.

[0658] In some configurations, the first and second conductive elements are spirally wound within, through, or around the conduit.

[0659] In some configurations, the first conductive element and the second conductive element form part of the conduit wall.

[0660] In some configurations, the first conductive element may be a sensing wire.

[0661] In some configurations, the first conductive element may be at least one heater wire.

[0662] In some configurations, the second conductive element may be at least one heater wire.

[0663] In some configurations, the water vapor permeable material and / or the liquid permeable material may be a dielectric material.

[0664] In some configurations, the dielectric material may be water vapor permeable or liquid permeable.

[0665] In some configurations, the water vapor permeable dielectric material may inhibit the passage of liquid water and breathing gases into the ambient air, while allowing water to evaporate into the ambient air.

[0666] In some configurations, the other components may include a patient interface.

[0667] In some configurations, the other components may include connectors and / or adapters.

[0668] In some configurations, the conduit may include a composite conduit.

[0669] In some configurations, the conduit may include water vapor permeable and / or liquid permeable beads.

[0670] In some configurations, the water vapor permeable beads allow evaporation of water into the ambient air while inhibiting the passage of liquid water and breathing gases into the ambient air.

[0671] In some configurations, the water vapor permeable beads can be activated perfluoropolymer materials with superhydrophilic properties, hydrophilic thermoplastics, breathable thermoplastic copolyesters, woven treated fabrics exhibiting breathable properties, and / or hydrophilic polyester block copolymers.

[0672] In some configurations, the signal may be indicative of a capacitance between the first conductive element and the second conductive element.

[0673] In some configurations, the signal may be indicative of a change in capacitance between the first conductive element and the second conductive element.

[0674] In some configurations, the first conductive element and the second conductive element are separated by a distance configured to allow sensing of a capacitive charge between the first conductive element and the second conductive element.

[0675] In some configurations, the humidification system may further include a dielectric material disposed between the first conductive element and the second conductive element.

[0676] In some configurations, the method may include determining at least one value indicative of moisture based on a comparison of the measurements of the first conductive element and / or the second conductive element.

[0677] In some configurations, the signal may be indicative of the temperature of the first conductive element or the second conductive element.

[0678] In some configurations, the signal may be indicative of a change in temperature of the first conductive element or the second conductive element.

[0679] In some configurations, the signals may be indicative of the thermal conductivity of a medium between the first conductive element and the second conductive element, or at least one signal may be indicative of the thermal conductivity of a medium proximate the first conductive element or the second conductive element.

[0680] In some configurations, the signal may be indicative of the resistance of the first conductive element or the second conductive element.

[0681] In some configurations, the first conductive element or the second conductive element includes at least two portions that are electrically isolated from one another.

[0682] In some configurations, the two sections may be in series with each other.

[0683] In some configurations, the humidification system may further include a signal generator, and the controller may determine at least one value indicative of the amount of moisture in the conduit based at least in part on the magnitude and / or phase of the at least one signal.

[0684] In some configurations, the at least one value indicative of the amount of moisture in the conduit may correspond to the inductance of the conduit.

[0685] In some configurations, the at least one value indicative of the amount of moisture in the conduit corresponds to a change in inductance of the conduit.

[0686] In some configurations, a predetermined level of moisture present in a component may indicate a predetermined amount of water within the water vapor permeable and / or liquid permeable materials of the component of the system.

[0687] In some configurations, the method may include, in response to determining that a predetermined level of moisture is present in the component, initially altering an operating parameter of at least one heater wire of the conduit. In some configurations, the altering may include reducing, limiting, or disabling the operating parameter. In some configurations, the reducing or limiting includes reducing or limiting power to the at least one heater wire to a range of 3.0 W / m to 7.0 W / m.

[0688] In some configurations, the method may include maintaining the initially altered operating parameters of the heater wire in the conduit.

[0689] In some configurations, maintaining the initially altered operating parameters of the at least one heater wire of the conduit may increase the saturation moisture content of the water vapor permeable material and / or the liquid permeable material, which change may optionally be an increase relative to a predetermined saturation moisture content.

[0690] In some configurations, the method may further include altering an operating parameter of at least one heater wire in the conduit.

[0691] In some configurations, the method may further include altering the operating parameters of the heater wire of the conduit after a predetermined time period after maintaining the initially altered operating parameters.

[0692] In some configurations, a further change may be an increase in an operating parameter.

[0693] In some configurations, the method may further include altering operating parameters of a heater in the conduit in response to determining that a predetermined level of moisture is present in the component.

[0694] In some configurations, the predetermined level may be a percentage threshold of maximum sensor output. In some configurations, the percentage threshold may be 80%. In some configurations, the percentage threshold may be 90%. In some configurations, the percentage threshold may be 100%. A fully saturated permeable material may be 100%.

[0695] In some configurations, the maximum sensor output may be an output that indicates that the beads in the conduit may be saturated with moisture.

[0696] In some configurations, the maximum sensor output may be an output that indicates that a predetermined or acceptable amount of moisture may be present.

[0697] In some configurations, the method may further include maintaining the altered operating parameters of at least one heater wire of the conduit to allow drying of the water vapor permeable material and / or the liquid permeable material via evaporation to the atmosphere.

[0698] In some configurations, the method may further include maintaining the altered operating parameters to increase the rate at which moisture can be transferred across the water vapor permeable material to the atmosphere.

[0699] In some configurations, the altered operating parameters may include increased power to at least one heater wire from 10 W / m to 14 W / m.

[0700] In some configurations, the method may further include returning to normal or original operating parameters of the at least one heater of the conduit after a predetermined time period after maintaining the altered operating parameters.

[0701] In some configurations, the method may further include repeating the increasing and maintaining of the operating parameter, followed by decreasing and maintaining the operating parameter multiple times, before returning to the normal or original operating parameter.

[0702] In some configurations, the method may further include returning to normal or original operating parameters of at least one heater in the conduit in response to determining that the predetermined level of moisture in the component is below a threshold. In some configurations, the threshold may be a percentage threshold. In some configurations, the percentage threshold may be 20%. In some configurations, the percentage threshold may be 15%. In some configurations, the percentage threshold may be 0%.

[0703] In some configurations, the method may further include returning to normal or original operating parameters of at least one heater wire of the conduit in response to the predetermined amount of water molecules in the water vapor permeable material and / or the liquid permeable material being determined to be below the water molecule threshold.

[0704] In some configurations, the method may further include returning to normal or original operating parameters of at least one heater wire of the conduit in response to determining that the predetermined level of condensation in the component is below the condensation threshold.

[0705] In some configurations, the operating parameters of the at least one heater wire of the conduit may include a patient end temperature set point and / or power to the at least one heater wire.

[0706] In some configurations, the method may further include increasing the temperature of the water vapor permeable material via a heater in the conduit to increase the rate at which water passes from one side of the material to the other side of the material.

[0707] In some configurations, the method may further include increasing the temperature of the liquid permeable material via a heater in the conduit to increase the evaporation rate of liquid water within the liquid permeable material into the atmosphere.

[0708] In some configurations, the method may further include controlling a relative humidity gradient between the water vapor permeable material and / or the liquid permeable material and the atmosphere to be greater than a relative humidity gradient between the water vapor permeable material and / or the liquid permeable material and the lumen of the conduit.

[0709] In some configurations, the humidification system may include a moisture exhaust assembly configured to collect condensed water and / or return the condensed water to the humidification chamber.

[0710] In some configurations, the moisture drainage assembly may include a water trap configured to collect condensed water.

[0711] In some configurations, the moisture evacuation assembly may include at least one valve electronically coupled to the controller. The method may further include actuating the at least one valve based on the at least one sensor signal.

[0712] In some configurations, the method may further include actuating at least one valve to an open position in response to determining that a predetermined level of moisture is present in the component.

[0713] In some configurations, the method may further include actuating at least one valve to an open position in response to determining that a predetermined level of condensed water is present in the component.

[0714] In some configurations, the moisture evacuation assembly may include a moisture transport assembly configured to return moisture collected in the water trap or conduit to the humidification chamber.

[0715] In some configurations, the moisture evacuation assembly may further include a conveying conduit and / or a pump, hi some configurations, the pump may be a peristaltic pump.

[0716] In some configurations, the method may further include determining a chamber flood event based on at least one value indicative of an amount of moisture present in the component.

[0717] In some configurations, the component may be located near the outlet of the humidification chamber of the humidifier.

[0718] In some configurations, the sensor may include a temperature sensor located near the distal end of the conduit.

[0719] In some configurations, the method may further include, in response to determining the presence of the predetermined amount of moisture, determining a dew point temperature of the gas flow or a value indicative thereof based on the temperature of the gas flow sensed by the temperature sensor.

[0720] In some configurations, the method may further include, in response to determining the presence of the predetermined amount of condensed water, determining a dew point temperature or a value indicative thereof based on the temperature of the gas flow sensed by the temperature sensor.

[0721] In some configurations, the dew point temperature or a value indicative thereof may be the temperature of the gas flow as sensed by a temperature sensor.

[0722] In some configurations, the method may further include controlling a heater of the humidifier or a heater of the conduit based on the determined dew point temperature or a value indicative thereof.

[0723] In some configurations, the method may further include decreasing an operating parameter of a heater in the conduit to increase the relative humidity in the conduit and induce the formation of condensation.

[0724] In some configurations, the method may further include controlling the gas exiting the humidifier to reach a dew point temperature setpoint.

[0725] In some configurations, the method may further include, in response to determining that the patient-end temperature may be above the dew point temperature setpoint and that a predetermined level of moisture may be present, determining that a source of gas for the humidifier may be ambient air or may come from a room-loaded ventilator.

[0726] In some configurations, the method may further include controlling the temperature setpoint of the humidifier to a constant value after determining that the source of gas for the humidifier is ambient air or from a room-loaded ventilator.

[0727] In some configurations, the temperature setpoint can be the chamber exit setpoint.

[0728] In some configurations, the chamber outlet set point may correspond to the dew point of the gas.

[0729] In some configurations, the method may further include determining, in response to the conduit being connected to the humidifier and / or prior to operation of the humidifier, the presence of a predetermined level of moisture in the conduit based on at least one value indicative of the amount of moisture in the conduit.

[0730] In some configurations, the method may further include determining the presence of a predetermined level of moisture in the conduit based on a comparison between a threshold value and at least one value indicative of an amount of moisture in the conduit.

[0731] In some configurations, the method may further include determining the presence of a predetermined level of moisture in the conduit when the conduit may initially be connected to the humidifier.

[0732] In some configurations, the predetermined level of moisture present in the conduit may be a level at which a new, unused conduit may be needed, or a level at which the conduit needs to be checked for defects or further dried.

[0733] In some configurations, the method may further include generating an alarm in response to determining the presence of a predetermined level of moisture in the conduit.

[0734] In some configurations, the alert may include a visual and / or audio indication.

[0735] In some configurations, the method may further include, in response to determining the presence of a predetermined level of moisture in the conduit, preventing the conduit from being used with a humidifier by preventing power to a heater in the conduit and / or preventing use of the humidifier while connected to the conduit.

[0736] In some configurations, the conduit may not include a patient-end sensor.

[0737] In some configurations, the at least one sensor signal based on the amount of moisture present in the component may further include a signal related to the humidity of gas within the component.

[0738] In some configurations, a signal relating to a humidifier of gas within the component may be filtered from the at least one signal or ignored by the controller.

[0739] In some configurations, the method may further include determining at least one value indicative of an amount of moisture present in the component based on the at least one sensor signal, and controlling a function of the gas source to reduce the moisture in response to a predetermined amount of moisture determined to be present in the component based on the value.

[0740] In some configurations, functions may include decreasing tidal volume, increasing inspiratory rise time, decreasing inhalation-to-exhalation ratio, increasing inlet gas temperature, and / or decreasing intake air volume, and / or switching to a wall or bottled gas source.

[0741] In some configurations, the gas source may include a ventilator.

[0742] In some configurations, the gas source may include a glow generator.

[0743] In some configurations, the method may further include determining at least one value indicative of an amount of moisture present in the component based on the at least one sensor signal, and determining a depletion state of the humidification chamber based on the at least one value indicative of the amount of moisture present in the component.

[0744] In some configurations, a dehydration condition may be determined in response to detecting an increased amount of moisture and / or humidity within the component.

[0745] In some configurations, a dehydration condition may be determined in response to an increase in the amount of moisture and / or humidity within the component exceeding a threshold value.

[0746] In some configurations, the dehydrated condition may include the absence of water or the presence of a predetermined level of moisture.

[0747] In some configurations, the method may further include increasing power to a heater plate of the humidifier and / or decreasing power to at least one heater wire of a conduit configured to provide gas from the humidifier to a user to increase humidity and / or increase moisture.

[0748] In some configurations, the increased moisture may be condensation or water in a water vapor permeable and / or liquid permeable material.

[0749] In some configurations, the method may further include, in response to determining that the predetermined amount of moisture and / or humidity is below a threshold, increasing power to the heater plate and / or decreasing power to at least one heater wire, followed by determining an out-of-water condition.

[0750] A method of delivering a flow of gas to a user according to the present disclosure may use a humidifier controller that may be part of a humidification system. The humidification system may include a humidifier that heats and humidifies gas, at least one sensor that outputs at least one sensor signal based on the amount of moisture and / or humidity present in a component of the system, and a controller that controls operation of the humidifier. The method may include determining at least one value indicative of the amount of moisture and / or humidity present in the component based on the at least one sensor signal, and determining humidity of the gas flow based on the at least one value indicative of the amount of moisture and / or humidity present in the component.

[0751] In some configurations, the method may further include assuming the relative humidity to be 100% upon detecting the presence of moisture based on the value.

[0752] In some configurations, a temperature sensor located near a distal end of the conduit may transport gas from the humidifier to a user. The method may further include determining the presence of a predetermined level of moisture based on at least one value indicative of the amount of moisture and / or humidity present in the component. The method may further include determining a dew point of the gas stream as a humidity of the gas stream.

[0753] In some configurations, the humidity may be a dew point temperature, a relative humidity value, or an absolute humidity value.

[0754] In some configurations, the controller may control a humidifier and / or a heater in the conduit based on the humidity to control the target humidity.

[0755] In some configurations, the method may further include determining the presence of a predetermined level of moisture based on at least one value indicative of an amount of moisture and / or humidity present within the component.

[0756] In some configurations, the method may further include controlling at least one operating parameter of the humidification system based on the determined dew point temperature or a value indicative thereof.

[0757] In some configurations, the method may further include controlling a humidifier heater and a conduit heater based on the determined dew point temperature or a value indicative thereof.

[0758] In some configurations, the operating parameters of the humidifier heater may include at least one of a heater plate temperature set point and power to the heater plate.

[0759] In some configurations, the operating parameters of the heater in the conduit may include at least one of a patient end temperature setpoint and power to at least one heater wire.

[0760] In some configurations, the determined dew point temperature or a value indicative thereof may be the temperature of the gas flow as sensed by a temperature sensor.

[0761] In some configurations, the method may further include decreasing an operating parameter of a heater in the conduit to increase the relative humidity in the conduit and induce the formation of condensation.

[0762] In some configurations, the method may further include controlling a heater in the conduit to reach a patient-end temperature setpoint.

[0763] In some configurations, the target patient end temperature may be greater than the determined dew point temperature or a value indicative thereof.

[0764] In some configurations, the determined humidity of the gas stream may be relative humidity or absolute humidity.

[0765] In some configurations, the output of the at least one sensor may be filtered to obtain at least one portion of the signal that may be related to humidity within the component.

[0766] In some configurations, the humidification system may include a flow generator.

[0767] In some configurations, the flow generator and humidifier may be in a single housing.

[0768] In some configurations, the conduit may include at least a first conductive element and a second conductive element, and the at least one sensor signal may include a signal generated using one or more of the at least first and second conductive elements.

[0769] In some configurations, the first conductive element and the second conductive element may be spirally wound around at least the length of the conduit.

[0770] In some configurations, the first and second conductive elements may be spirally wound within, through, or around the conduit.

[0771] In some configurations, the first conductive element and the second conductive element form part of the conduit wall.

[0772] In some configurations, the first conductive element may be a sensing wire.

[0773] In some configurations, the first conductive element may be at least one heater wire.

[0774] In some configurations, the second conductive element may be a sensing wire.

[0775] In some configurations, the second conductive element may be at least one heater wire.

[0776] In some configurations, the at least one signal may be indicative of a capacitance between the first conductive element and the second conductive element.

[0777] In some configurations, the at least one signal may be indicative of a change in capacitance between the first conductive element and the second conductive element.

[0778] In some configurations, the first conductive element and the second conductive element may be separated by a distance that may allow for sensing a capacitive charge between the first conductive element and the second conductive element.

[0779] In some configurations, the humidification system may include a dielectric material disposed between the first conductive element and the second conductive element.

[0780] In some configurations, the dielectric material may be water vapor permeable or liquid permeable.

[0781] In some configurations, the water vapor permeable dielectric material may allow evaporation of water into the ambient air while inhibiting the passage of liquid water and breathing gases into the ambient air.

[0782] In some configurations, the method may further include determining at least one value indicative of moisture based on a comparison of the measurements of the first conductive element and / or the second conductive element.

[0783] In some configurations, the at least one signal may be indicative of a temperature of the first conductive element or the second conductive element.

[0784] In some configurations, the at least one signal may be indicative of a change in temperature of the first conductive element or the second conductive element.

[0785] In some configurations, the at least one signal may be indicative of the thermal conductivity of a medium between the first conductive element and the second conductive element, or the at least one signal may be indicative of the thermal conductivity of a medium proximate the first conductive element or the second conductive element.

[0786] In some configurations, the at least one signal may be indicative of a resistance of the first conductive element or the second conductive element.

[0787] In some configurations, the first conductive element or the second conductive element may include at least two portions that are electrically isolated from one another.

[0788] In some configurations, at least two portions may be in series with one another.

[0789] In some configurations, at least two portions may be parallel to one another.

[0790] In some configurations, the humidification system may further include a signal generator. The method may further include determining at least one value indicative of an amount of moisture in the conduit based at least in part on the magnitude and / or phase of the at least one signal.

[0791] In some configurations, the at least one value indicative of the amount of moisture in the conduit corresponds to an inductance of the conduit.

[0792] In some configurations, at least one value indicative of the amount of moisture in the conduit may correspond to a change in inductance of the conduit.

[0793] A method of delivering a flow of gas to a user according to the present disclosure may use a humidifier controller that may be part of a humidification system. The humidification system may include a humidifier that heats and humidifies gas, a first sensor associated with a first location, a second sensor associated with a second location, and a controller that controls operation of the humidifier. The first sensor may output at least one first sensor signal based on the amount of moisture present at the first location. The second sensor may output at least one second sensor signal based on the amount of moisture present at the second location. The method may include determining a first value indicative of the amount of humidity and / or moisture present at the first location based on the first sensor signal, and determining a second value indicative of the amount of humidity and / or moisture present at the second location based on the second sensor.

[0794] In some configurations, the first location may be associated with a first component of the system.

[0795] In some configurations, the second location may be associated with a second component of the system.

[0796] In some configurations, the first and / or second components may include a conduit, a portion of a conduit, a connector, a portion of a chamber that may be exposed to a flow of gas, and / or a patient interface.

[0797] In some configurations, the connector may include one or more adapters.

[0798] In some configurations, during normal operation of the system, the first location may be upstream of the second location.

[0799] In some configurations, the method may further include determining that no flow and / or a flow rate below a threshold may be occurring in the system by detecting a first predetermined amount of moisture at the first location and determining that a second predetermined amount of moisture may not be detected at the second location a predetermined time period after detecting the predetermined amount of moisture at the first location.

[0800] In some configurations, the method may further include determining that the gas flow rate is likely to be within a range based on readings from the first temperature sensor at the first location and the second temperature sensor at the second location in response to detecting a first predetermined amount of moisture at the first location and not detecting a second predetermined amount of moisture at the second location a predetermined period after detecting the predetermined amount of moisture at the first location.

[0801] In some configurations, the first temperature sensor may be located at the chamber outlet of the humidifier.

[0802] In some configurations, the second temperature sensor may be located at or near the patient end of the inhalation conduit or the distal end of the patient delivery conduit configured to carry gases from the humidifier to the user.

[0803] In some configurations, the method may further include determining that the flow direction is likely correct in response to the moisture at the upstream location exceeding the moisture at the downstream location.

[0804] In some configurations, the intake conduit may include an upstream location.

[0805] In some configurations, a conduit positioned between the gas source and the humidifier may include a downstream location.

[0806] In some configurations, the humidification system may include a third sensor associated with a third location of the system, the third sensor may output at least one third sensor signal based on the amount of moisture present at the third location.

[0807] In some configurations, the third location can be upstream of the first location and the second location.

[0808] In some configurations, the first location may be in the intake conduit.

[0809] In some configurations, the third location may be in the expiratory conduit.

[0810] In some configurations, the second location may be at the chamber inlet of the humidification chamber.

[0811] In some configurations, the method may further include determining a flow direction based on a direction of moisture detected from the humidifier. The method may further include, if properly connected, detecting a backflow condition in response to moisture being detected in a component upstream of the humidifier.

[0812] A method of delivering a flow of gas to a user according to the present disclosure may use a humidifier controller that may be part of a humidification system. The humidifier may include a humidifier that can heat and humidify the gas, a conduit that transports the gas from the humidifier to the user, at least one sensor that can output at least one sensor signal based on the amount of moisture present in a component of the system, and a controller that controls operation of the humidifier. The method may include determining a value indicative of the amount of moisture present in the component based on the at least one sensor signal, and controlling a function of the gas source to reduce the moisture in response to the determined amount of moisture present in the component based on the value.

[0813] In some configurations, functions may include decreasing tidal volume, increasing inspiratory rise time, decreasing the inhalation-to-exhalation ratio, increasing inlet gas temperature, and / or decreasing the amount of air entrained, and / or switching to a wall or bottled gas source.

[0814] In some configurations, the gas source may include a ventilator.

[0815] In some configurations, the gas source may include a glow generator.

[0816] In some configurations, the conduit may include at least a first conductive element and a second conductive element, and the at least one sensor signal may include a signal generated using one or more of the at least first and second conductive elements.

[0817] In some configurations, the first conductive element and the second conductive element may be spirally wound around at least the length of the conduit.

[0818] In some configurations, the first and second conductive elements may be spirally wound within, through, or around the conduit.

[0819] In some configurations, the first conductive element and the second conductive element form part of a wall of the conduit.

[0820] In some configurations, the first conductive element may be a sensing wire.

[0821] In some configurations, the first conductive element may be at least one heater wire.

[0822] In some configurations, the second conductive element may be a sensing wire.

[0823] In some configurations, the second conductive element may be at least one heater wire.

[0824] In some configurations, the at least one signal may be indicative of a capacitance between the first conductive element and the second conductive element.

[0825] In some configurations, the at least one signal may be indicative of a change in capacitance between the first conductive element and the second conductive element.

[0826] In some configurations, the first conductive element and the second conductive element may be separated by a distance that may allow for sensing a capacitive charge between the first conductive element and the second conductive element.

[0827] In some configurations, the humidification system may include a dielectric material disposed between the first conductive element and the second conductive element.

[0828] In some configurations, the dielectric material may be water vapor permeable or liquid permeable.

[0829] In some configurations, the water vapor permeable dielectric material may inhibit the passage of liquid water and breathing gases into the ambient air, while allowing water to evaporate into the ambient air.

[0830] In some configurations, the method may further include determining at least one value indicative of moisture based on a comparison of the measurements of the first conductive element and / or the second conductive element.

[0831] In some configurations, the at least one signal may be indicative of a temperature of the first conductive element or the second conductive element.

[0832] In some configurations, the at least one signal may be indicative of a change in temperature of the first conductive element or the second conductive element.

[0833] In some configurations, the at least one signal may be indicative of the thermal conductivity of a medium between the first conductive element and the second conductive element, or the at least one signal may be indicative of the thermal conductivity of a medium proximate the first conductive element or the second conductive element.

[0834] In some configurations, the at least one signal may be indicative of a resistance of the first conductive element or the second conductive element.

[0835] In some configurations, the first conductive element or the second conductive element may include at least two portions that are electrically isolated from one another.

[0836] In some configurations, at least two portions may be in series with one another.

[0837] In some configurations, at least two portions may be parallel to one another.

[0838] In some configurations, the humidification system may further include a signal generator. The method may further include determining at least one value indicative of an amount of moisture in the conduit based at least in part on the magnitude and / or phase of the at least one signal.

[0839] In some configurations, the at least one value indicative of the amount of moisture in the conduit corresponds to an inductance of the conduit.

[0840] In some configurations, the at least one value indicative of the amount of moisture in the conduit may correspond to a change in inductance of the conduit.

[0841] A method of delivering a flow of gas to a user according to the present disclosure may use a humidifier controller that may be part of a humidification system. The humidifier may include a humidifier that can heat and humidify the gas, a conduit that transports the gas from the humidifier to the user, at least one sensor that can output at least one sensor signal based on the amount of moisture present in a component of the system, and a controller that controls operation of the humidifier. The method may include determining at least one value indicative of the amount of moisture present in the component based on the at least one sensor signal, and determining a depletion status of the humidification chamber based on the at least one value indicative of the amount of moisture present in the component.

[0842] In some configurations, a dehydration condition may be determined in response to detecting an increased amount of moisture and / or humidity within the component.

[0843] In some configurations, a dehydration condition may be determined in response to an increase in the amount of moisture and / or humidity within the component exceeding a threshold value.

[0844] In some configurations, the dehydrated condition includes the absence of water or the presence of a predetermined level of moisture.

[0845] In some configurations, the method may further include increasing power to a heater plate of the humidifier and / or decreasing power to at least one heater wire of a conduit configured to provide gas from the humidifier to a user to increase humidity and / or increase moisture.

[0846] In some configurations, the increased moisture may be condensation or water in a water vapor permeable and / or liquid permeable material.

[0847] In some configurations, the method may further include, in response to determining that the predetermined amount of moisture and / or humidity is below a threshold, increasing power to the heater plate and / or decreasing power to at least one heater wire, followed by determining an out-of-water condition.

[0848] In some configurations, the conduit may include at least a first conductive element and a second conductive element, and the at least one sensor signal may include a signal generated using one or more of the at least first and second conductive elements.

[0849] In some configurations, the first conductive element and the second conductive element may be spirally wound around at least the length of the conduit.

[0850] In some configurations, the first and second conductive elements may be spirally wound within, through, or around the conduit.

[0851] In some configurations, the first conductive element and the second conductive element form part of the conduit wall.

[0852] In some configurations, the first conductive element may be a sensing wire.

[0853] In some configurations, the first conductive element may be at least one heater wire.

[0854] In some configurations, the second conductive element may be a sensing wire.

[0855] In some configurations, the second conductive element may be at least one heater wire.

[0856] In some configurations, the at least one signal may be indicative of a capacitance between the first conductive element and the second conductive element.

[0857] In some configurations, the at least one signal may be indicative of a change in capacitance between the first conductive element and the second conductive element.

[0858] In some configurations, the first conductive element and the second conductive element may be separated by a distance that may allow for sensing a capacitive charge between the first conductive element and the second conductive element.

[0859] In some configurations, the humidification system may include a dielectric material disposed between the first conductive element and the second conductive element.

[0860] In some configurations, the dielectric material may be water vapor permeable or liquid permeable.

[0861] In some configurations, the water vapor permeable dielectric material may allow evaporation of water into the ambient air while inhibiting the passage of liquid water and breathing gases into the ambient air.

[0862] In some configurations, the method may further include determining at least one value indicative of moisture based on a comparison of the measurements of the first conductive element and / or the second conductive element.

[0863] In some configurations, the at least one signal may be indicative of a temperature of the first conductive element or the second conductive element.

[0864] In some configurations, the at least one signal may be indicative of a change in temperature of the first conductive element or the second conductive element.

[0865] In some configurations, the at least one signal may be indicative of the thermal conductivity of a medium between the first conductive element and the second conductive element, or the at least one signal may be indicative of the thermal conductivity of a medium proximate the first conductive element or the second conductive element.

[0866] In some configurations, the at least one signal may be indicative of a resistance of the first conductive element or the second conductive element.

[0867] In some configurations, the first conductive element or the second conductive element may include at least two portions that are electrically isolated from one another.

[0868] In some configurations, at least two portions may be in series with one another.

[0869] In some configurations, at least two portions may be parallel to one another.

[0870] In some configurations, the humidification system may further include a signal generator. The method may further include determining at least one value indicative of an amount of moisture in the conduit based at least in part on the magnitude and / or phase of the at least one signal.

[0871] In some configurations, the at least one value indicative of the amount of moisture in the conduit corresponds to an inductance of the conduit.

[0872] In some configurations, the at least one value indicative of the amount of moisture in the conduit may correspond to a change in inductance of the conduit.

[0873] A method of delivering a flow of gas to a user according to the present disclosure may use a controller for a humidifier, which may be part of a humidification system. The humidification system may include a humidifier that heats and humidifies gas and a conduit that transports the gas from the humidifier to the user. The conduit may include a first conductive element and a second conductive element. The method may include monitoring the capacitance and / or change in capacitance of a capacitor formed between the first conductive element and the second conductive element to detect the presence of skin in proximity to or in contact with the conduit.

[0874] In some configurations, the capacitance and / or change in capacitance includes measuring a time constant, a resonant frequency, a change in the time constant, or a change in the resonant frequency of a capacitor formed between the first conductive element and the second conductive element.

[0875] In some configurations, the method may further include detecting a change in the dielectric constant of the capacitor based on the monitored capacitance and / or change in capacitance.

[0876] In some configurations, the method may further include comparing the detected change in permittivity to one or more permittivity threshold values.

[0877] In some configurations, the method may further include detecting the presence of skin near or in contact with the conduit in response to the detected change in dielectric constant exceeding one or more thresholds.

[0878] In some configurations, the method may further include outputting an alarm in response to detecting the presence of skin in proximity to or in contact with the conduit.

[0879] In some configurations, the method may further include outputting an alarm in response to detecting the presence of skin in close proximity to or in contact with the conduit, either continuously or intermittently, for a predefined duration.

[0880] In some configurations, the predefined duration may be variable based on the expected conduit surface temperature.

[0881] In some configurations, the conduit may include a dielectric material between the first and second conductive elements.

[0882] In some configurations, the first conductive element and the second conductive element are spirally wound around at least the length of the conduit.

[0883] In some configurations, the first and second conductive elements are spirally wound within, through, or around the conduit.

[0884] In some configurations, the first conductive element and the second conductive element form part of the conduit wall.

[0885] In some configurations, the first conductive element may be a sensing wire.

[0886] In some configurations, the first conductive element may be a heater wire.

[0887] In some configurations, the second conductive element may be a sensing wire.

[0888] In some configurations, the second conductive element may be a heater wire.

[0889] In some configurations, the first conductive element and the second conductive element can be separated by a distance that allows a capacitive charge to be sensed between the first conductive element and the second conductive element.

[0890] In some configurations, the first conductive element or the second conductive element may include at least two portions that are electrically isolated from one another.

[0891] In some configurations, at least two portions may be in series with one another.

[0892] In some configurations, at least two portions may be parallel to one another.

[0893] The present disclosure includes a method for determining a status of a medical humidifier configured to provide gas to a patient. The method may include reducing power to a heater wire of a respiratory tube coupled to the medical humidifier, where the medical humidifier may include a heater plate and a temperature-based flow sensor, measuring a condensate reference value, determining whether the measured condensate reference value meets an expected condensate reference value, and outputting a status of the medical humidifier to a controller of the medical humidifier in response to the measured condensate reference value not meeting the expected condensate reference value, where outputting the status of the medical humidifier may include disregarding a reading from the temperature-based flow sensor for control of the medical humidifier.

[0894] In some configurations, the method may further include determining whether the measured condensation reference value meets the expected condensation reference value includes comparing the condensation level in the breathing tube to a predetermined threshold.

[0895] In some configurations, the measured condensate baseline not meeting the expected condensate baseline may include a condensate level in the breathing tube being greater than a predetermined threshold.

[0896] In some configurations, outputting the status of the medical humidifier can include disabling a temperature-based flow sensor.

[0897] In some configurations, reducing the power to the heater wire can include disabling power to the heater wire.

[0898] In some configurations, outputting the status of the medical humidifier may include implementing an alternative method for determining a value indicative of the flow rate of the gas.

[0899] In some configurations, the alternative method may include an algorithmic method that does not require further input from a sensor.

[0900] In some configurations, outputting the status of the medical humidifier may include adjusting settings of the medical humidifier that are displayed on a user interface of the medical humidifier.

[0901] In some configurations, adjusting the settings of the medical humidifier can include at least one of adjusting PID coefficients, increasing control loop timing, and / or applying a maximum increase in the heater plate set point.

[0902] In some configurations, the state may be Heliox mode.

[0903] In some configurations, outputting the status of the medical humidifier may include determining a type of gas source.

[0904] In some configurations, power to the heater wire of the breathing tube can be reduced or disabled for a predetermined period of time.

[0905] 1. A method for determining a status of a medical humidifier configured to provide gas to a patient, the method comprising: reducing power to a heater wire of a respiratory tube coupled to the medical humidifier, the medical humidifier including a heater plate; measuring a condensate reference value; determining whether the measured condensate reference value meets an expected condensate reference value; and outputting a status of the medical humidifier to a controller of the medical humidifier in response to the measured condensate reference value not meeting the expected condensate reference value.

[0906] In some configurations, reducing power to the heater wire of the respiratory tube may include disabling power to the heater wire.

[0907] In some configurations, the power to the heater wire of the breathing tube can be reduced for a predetermined period of time.

[0908] In some configurations, determining whether the measured condensate baseline meets the expected condensate baseline may include comparing the condensate level in the breathing tube to a predetermined threshold.

[0909] In some configurations, the measured condensate baseline not meeting the expected condensate baseline may include the condensate level in the breathing tube exceeding a predetermined threshold.

[0910] In some configurations, the measured condensate baseline not meeting the expected condensate baseline may include the condensate level in the breathing tube being below a predetermined threshold.

[0911] In some configurations, the condition can include a reflux condition.

[0912] In some configurations, the measured condensate reference value not meeting the expected condensate reference value may include a condensate level in a dry line connected to the medical humidifier and the gas source exceeding a condensate level in the breathing tube.

[0913] In some configurations, outputting the status may include outputting a backflow alarm.

[0914] In some configurations, the condition may include the medical humidifier just starting up or malfunctioning.

[0915] In some configurations, the medical humidifier condition can include no flow or out of water.

[0916] In some configurations, the method may include confirming the determination by performing a flow test or a drain test.

[0917] In some configurations, the method may include indicating the condition to the patient with an audio or visual message.

[0918] In some configurations, the failure of the measured condensation reference value to meet the expected condensation reference value may include a duration for drying condensation in the breathing tube being greater than a predetermined threshold duration.

[0919] In some configurations, in response to the duration for drying condensed water in the breathing tube being greater than a predetermined threshold duration, a status is output that includes the breathing tube being covered.

[0920] In some configurations, measuring the condensate reference value can include measuring a first condensate reference value in a first section of the intake duct and a second condensate reference value in a second section of the intake duct; determining whether the measured condensate reference value meets an expected condensate reference value includes comparing the first condensate reference value in the first section of the intake duct with the second condensate reference value in the second section of the intake duct, and the condition includes an incubator used with a medical humidifier.

[0921] In some configurations, the incubator can be determined to be in use in response to the first condensate reference value of the first section being greater than the second condensate reference value of the second section.

[0922] In some configurations, the first condensate reference value and the second condensate reference value may each correspond to the presence of condensate.

[0923] In some configurations, the presence of condensed water in the first section of the intake tube and the absence of condensed water in the second section of the intake tube can indicate that the incubator is in use.

[0924] In some configurations, the method can include reducing power delivered to the heater wire in the second section of the intake tract when the incubator is in use.

[0925] In some configurations, the method can include increasing power delivered to a heater wire in a first section of the intake tract when the incubator is in use.

[0926] In some configurations, the condition can be the orientation of the breathing tube.

[0927] In some configurations, the measured condensate reference value not meeting the expected condensate reference value may include the measured condensate reference value at the patient end of the respiratory tube being greater than the measured condensate reference value at the outlet of the humidification chamber of the medical humidifier.

[0928] In some configurations, the measured condensate reference value not meeting the expected condensate reference value can include the measured condensate reference value at the patient end being greater than the measured condensate reference value in the region between the patient end and the outlet.

[0929] 1. A method for determining a status of a humidifier configured to provide gas to a patient, the method comprising: determining an activation status; reducing power to a heater plate of a medical humidifier coupled to a respiratory tube and including the heater plate; determining whether a measured condensate reference value meets an expected condensate reference value; and outputting a status of the humidifier to a controller of the humidifier based on whether the measured condensate reference value does not meet the expected condensate reference value.

[0930] In some configurations, the activation state may include determining a duration that the humidifier has been powered on and determining a duration that indicates the humidifier has recently been powered on.

[0931] In some configurations, the method may include resuming status or normal control in response to the measured condensate baseline meeting the expected condensate baseline.

[0932] In some configurations, the condition may include an alert that the breathing tube is contaminated.

[0933] In some configurations, the humidifier may have only recently been turned on.

[0934] In some configurations, the method can include powering off the heater plate and ensuring that the heater plate is substantially cool.

[0935] In some configurations, the method may include issuing a circuit moisture alarm when condensation is detected.

[0936] 1. A method for controlling power to a heating element of an inlet tube coupled to a humidifier of a humidification system, the method comprising: measuring a condensate reference value of the humidification system; determining whether the measured condensate reference value meets an expected condensate reference value; and controlling power to the heating element based at least on whether the measured condensate reference value meets the expected condensate reference value.

[0937] In some configurations, determining whether the measured condensate reference value meets the expected condensate reference value may include detecting whether the measured condensate reference value is greater than a predetermined threshold.

[0938] In some configurations, the method may further include increasing power to the heating element in response to the measured condensate metric being greater than a predetermined threshold.

[0939] In some configurations, the method may include reducing power to the heating element in response to the measured condensate reference value being below a predetermined threshold.

[0940] In some configurations, the method may include determining whether the power to the heating element is at a maximum.

[0941] In some configurations, the method may reduce the set point of a heater plate of a humidifier of a humidification system when power to the heating element is at a maximum.

[0942] In some configurations, lowering the heater plate set point can be based on determining that the measured condensate meets an expected condensate standard.

[0943] In some configurations, the inspiratory tube can be sensorless at the patient end.

[0944] In some configurations, whether the measured condensate baseline meets the expected condensate baseline can be determined without input from a patient-end-located sensor.

[0945] In some configurations, the humidification system can be sensorless at the outlet of the humidification chamber of the system.

[0946] A method for identifying a tube type in a humidification system may include determining a capacitance value of the tube and mapping the capacitance value to a tube type.

[0947] In some configurations, the method may be performed at start-up of the humidification system.

[0948] Although primarily discussed with respect to respiratory assistance devices and surgical inhalers, it should be understood that the moisture detection disclosure provided by this application may also be applied to other medical or non-medical uses of conduits or humidified gas delivery systems where it is desirable to detect the presence or level of moisture.

[0949] These and other features, aspects, and advantages of the present disclosure are described with reference to the drawings of particular implementations, which are intended to be schematic illustrations of particular implementations and not to limit the disclosure. [Brief explanation of the drawings]

[0950] [Figure 1A] 1 illustrates schematically an exemplary respiratory humidification system. [Figure 1B] 1 illustrates an exemplary humidifier. [Figure 1C] 1 illustrates an exemplary heater base and cartridge. [Figure 1D] 1C illustrates an exemplary humidifier with the electro-pneumatic connector disconnected from the humidifier of FIG. 1B. [Figure 1E] 1 illustrates an exemplary heater base and humidification chamber. [Figure 1F] 1 illustrates an exemplary cartridge. [Figure 1G] 1C illustrates an electro-pneumatic connector of the humidifier of FIG. 1B. [Figure 2] 1 schematically illustrates an exemplary surgical humidification system. [Figure 3A] 1 illustrates a side plan view of a portion of an exemplary composite conduit. [Figure 3B] 3B shows a longitudinal cross section of the upper portion of a tube similar to the exemplary composite conduit of FIG. 3A. [Figure 3C] 10 shows another longitudinal cross section illustrating a first elongated member within a composite conduit. [Figure 4A] 1 illustrates condensed water interacting with non-permeable beads in a composite conduit. [Figure 4B] 1 illustrates condensed water interacting with permeable beads in a composite conduit. [Figure 5A]1 illustrates an exemplary modeled circuit system of a condensation detection system using capacitance to detect condensation. [Figure 5B] 1 illustrates an exemplary modeled circuit system of a condensation detection system that uses capacitance to detect condensation. [Figure 6] 1 shows an exemplary modeled circuit system of a condensation detection system that uses a time constant or resonant frequency derived from an inductance to detect condensation. [Figure 7A] 1 illustrates an exemplary modeled circuit system of a condensation detection system that uses a resistor to detect condensation. [Figure 7B] 1 illustrates an exemplary modeled circuit system of a condensation detection system that uses a resistor to detect condensation. [Figure 8A] 1 illustrates an exemplary modeled circuit system for a condensation detection system that uses a resistor and a short circuit to detect condensation. [Figure 8B] 1 illustrates an exemplary modeled circuit system for a condensation detection system that uses a resistor and a short circuit to detect condensation. [Figure 9A] 1 illustrates schematically an exemplary condensation detection system using signal attenuation to detect condensation. [Figure 9B] 1 illustrates a conduit wall structure configured to detect moisture using signal attenuation. [Figure 10A] 1 illustrates an exemplary modeled circuit system of a condensation detection system using signal attenuation to detect condensation. [Figure 10B] 1 illustrates an exemplary modeled circuit system of a condensation detection system using signal attenuation to detect condensation with a monopole. [Figure 11A] 1 illustrates heat dissipation from a wire within a bead. [Figure 11B] 1 illustrates an exemplary modeled circuit system of a condensation detection system using temperature or thermal conductivity to detect condensation. [Figure 12]1 illustrates a table of time constants versus resistor voltage in a condensation detection system. [Figure 13A] 1 illustrates a flow diagram of a condensation detection mode. [Figure 13B] 1 illustrates a flow diagram of a condensate measurement mode. [Figure 13C] 10 illustrates a flow diagram of a condensation measurement mode using a resonant frequency. [Figure 13D] 10 illustrates a flow diagram of a condensate measurement mode using signal attenuation. [Figure 13E] 1 illustrates a flow diagram of a condensation measurement mode using thermal conductivity. [Figure 14] 1 illustrates exemplary beads with various conduit wall structures configured to detect moisture. [Figure 15] 1 illustrates an exemplary configuration of beads with apertures. [Figure 16] 1 illustrates a second exemplary configuration of beads with apertures. [Figure 17A] 1 illustrates a cross section of an exemplary configuration of a portion of a tube wall. [Figure 17B] 10 illustrates a cross section of a second exemplary configuration of a portion of a tube wall. [Figure 18] 1 illustrates a section of a tube wall with parallel elements. [Figure 19] 1 illustrates a portion of a tube wall along which an element can pivot. [Figure 20] 1 illustrates an example of a permeable wall portion of a conduit wall. [Figure 21] 1 illustrates a second example of a permeable wall portion of a conduit wall. [Figure 22] 1 illustrates an exemplary conduit configuration in which the elements lie in the same plane parallel to the surface of the outer conduit wall. [Figure 23] 1 illustrates an exemplary conduit cross section in which elements are provided longitudinally parallel to the lumen and spaced equidistantly around the tube. [Figure 24] 1 illustrates an exemplary conduit cross section in which additional conduit elements are wrapped around the outside of the conduit wall. [Figure 25]1 illustrates an exemplary conduit cross section in which the individual strands of two meshes can be insulated and multiplexed. [Figure 26] 10 illustrates an exemplary manner in which a humidifier controller implements various moisture management measures. [Figure 27] 1 illustrates an exemplary method of absolute humidity reduction for moisture management. [Figure 28] 1 illustrates an exemplary method of reducing relative humidity for moisture management. [Figure 29] 1 illustrates an exemplary method of moisture management using a drying strategy. [Figure 30] 1 illustrates an exemplary method of automatic condensate drainage for moisture management. [Figure 31A] 1 illustrates an exemplary passive method of moisture sensing. [Figure 31B] 1 illustrates an exemplary active method of moisture sensing. [Figure 32A] 1 illustrates an exemplary method of flow-related sensing using moisture detection as disclosed herein. [Figure 32B] 1 illustrates an exemplary method of flow-related sensing using moisture detection as disclosed herein. [Figure 32C] 1 illustrates an exemplary method of flow-related sensing using moisture detection as disclosed herein. [Figure 32D] 1 illustrates an exemplary method of flow-related sensing using moisture detection as disclosed herein. [Figure 33] 1 illustrates an exemplary method for detecting water shortage. [Figure 34A] 1 shows an exemplary humidification system with correct connections. [Figure 34B] 1 shows an exemplary humidification system with correct connections. [Figure 35A] 1 illustrates an exemplary humidification system with incorrect connections. [Figure 35B] 1 illustrates an exemplary humidification system with incorrect connections. [Figure 35C] 1 illustrates an exemplary humidification system with incorrect connections. [Figure 35D] 1 illustrates an exemplary humidification system with incorrect connections. [Figure 36]1 illustrates an exemplary humidification system capable of providing high-flow respiratory support. [Figure 37] 1 shows a flow chart of an exemplary process for gas-type and room-capture vent detection based on the condensation detection / measurement method disclosed herein. [Figure 38A] 1 illustrates a flow chart of an exemplary process for no-flow / out-of-water detection based on the condensation detection / measurement method disclosed herein. [Figure 38B] 1 illustrates a flow chart of an exemplary process for no-flow / out-of-water detection based on the condensation detection / measurement method disclosed herein. [Figure 38C] 10 shows a flowchart of an exemplary process for using no-humidity detection for fault detection. [Figure 39] 1 shows a flowchart of an exemplary process for backflow detection based on capacitance measurements disclosed herein. [Figure 40] 1 shows a flow chart of an exemplary process for coated tube detection according to the condensation detection / measurement method disclosed herein. [Figure 41] 1 shows a flow chart of an exemplary process for contaminated tube detection according to the condensation detection / measurement method disclosed herein. [Figure 42] 1 shows a flow chart of an exemplary process for incubator occupancy detection based on the condensation detection / measurement method disclosed herein. [Figure 43] 1 shows a flow chart of an exemplary process for tube type detection based on the condensation detection / measurement method disclosed herein. [Figure 44] 1 shows a flowchart of an exemplary process for tube orientation detection in accordance with the condensation detection and measurement methods disclosed herein. [Figure 45] 10 illustrates a flowchart of an exemplary process for calculating power to intake tube heating element power based on the condensation detection / measurement method disclosed herein. [Figure 46]10 illustrates a flowchart of an exemplary process for calculating power to multiple zones of an intake tube heating element based on the condensation detection / measurement method disclosed herein. [Figure 47] An exemplary longitudinal cross section of a bubble tube 4701 in a quadruple helix configuration is shown. DETAILED DESCRIPTION OF THE INVENTION

[0951] While specific implementations and examples are described below, those skilled in the art will understand that the disclosure extends beyond the specifically disclosed implementations and / or uses, as well as obvious modifications and equivalents thereof. It is intended that the scope of the disclosure disclosed herein should not be limited by any specific implementations described below. For example, the dimensions provided in this disclosure are exemplary and not limiting. Similarly, while primarily described with respect to respiratory or surgical humidification systems, the disclosure is applicable to any tubing arrangement where it is desirable to measure moisture. While the examples below describe detecting the presence, and optionally the amount and / or location, of moisture within a conduit, e.g., condensation, water, bodily fluids such as saliva, blood, mucus, or any liquid, the disclosed methods and apparatus may alternatively or additionally be applied to detecting the humidity of gases and / or the presence of other moisture or fluids within a conduit system.

[0952] Exemplary Gas Delivery System 1 shows a schematic diagram of an exemplary respiratory support device including a conduit system with one or more conduits 103, 117, a patient interface 115, and a Y-piece 113. The respiratory support device may be a mechanical ventilator, a continuous, variable, or bilevel positive airway pressure (PAP) system, or may provide another form of respiratory therapy, such as high-flow therapy.

[0953] Gas may be delivered through the breathing circuit of Figure 1 as follows: dry or relatively dry gas passes from gas source 105 through dry line or supply tube 157 to humidifier 107, which humidifies the dry gas. Gas source 105 may be, for example, a ventilator or blower. Gas source 105 may be separate from humidifier 107 or may be integrated with humidifier 107 in a single housing.

[0954] The humidifier 107 connects via port 111 to the end 109 of a conduit, such as the inspiratory tube 103. The inspiratory tube 103 is connected to the patient 101 via a patient interface 115, optionally using a Y-piece 113. An optional expiratory conduit, such as an expiratory tube 117, is similarly connected to the patient interface 115 via the Y-piece 113. The expiratory tube 117 can be configured to direct exhaled gases away from the patient 101. As shown in FIG. 1 , the expiratory tube 117 returns exhaled gases from the patient 101 to the gas source 105. Alternatively, the inspiratory tube 103 connects directly to the patient interface 115 without the Y-piece 113. In such an embodiment, the exhaled gases can flow directly to the ambient environment without the need for an expiratory tube.

[0955] The inspiratory tube 103 may include conductive elements such as a heater, sensor, and / or moisture sensing element 145. Similarly, the expiratory tube 117 may include a heater, sensor, and / or moisture sensing element 147. Additionally, the Y-piece 113 and patient interface 115 may also include heaters, sensors, and / or moisture sensing elements. As described in more detail below, the heaters, sensors, and / or moisture sensing elements 145, 147 may be wires or filaments.

[0956] As shown in the exemplary respiratory assistance device of FIG. 1 , dry or relatively dry gases enter gas source 105 through vent 119. Fan 121 may enhance the flow of gas into gas source 105 by drawing air or other gases through vent 119. Fan 121 may be a variable speed fan, for example, where electronic controller 123 controls the speed of the fan. Electronic controller 123 may also, in some implementations, be controlled by second electronic controller 125, or vice versa.

[0957] The humidifier 107 may include a humidification chamber 129 containing a volume of water 130 or other suitable humidification liquid. The humidification chamber 129 may be removable from the humidifier 107. The humidification chamber 129 may include a high-temperature, thermally conductive base (e.g., an aluminum base) in contact with or associated with a heater plate 131 on the humidifier 107. Examples in this disclosure describe a heater plate as the heater for the humidifier and a heater wire as the heater for the tubing. It will be understood that other heaters for the humidifier are possible (e.g., heater wire, or other types of heating elements) and other heaters for the conduits are possible (e.g., other types of heating elements).

[0958] The humidifier 107 may also include an electronic control unit. In FIG. 1 , for example, the humidifier 107 includes an electronic, analog, or digital controller 125. The controller 125 may be a microprocessor-based controller that executes computer software commands stored in associated memory. In response to humidity, temperature, or other feedback values ​​provided via the user interface 133 and / or integrated sensors, the controller 125 determines the heat, flow, pressure, and / or other variables used to provide humidified gas to the patient (also referred to herein as the user). The user interface 133 can be one or more hardware buttons and / or a display or touchscreen display. The user interface 133 can provide audio and / or visual feedback to the user. When condensation is detected, any number of alarms, warnings, feedback, indicators, or instructions can be provided to the user to indicate the presence, extent, or treatment of the condensation condition. For example, the user interface 133 can provide an alarm when condensation is detected. The user interface 133 can provide a visual indication of the condensation. The user interface 133 may also provide animations to instruct the user on how to properly drain the condensate.

[0959] Any suitable patient interface may be used. Patient interface is a broad term that should be given its ordinary and customary meaning to those skilled in the art (i.e., not limited to any specific or customized meaning), and includes, without limitation, masks (such as tracheal masks, face masks, and nasal masks), endotracheal tubes, tracheostomy tubes, cannulas, and nasal pillows. A temperature probe 135 may be incorporated into or coupled to the inspiratory tube 103 near the Y-piece 113, or directly to the Y-piece 113 or patient interface 115. The temperature probe 135 monitors the temperature of the gas stream near or at the patient interface 115. Heated wires (such as moisture sensing element 145) can be used to regulate the temperature of the patient interface 115, Y-piece 113, and / or inspiratory tubing 103 to maintain the temperature of the gas stream above the saturation temperature (which is the dew point temperature of the gas stream), thereby reducing the chance of unwanted condensation and / or delivering gas at an optimal temperature for patient treatment (e.g., 40°C at the patient end of the inspiratory tubing and / or 37°C for the patient in non-invasive treatments). As shown in Figure 1, exhaled gases are optionally returned from the patient interface 115 to the gas source 105 via the exhalation tubing 117.

[0960] 1 may be readily adapted for other applications involving the delivery of heated and / or humidified gas flows to a user or patient, including, but not limited to, laparoscopy, and the like. Such applications may use alternative gases, operating parameters (e.g., flow, pressure, temperature, or humidity), and patient interfaces. Furthermore, while shown with respect to separate ventilator and humidification systems, it should be understood that the present disclosure may also be used with an integrated ventilator / blower and humidification system.

[0961] The system of Figure 1 can also provide oxygen (O2) or O2 concentration to the user through port 149. The system of Figure 1 can receive O2 from a remote source and / or by mixing ambient air with incoming O2 from a remote source. Mixing of ambient air with incoming O2 can occur via a venturi or similar inlet located within gas source 105 or humidifier 107.

[0962] 1B illustrates an exemplary respiratory humidifier in more detail. Aside from the differences described below, the humidifier is otherwise similar to humidifier 107 of the system illustrated in FIG.

[0963] The illustrated humidifier includes a heater base 151 with a heater plate 152, a user interface 154, and a control device 125 (see FIG. 1), a removable and replaceable humidification chamber 153, and a removable and replaceable cartridge 155. FIGS. 1C-1F show the cartridge 155 in more detail. As shown in FIGS. 1B and 1D, an intake tube 159 is connectable to the cartridge 155. The humidification chamber 153 is received by the heater base 151 in thermal contact with the heater plate 152. In some embodiments, the cartridge 155 is not removable and replaceable but is integral with or permanently connected to the heater base.

[0964] The cartridge 155 houses electronics and one or more sensors that, in use, sense one or more properties of the gas flowing through the humidification chamber 153. The sensors may be provided on probes that, in use, protrude from the cartridge 155 through holes in the inlet or outlet of the humidification chamber 153. The cartridge 155 also includes an electrical connector 161 that provides electrical connection with the heater base 151 for communication (e.g., serial communication) with a controller. The cartridge 155 may also partially or entirely house electronics configured to determine or estimate capacitance or changes in capacitance of the inlet tube 159 and communicate this with the controller via the electrical connector 161, as described in more detail below. The cartridge 155 therefore preferably includes a microcontroller communicatively connected to the sensors and controller. Alternatively or additionally, a controller provided partially or entirely within the heater plate 151 may be configured to determine or estimate capacitance from data received from the sensors via the electrical connection.

[0965] In use, the outlet of the dry line tubing 157, which receives the flow of gas from the gas source, is pneumatically connected to the inlet of the humidification chamber 153, and the inspiratory tubing 159, which includes an electro-pneumatic connector 161, is electrically connected to the cartridge 155 and pneumatically connected to the outlet of the humidification chamber 153 for delivering a humidified flow of gas towards the patient. The electro-pneumatic connector 161 provides a releasable, lockable connection with the humidification chamber 153 and / or cartridge 155 and includes a release button 163.

[0966] The electro-pneumatic connector 161, shown in further detail in FIG. 1G, includes electrical terminals or pads 171 that couple to a pair of sensor wires 173 and a pair of heater wires 175 embedded within the inhalation tube 159, respectively, to form respective sensing and heating loops. The electrical terminals or pads 171 can be electrically coupled to an identification resistor or other identification element embedded within the electro-pneumatic connector 161, which can be used by the humidifier to identify the type of inhalation tube coupled to the cartridge 155. Alternatively, the type of inhalation tube coupled to the cartridge 155 may be identified using the method shown in FIG. 43 and further described below. As described in further detail, moisture within the inhalation conduit 159 may be detected from a capacitance measurement between electrically isolated heating and sensing loops. The connector 161 may further include additional wires or conductors configured to detect moisture within the inhalation tube 159, either alone or in combination with one or more of the sensor or heater wires 173, 175. Corresponding moisture detection terminals or pads 171 may be connected to the additional wires or conductors. Alternatively, an additional wire or conductor can be electrically coupled to the "identification" terminal or pad in place of an identification resistor or other identification element, and can optionally have a predetermined resistance (or resistance within a predetermined range), capacitance, or resonant frequency unique to each tubing model. This arrangement provides the dual function of identification and moisture detection. For example, a moisture detection wire with a specific resistance value can be used in a humidifier to identify the tubing as configured for capacitive moisture detection and / or to allow calibration of the cartridge and / or heater base for moisture detection with that particular tubing model.

[0967] The aforementioned electrical terminals or pads 171 of the electro-pneumatic connector 161 are configured to electrically connect with corresponding pads or terminals on the cartridge (155 in FIGS. 1B and 1D). Thus, in embodiments with a removable and replaceable cartridge 155, an existing humidifier base can be retrofitted with a replacement cartridge that includes the additional electronics and / or electrical pads or terminals necessary to detect moisture in the inspiratory tube. Similarly, the disclosed humidifiers, such as those shown in FIGS. 1C-1E, can be retrofitted with replacement cartridges to accommodate alternative inspiratory tube routings, as needed. Alternatively, the electrical terminals or pads on the electro-pneumatic connector and cartridge can be arranged such that selected "core" terminals or pads make electrical connections with corresponding terminals or pads on two or more different cartridges, and "optional" terminals or pads make electrical connections only with specific terminals or pads on selected cartridges configured to use those connections. Tubing can be matched to specific cartridges based on the terminals or pads.

[0968] The distal (patient) end of the inspiratory conduit 159 is provided with a temperature sensor electrically coupled to a pair of embedded sensing wires 173 to form a sensing loop, and heating wires 175 are also electrically coupled to each other to form a heating loop. Additional wires or conductors of the connector 161 described above may be electrically coupled at the distal end of the tube as well, although this may not be necessary in at least some embodiments.

[0969] The cartridge 155 may further include a connector and / or cable configured to connect to a corresponding connector on the expiratory conduit (147 in FIG. 1A) to provide power to the expiratory heating wire. In some implementations, the cartridge 155 and expiratory conduit 147 may alternatively or additionally be configured to detect moisture in the expiratory tube 147 with a connector and / or cable providing the necessary electrical connection.

[0970] FIG. 2 illustrates an exemplary surgical insufflation device that can be used, for example, in laparoscopic surgery. A laparoscopic cannula 207 can be connected to a gas delivery conduit 206, for example, via a Luer lock connector 4. The cannula 207 can be used to deliver gas into a surgical site, such as within a patient's cavity 2. The cannula 207 can include one or more passageways for directing gas and / or one or more surgical instruments into the surgical cavity. The surgical instrument can be a scope, an electrocautery tool, or any other instrument. The surgical instrument can be connected to an imaging device, which can have a screen. The imaging device can be part of a surgical set, which can include multiple surgical tools and / or devices.

[0971] The humidification chamber 205 may optionally or preferably be connected in series to a gas supply 9 via a further conduit 204. The gas supply 9 may provide one or more inhalation gases, such as carbon dioxide, to the humidification chamber 205. The gas supply may provide a continuous or intermittent gas flow. The gas may be humidified as it passes through the humidification chamber 205, which may contain a quantity of water 220.

[0972] A humidifier incorporating the humidification chamber 205 can be any suitable type or kind of humidifier. The humidification chamber 205 can include a chamber formed of metal or alternatively plastic with a conductive base sealed thereto. The base can be in contact with a heater plate 212 during use. A quantity of water 220 contained within the chamber 205 can be heated by the heater plate 212, which can be under the control of a humidifier controller or control means 208. The quantity of water 220 within the chamber 205 can be heated to evaporate, mixing the water vapor with the gas flowing through the chamber 205 to heat and humidify the gas.

[0973] The controller or control means 208 may be housed within a humidifier base unit 221, which may also house a heater plate 212. The heater plate 212 may have an electric heating element therein or in thermal contact with it. The humidifier base unit 221 and / or heater plate 212 may be removably engageable with the humidification chamber 205. The humidification chamber 205 may alternatively or additionally include an integral heater.

[0974] A temperature sensor may also be placed at or near the outlet 209 to monitor the temperature of the humidified gas exiting the humidification chamber 205 through the outlet 209. Additional sensors may also optionally be incorporated to sense, for example, properties of the gas (such as temperature, humidity, flow, or other) at the patient end and / or elsewhere along the gas delivery conduit 206. The temperature sensor may be coupled to the controller 208 through a sensor wire within, throughout, or around the gas delivery conduit 206.

[0975] Gas can exit through the humidifier outlet 209 and enter the gas delivery conduit 206. The gas can move through the gas delivery conduit 206 and through the cannula 207 into the patient's surgical cavity 2, thereby expanding and maintaining intracavity pressure. Preferably, the gas exiting the humidification chamber 205 outlet 209 can have a relative humidity of approximately 100%. The gas travels along the gas delivery conduit 206. As with all of the various exemplary humidification systems discussed above, "rainout" can occur, causing water vapor to condense on the walls of the gas delivery conduit 206. Condensed water can have undesirable effects, such as detrimentally reducing the moisture content of the gas delivered to the patient. To reduce and / or minimize the occurrence of condensation within the gas delivery conduit 206, a heater wire 210 can be provided within, throughout, or around the gas delivery conduit 206. The heater wire 210 may be electronically connected to the humidifier base unit 221, for example, by an electro-pneumatic connector in the gas delivery conduit 206.

[0976] Composite Tube FIG. 3A shows a side plan view of a portion of an exemplary composite conduit or tube 301. Generally, the composite tube 301 includes a first elongated member 303 and a second elongated member 305. Member is a broad term that should be given its ordinary and customary meaning to those skilled in the art and should not be limited to any specific or customized meaning, including, without limitation, a unitary section, a unitary component, and distinct components. Thus, while FIG. 3A illustrates an implementation comprised of two distinct components, it will be recognized that in other implementations, the first elongated member 303 and the second elongated member 305 can represent regions within a tube formed from a single material. In some configurations, the first elongated member 303 can represent a hollow section of the tube, as described below, while the second elongated member 305 can represent a structural support or reinforcement section of the tube that adds structural support to the hollow section. The hollow section and structural support section can have a helical configuration, as described herein. Composite tube 301 may be used to form inhalation and / or exhalation tubes of any type of system, such as those described above, coaxial tubes, such as those described above, or any other tubes as described anywhere in this disclosure.

[0977] In this example, the first elongated member 303 includes an elongated tube having a longitudinal axis LA-LA and a hollow body helically wound to form at least a portion of the lumen 307 extending along the longitudinal axis LA-LA. In at least one implementation, the first elongated member 303 is a helical tubular member. Preferably, the first elongated member 303 is flexible. Additionally, the first elongated member 303 is preferably transparent, or at least translucent or semi-opaque. A degree of light transmission allows a caregiver or user to inspect the lumen 307 for blockages or contaminants or to identify the presence of condensed water. Various plastics, including medical-grade plastics, are suitable for the body of the first elongated member 303. Examples of suitable materials include polyolefin elastomers, polyether block amides, thermoplastic copolyester elastomers, EPDM polypropylene blends, and thermoplastic polyurethanes.

[0978] The hollow body structure of the first elongated member 303 contributes to the insulating properties of the composite tube 301. Insulated tube 301 is desirable because it reduces heat loss, allowing tube 301 to deliver gas from the heated humidifier to the patient with improved heat loss and condensation formation while consuming less energy than an uninsulated tube (or a tube lacking a hollow body member for insulation).

[0979] The hollow portion of the first elongated member 303 may optionally be filled with a gas. The gas may be air, which has a low thermal conductivity (2.62x10 at 300K). -2 Gases more viscous than air can also be used advantageously, since higher viscosity reduces convective heat transfer. Thus, argon (17.72 x 10 at 300 K) -3 W / mK), krypton (9.43x10 at 300K) -3 W / mK), and xenon (5.65x10 at 300K) -3Gases such as HCl (Hg, HCl / ...

[0980] The second elongated member 305 is also helically wound and joined to the first elongated member 303 between adjacent twists of the first elongated member 303. The second elongated member 305 forms at least a portion of the lumen 307 of the elongated tube. The second elongated member 305 acts as structural support for the first elongated member 303.

[0981] The second elongate member 305 can optionally be wider at the base (near the lumen 307) and narrower at the top. For example, the second elongate member can be generally triangular, generally T-shaped, or generally Y-shaped. However, any shape that matches the outer shape of the corresponding first elongate member 303 is suitable.

[0982] The second elongated member 305 can be flexible to facilitate bending of the tube. The second elongated member 305 can be less flexible than the first elongated member 303. This improves the second elongated member's ability to provide structural support to the first elongated member 303. For example, the second elongated member 305 preferably has a modulus of 30-50 MPa (or approximately 30-50 MPa). The first elongated member 303 has a modulus less than the second elongated member 305. The second elongated member 305 can be solid or nearly solid. Additionally, the second elongated member 305 can encapsulate or house a conductive material, such as a heating element, a sensing wire, or an antenna. In some embodiments, the second elongated member 305 can protrude. The heating element (also referred to herein as a heating wire, heating filament, or filament) can minimize cold surfaces on which condensation from moisture-rich air can form. The heating element can also be used to vary the temperature distribution of the gas within the lumen 307 of the composite tube 301. Sensing wires, coupled with sensors such as temperature sensors, integrated into or otherwise provided at the distal end of the tube, provide measurements that, in use, may be used by a gas delivery system, such as the humidifier 107, in a feedback control system to adjust the amount of heat provided by one or more heating wires or other components of the gas delivery system. Various polymers and plastics, including medical-grade plastics, are suitable for the body of the second elongated member 305. Examples of suitable materials include polyolefin elastomers, polyether block amides, thermoplastic copolyester elastomers, EPDM polypropylene blends, thermoplastic polyurethanes, thermoset and thermochromic materials. In some configurations, the first elongated member 303 and the second elongated member 305 can be made from the same material. The second elongated member 305 can also be made from a material of a different color than the first elongated member 303 and can be transparent, translucent, or opaque.For example, the first elongate member 303 may be made from a clear plastic, and the second elongate member 305 may be made from an opaque blue (or other color) plastic. Further material options are described below, particularly with respect to transparent or breathable materials.

[0983] This spirally wound structure with a flexible hollow body and integral support can provide crush resistance while leaving the conduit wall sufficiently flexible to allow short-radius bending without kinking, obstruction, or collapse. Preferably, the tube can be bent around a 25 mm diameter metal cylinder without kinking, obstruction, or collapse, as defined, for example, by the test for increased flow resistance with bending according to ISO 5367:2014(E). This structure can also provide a substantially smooth lumen 307 surface (tube bore), which helps keep the tube free of deposits and improves gas flow. The hollow body of the first elongated member 303 has been found to improve the insulating properties of the tube while allowing it to remain lightweight. However, in other embodiments, a non-smooth lumen surface or tube bore may be preferred, as described below.

[0984] The composite tube 301 can be used as an expiratory and / or inspiratory tube in a conduit system or part of a conduit system.

[0985] The first elongate member 303 and the second elongate member 305 (with their enclosed heating elements and sensing wires) can each be extruded adjacent to one another on a rotating mandrel in a double helix arrangement to form a continuous length of tubing. The continuous length of tubing can be cut to any desired length suitable for use in a conduit system (severing the heating elements and sensing wires in the process) and terminated with appropriate connectors at each end. For example, with reference to the system of FIG. 1 , the inspiratory conduit can be terminated at one end with a chamber-end connector for pneumatic coupling to the humidification chamber 129 and electrical coupling to the humidifier 107 (or humidifier cartridge), and at the other end with a patient-end connector for pneumatic coupling to the Y-piece 135 or patient interface 115. The patient-end connector can include an integrated temperature sensor that is electrically connected to the severed sensing wires to form a sensing circuit. At or near the patient-end connector, the severed heating elements can also be electrically connected to each other to form a heating circuit. Alternatively, the heating element and / or sensing wires may terminate with respective heating and / or sensing terminations at the patient-end connector for electrical connection with another component of the conduit system. At the chamber-end connector, the disconnected heating element and sensing wires may be electrically connected with respective heating and / or sensing terminations integrated within the chamber-end connector. The chamber-end connector may be configured to simultaneously pneumatically connect with the outlet of the humidification chamber 129 and electrically connect with the humidifier 107. Alternatively, the chamber-end connector may include electrical sockets, for example, for independent pneumatic and electrical connection with each of the humidification chamber 129 and the humidifier 107.

[0986] In some embodiments, the tube may further include one or more intermediate connectors, such as a midpoint connector with a diode that allows selective heating of either a first half or section or the entire length of the tube by supplying power to the heater wire in a first polarity or a second polarity. For example, the first half or section of the tube may be supplied with power in a first polarity, and the entire length of the tube may be supplied with power in a second polarity. The midpoint connector may additionally or alternatively include an additional sensor, such as a temperature sensor. Alternatively, two or more zones of the tube may be configured to be controlled completely independently of one another, such that any one or more of the zones may be selectively heated and / or sensed.

[0987] FIG. 3B shows a longitudinal cross-section of the upper portion of the exemplary composite tube 301 of FIG. 3A. FIG. 3B has the same orientation as FIG. 3A. This example further illustrates the hollow body shape of the first elongated member 303. As can be seen in this example, the first elongated member 303 forms a longitudinal cross-section of an enclosed portion 309. This cross-section of the first elongated member 303 appears as a "bubble" in FIG. 3B. Portion 309 of the first elongated member 303 overlaps the adjacent winding of the second elongated member 305. A portion 311 of the first elongated member 303 forms the wall of the lumen (tube bore).

[0988] The gaps 313 between adjacent turns of the first elongated member 303 can improve the overall insulating properties of the composite tube 301. Furthermore, the gaps 313 between adjacent cells can increase the thermal resistivity (R-value), correspondingly decreasing the thermal conductivity of the composite tube 301. This gap configuration also improves the flexibility of the composite tube 301 by allowing for shorter bend radii. A T-shaped second elongated member 305, as shown in FIG. 3B, can help maintain the gaps 313 between adjacent cells. Nevertheless, adjacent portions of the first elongated member 303 can be configured to contact. For example, adjacent portions may or may not be bonded to each other. In such a bonded configuration, or when adjacent portions are not bonded, a water-permeable or wicking material-made elongated member, such as the T-shaped second elongated member 305 or other shaped members, can be included to improve capacitive measurements in the presence of condensed water, as described further below.

[0989] One or more conductive materials (referred to herein as "elements," "conductive elements," or "filaments") can be arranged within the second elongated member 305 for heating and / or sensing the gas flow. In this example, two elements 315 are encapsulated within the second elongated member 305, one on each side of the vertical section of the "T." The elements 315 comprise 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 305 is selected so that it does not react with the metal within the elements 315 when the elements 315 reach their operating temperature. The elements 315 can be spaced from the lumen 307 so that they are not exposed to the lumen 307. At one end of the composite tube, a pair of elements can be formed into a connecting loop.

[0990] Multiple elements can be arranged within the second elongated member 305. The elements can be electrically connected together to share a common rail. A first element, such as a heating element, can be arranged on a first side of the second elongated member 305. A second element, such as a sensing element or wire, can be arranged on a second side of the second elongated member 305. An optional third element, such as a ground element shown in FIG. 3C , can be arranged between the first and second elements. The first, second, and / or third elements can be connected together at one end of the second elongated member 305. The third element can also be configured to emit power to heat the tube and / or gas, and the humidifier can include a bias generator circuit configured to allow a sensor connected to the second elongated member 305 to be read whether or not the heater wire is powered. Alternatively, as shown in Figures 4A-4B, four wires (two heating element pairs and two sensing wire pairs) can be provided, with the respective ends of each pair electrically connected, i.e., continuous, at the distal end of the tubing so that the heating and sensing circuits are independent of each other. Arrangements can include one, two, three, four, or more wires. These elements can be connected to the gas supply system using electrical connectors separate from or integrated with the pneumatic connector of the composite tubing. The pitch of the helically wound conduit (e.g., the pitch of the first and second elongated members) can be varied (e.g., decreased) to enhance capacitive measurements in some areas of the conduit, as described in further detail below.

[0991] In other implementations, the tube may include one or more additional wires or conductive elements, commonly referred to as capacitive wires, specifically provided for the purpose of capacitively coupling with another wire or circuit. The capacitive wires do not necessarily form a closed loop or circuit, as heating and sensing wires generally do. The capacitive wires also do not necessarily need to extend the entire length of the tube. In some implementations, there may be multiple capacitive wires of different lengths, which may allow the general location of any moisture within the tube to be detected.

[0992] In some embodiments, a composite tube can include respective pairs of first and second elongated members wound in a quadruple helix configuration. FIG. 47 shows a cross section of a bubble tube 4701 in a quadruple helix configuration. The tube 4701 includes a first pair of first elongated members 4710 and second elongated members 4720 and a second pair of first elongated members 4730 and second elongated members 4740. In particular, a sensing wire is provided on one of the second elongated members (e.g., second elongated member 4740), and a heating wire and at least one capacitive wire are provided on the other second elongated member (e.g., second elongated member 4720), separated by a pair of first elongated members 4710, 4730, respectively. The first elongated members of the pair can be the same or different from each other. Such an arrangement may be preferred to provide moisture-dependent capacitive coupling between the heating wire and the capacitive wire while minimizing capacitive coupling with the sensing wire, which may affect the sensor measurements.

[0993] The above description of composite tubing is not meant to be limiting and is provided by way of example only. It should be understood that any other type of conduit can be used for condensation detection according to the present disclosure. This includes tubing of any size, shape, or configuration incorporating heating, sensor, and / or condensation detection elements within the tube's walls and / or lumen, such as elements that float or hang freely within or outside the tube, or elements that are attached to one or more locations within or outside the tube, as shown in FIG. 3C. As shown in FIG. 3C, tube 391 includes wall 393 and floating or hanging element 395. As will be appreciated by those skilled in the art, a "floating" element within the lumen (not enclosed within the wall) may be provided as shown, coiled or wrapped within the lumen and held in place within the lumen by a retainer, or in other configurations known in the art. As described in more detail below, moisture may be detected from variations in capacitance between adjacent elements. Different conduit structures have different characteristics that can be exploited to enhance this detection. Spiral-wound elements, such as the heating elements and sensing wires described above with respect to Figures 3A-3B, can have relatively high capacitance characteristics due to the length of the elements and may detect condensation anywhere on the conduit wall. On the other hand, floating elements within tubes may have the advantage of tending to sit at the bottom of the conduit where condensation may also accumulate, which may be preferable in some arrangements. Floating elements also do not need to be extruded with the tube, allowing for more flexibility in the design of the floating element (e.g., materials, manufacturing methods, and / or dimensional variations along the length of the floating element). As should be appreciated by those skilled in the art, there are many different types of tubes and elements known and used in the art, any of which may be used in the present disclosure.

[0994] Condensation detection Condensation detection based on capacitance and inductance When two or more elements or wires are placed within a conduit, parasitic capacitance (reactance and / or inductance) may exist between them. This parasitic capacitance can adversely affect sensor measurements, and therefore efforts have been made to mitigate the parasitic capacitance effect (e.g., as discussed in International Publication No. WO2018116187, incorporated herein by reference in its entirety). However, it has been discovered that parasitic capacitance can be dependent on moisture within the conduit and thus can be used as an indication and / or measurement of humidity, moisture, fluid, and / or condensate (collectively referred to herein as "condensate" for brevity). Applicant has surprisingly discovered that in this manner, the elements can be treated as the "plates" of a capacitor, and the change in capacitance due to the presence of moisture can be observed and measured. In certain embodiments, measuring capacitance does not require any type of sensor to be exposed to the flow path of gas within the conduit, while in other embodiments, any known sensor can be used to measure capacitance. By utilizing existing conductive elements in the conduit (e.g., existing heating or sensor elements or wires), this discovery provides an inexpensive and accurate solution for detecting the presence and / or amount of condensation in a conduit without significantly modifying the conduit or gas delivery system. Alternatively, additional conductive elements dedicated to this purpose can be included in the tube. This allows the tube to be designed to minimize adverse or undesirable effects of the parasitic capacitance of the sensing wires and / or to increase sensitivity to condensation without compromising the performance of the heating and / or sensing wires. For example, the heating element and moisture sensing element may be provided in close proximity to each other, where the sensing wires are spaced apart and / or embedded in a non-permeable material. In another arrangement, the tube may include a sensing wire embedded in the conduit wall and a heating element and dedicated condensation sensing wire or moisture sensing element floating freely within the lumen, as partially shown in FIG. 3C. In another arrangement, as disclosed above, the sensing wire may be provided in a separate second elongated member 305 relative to the heating element and moisture sensing element or wire in the quadruple helix tube.

[0995] The dielectric constant, and therefore capacitance, between two electrically isolated conductive elements (e.g., for a sensing element, heating element, etc.) varies depending not only on the distance between the elements but also on the presence or amount of condensed water on the inner wall surface of the conduit (or, in the case of a water vapor-permeable wall material, the amount of individual water molecules that migrate into the wall). Generally, dielectric constant and capacitance are positively related. Moisture near conductive elements, such as on the inner wall surface of a conduit, can have a parasitic or peripheral effect on capacitance. In other words, for elements at a fixed distance, the inherent capacitance of a conduit can change depending on the amount and proximity of condensed water present within the tube. The distance at which elements are separated requires design consideration to properly balance the use of elements. For example, the elements must be close enough to create detectable capacitance, yet spaced far enough apart so that there is a sufficient moisture change to create a detectable change in capacitance. Thus, the distance at which elements are separated can be designed so that the elements are close enough to create detectable capacitance and spaced far enough apart so that there is a sufficient moisture change to create a detectable change in capacitance.

[0996] Although the conductive elements (referred to herein for brevity as "elements") are primarily described in terms of wires or filaments, such as heater wires or sensor wires, it should be understood that the elements can be other than physical wires. For example, the elements can be conductive plates, polymers, tapes or ribbons, conductive inks, conductive threads, or any other conductive material.

[0997] FIG. 4A schematically illustrates how condensed water 407 present on the conduit wall 401, which now contains each pair of conductive heating and sensing elements 415, as well as on the inner wall of the tube, affects the dielectric between any two electrically insulating wires. In some implementations, the elongated members 305 of FIGS. 3A-3B are beads 405. For example, in FIG. 4A , the beads 405 are impermeable to fluids. It has been found that condensed water 407 in this arrangement, although adjacent to the heating element 415 and the sensing element 415 rather than directly between them, causes a measurable change in the parasitic capacitance between the conductive elements. Alternatively or additionally, as described in more detail below, the profile of the beads 405 may be modified to increase sensitivity to condensed water, for example, by providing a channel between adjacent conductive elements that opens to the lumen for receiving the condensed water 407 between the two elements 415.

[0998] The wires may be provided side by side in an alternating or interleaved arrangement, i.e., heat-sense-heat-sense, to increase the capacitance between elements 415. Other arrangements, such as heat-sense-sense-heat or heat-heat-sense-sense, may alternatively be used.

[0999] FIG. 4B schematically illustrates a second example, which is either water vapor permeable and / or fluid permeable. It has been found that water vapor permeable materials allow for more accurate detection because the parasitic capacitance between wires increases the effect of condensed water when coupled. In one example, the material can be water vapor permeable, allowing water molecules to evaporate into the ambient air while effectively blocking the passage of liquid water and respiratory gases to the ambient air. While using water vapor or fluid permeable materials in the inspiratory tube is generally undesirable because it reduces the humidity of the gas delivered to the patient, drying of this gas is minimized when used only in the bead 405. Furthermore, this material can be covered on the outside by another material that is not water vapor or fluid permeable, allowing water vapor or fluid for measurement purposes to penetrate without allowing water vapor or fluid to leak into the environment. For example, in FIG. 3B, when the proximal portions of the elongated members 303 are joined together, the water vapor or fluid permeable elongated members 305 should not leak into the environment.

[1000] The beads 405 can be fabricated from one or more of the following materials: activated perfluoropolymer materials with extreme hydrophilicity (such as NAFION brand products); hydrophilic thermoplastics; woven treated fabrics exhibiting breathable properties; hydrophilic polyester block copolymers (such as SYMPATEX brand products); breathable thermoplastic copolyesters (TPCs) (more specifically, breathable copolyesters with polyether soft segments) (including materials such as ARNITEL® VT3108 or materials with equivalent or greater breathability); or any other material that allows water vapor to evaporate into the ambient air while inhibiting or blocking the passage of liquid water and breathing gases to the surroundings. Using such materials, individual molecules 409 can pass through the beads by diffusion, directly affecting the dielectric constant between two electrically isolated wires or elements. The dielectric constant can also be affected by the presence of condensed water on the inner wall of the tube. It should be noted that one skilled in the art would understand that wires can be insulated with a sheath to prevent short circuits and / or corrosion.

[1001] Hereinafter and throughout this specification, a material that allows water molecules to pass through the monolithic wall of the material via a solution-diffusion mechanism without permitting the bulk passage of liquid water or the bulk flow of respiratory gases throughout the wall will be described as a "breathable" material. Those skilled in the art should recognize that water molecules within the wall are molecularly dispersed within a medium and therefore do not have a state (solid, liquid, or gas), but are sometimes referred to in the art as vapors (e.g., transport rates are often referred to as water vapor transmission rates, etc.). It should be further recognized that because monolithic walls do not contain open channels or through-holes from one major surface to another, viruses can be transported through such channels or pores along with air or liquid water droplets via a perforation flow mechanism. It should be further recognized, even more so, that, like all macromolecules, transport of some small molecules of respiratory gases (such as oxygen, carbon dioxide, or nitrogen) can occur in trace or de minimis amounts (i.e., not "bulk" flow), which, for breathable materials as defined herein, should typically be at least an order of magnitude lower than that for water molecules. Further, with particular reference to respiratory gases delivered to or from a patient, the transport of such small molecules in the respiratory gas should be of less than the amount found to be compliant with the relevant standard, e.g., in the leak test of Section 5.4 of ISO 2367:2014, tested via the method set out in Annex E, which is incorporated herein by reference in its entirety.

[1002] Other element structures within the conduit may also be used. For example, the element need not be contained within the conduit wall but could float within the conduit. In such a configuration, the element tends to rest in the condensate at the lowest portion of the tube, which can improve condensate detection. Furthermore, a vapor- and / or liquid-permeable material may be used to surround and bond the element to improve condensate measurement. Alternatively, as shown in FIG. 3C, a liquid-water-absorbent, wicking, and / or hydrophilic material 397, such as cotton, organic or inorganic cloth or fiber, or open-cell foam material, may be used to surround and bond the element 399 to improve condensate measurement. Such a material also provides the advantage of inhibiting migration of condensate toward the sensor, the patient, or the ventilator or other gas source, where condensate is least desired. Additionally, or alternatively, the conduit may include microstructures, such as channels, to transport liquid condensate toward and / or along the appropriate measurement element by capillary action. Further examples of these structures are described below with respect to FIGS. 8-18.

[1003] The inner wall of the tube may also have apertures to promote the accumulation of condensed water within the apertures (e.g., including depressions, pleats, valleys, rectangular channels, and / or undulations of different sizes and shapes). For example, this may include parallel or spiral pleats or longitudinal channels with valleys adjacent to associated elements so that condensed water accumulates, affecting the capacitance between elements. This may provide safety for the patient by reducing the likelihood of condensed water flowing into the patient interface, and may also provide a specific measurement site.

[1004] In some implementations, capacitance measurements can be made by generating a signal that passes through a tube along one or more elements. This is used by a detector 507 to detect and measure a time constant that depends on the inherent capacitance "C" between the element and one or more adjacent elements. This process is represented diagrammatically in FIG. 5. An applied power step change or pulse or series of pulses can be used as the generated signal to measure the change in capacitance. These measurements can be simultaneous or interleaved with either or both temperature sensing measurements or the use of heated wires. Capacitance can also be measured by any known method of measuring or determining capacitance.

[1005] FIG. 5A schematically illustrates a signal generator 501, a conduit system 503, a resistor R 505, and a detector 507. The signal generator 501, resistor 505, and detector 507 would generally be integrated with the humidifier in electrical communication with the conduit system 503, such as in a cartridge and / or heater base, as described above. The conduit system 503 is represented by a variable capacitor C. The conductive elements of the conduit system also have their own electrical resistances, provided by, for example, heaters, sensors, and / or capacitance measurement elements, which are omitted for clarity. The elements in conjunction with the capacitance C of the conduit system 503 and the series resistance of resistor R 505 form a circuit with a characteristic time constant. The time constant can be expressed mathematically as τ=RC, where τ is the time it takes for the voltage to flow from an initial charging voltage of zero through the resistor to approximately 63.2% (1-e -1 ) or through the same resistor to charge the capacitor to about 36.8% of its initial charging voltage (e -1 ) is the time required to discharge the current into the conduit. If the resistance R becomes very large compared to the element resistance, the element resistance can be ignored, and the time constant τ is approximately equal to the product of the resistance R and the capacitance C of the conduit. If the resistance R is constant, the time constant is proportional to the capacitance of the conduit.

[1006] The capacitance varies depending on the amount of condensed water in the conduit. The capacitance and the amount of condensed water in the conduit can be configured to be positively related through the conduit design. The presence of condensed water in the conduit may therefore be estimated from the ratio of a measurement representing the capacitance (e.g., the time constant τ) to a predetermined threshold. Alternatively or additionally, the approximate amount of condensed water in the conduit can be estimated from an absolute measurement of the measurement indicative of the capacitance. Alternatively or additionally, whether water is currently condensing or evaporating in the tube may be estimated by comparing two or more measurements of values ​​indicative of the capacitance over time.

[1007] Voltage V across resistor R R is as follows: [1]V R =V in e -t / RC

[1008] If R is the resistor value, C is the capacitance of the tube, and V in is the output of the signal generator.

[1009] The following is also known: [2]V in =V C +V R [3]V R =V in -V C

[1010] The voltage across resistor R may be measured by any suitable means, for example, by using a detector, the output of which may be read by using a general purpose input / output (GPIO) pin of a microcontroller. Additionally or alternatively, frequency domain techniques such as a fast Fourier transform (FFT) may be used to estimate the capacitance. For example, signal generator 501 may be configured to generate a signal at a particular frequency. At any given frequency, capacitance impedes current flow with a reactance X C In this case, X C= 1 / (2πfC), where f is frequency. Conduit system 503 and resistor R 505 then form a voltage divider whereby detector 507 can be configured to detect a certain voltage level that represents a certain capacitance or condensate level.

[1011] Alternatively, the tube capacitance can be included in an RC oscillator circuit to determine the presence and / or amount of condensate. FIG. 5B is an exemplary RC oscillator circuit, but any equivalent RC oscillator circuit can be used. The exemplary RC oscillator circuit in FIG. 5B may include a variable tube capacitance C511, an oscillator resistor R513, an active amplifier 515, a first resistor 517, and a second resistor 519, all electrically connected. The oscillator circuit may be electrically connected to a frequency sensor. The frequency sensor may be located in the heater base, an external accessory, a sensor cartridge, an intermediate tube connector, or within the tube itself.

[1012] The frequency sensor determines the frequency of the oscillator circuit's output. For example, the frequency sensor can measure the oscillator's output frequency by counting the number of pulses that occur over a fixed time window, which can then be used to determine the frequency of the oscillator circuit. The oscillator circuit's output frequency can be proportional to the change in capacitance of the variable tube; specifically, as the capacitance increases, the oscillator's frequency decreases as shown in the following equation, where k is a constant representing the ratio between resistors R1 and R2:

number

[1013] The capacitance of the tube varies depending on the amount of condensed water in the tube. The presence of condensed water in the tube may be inferred from a comparison of a measurement indicative of the capacitance (such as frequency f) with a predetermined threshold. Alternatively or alternatively, the approximate amount of condensed water in the conduit may be inferred from an absolute measurement of the measurement indicative of the capacitance. Alternatively or additionally, whether water is currently condensing or evaporating in the tube may be inferred by comparing two or more measurements of a value indicative of the capacitance over time.

[1014] Alternatively, a fixed inductor may be added to the circuit and a capacitance calculated or estimated from the resonant frequency of the resistor-inductor-capacitor (RLC) or inductor-capacitor (LC) circuit. In an inductance-based detection system, the inductance of one or more wires within the breathing tube can be measured to detect the presence of condensed water. For example, a wire embedded within a bead (e.g., bead 405 in FIG. 4A) in the breathing tube can be configured to function as an inductor. The inductance of the inductor is a function of the permeability of the medium present within the core of the inductor. Air and water have different relative permeabilities, and thus the inductance of the breathing tube, which can be measured at one end, may differ due to changes in the water content within the breathing tube.

[1015] 6 is an example inductance-based condensation detection system that schematically illustrates an LC-type circuit 600 that may have a first component 601 electrically connected to a second component 610. The first component 601 includes a first capacitor C tube A first inductor L in parallel with 602 tube 603. The second component is a second capacitor C tank 613, an excitation module 615 (e.g., a sensor), and a second inductor L in parallel with the controller 617. tank 611. In some implementations, the first inductor L tube 603, first capacitor C tube602, second inductor L tank 611, second capacitor C tank 613, or any combination thereof, are actually electrical components such as inductors and capacitors. In some implementations, the first inductor L tube 603, first capacitor C tube 602, second inductor L tank 611, second capacitor C tank 613, or any combination thereof, is the result of the inherent capacitance or inductance. tank 611 and the second capacitor C tank The combination of 613 may be referred to as a resonant tank, a resonant circuit, a tank circuit, a tuned circuit, an LC network, or an LC oscillator, or any other parallel combination of inductors and capacitors that exhibits resonant behavior when excited. The resonant tank may be electrically connected to an excitation module 615, which is in turn electrically connected to a controller 617.

[1016] In some implementations, the second component 610 may be on-board and located in the humidifier heater base (e.g., heater base 151 in FIG. 1B), while the first component 601 may be off-board and located in the tube (e.g., inlet tube 159 in FIG. 1B). As a result, the resonant tank may be located in the humidifier heater base and coupled in parallel to one of the embedded wires and the excitation module 615. The resonant tank may be excited by the injection of energy. One example of energy injection is a step change in current that may be injected by the excitation module 615 toward the controller 617. Oscillations in current and voltage occurring at a frequency known as the "resonant frequency" (ω) are thus observed.

[1017] Alternatively, the resonant tank, excitation module 615, controller 617, or any combination of the resonant tank, excitation module 615, and controller 617 can be located in an external attachment, a sensor cartridge, an intermediate tube connector, or within the tube itself.

[1018] In some embodiments, the first component 601 and the second component 610 are not electrically connected. For example, the resonant tank may not be electrically connected to the first component 601, but may comprise a separate wire wrapped around the tube. This can result in high inductance in the resonant tank. In some embodiments, the separate wire implementation of the resonant tank is within the wall of the tube but external to the bead (in embodiments where the first component is embedded in the bead 405).

[1019] The resonant frequency depends on the inductance and capacitance in the circuit. tank and C tank is known and fixed by design, and therefore the change in resonant frequency is due to the change in the first inductor L tube or the first capacitor C tube can be estimated from the change in

[1020] The resonant frequency of the system (ω) can be determined by the total system inductance L and total system capacitance C determined by the following equations:

number

[1021] L tank and C tank is known and fixed by design. As seen in the above equation, the resonant frequency is tube or C tube It is influenced by both. tube C tube If it is much larger than (for example, by an order of magnitude or more), tube is therefore the dominant factor in the tube model. The measured change in resonant frequency is tube can be related to changes in C tube can be ignored.

[1022] Inductance is related to permeability, and since water has a lower permeability than air, increasing levels of condensed water in the tubes will reduce L tube decreases, which is reflected in the measured resonant frequency, which increases correspondingly. tube (C tube The correct formula for (ignoring ) is:

number

[1023] ω and L tube Since all parameters are fixed except for L tube If decreases, then ω must increase.

[1024] Alternatively, C tube L tube If it is much larger than (for example, by an order of magnitude or more), tube is therefore the dominant factor in the tube model. The measured change in resonant frequency is tube can be related to changes in L tube can be ignored.

[1025] Capacitance is related to permeability, and the permeability of water is much higher than that of air / bead material, so C tube increases in the presence of moisture, which is reflected in the measured resonant frequency, which decreases correspondingly. tube Ignore C tube can be roughly calculated as follows:

number

[1026] In this case, ω and C tube Since only the capacitance of the tube changes, the resonant frequency decreases as the capacitance of the tube increases.

[1027] In some implementations, the tube is tube L tubeIn some implementations, the tube can be configured to be much larger than L tube C tube It can be configured to be much larger.

[1028] To measure the tube inductance contribution to the total inductance of the LC tank, the resonant tank is connected in parallel with any embedded tube wires, taking advantage of the inherent inductance of the elongated wire coil and water, particularly the way in which they are present which affects the resonant frequency of the resonant tank when it is actively excited by the excitation module 615.

[1029] By measuring the resonant frequency of the resonant tank, the inductance, L tank The known nominal value of and the unknown L tube or C tube (which was much larger) and C tank If the humidification device contains a known nominal value of L, the control unit of the humidification device will detect different L due to the presence of condensed water in the tubes. tube or C tube We can determine an approximation of L tube Or C tube and / or L tube Or C tube The way in which this changes over time can provide an indication of the presence and / or amount of condensed water in the tube.

[1030] First inductor L tube 603 and the first capacitor C tube Either or both of the first and second inductors L 602 can be a combination of elements to provide the necessary inductance and / or capacitance for the first component 601. In some implementations, the second inductor L tank 611 and the second capacitor C tank Either or both of 613 can be a combination of elements to provide the necessary inductance and / or capacitance to the second component 610 .

[1031] In some implementations, the excitation module 615 (e.g., a sensor) is not part of the second component 610, but instead the excitation module 615 is part of the first component 601. In other implementations, the excitation module 615 is optional and may not be part of either the second component 610 or the first component 601.

[1032] In some implementations, the LC type circuit 600 is instead an RLC circuit.

[1033] In some implementations, alternative devices or circuits for measuring the resonant frequency may be utilized in place of either the excitation module 615, the controller 617, or a combination thereof. Exemplary alternatives include any of the following: a digital signal processor and analog-enabled amplifier circuitry, or similar devices and circuits, or a combination thereof.

[1034] Some features of the moisture (e.g., condensation) detection / sensing techniques disclosed herein can be implemented using alternative methods for detecting and monitoring moisture and / or humidity.

[1035] While moisture detection / sensing techniques have been described primarily with respect to capacitance-based sensor signals, other sensor signals, such as those derived from inductance, resistance, RF signal attenuation, and changes in thermal conductivity, can also be used, as discussed above. Depending on the sensor signal used, there may be some differences in the implementation of moisture detection. For example, an inductance-based approach detects whether the temperature of a gas flow is equal to or lower than the dew point temperature by measuring changes in the resonant frequency of an LC or RLC circuit, which also relies on inductance. In this case, the system hardware and detection criteria (implemented in software / firmware) may be similar to capacitance-based approaches, with appropriate differences. These differences may include different thresholds appropriate for changes in inductance. As another example, if an RF signal attenuation approach is used, the moisture detection method may differ more from capacitance-based approaches, in part because such approaches require active transmission of an RF signal to function, and the relationship between the propagation quality of the RF signal and the presence of moisture differs from that of electrical reactances (e.g., capacitance and inductance).

[1036] Tube type detection In addition to moisture detection, the capacitance measurements disclosed herein can also be used to detect the type of tubing or conduit in a humidification system. For example, the type of inhalation tubing being used can be detected based on capacitance measurements. Each tubing may include two parallel wires, which may be heater wires or heater wire coils, or sense wires. An exemplary formula for calculating the approximate capacitance between two parallel wires or wire coils in a tubing is provided below:

number

[1037] In the formula, C is the capacitance between two parallel wires, D is the length of an individual wire in the tube, s is the distance between the centers of the two parallel wires, d is the diameter of an individual wire, εr is the relative permittivity of the space surrounding the wire, and ε0 is the permittivity of free space. The above formula can approximate the capacitance between two parallel wires when the diameters of both parallel wires are equal (d1 = d2 = d) and the distance between the two conductors is greater than or much greater than their diameters (d << s).

[1038] The capacitance value of the tube can be changed by changing any of the parameters of the formula shown above. In some examples, the distance between two parallel heater wire coils may be changed. Thereby, the distance s between the centers of the two parallel wires can change. In some examples, the length of two parallel heater wire coils may be changed. Thereby, the length D of an individual wire in the tube can change. In some examples, the dielectric material between the two conductors can be adjusted. This can be done by using different materials for each tube type and / or by removing or adding dielectric material between the sensing wires in the tube. Thereby, the relative permittivity εr of the space surrounding the wire can change. In some examples, the diameters of two parallel heater wires can be adjusted. Thereby, the diameter d of an individual wire can change.

[1039] FIG. 43 shows an overview of a process for determining tubing type in a humidification system. In block 4310, a system controller (e.g., a humidifier controller) may measure the capacitance value of the tubing. In block 4320, the controller may map the measured capacitance value to a tubing type. The system controller may include a memory device that stores a lookup table or database that allows the measured capacitance value to be associated with a tubing type, etc. In block 4330, the controller may adjust the control of the tubing (e.g., control of power to the heater wire or control of a setpoint of a sensor in the tubing) and / or the control of the heater base (or cartridge) (e.g., adjusting the power to the heater plate or the setpoint of a sensor in the heater base or cartridge) based on the detected tubing type. Optionally, before or after adjusting the control based on tubing type, the system may query a system user regarding a desired therapy or control mode (e.g., based on patient type or therapy type or both) or system parameter settings (e.g., setpoints of temperature sensors, flow sensors, etc.) to confirm or approve the adjusted control. This may be accomplished via any suitable user interface, display, and / or input device as known in the art and as described herein.

[1040] Patient types may include, for example, infant or neonatal patients, pediatric patients, adult patients, etc. Treatment types may include, for example, high-flow gas therapy (typically 15 liters / minute or more of gas via a non-sealing interface), non-invasive ventilation (typically ventilation via a sealing interface such as a mask), invasive ventilation (where the patient's upper airway is bypassed), closed surgery (for laparoscopic or keyhole surgery), open surgery (for surgery with an open surgical site), anesthesia (typically for apneic patients under general anesthesia via a non-sealing interface at gas flows greater than 30 liters / minute), etc.

[1041] Resistance-Based Sensing Water and condensed water may also be more conductive than the bead material, so that resistance may be measured at specific sections or locations of the tube wire to determine if condensed water is present.

[1042] 7A is an exemplary schematic diagram of a resistance-based condensation detection system, schematically illustrating a first detection wire 701 and a second detection wire 703 disposed within a bead 710. In some implementations, the first detection wire 701 and the second detection wire 703 may be the same wire or different wires. Moisture can be absorbed into the bead 710, which can create a low-resistance path 707 between the first detection wire 701 and the second detection wire 703, allowing a current 705 to flow between the first detection wire 701 and the second detection wire 703. The current 705 is considered a leakage current. The first detection wire 701 and the second detection wire 703 are connected to one or more sensors that can measure the resistance or current on the first detection wire 701 and / or the second detection wire 703.

[1043] In some implementations, the first detection wire 701 and the second detection wire 703 run parallel to each other within the bead 710. In some implementations, the first detection wire 701 and the second detection wire 703 run parallel to each other within the bead 710 such that the first detection wire 701 and the second detection wire 703 are equidistant from the center or centerline of the bead. In some implementations, the first detection wire 701 and the second detection wire 703 run parallel to each other within the bead 710 such that the first detection wire 701 and the second detection wire 703 are not equidistant from the center or centerline of the bead.

[1044] In some implementations, the first detection wire 701 and the second detection wire 703 are not electrically connected to any other wires or components at one end of the bead 710, and thus both detection wires should be an open circuit at one end of the bead so that no current can flow along the first detection wire 701 and the second detection wire 703.

[1045] When more moisture is present, whether at one location or multiple locations, more current is measured on the first detection wire 701 and / or the second detection wire 703 by one or more sensors between the first detection wire 701 and the second detection wire 703.

[1046] In some implementations, the first sensing wire 701 and the second sensing wire 703 can be heater wires, thermistor wires, or any other wires within the bead 710.

[1047] 7B is an exemplary schematic diagram of a resistance-based condensation detection system, generally illustrating a first set of sense wires 721, a second set of sense wires 723, and a third set of sense wires 725 disposed within a bead 710. Moisture can be absorbed into the bead 710, which can create a low resistance path between the set of sense wires, which should allow current to flow between the set of sense wires. For example, moisture may be absorbed into the bead 710, which creates a low resistance path between the first set of sense wires 721, such that current can flow between the first set of sense wires 721.

[1048] In some implementations, moisture can be absorbed into beads 710 that can create a low resistance path between one or more detection wires of different sets of detection wires, where the low resistance path should allow current to flow. For example, moisture may be absorbed into beads 710 that create a low resistance path between one wire of a first set of detection wires 721 and another wire of a second set of detection wires 723, allowing current to flow.

[1049] In some implementations, the first detection wire 701 and the second detection wire 703 are not electrically connected to any other wires or components at one end of the bead 710, and thus both detection wires should be an open circuit at one end of the bead so that no current can flow along the first detection wire 701 and the second detection wire 703.

[1050] In some implementations, the length of the first set of detection wires 721 is different from the length of the second set of detection wires 723. In some implementations, the length of the second set of detection wires 721 is different from the length of the third set of detection wires 723. For example, the first set of detection wires 721 may run one-third of the length of the bead 710, the second set of detection wires 723 may run two-thirds of the length of the bead 710, and the third set of detection wires 725 may run the entire length of the bead 710. The detection wires of any set can be any length along or portion of the bead 710.

[1051] In some implementations, the length of one wire in the first set of detection wires 721 is different from the length of another wire in the first set of detection wires 721. For example, one wire in the first set of detection wires 721 may run one-third of the length of the bead 710, while another wire in the first set of detection wires 721 may run two-thirds of the length of the bead 710. The detection wires in any set can be any length along a portion. Any wire in a set of detection wires can be any length along or part of the bead 710.

[1052] In some implementations, the longer sets of sensing wires may be insulated along their lengths relative to the shorter sets of sensing wires, which would prevent or reduce current flow between wires of different sets along their lengths. For example, the second set of sensing wires 723 has insulators 731 along their lengths relative to the first set of sensing wires 721, and the third set of sensing wires 725 has insulators 731 along their lengths relative to the second set of sensing wires 723. This insulation can be any form of moisture insulation. Examples of moisture insulation include a film or layer of material within the bead 710 that is permeable to water, or a film or layer of material within the bead 710 that absorbs less moisture than other portions of the bead 710.

[1053] In some implementations, four or more sets of detection wires are placed within the bead 710. In some implementations, two or fewer sets of detection wires are placed within the bead 710.

[1054] In some implementations, any of the detection wires in any combination of the first set of detection wires 721, the second set of detection wires 723, and the third set of detection wires 725 can be heating wires, thermistor wires, or any other wires within the bead 710.

[1055] It should be understood that there may be approximately three sets of sense wires. It should also be understood that the above descriptions of the first set of sense wires 721, the second set of sense wires 723, and the third set of sense wires 725 are interchangeable with any other set of sense wires.

[1056] Short-Circuit Based Detection Additionally, water or condensation may cause an electrical short between one or more wires at a certain threshold. This occurs because water or condensation may be more conductive than the bead material. FIG. 8A is an exemplary schematic diagram of a short-circuit-based condensation detection system, schematically illustrating one or more detection wires 801 exposed through an inner tube wall 810 to a conduit lumen 811, where the one or more detection wires 801 are electrically connected to a power source within a heater base or sensor cartridge and measurement components. The one or more detection wires 801 may have one or more exposed portions 813 in the conduit lumen 811. In some implementations, the exposed portions 813 protrude from the one or more detection wires 801 into the conduit lumen 811. The one or more detection wires 801 can be spaced throughout the tube for either the entire length of the tube or only a portion of the length of the tube. In some implementations, the one or more detection wires are periodically spaced. The one or more detection wires 801 can be electrically connected to a power source. In some implementations, the power source electrically connected to the one or more detection wires 801 is one or more separate power sources.

[1057] One or more exposed portions 813 of one or more sensing wires 801 can be used to detect condensed water. For example, there may be one or more exposed portions 813 of one or more sensing wires 801 that typically provide a measured resistance of 100 MΩ. However, when one or more exposed portions 813 are shorted together by moisture (e.g., at potential short locations 815), the measured resistance may drop to 90 MΩ or less. Alternatively, a change in the measured current may indicate a possible short circuit formed by condensed water. The potential short locations 815 may be between one or more exposed portions 813 of different sensing wires 801 or between multiple exposed portions of the same sensing wire 801. Such short locations 815 may be used to detect condensed water along the length of the tube. In some implementations, one or more exposed portions 813 of one or more sensing wires 801 can be configured to detect moisture in a cross-section of the tube, for example, by having one or more exposed portions at the same or approximately the same length along the tube.

[1058] One or more detection wires 801 may be used to find exactly where the condensed water is located. For example, there may be a drop in resistance along two detection wires 801. This may mean that there is condensed water around and / or between one or more exposed portions 813 of both detection wires, resulting in a short circuit.

[1059] Alternatively, the one or more sensing wires 801 can be one or a combination of heater wires, thermistor wires, or any other wires within the tube.

[1060] FIG. 8B is an exemplary schematic diagram of a short-circuit-based condensation detection system, schematically illustrating a detection wire 821 within a bead 830, which is electrically connected to a power source within the heater base or sensor cartridge and the measurement component. The detection wire 821 may have one or more exposed portions 833 to the bead channel 831. In some implementations, the exposed portions 833 protrude from the detection wire 821 into the bead channel 831. The detection wire 821 can run through the bead 830 for either the entire length of the tube or only a portion of the length of the tube. There may be one or more exposed portions 833 of the detection wire 821 that may provide a measured resistance of, for example, 100 MΩ. However, when one or more exposed portions 833 are shorted together by moisture (e.g., at potential short location 835), the measured resistance may drop to 90 MΩ or less. The potential short location 835 may short one or more exposed portions 833 that are in series with each other or in parallel with each other. Alternatively, the measured current may increase.

[1061] Water or condensed water is more conductive than air. Similarly, water or condensed water may be more conductive than the bead material. This means that the water or condensed water could partially or completely short circuit the sensing wire 821 at exposed portion 833, thereby reducing the measured resistance or increasing the current measured by the measuring component to detect water or condensed water.

[1062] The bead 830 can have a condensed water drainage channel (e.g., one or more openings 903 in FIG. 15 described below). Portions of the sensing wire 821 can be periodically exposed inside the channel. In some implementations, the sensing wire may not be a complete circuit (e.g., the patient end is open). Thus, when moisture bypasses into the bead channel, the water may complete a circuit between the exposed portions of the sensing wire. This can be detected by measuring the wire resistance, which can be very high if there is no condensed water in the bead channel, or the current, which can be very low if the circuit is not completed.

[1063] In some implementations, a resistance-based condensation detection system may also be able to detect the amount of water or condensation present by measuring changes in resistance or current at points measured by one or more detection wires 801, 821.

[1064] A resistance-based condensation detection system may be beneficial if one or more detection points are located at known points in the tubing where condensation tends to be very high, such as the midpoint of the tubing where flexing can cause condensation to accumulate, which can occur due to placement of the humidifier and tubing next to a patient's bed.

[1065] Alternatively, the sensing wire 821 can be one or a combination of heater wire, thermistor wire, or any other wire within the bead 830.

[1066] Radio Frequency (RF) Attenuation-Based Detection Water and condensation are poor propagation media for high frequency signals, and this property can be used to detect whether condensation is present in the breathing tube.

[1067] 9A is an exemplary schematic diagram of an RF attenuation-based condensation detection system, schematically illustrating a sensor cartridge 901, a transmitter 911 (Tx), and a receiver 913 (Rx). The sensor cartridge 901 may have a controller 903, a signal generator 905, and signal measurement components 907.

[1068] 9A, the controller 903 is electrically connected to a signal generator 905 and a signal measuring component 907. The signal generator 905 is electrically connected to a transmitter 911. The signal measuring component 907 is electrically connected to a receiver 913.

[1069] The controller 903 can instruct the signal generator 905 to generate a signal 915 that is transmitted by the transmitter 911. The signal 915 is then received by the receiver 913 and then measured by the signal measurement component 907. Once the signal 915 is measured, the signal measurement component 907 can communicate the measurement information of the signal 915 to the controller 903 to determine how to respond. If condensed water forms in the transmission path between the transmitter 911 and the receiver 913, the condensed water can result in significantly increased attenuation of the signal 915 when received by the receiver 913. Attenuation is the reduction in the magnitude or strength of a signal as it propagates through a medium. Thus, the signal received at the receiver 913 is an attenuated version of the signal 915. The presence of water between the transmitter 911 and the receiver 913 can be detected by measuring the magnitude of the received signal. The magnitude of the received signal can also be used to determine the amount of water or condensed water present between the transmitter 911 and the receiver 913.

[1070] The signal frequency may encompass a broad spectrum of frequencies, i.e., any frequency at which transmission through water or condensed water would attenuate the signal. This may include, for example, the frequency band 30 Hz to 300 GHz. In some implementations, the signal has a frequency in the 1 to 100 MHz band. In some implementations, the signal has a frequency of approximately 10 MHz. At approximately 10 MHz, the antenna lengths of the transmitter 911 and receiver 913 may be one-quarter of the wavelength of the signal. A quarter-wavelength antenna may be beneficial for resonance, which may maximize the power of the transmitted signal 915 and therefore the received signal. In some implementations, the resonant frequency of water (approximately 2.45 GHz) is the frequency of the signal 915. Using the resonant frequency of water may result in the lowest signal-to-noise ratio at the receiver antenna and may also increase the receiver antenna's sensitivity to changes in condensed water.

[1071] Signal generator 905 can be any suitable high frequency signal generator, and similarly, signal measurement component 907 can be any suitable high frequency converter, such as an AM receiver, an RF rectifier circuit, or an RF sampling ADC.

[1072] In some implementations, any combination of the control device 903, the signal generator 905, and the signal measurement component 907 can be located within the base (e.g., the base 151 in FIG. 1B) or within a portion of the respiratory tube (e.g., the respiratory tube 159 in FIG. 1B).

[1073] 9B provides an example cross-section of a tube bead 920 with embedded wires, including a heater wire 922 and a thermistor wire 924 in a condensation detection system based on RF attenuation. In this example, a radio frequency signal is injected into the heater wire 922 by a signal generator (e.g., signal generator 905 in FIG. 9A), causing the heater wire 922 to act as a transmitter of a signal 926. The thermistor wire 924 acts as a receiver of the signal 926 and conveys the signal to a signal measuring component (e.g., signal measuring component 907 in FIG. 9A).

[1074] 9B, the heater wire 922 is adjacent to the thermistor wire 924. In some implementations, the heater wire 922 and thermistor wire 924 are non-adjacent wires.

[1075] 10A is an exemplary schematic diagram of an RF attenuation-based condensation detection system using a heater wire 1011 as a transmitter (e.g., transmitter 911 in FIG. 9A) and a thermistor wire 1013 as a receiver (e.g., receiver 913 in FIG. 9A). FIG. 10A schematically illustrates a sensor cartridge 1001, heater wire 1011, and thermistor wire 1013. The sensor cartridge 1001 may include a signal generator 1003, a filter 1005, and a signal measurement component 1007.

[1076] 10A, the signal generator 1003 is electrically connected to the heater wire 1011. The thermistor wire is electrically connected to the filter 1005, which is in turn electrically connected to the signal measuring component 1007. The signal generator 1003, the filter 1005, and the signal measuring component 1007 are electrically connected to other components within the sensor cartridge 1001 or to other components of the humidifier.

[1077] The signal generator 1003 generates a signal 1015 that is transmitted by the heater wire 1011. The signal 1015 is then received by the thermistor wire 1013. The heater wire 1011 is used as a transmitter, and the thermistor wire 1013 is used as a receiver, as described with respect to FIG. 9A. The received signal may then be filtered by a filter 1005 to remove extraneous frequencies other than the one or more frequencies generated by the signal generator 1003, so that only an attenuated version of the signal 1015 is measured by a signal measurement component 1007. An exemplary filter can be a high-pass or band-pass filter. The filter can also be configured to filter from mains frequencies, which refers to the frequency of the mains power source. The mains power can be power derived from a wall / outlet or a power grid.

[1078] As described with respect to FIG. 9A, the magnitude of the received signal can be used to detect the presence of water between the heater wire 1011 and the thermistor wire 1013 or to determine the amount of water or condensation present therebetween.

[1079] The heater wire 1011 and thermistor wire 1013 can be separate wires from other wires used to carry signals within the bead, but in some implementations, the heater wire 1011 and thermistor wire 1013 are not separate wires used to carry signals within the bead.

[1080] In some implementations, filter 1005 is not present. As a result, signal measurement component 1007 measures any signal on the thermistor wire 1013. In some implementations, there may be an additional filter or alternative filter configuration to separate the heater wire signal from other RF signals and / or thermistor wire signal from other RF signals. This allows for differentiation between condensation detection signals on the heater wire and / or thermistor wire and other RF signals, such as signals used for purposes other than condensation detection.

[1081] 10A, the heater wire 1011 and thermistor wire 1013 are both electrically connected to the sensor cartridge 1001 and / or the humidifier. As a result, both the heater wire 1011 and thermistor wire 1013 form a loop antenna. This implementation may be suitable for transmitting and receiving low frequency signals 1015, as loop antennas can be effective for frequencies below 30 MHz.

[1082] The signal generator 1003 can be a separate signal generator from the signal generators for other signals across the heater wire 1011 or thermistor wire 1013 .

[1083] FIG. 10B is an exemplary schematic diagram of an RF attenuation-based condensation detection system similar to FIG. 10A . Again, a heater wire 1011 is used as a transmitter and a thermistor wire 1013 is used as a receiver. However, in the exemplary implementation of FIG. 10B , switches 1004, 1008 are utilized to disconnect one end of each of the heater wire 1011 and thermistor wire 1013 from the rest of the humidifier or sensor cartridge 1001. By disconnecting one end of each of the heater wire 1011 and thermistor wire 1013, a monopole antenna is formed. In some implementations, the monopole antenna formed by the heater wire 1011 and thermistor wire 1013 is a quarter-wave monopole antenna. The switches 1004, 1008 are located in one of the following: the heater base, the sensor cartridge, the conduit, an external component, or an intermediate connector. A neonatal bubble tube with a heated zone is an exemplary intermediate connector.

[1084] 9B, heater wire 1011 is adjacent to thermistor wire 1013. In some implementations, heater wire 1011 and thermistor wire 1013 are non-adjacent wires.

[1085] In some implementations, any combination of the switches 1004, 1008, the signal generator 1003, the filter 1005, and the signal measurement components 1007 are located in a base (e.g., the heater base 151 in FIG. 1B ) or another portion of the humidifier (e.g., the cartridge 155 in FIG. 1B ). In some implementations, any combination of the switches 1004, 1008, the signal generator 1003, the filter 1005, and the signal measurement components 1007 are located in the breathing tube (e.g., at the midpoint of the inspiratory tube 159 in FIG. 1B ). In some implementations, any combination of the switches 1004, 1008, the signal generator 1003, the filter 1005, and the signal measurement components 1007 are located in a cartridge (e.g., the cartridge 155 in FIG. 1B ) that can be attached to the base or the tube. In some implementations, any combination of switches 1004, 1008, signal generator 1003, filter 1005, and signal measurement components 1007 are placed between both the base and the tube.

[1086] Heat-Based Detection The properties of a particular medium or medium affect the efficiency and / or magnitude of heat transfer. Water has a thermal conductivity that may differ from that of the bead material. Similarly, water has a specific heat capacity that may differ from that of the bead material. The difference in thermal conductivity and / or specific heat capacity between water and the bead material can be used to detect whether condensed water is present within the breathing tube. When condensed water is present around and / or within the beads, heat transfer between a pair of embedded tube wires may be enhanced.

[1087] 11A is an exemplary diagram of thermal conductivity between two wires, illustrating a thermistor wire 1113, a heater wire 1111, and a radius r 1117 representing the distance between the heater wire 1111 and the thermistor wire 1113.

[1088] The relationship between thermal conductivity and the rate of temperature change in the presence of a line heat source is expressed as follows:

number

[1089] The temperature T is a function of the radius r and the time t, where λ is the thermal conductivity,

number

[1090] If the radius r is constant, the temperature T may be measured at two different points in time and the temperature change can be easily calculated without needing to know the thermal diffusivity or the actual radius.

[10] ΔT = T(r,t2) - T(r,t1)

[1091] The thermal conductivities are rearranged as follows:

number

[1092] This step requires the assumption of zero convective heat losses, which is accurate if measurements are taken within the linear region. There is a region where changes in temperature T are linearly related to changes in In(t). This linear region can be time-dependent, such that after the initial temperature rise but before stabilization, there is a time window where there is an approximately linear relationship between T and In(t).

[1093] In some implementations, the condensation detection system uses thermal conductivity to detect the presence and / or amount of condensation present. For example, condensation can be detected by applying a step change in power to the heater wire 1111 and measuring the subsequent temperature rise of the thermistor wire 1113 or the heater wire 1111 itself.

[1094] Water can be detected either within the beads, on the beads, or within the tube. Water within the beads will change the thermal conductivity the most, but the change in thermal conductivity can detect if water is present anywhere within the tube.

[1095] 11B is an exemplary schematic diagram of a thermal conductivity-based condensation detection system using a heater wire 1111 as a heat source and a thermistor wire 1113. FIG. 11B schematically illustrates a sensor cartridge 1101, heater wire 1111, and thermistor wire 1113. The thermistor wire 1113 may include a bypass (shunt) diode 1117 and a thermistor 1119, where the thermistor 1119 is bypassed by the use of the bypass diode 1117.

[1096] 11B, the sensor cartridge 1101 is electrically connected to both the heater wire 1111 and the thermistor wire 1113. In some implementations, one or both of the heater wire 1111 and thermistor wire 1113 are electrically connected to a heater base or other component of the humidifier.

[1097] Condensation can be detected by applying a step change in power to the heater wire 1111 and measuring the subsequent temperature rise of the thermisto...

Claims

1. 1. A medical humidifier configured to provide a flow of gas to a patient through a respiratory tube coupled to the medical humidifier, A heater plate; A control device, reducing power to a heater wire of the respiratory tube coupled to the medical humidifier; measuring a condensate baseline following reducing power to the heater wire; determining whether the measured condensate baseline meets an expected condensate baseline; outputting a status of the medical humidifier in response to the measured condensate reference value not meeting the expected condensate reference value; a controller configured to determine a status of the medical humidifier by the steps of Medical humidifiers, including:

2. 10. The medical humidifier of claim 1, wherein reducing power to the heater wire of the respiratory tube comprises disabling power to the heater wire.

3. 10. The medical humidifier of claim 1, wherein power to the heater wire of the respiratory tube is reduced for a predetermined period of time.

4. the condensate reference value is a condensate level, 4. The medical humidifier of claim 1, wherein determining whether the measured condensation reference value meets the expected condensation reference value comprises comparing the condensation level in the breathing tube to a predetermined threshold.

5. The medical humidifier of any one of claims 1 to 3, wherein the condition comprises a reflux condition.

6. 6. The medical humidifier of claim 5, wherein determining whether the measured condensate baseline does not meet the expected condensate baseline comprises determining whether the condensate level in a dry line connected to the medical humidifier and a gas source exceeds a condensate level in the respiratory tubing.

7. The medical humidifier of any one of claims 1 to 3, wherein the condition of the medical humidifier comprises no flow or running out of water.

8. 8. The medical humidifier of claim 7, wherein the controller is configured to confirm the determination by performing a flow test or a water runout test.

9. 8. The medical humidifier of claim 7, wherein the condensation reference value includes moisture and / or humidity.

10. The control device Detecting the condensate reference value during normal use; Determining the decrease in the condensate reference value over time 8. The medical humidifier according to claim 7, wherein the medical humidifier is configured as follows:

11. the controller, in response to determining the decrease, increasing an operating parameter of the medical humidifier; monitoring an increase in the condensate reference value within a component of the medical humidifier; If no increase is detected, determine if the water is depleted The medical humidifier according to claim 10, wherein the medical humidifier is configured as follows:

12. The medical humidifier according to any one of claims 1 to 3, wherein the condition is the position of the humidifier relative to the patient.

13. 13. The medical humidifier of claim 12, wherein determining whether the measured condensate reference value does not meet the expected condensate reference value comprises determining whether the measured condensate reference value at the patient-end of the respiratory tube exceeds the measured condensate reference value at an outlet of a humidification chamber of the medical humidifier.

14. 13. The medical humidifier of claim 12, wherein determining whether the measured condensate reference value does not meet the expected condensate reference value comprises determining whether the measured condensate reference value at the patient end of the respiratory tube exceeds the measured condensate reference value in a region between the patient end and the outlet.

15. 1. A method for determining a status of a medical humidifier configured to provide gas to a patient through a respiratory tube coupled to the medical humidifier, the medical humidifier including a heater plate, the method comprising: reducing power to a heater wire of the respiratory tube coupled to the medical humidifier; measuring a condensate baseline following reducing power to the heater wire; determining whether the measured condensate baseline meets an expected condensate baseline; outputting a status of the medical humidifier to a control device of the medical humidifier in response to the measured condensate reference value not meeting the expected condensate reference value; A method comprising:

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