Medical tube and method for manufacturing the same

Abstract

The present disclosure relates to medical tubes and methods for making the same. The tube may be a composite structure made of two or more dissimilar components that are spirally wound to form an elongated tube. For example, one of the components may be an elongated hollow body that is spirally wound, and the other components may be elongated structural components that are also spirally wound between multiple turns of the spirally wound hollow body. However, the tube need not be made of dissimilar components. For example, an elongated hollow body formed (e.g., extruded) by a single material may be spirally wound to form an elongated tube. The elongated hollow body itself may have a thin-walled portion and a relatively thicker or more rigid reinforcement portion in its transverse cross-section. These tubes may be incorporated into various medical circuits, or may be used for gas medical purposes.

Description

[0001] This application is a divisional application of an invention patent application with an application date of December 4, 2013, application number 201380072143.7, PCT international application number PCT / NZ2013 / 000222, and invention name “Medical tube and method for manufacturing the same”.

[0002] Cross-references

[0003] This application claims under 35 U.S.C. §119(e) U.S. Provisional Application No. 61 / 733,359, filed on December 4, 2012, entitled MEDICAL TUBES AND METHODS OF MANUFACTURE; U.S. Provisional Application No. 61 / 733,360, filed on December 4, 2012, entitled MEDICAL TUBES AND METHODS OF MANUFACTURE; U.S. Provisional Application No. 61 / 877,622, filed on September 13, 2013, entitled MEDICAL TUBES AND METHODS OF MANUFACTURE; U.S. Provisional Application No. 61 / 877,566, filed on September 13, 2013, entitled HUMIDIFICATION SYSTEM; U.S. Provisional Application No. 61 / 877,566, filed on September 13, 2013, entitled CONNECTIONS FOR ... and U.S. Provisional Application No. 61 / 877,736, filed on September 13, 2013, entitled ZONE HEATING FOR RESPIRATORY CIRCUITS, each of which is incorporated herein by reference in its entirety.

[0004] In addition, PCT Application No. PCT / IB2012 / 001786, filed on May 30, 2012, and entitled MEDICAL TUBE AND METHOD OF MANUFACTURE THEREOF, is also incorporated herein by reference in its entirety. Technical Field

[0005] The present disclosure relates generally to tubes suitable for medical use, and more particularly to tubes used in medical circuits suitable for providing and / or removing gases from a patient, such as in positive airway pressure (PAP), respirator, anesthesia, ventilator, and insufflation systems. Background Art

[0006] In a medical circuit, different components deliver warm and / or humidified gases to and from a patient. For example, in some breathing circuits, such as PAP or assisted breathing circuits, the gas inhaled by the patient is delivered from a heated humidifier through an inspiratory tube. As another example, a tube can deliver humidified gas (usually CO2) to the abdominal cavity in an insufflation circuit. This can help prevent "dehydration" of the patient's internal organs and can reduce the amount of time required for postoperative recovery. Unheated tubes can cause a large amount of heat loss to natural cooling. This cooling may cause unwanted condensation or a "rain wash effect" to form along the length of the tube that delivers warm, humidified air. There is also a need for tubes that can be insulated from heat loss and, for example, can have improved temperature and / or humidity control in a medical circuit. Therefore, the purpose of the present invention is to overcome or improve one or more shortcomings of the prior art or at least provide the public with a useful choice. Summary of the invention

[0007] Disclosed herein in different embodiments are medical tubes and methods for manufacturing medical tubes. In some embodiments, the tube can be a composite structure made of two or more dissimilar components that are spirally wound to form an elongated tube. For example, one of these components can be an elongated hollow body that is spirally wound, and the other components can be elongated structural components that are also spirally wound between multiple turns of the spirally wound hollow body. In other embodiments, the tube does not have to be made of dissimilar components. For example, an elongated hollow body formed (e.g., extruded) by a single material can be spirally wound to form an elongated tube. The elongated hollow body itself can have a thin-walled portion and a relatively thicker or more rigid reinforcement portion in its transverse cross-section. These tubes can be incorporated into various medical circuits, or can be used for other medical purposes.

[0008] In at least one embodiment, a composite tube can include a first elongated member including a hollow body helically wound to at least partially form an elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall around the lumen. A second elongated member can be helically wound and bonded between adjacent turns of the first elongated member, the second elongated member forming at least a portion of the lumen of the elongated tube. The names "first elongated member" and "second elongated member" do not necessarily imply an order, such as the order in which these components are assembled. As described herein, the first elongated member and the second elongated member can also be multiple portions of a single tubular shaped element.

[0009] In various embodiments, the aforementioned components have one, some, or all of the following characteristics, as well as those described elsewhere in this disclosure.

[0010] The first elongated member can be a tube. The first elongated member can form a plurality of bubbles in its longitudinal section, and these bubbles have a flat surface on the lumen. Adjacent bubbles can be separated by a gap above the second elongated member, or these adjacent bubbles may not be directly connected to each other. These bubbles may have holes. The second elongated member may have a longitudinal section, which is wider at the proximal side of the lumen and narrows in the radial distance of the lumen. Specifically, the second elongated member may have a longitudinal section, which is generally triangular, generally T-shaped, or generally Y-shaped. One or more conductive filaments may be embedded or encapsulated in the second elongated member. The one or more conductive filaments may be heating filaments (or more specifically, resistive heating filaments) and / or sensing filaments. The tube may include pairs of conductive filaments, such as two or four conductive filaments. Pairs of conductive filaments may be formed as connecting rings at one end of the composite tube. The one or more conductive filaments may be separated from the lumen wall. In at least one embodiment, the second elongated member can have a longitudinal cross-section that is generally triangular, generally T-shaped, or generally Y-shaped, and one or more conductive filaments can be embedded or encapsulated on opposite sides of the triangle, T-shape, or Y-shape of the second elongated member.

[0011] The foregoing components according to any or all of the foregoing embodiments may be incorporated into medical circuit components, inspiratory tubes, expiratory tubes, PAP components, insufflation circuits, respiratory components, or surgical components, among other applications.

[0012] A method of making a composite tube is also disclosed. The resulting tube may have one, some, or all of the characteristics described above or elsewhere in this disclosure. In at least one embodiment, the method includes providing a first elongated member including a hollow body, and a second elongated member configured to provide structural support for the first elongated member. The second elongated member is helically wrapped around a mandrel, wherein opposite edge portions of the second elongated member are spaced apart on adjacent sheaths, thereby forming a second elongated member spiral. The first elongated member is helically wrapped around the second elongated member spiral such that portions of the first elongated member overlap adjacent sheaths of the second elongated member spiral, and a portion of the first elongated member is disposed adjacent to the mandrel in a space between sheaths of the second elongated member spiral, thereby forming a first elongated member spiral.

[0013] In various embodiments, the foregoing method may include one, some or all of the following. The method may include supplying air at a pressure greater than atmospheric pressure to one end of the first elongated member. The method may include cooling the second elongated member spiral and the first elongated member spiral to form a composite tube having a lumen extending along a longitudinal axis and a hollow space around the lumen. The method may include forming the first elongated member. The method may include extruding the first elongated member with a first extruder. The method may include forming the second elongated member. The method may include extruding the second elongated member with a second extruder. The second extruder may be configured to encapsulate one or more conductive filaments in the second elongated member. Forming the second elongated member may include embedding conductive filaments in the second elongated member. The conductive filaments may not react with the second elongated member. The conductive filaments may include alloys of aluminum or copper or other conductive materials. The method may include forming pairs of conductive filaments into connecting rings at one end of the composite tube. The first extruder may be different from the second extruder.

[0014] A medical tube is also disclosed. In at least one embodiment, the tube includes an elongated hollow body helically wound to form an elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall around the lumen, wherein the elongated hollow body has a wall defining at least a portion of the hollow body in a transverse cross-section thereof. The tube may further include a reinforcing portion extending along the length of the elongated hollow body, helically positioned between adjacent turns of the elongated hollow body, wherein the reinforcing portion forms a portion of the lumen of the elongated tube. The reinforcing portion may be relatively thicker or more rigid than the wall of the elongated hollow body.

[0015] In different embodiments, the aforementioned tube has one, some, or all of the following characteristics, as well as the characteristics described elsewhere in this disclosure. The reinforcing portion may be formed of the same piece of material as the elongated hollow body. The elongated hollow body may include two reinforcing portions in its transverse cross-section, the two reinforcing portions being on opposite sides of the elongated hollow body, wherein the spiral winding of the elongated hollow body combines adjacent reinforcing portions to each other so that the relative edges of the reinforcing portions contact on adjacent turns of the elongated hollow body. The opposite side edges of the reinforcing portions may overlap on adjacent turns of the elongated hollow body. The reinforcing portion and the elongated hollow body may be made of separate sheets of material. The hollow body may form a plurality of bubbles in its longitudinal cross-section, the bubbles having a flat surface on the lumen. The bubbles may have holes. The medical tube may also include one or more conductive filaments, the one or more conductive filaments being embedded or encapsulated in the reinforcing portion. The conductive filaments may be heating filaments and / or sensing filaments. The medical tube may include two conductive filaments, wherein each reinforcing portion embeds or encapsulates one conductive filament. The medical tube may include two conductive filaments positioned on only one side of the elongated hollow body. Pairs of conductive filaments may be formed as a connecting ring at one end of the composite tube. The one or more filaments may be spaced apart from the lumen wall.

[0016] The aforementioned tube according to any or all of the aforementioned embodiments may be incorporated into medical circuit components, inspiratory tubes, expiratory tubes, PAP components, insufflation circuits, respiratory components, or surgical components, among other applications.

[0017] A method of manufacturing a medical tube is also disclosed. In at least one embodiment, the method includes: spirally winding an elongated hollow body around a mandrel to form an elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall around the lumen, wherein the elongated hollow body has a wall in a transverse cross-section thereof, the wall defining at least a portion of the hollow body; and two reinforcing portions on opposite sides of the elongated body, the two reinforcing portions forming a portion of the lumen wall, the two reinforcing portions being relatively thicker or more rigid than the wall defining at least a portion of the hollow body. The method may further include bonding adjacent reinforcing portions to each other such that opposing edges of the reinforcing portions touch on adjacent turns of the elongated hollow body.

[0018] In different embodiments, the foregoing method may include one, some, or all of the following characteristics, as well as any other characteristics described elsewhere in this disclosure. Joining adjacent reinforcement portions to each other may cause the edges of these reinforcement portions to overlap. The method may further include supplying air at a pressure greater than atmospheric pressure to one end of the elongated hollow body. The method may further include cooling the elongated hollow body so that these adjacent reinforcement portions are joined to each other. The method may further include extruding the elongated hollow body. The method may further include embedding conductive filaments in these reinforcement portions. The method may further include forming pairs of conductive filaments into a connecting ring at one end of the elongated tube.

[0019] A breathing tube is also disclosed. In at least one embodiment, the tube includes a first elongated member including a hollow body helically wound to at least partially form an elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall around the lumen, the wall having an inner portion proximal to the lumen and an outer portion facing away from the lumen, wherein the inner portion of the wall has a smaller thickness than the outer portion of the wall.

[0020] In various embodiments, the aforementioned breathing tube may include one, some, or all of the following characteristics, as well as any other characteristics described elsewhere in this disclosure. The breathing tube may further include a second elongated member, the second elongated member being helically wound and joined between adjacent turns of the first elongated member, the second elongated member forming at least a portion of the lumen of the elongated tube. The thickness of the outer portion of the wall may be in the range of about 0.14 mm to about 0.44 mm. The thickness of the outer portion of the wall may be about 0.24 mm. The thickness of the inner portion of the wall may be in the range of about 0.05 mm to about 0.30 mm. The thickness of the inner portion of the wall may be about 0.10 mm.

[0021] A breathing tube is also disclosed. In at least one embodiment, the tube includes a first elongated member, the first elongated member including a hollow body helically wound to at least partially form an elongated tube, the elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall around the lumen, the hollow body forming a plurality of bubbles in a longitudinal cross-section thereof, the bubbles having a maximum width along the longitudinal axis and a maximum height between an outwardly facing apex of the wall and the lumen, perpendicular to the longitudinal axis, wherein a ratio of the maximum height to the maximum width is at least about 0.16.

[0022] In various embodiments, the aforementioned breathing tube may include one, some, or all of the following characteristics, as well as any other characteristics described elsewhere in this disclosure. The breathing tube may further include a second elongated member, the second elongated member being helically wound and joined between adjacent turns of the first elongated member, the second elongated member forming at least a portion of the lumen of the elongated tube. The maximum height may be in the range of about 1.2 mm to about 8.2 mm. The maximum height may be about 3.2 mm. The maximum width may be in the range of about 3.5 mm to about 7.5 mm. The maximum width may be about 5.5 mm. The ratio of the maximum height to the maximum width may be greater than 1.0.

[0023] A breathing tube is also disclosed. In at least one embodiment, the tube includes a first elongated member, the first elongated member including a hollow body helically wound to at least partially form an elongated tube, the elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall around the lumen, the hollow body forming a plurality of bubbles in a longitudinal cross-section thereof, wherein a vertical distance between corresponding points on adjacent bubbles defines a pitch, wherein a ratio of the pitch to the maximum outer diameter of the composite tube is less than about 0.35.

[0024] In various embodiments, the aforementioned breathing tube may include one, some, or all of the following characteristics, as well as any other characteristics described elsewhere in this disclosure. The breathing tube may further include a second elongated member, the second elongated member being helically wound and joined between adjacent turns of the first elongated member, the second elongated member forming at least a portion of the lumen of the elongated tube. The pitch may be in the range of about 1.2 mm to about 8.1 mm. The pitch may be about 5.1 mm. The maximum outer diameter may be in the range of about 19.5 mm to about 25.5 mm. The maximum outer diameter may be about 22.5 mm.

[0025] A composite tube is also disclosed. In at least one embodiment, the tube includes a first elongated member, the first elongated member including a hollow body helically wound to at least partially form an elongated tube, the elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall around the lumen, the hollow body forming a plurality of bubbles in a longitudinal cross-section thereof, the bubbles having a maximum height between an outwardly facing vertex of the wall and the lumen, perpendicular to the longitudinal axis, the maximum height defining a maximum height of the first elongated member; and a second elongated member helically wound and bonded between adjacent turns of the first elongated member, the second elongated member forming at least a portion of the lumen of the elongated tube, the second elongated member having a maximum height between an outwardly facing vertex of the second elongated member and the lumen, perpendicular to the longitudinal axis, wherein the ratio of the difference between the maximum height of the first elongated member and the maximum height of the second elongated member to the maximum outer diameter of the composite tube is less than about 0.049:1.

[0026] In various embodiments, the aforementioned composite tube may include one, some, or all of the following characteristics, as well as any other characteristics described elsewhere in this disclosure. The wall may have an inner portion proximal to the lumen and an outer portion facing away from the lumen, and the inner portion of the wall has a smaller thickness than the outer portion of the wall.

[0027] A composite tube is also disclosed. In at least one embodiment, the tube includes a first elongated member including a hollow body helically wound to at least partially form an elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall around the lumen, the wall having an inner portion proximal to the lumen and an outer portion facing away from the lumen; and a second elongated member helically wound between adjacent turns of the first elongated member, the second elongated member forming at least a portion of the lumen of the elongated tube, and the first elongated member joined at connection points on adjacent turns of the second elongated member; wherein the bending radius of the composite tube is limited by the length of the outer portion between the connection points.

[0028] In various embodiments, the aforementioned composite tube may include one, some, or all of the following characteristics, as well as any other characteristics described elsewhere in this disclosure: The wall has an inner portion proximal to the lumen and an outer portion facing away from the lumen, and the inner portion of the wall has a smaller thickness than the outer portion of the wall.

[0029] A breathing tube is also disclosed. In at least one embodiment, the tube includes a first elongated member including a hollow body component, wherein the weight / length of the tube within at least a portion of 300 mm closest to one end of the tube is less than about 0.08 g / mm.

[0030] In various embodiments, the aforementioned breathing tube may include one, some, or all of the following characteristics, as well as any other characteristics described elsewhere in this disclosure. The first elongated member may include a hollow body that is helically wound to at least partially form an elongated tube, the elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall around the lumen. The breathing tube may further include a second elongated member that is helically wound and joined between adjacent turns of the first elongated member, the second elongated member forming at least a portion of the lumen of the elongated tube. The breathing tube may include one or more conductive filaments that are embedded or encapsulated within the second elongated member. At least one of the one or more conductive filaments may be a heating filament. At least one of the one or more conductive filaments may be a sensing filament. The mass of the tube within 300 mm closest to one end of the tube may be less than about 24 g. The weight / length of the tube within at least a portion of the 300 mm closest to one end of the tube may be less than about 0.06 g / mm. The mass of the tube within 300 mm closest to one end of the tube may be less than about 16 g. The thickness of the wall may be at most about 0.50 mm.

[0031] A breathing tube is also disclosed. In at least one embodiment, the tube includes a first elongated member, the first elongated member including a hollow body helically wound to at least partially form an elongated tube, the elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall around the lumen, the wall having an inner portion proximal to the lumen and an outer portion facing away from the lumen, wherein in at least a portion of the composite tube, when a force is applied to the outer portion of the wall with a 2.5 mm probe until the outer portion of the wall contacts the inner portion, the outer portion deflects a vertical distance that satisfies the following equation: D>0.5×F 2.5 , where D represents the vertical distance in millimeters, and F 2.5 The force in Newtons applied by the 2.5 mm probe is expressed.

[0032] In various embodiments, the aforementioned breathing tube may include one, some, or all of the following characteristics, as well as any other characteristics described elsewhere in this disclosure. The breathing tube may further include a second elongated member that is helically wound and coupled between adjacent turns of the first elongated member, the second elongated member forming at least a portion of the lumen of the elongated tube. The outer portion may deflect more than about 1 mm when a force of about 1 N is applied with a 2.5 mm probe.

[0033] A catheter suitable for use with a tube for delivering humidified gas to a patient is also disclosed. In at least one embodiment, the catheter includes a connector configured to be connected to the tube, the connector including a lumen extending along a longitudinal axis and a wall around the lumen, the lumen defining a flow path for the humidified gas when in use; and a printed circuit board assembly, the printed circuit board assembly including a printed circuit board, and further including a segment embedded in the walls of the connector and extending through the lumen of the connector along a diameter or chord line, such that the segment generally divides at least a portion of the flow path into two, at least a portion of the segment being overmolded by an overmolding composition, a wiring portion being adjacent to the segment and protruding outwardly from the wall of the connector in a direction away from the lumen of the connector, and a sensor portion being disposed in the lumen of the connector and protruding from the segment along the longitudinal axis, the sensor portion including at least one sensor, and the sensor portion being overmolded by the overmolding composition.

[0034] In different embodiments, the aforementioned conduit may include one, some, or all of the following characteristics, as well as any other characteristics described elsewhere in this disclosure. The printed circuit board assembly may further include a support portion, which is adjacent to the segmentation portion and protrudes outward from the connector in a direction away from the lumen and in a direction opposite to the wiring portion. The wiring portion may be configured to be electrically connected to one or more heating wires from the conduit. The at least one sensor may include a thermistor. The sensor portion may protrude upstream of the flow path. The at least one sensor may include a sensor adjacent to the upstream leading edge of the sensor portion. The sensor portion may protrude downstream of the flow path. The at least one sensor may include a sensor adjacent to the downstream leading edge of the sensor portion. The overmolding composition proximal to the sensor portion may have a conical shape extending along the longitudinal axis. The overmolding portion may be thinnest proximal to the leading edge of the sensor portion. The sensor portion may have an airfoil shape extending along the longitudinal axis. The sensor portion may have a bullet or torpedo shape.

[0035] A breathing catheter is also disclosed. In at least one embodiment, the catheter includes a lumen extending along a longitudinal axis, and a wall around the lumen, the lumen defining a gas flow path when in use; and an overmolded printed circuit board assembly fixed to the wall, the printed circuit board assembly including a printed circuit board, and further including a mounting portion disposed in the lumen of the connector and protruding along the longitudinal axis, and a temperature sensor on a surface of the mounting portion.

[0036] In various embodiments, the aforementioned catheter may include one, some, or all of the following characteristics, as well as any other characteristics described elsewhere in this disclosure. The temperature sensor may be a thermistor.

[0037] A breathing catheter is also disclosed. In at least one embodiment, the catheter includes a lumen extending along a longitudinal axis, and walls surrounding the lumen, the lumen defining a gas flow path when in use; and a component fixed to the walls and extending through the lumen along a diameter or chord line such that the component substantially bisects at least a portion of the flow path, the component including a mounting portion disposed in the lumen and protruding along the longitudinal axis; a temperature sensor on a surface of the mounting portion; and an electrical connection on the sensor.

[0038] In various embodiments, the aforementioned conduit may include one, some, or all of the following characteristics, as well as any other characteristics described elsewhere in this disclosure. The temperature sensor may be a thermistor. The component may be a printed circuit board. The electrical connection may span the length of the component along the diameter or chord line.

[0039] A breathing catheter is also disclosed. In at least one embodiment, the catheter includes a lumen extending along a longitudinal axis, and a wall around the lumen, the lumen defining a gas flow path when in use; and an overmolded printed circuit board assembly fixed to the wall, the printed circuit board assembly including a printed circuit board and further including a mounting portion disposed in the lumen and protruding along the longitudinal axis, and a temperature sensor on a surface of the mounting portion, wherein the overmolding portion proximal to the mounting portion has a tapered shape.

[0040] In various embodiments, the aforementioned catheter may include one, some, or all of the following characteristics, as well as any other characteristics described elsewhere in this disclosure. The temperature sensor may be a thermistor.

[0041] A breathing catheter is also disclosed. In at least one embodiment, the catheter includes a lumen extending along a longitudinal axis, and a wall around the lumen, the lumen defining a gas flow path when in use; and a component connected to the wall and including a mounting portion disposed in the lumen and protruding along the longitudinal axis, the mounting portion including a temperature sensor positioned longitudinally upstream of the connection on the wall.

[0042] In various embodiments, the aforementioned breathing tube may include one, some, or all of the following characteristics, as well as any other characteristics described elsewhere in this disclosure. The temperature sensor may be a thermistor. The temperature sensor may be proximal to the upstream end of the mounting portion. The mounting portion may be overmolded. The overmolded portion may be thinnest proximal to the temperature sensor. The mounting portion may protrude longitudinally downstream. The mounting portion may have an airfoil shape extending along the longitudinal axis. The mounting portion may have a bullet or torpedo shape. The vertical distance between the mounting portion and the wall may be at least 30% of the diameter of the lumen.

[0043] A breathing tube segment is also disclosed. In at least one embodiment, the segment includes a lumen extending along a longitudinal axis, and a wall around the lumen, the lumen defining a gas flow path when in use; and a printed circuit board assembly, the printed circuit board assembly including a printed circuit board and including a first portion extending through the lumen along a diameter or chord line, such that a portion of the printed circuit board assembly substantially bisects at least a portion of the flow path, the first portion being overmolded with an overmolding composition, a second portion adjacent to the first portion protruding outwardly from the wall in a direction away from the lumen, the second portion including one or more connection pads on the printed circuit board, the one or more The connection pads are configured to receive one or more metal wires from a first component, a third portion adjacent to the first portion protrudes outward from the wall in a direction away from the lumen and in a direction opposite to the second portion, the third portion includes one or more connection pads on the printed circuit board, the one or more connection pads are configured to receive one or more metal wires from a second component different from the first component, and one or more conductive tracks on the printed circuit board are electrically coupled to the one or more connection pads of the second portion and the one or more connection pads of the third portion, and are configured to provide an electrical connection between the first component and the second component.

[0044] In various embodiments, the aforementioned sections may include one, some, or all of the following characteristics, as well as any other characteristics described elsewhere in this disclosure. The first component may be a breathing tube. The second component may be a breathing tube. The printed circuit board assembly may further include a mounting portion disposed in the lumen of the connector and protruding along the longitudinal axis, and a temperature sensor on a surface of the mounting portion.

[0045] In various embodiments, a breathing tube includes a first elongated member including a hollow body helically wound to at least partially form an elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall around the lumen, the hollow body forming a plurality of bubbles in a longitudinal cross-section thereof, the bubbles having a maximum width along the longitudinal axis and a maximum height perpendicular to the longitudinal axis between an outwardly facing vertex of the wall and the lumen, wherein the ratio of the maximum height to the maximum width is at least about 0.16. A second elongated member may be helically wound and bonded between adjacent turns of the first elongated member, the second elongated member forming at least a portion of the lumen of the elongated tube. The maximum height may be in the range of about 0.7 mm to about 7.7 mm. The maximum height may be about 2.7 mm. The maximum width may be in the range of about 2.0 mm to about 6.0 mm. The maximum width may be about 4.0 mm. The ratio of the maximum height to the maximum width may be greater than 1.0.

[0046] In various embodiments, a breathing tube includes a first elongated member including a hollow body helically wound to at least partially form an elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall around the lumen, the hollow body forming a plurality of bubbles in a longitudinal cross-section thereof, wherein the vertical distance between corresponding points on adjacent bubbles defines a pitch, wherein the ratio of the pitch to the maximum outer diameter of the composite tube is less than about 0.35. A second elongated member may be helically wound and bonded between adjacent turns of the first elongated member, the second elongated member forming at least a portion of the lumen of the elongated tube. The pitch may be in the range of about 1.2 mm to about 8.1 mm. The pitch may be about 5.1 mm. The maximum outer diameter may be in the range of about 19.5 mm to about 25.5 mm. The maximum outer diameter may be about 22.5 mm.

[0047] In various embodiments, a composite tube comprises a first elongated member comprising a hollow body helically wound to at least partially form an elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall around the lumen, the hollow body forming a plurality of bubbles in a longitudinal cross-section thereof, the bubbles having a maximum height between an outward-facing vertex of the wall and the lumen, perpendicular to the longitudinal axis, the maximum height defining a maximum height of the first elongated member; and a second elongated member helically wound and coupled between adjacent turns of the first elongated member, the second elongated member forming at least a portion of the lumen of the elongated tube, the second elongated member having a maximum height between an outward-facing vertex of the second elongated member and the lumen, perpendicular to the longitudinal axis, wherein the ratio of the difference between the maximum height of the first elongated member and the maximum height of the second elongated member to the maximum outer diameter of the composite tube is less than about 0.049:1. The wall may have an inner portion proximal to the lumen and an outer portion facing away from the lumen, and the inner portion of the wall may have a smaller thickness than the outer portion of the wall.

[0048] In various embodiments, a composite tube includes a first elongated member including a hollow body helically wound to at least partially form an elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall around the lumen, the wall having an inner portion proximal to the lumen and an outer portion facing away from the lumen; and a second elongated member helically wound between adjacent turns of the first elongated member, the second elongated member forming at least a portion of the lumen of the elongated tube, and the first elongated member joined at connection points on adjacent turns of the second elongated member; wherein the bending radius of the composite tube is limited by the length of the outer portion between the connection points. The wall can have an inner portion proximal to the lumen and an outer portion facing away from the lumen, and the inner portion of the wall can have a smaller thickness than the outer portion of the wall.

[0049] In various embodiments, a catheter is provided for use with a tube for delivering humidified gas to a patient, the catheter comprising a connector configured to be connected to the tube, the connector comprising a lumen extending along a longitudinal axis and a wall surrounding the lumen, the lumen defining a flow path for the humidified gas when in use; and a printed circuit board assembly comprising a printed circuit board and further comprising a segmented portion embedded in the walls of the connector and extending through the lumen of the connector along a diameter or chord line, such that the segmented portion substantially divides at least a portion of the flow path into two, at least a portion of the segmented portion being overmolded with an overmolding composition, a wiring portion being adjacent to the segmented portion and protruding outwardly from the wall of the connector in a direction away from the lumen of the connector, and a sensor portion being disposed in the lumen of the connector and protruding from the segmented portion along the longitudinal axis, the sensor portion comprising at least one sensor, and the sensor portion being overmolded with the overmolding composition. The printed circuit board assembly may further include a support portion, which is adjacent to the segmentation portion and protrudes outward from the connector in a direction away from the lumen and in a direction opposite to the wiring portion. The wiring portion may be configured to be electrically connected to one or more heating wires from the conduit. The at least one sensor may include a thermistor. The sensor portion may protrude upstream of the flow path. The at least one sensor may include a sensor adjacent to the upstream leading edge of the sensor portion. The sensor portion may protrude downstream of the flow path. The at least one sensor may include a sensor adjacent to the downstream leading edge of the sensor portion. The overmolding composition near the sensor portion may have a conical shape extending along the longitudinal axis. The overmolding portion may be thinnest near the leading edge of the sensor portion. The sensor portion may have an airfoil shape extending along the longitudinal axis. The sensor portion may have a bullet or torpedo shape.

[0050] In various embodiments, the breathing conduit comprises a lumen extending along a longitudinal axis, and a wall around the lumen, the lumen defining a gas flow path when in use; and an overmolded printed circuit board assembly fixed to the wall, the printed circuit board assembly comprising a printed circuit board, and further comprising a mounting portion disposed in the lumen and protruding along the longitudinal axis, and a temperature sensor on a surface of the mounting portion, wherein the overmolding proximal to the mounting portion has a tapered shape. The temperature sensor may be a thermistor.

[0051] In various embodiments, the breathing conduit includes a lumen extending along a longitudinal axis, and a wall around the lumen, the lumen defining a gas flow path when in use; and a component connected to the wall and including a mounting portion disposed in the lumen and protruding along the longitudinal axis, the mounting portion including a temperature sensor positioned longitudinally upstream of the connection on the wall. The temperature sensor may be a thermistor. The temperature sensor may be proximal to the upstream end of the mounting portion. The mounting portion may be overmolded. The overmolded portion may be thinnest proximal to the temperature sensor. The mounting portion may protrude longitudinally downstream. The mounting portion may have an airfoil shape extending along the longitudinal axis. The mounting portion may have a bullet or torpedo shape. The vertical distance between the mounting portion and the wall may be at least 30% of the diameter of the lumen.

[0052] In various embodiments, a breathing tube segment includes a lumen extending along a longitudinal axis and a wall around the lumen, the lumen defining a gas flow path when in use; and a printed circuit board assembly including a printed circuit board and including a first portion extending through the lumen along a diameter or chord line such that a portion of the printed circuit board assembly substantially bisects at least a portion of the flow path, the first portion being overmolded with an overmolding composition, a second portion adjacent to the first portion protruding outwardly from the wall in a direction away from the lumen, the second portion including one or more connection pads on the printed circuit board, the one or more connection pads The invention relates to a device for providing a breathing tube and a third part of the connector. The device comprises a first part and a second part, wherein the first part includes a first connection pad configured to receive one or more wires from a first component, a third part adjacent to the first part protrudes outward from the wall in a direction away from the lumen and in a direction opposite to the second part, the third part includes one or more connection pads on the printed circuit board, the one or more connection pads are configured to receive one or more wires from a second component different from the first component, and one or more conductive tracks on the printed circuit board are electrically coupled to the one or more connection pads of the second part and the one or more connection pads of the third part, and are configured to provide an electrical connection between the first component and the second component. The first component can be a breathing tube. The second component can be a breathing tube. The printed circuit board assembly can further include a mounting portion disposed in the lumen of the connector and protruding along the longitudinal axis, and a temperature sensor on a surface of the mounting portion.

[0053] In various embodiments, a composite tube comprises a first elongated member comprising a hollow body helically wound to at least partially form an elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall around the lumen; a second elongated member helically wound and joined between adjacent turns of the first elongated member, the second elongated member forming at least a portion of the lumen of the elongated tube; wherein at least a portion of the first elongated member is formed of a breathable material. In one example, the composite tube may be provided with a humidification fluid source and / or pre-filled with a volume of humidification fluid, and a heater is provided to heat the fluid so that fluid vapor passes through the breathable material into the lumen or from the lumen through the breathable material. The heater may include one or more heating filaments disposed in the second elongated member.

[0054] To summarize the present invention, certain aspects, advantages and novel features of the present invention are described herein. It should be understood that not all of these advantages may be achieved according to any particular embodiment of the present invention. Therefore, the present invention can be embodied or implemented in a manner that achieves or optimizes one or a group of advantages as taught herein without requiring the realization of other advantages as may be taught or suggested herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Exemplary embodiments implementing the various features of the disclosed systems and methods will now be described with reference to the drawings. The drawings and associated descriptions are provided for illustrating the embodiments and not to limit the scope of the present disclosure.

[0056] Figure 1 A schematic diagram of a medical circuit incorporating one or more medical tubes is shown.

[0057] Figure 2A A side top view of a cross section of an example composite tube is shown.

[0058] Figure 2B A longitudinal section of the top portion of the tube is shown, which is connected to Figure 2A The example composite tube is similar.

[0059] Figure 2C Another longitudinal cross section is shown showing a first elongate member in the composite tube.

[0060] Figure 2D Another longitudinal cross section of the top end portion of the tube is shown.

[0061] Figure 2E Another longitudinal cross section of the top end portion of the tube is shown.

[0062] Figure 2FA tube is shown with a portion of the tube exposed in its longitudinal section.

[0063] Figure 2G A longitudinal section of a portion of a tube is shown, the tube being Figure 2F The example tube is similar.

[0064] Figure 2H A longitudinal section of the top end portion of the tube is shown.

[0065] Figure 3 A fixture suitable for determining bubble deflection is shown.

[0066] Figure 4 A curve of force versus bubble deflection is shown.

[0067] Figures 5A-5C An example of a shape of a first elongated member configured to improve thermal efficiency is shown.

[0068] Figure 5D-5F Examples of filament arrangements configured to improve thermal efficiency are shown.

[0069] Fig. 6A A longitudinal cross section of a portion of a composite tube is shown in a neutral position.

[0070] Figure 6B Shown in a bent position Fig. 6A A portion of a composite pipe, wherein the composite pipe has been bent into a ∩ shape.

[0071] Figure 6C The composite tube is shown having been bent into a ∩ shape.

[0072] Fig.6D A composite tube is shown that has been bent beyond a minimum radius of curvature.

[0073] Fig. 7A A transverse cross-section of a second elongate member in a composite tube is shown.

[0074] Figure 7B Another transverse cross-section of the second elongate member is shown.

[0075] Figure 7C Another example second elongate member is shown.

[0076] Fig.7D Another example second elongate member is shown.

[0077] Fig. 7E Another example second elongate member is shown.

[0078] Figure 7F Another example second elongate member is shown.

[0079] Figure 7G Another example second elongate member is shown.

[0080] Fig. 8A A schematic diagram of a composite tube with variable pitch is shown.

[0081] Figure 8B is a graph depicting an example temperature profile in a variable pitch composite tube.

[0082] Fig. 9A A schematic cross-sectional view of the front side of the elastic clamp is shown.

[0083] Fig. 9B Shows Fig. 9A Detailed front side top cross-sectional diagram of the roller on the elastic clamp.

[0084] Figures 9C-9F The resilient clamp is shown in use. Fig. 9C and Fig.9E Shown is a front perspective view of the sample under test in the fixture. Fig.9D and Fig.9F A rear perspective view of the sample under test is shown in the fixture.

[0085] Fig. 10A A crush resistance test fixture is shown.

[0086] Fig. 10B A graph of load versus extension is shown for determining the crush stiffness.

[0087] Figures 11A-11D The curvature radius characteristics of the tube are shown.

[0088] Figures 12A-12C An example of a first elongate member stack is shown.

[0089] Fig.13 An alternative embodiment of the second elongate member is shown.

[0090] Figures 14A-14E A number of variations of the tube are shown which are adapted to provide increased lateral extension of the tube.

[0091] Figures 15A-15E They are shown respectively Figures 14A-14E The stretched state of the tube is shown in .

[0092] Fig.16 An example medical circuit is shown in accordance with at least one embodiment.

[0093] Fig.17 An air blowing system according to at least one embodiment is shown.

[0094] Fig.18is a schematic diagram of a coaxial tube according to at least one embodiment.

[0095] Figures 19A-19B A composite tube is shown for use with a patient interface.

[0096] Fig. 20A A composite tube is shown for use with a full face mask.

[0097] Fig. 20B A composite tube is shown for use with a nasal mask.

[0098] Fig. 20C A composite tube is shown for use with a nasal / pillow mask.

[0099] Fig.21A An aspect of a method for forming a composite tube is shown.

[0100] Fig. 21B A helically wound second elongate member is shown.

[0101] Fig. 21C Another aspect of a method for forming a composite tube is shown.

[0102] Fig.21D Another aspect of a method for forming a composite tube is shown.

[0103] Fig.21E Another aspect of a method for forming a composite tube is shown.

[0104] Fig.21F Another aspect of a method for forming a composite tube is shown.

[0105] Figures 22A-22C Example configurations of longitudinal cross-sections of multiple tubes are shown.

[0106] Figures 23A-23H An alternative method of forming the tube is shown.

[0107] Figures 24A-24B Another example is shown illustrating a single elongated hollow body that is helically wound to form a medical tube.

[0108] Figures 24C-24F Other examples of single elongated hollow bodies that are helically wound to form medical tubing are shown.

[0109] Figures 25A-25L A general flow chart is shown, as well as more detailed schematic diagrams and photographs, relating to a method for attaching a connector to an end of a tube configured to be connected to a humidifier in use.

[0110] Figures 26A-26EA connector for attaching a filament to an electrical connector is shown.

[0111] Figures 27A-27E Shows the suitability for Figures 25A-25L A clamshell piece is used with a connector.

[0112] Figures 28A-28F and Figures 29A-29L Connectors are shown that may be used in methods of having a medical circuit through which electrical wires pass, and associated components.

[0113] Figures 30A-30O A schematic diagram of a connector suitable for attaching a tube to a patient interface is shown.

[0114] Figures 31A-31B Shows the suitability for Figures 30A-30O The top portion is used together with a connecting piece.

[0115] Figures 32A-32D Shows the suitability for Figures 30A-30O The anti-rotation structural part is used together with the connecting piece.

[0116] Figures 33A-33D An example PCB assembly is shown.

[0117] Fig.34 A segmented inspiratory branch for use with a humidification system is shown having an intermediate connector configured to couple heating filaments and / or temperature sensors within two segments.

[0118] Figures 35A-35E A schematic diagram is shown of a connector suitable for attaching a tube to a humidifier port, a patient interface, or any other suitable component.

[0119] Figures 36A-36K A schematic diagram is shown of another connector suitable for attaching a tube to a humidifier port, a patient interface, or any other suitable component.

[0120] Fig.37A A longitudinal cross section of a top end portion of a tube is shown, the tube comprising two first elongate members.

[0121] Fig.37B Another longitudinal cross-section of a top end portion of a tube is shown, the tube comprising two first elongate members.

[0122] Generally throughout the drawings, reference numbers are reused to indicate correspondence between referenced (or similar) elements. However, corresponding referenced (similar) elements may have different reference numbers in some cases. In addition, the first digit or digits of each reference number generally indicate the drawing in which the element first appears. Specific embodiments

[0123] Details regarding several illustrative embodiments for implementing the apparatus and methods described herein are described below with reference to the accompanying drawings. The present invention is not limited to these described embodiments.

[0124] A breathing circuit comprising one or more medical tubes

[0125] To understand this disclosure in more detail, first refer to Figure 1 , which shows a breathing circuit according to at least one embodiment, the breathing circuit including one or more medical tubes. Tube is a broad term and is given its common and customary meaning to a person of ordinary skill in the art (that is, it is not limited to a special or customized meaning), and includes but is not limited to cylindrical and non-cylindrical channels. Certain embodiments may incorporate a composite tube, which may generally be defined as a tube comprising two or more parts, or specifically, in some embodiments, comprising two or more components, as described in more detail below. Such a breathing circuit may be a continuous, variable, or bi-level positive airway pressure (PAP) system or another form of respiratory therapy.

[0126] You can do it as follows Figure 1 The dry gas is delivered from the ventilator / blower 105 to the humidifier 107, which humidifies the dry gas. The humidifier 107 is connected to the inlet 109 (the end for receiving the humidified gas) of the inspiratory tube 103 via the port 111, thereby supplying the humidified gas to the inspiratory tube 103. The inspiratory tube is a tube configured to deliver respiratory gas to the patient, and may be composed of a composite tube as further described in detail below. The gas flows through the inspiratory tube 103 to the outlet 113 (the end for discharging the humidified gas), and then flows to the patient 101 through the patient interface 115 connected to the outlet 113.

[0127] The exhalation tube 117 is optionally connected to the patient interface 115. The exhalation tube is a tube configured to move the exhaled humidified gas away from the patient. Here, the exhalation tube 117 returns the exhaled humidified gas from the patient interface 115 to the ventilator / blower 105.

[0128] In this example, dry gas enters the ventilator / blower 105 through the vent 119. The fan 121 can improve the airflow into the ventilator / blower by drawing air or other gas through the vent 119. For example, the fan 121 can be a variable speed fan, wherein the electronic controller 123 controls the fan speed. Specifically, the functions of the electronic controller 123 can be controlled by the electronic main controller 125 in response to inputs from the main controller 125 and predetermined desired values ​​(preset values) of pressure or fan speed or gas flow rate set by the user via the dial 127.

[0129] The humidifier 107 includes a humidification chamber 129, which contains a certain volume of water 130 or other suitable humidification liquid. Preferably, the humidification chamber 129 is removable from the humidifier 107 after use. Removability allows the humidification chamber 129 to be more easily sterilized or disposed of. However, the humidification chamber 129 portion of the humidifier 107 can be an integral structure. The body of the humidification chamber 129 can be formed of a non-conductive glass or plastic material. But the humidification chamber 129 can also include multiple conductive components. For example, the humidification chamber 129 can include a high thermal conductivity base (e.g., an aluminum base) that contacts or is associated with a heater plate 131 on the humidifier 107.

[0130] The humidifier 107 may also include a plurality of electronic controls. In this example, the humidifier 107 includes an electronic analog or digital main controller 125. Preferably, the main controller 125 is a microprocessor-based controller that executes computer software commands stored in an associated memory. In response to humidity or temperature values ​​set by a user and other inputs entered via, for example, a user interface 133, the main controller 125 determines when (or at what level) to energize the heater plate 131 to heat the water 130 in the humidification chamber 129.

[0131] Any suitable patient interface 115 may be incorporated. Patient interface is a broad term and is given its common and customary meaning to one of ordinary skill in the art (that is, it is not limited to a special or customized meaning), and includes, but is not limited to, masks (such as tracheal masks, face masks, and nasal masks), cannulas, and nasal pillows. A temperature probe 135 may be connected to the inspiratory tube 103 proximate to the patient interface 115, or to the patient interface 115. The temperature probe 135 monitors the temperature near or at the patient interface 115. A heating filament (not shown) associated with the temperature probe may be used to adjust the temperature of the patient interface 115 and / or the inspiratory tube 103 so as to raise the temperature of the inspiratory tube 103 and / or the patient interface 115 above the saturation temperature, thereby reducing the chance of unwanted condensation.

[0132] exist Figure 1In the embodiment of the present invention, the exhaled humidified gas is returned to the ventilator / blower 105 from the patient interface 115 via the expiratory tube 117. The expiratory tube 117 may also be a composite tube, as described in more detail below. However, the expiratory tube 117 may also be a medical tube as previously known in the art. In either case, the expiratory tube 117 may have a temperature probe and / or a heating filament (as described above for the inspiratory tube 103) integrated with it, thereby reducing the chance of condensation. In addition, the expiratory tube 117 does not need to return the exhaled gas to the ventilator / blower 105. Alternatively, the exhaled humidified gas may be directly delivered to the surrounding environment or delivered to other auxiliary equipment, such as an air scrubber / filter (not shown). In certain embodiments, the expiratory tube is completely omitted.

[0133] Composite pipe

[0134] Figure 2A A side top view of a cross section of an example composite tube 201 is shown. Generally, composite tube 201 includes a first elongated member 203 and a second elongated member 205. Member is a broad term and is given its ordinary and customary meaning to one of ordinary skill in the art (i.e., it is not limited to a specific or customary meaning) and includes, without limitation, an integral part, an integral component, and a distinct component. Thus, while Figure 2A An embodiment consisting of two distinct parts is shown, but it will be appreciated that in other embodiments (as described below), the first elongated member 203 and the second elongated member 205 may also represent multiple regions in a tube formed from a single material. Thus, the first elongated member 203 may represent a hollow portion of the tube, while the second elongated member 205 represents a structural support or reinforcement portion of the tube that adds structural support to the hollow portion. The hollow portion and the structural support portion may have a helical configuration as described herein.

[0135] Composite tube 201 may be used to form an inspiratory tube 103 and / or an expiratory tube 117 in a breathing circuit as described above, or any other tube as described elsewhere in this disclosure. In certain embodiments, composite tube 201 is at least one inspiratory tube 103 .

[0136] The components and features of the example composite tube 201 are described in more detail below. Subheadings such as "First Elongated Member" and "Second Elongated Member" are used. These subheadings are not and should not be considered limiting. For example, aspects of one or more embodiments described under the First Elongated Member subheading may also apply to one or more embodiments described under the Second Elongated Member subheading, and vice versa.

[0137] first elongated member

[0138] exist Figure 2AIn the embodiment, the first elongated member 203 includes a hollow body that is spirally wound to at least partially form an elongated tube having a longitudinal axis LA-LA and a lumen 207 (tube hole) extending along the longitudinal axis LA-LA. The first elongated member 203 has an inner portion 211 near the lumen 207. In some embodiments, the surface of the inner portion 211 forms the lumen 207. The first elongated member 203 also has an outer portion 219 that is opposite to the inner portion and radially away from the lumen 207. As discussed in more detail below, the first elongated member 203 can form a plurality of bubbles in its longitudinal cross-section. In some embodiments, these bubbles have a cross-sectional profile similar to the letter "D". These bubbles can be arc-shaped at the surface facing outward. These bubbles can be flatter at the surface of the lumen 207. In at least one embodiment, the first elongated member 203 is a tube.

[0139] Preferably, the first elongated member 203 is flexible. Flexibility refers to the ability to bend. In addition, the first elongated member 203 is preferably transparent, or at least translucent or semi-opaque. The light transmittance enables a caregiver or user to check whether the lumen 207 is blocked or contaminated, or to determine whether moisture is present.

[0140] A variety of plastics, including medical grade plastics, are suitable for the body of first elongated member 203. Examples of suitable materials include polyolefin elastomers, polyetheramide blocks, thermoplastic copolyester elastomers, EPDM-polypropylene blends, and thermoplastic polyurethanes. In certain embodiments, the material is selected such that the resulting material density of first elongated member 203 is less than or equal to 1 g / cm 3 (or about 1g / cm 3 ).

[0141] The first elongated member 203 material is preferably soft. Softness reflects the amount a material "gives" or compresses after a force is applied. A soft material will stretch or compress more than a firm material. Bubble deflection can be used to quantify the softness of the first elongated member 203 material. Bubble deflection is the distance that the outer portion 219 of the first elongated member 203 deflects vertically (that is, displaces radially inward in the direction of the lumen 207) after a force is applied. This can be accomplished, for example, using a bubble deflection fixture such as Figure 3 The fixture 301 shown in the photo is used to test bubble deflection.

[0142] In a softness test, Figure 3 Four samples of composite tubes having the properties shown in Table 1 (hereinafter referred to as “Type 1”) and four samples of composite tubes having the properties shown in Table 2 (hereinafter referred to as “Type 2”) were respectively tested on the fixture 301 of FIG.

[0143] Table 1

[0144] feature Dimensions (mm) Range(±) Lumen diameter 17.2 5.0 Pitch 5.1 3.0 Bubble Width 4.0 2.0 Bead width 2.3 +3.0 / -2.0 Bubble height 2.7 +5.0 / -2.0

[0145]

[0146] Table 2

[0147]

[0148] A probe 303 having a 2.5 mm diameter applied force to each sample 305 and the bubble deflection was measured. Figure 4 The resulting curves are plotted in . Until their respective outer portions 219 contact the inner portion 211, the Type 1 samples generally require less force to achieve similar bubble deflection as the Type 2 samples. In some embodiments, until the outer portion 219 contacts the inner portion 211, the bubble deflection may satisfy the equation: D>0.5×F 2.5 , where D represents the bubble deflection in millimeters, and F 2.5 represents the force in Newtons applied by a 2.5 mm probe. For example, the first elongate member 203 may deflect more than 1 mm when a force of 1 N is applied by a 2.5 mm probe 303 until the outer portion 219 contacts the inner portion 211 .

[0149] It should be appreciated that while the configurations in Table 1 may be preferred in certain embodiments, other configurations and variations may be used in other embodiments as may be desired.

[0150] Figure 2B Shows Figure 2A 201. A longitudinal cross section of a top portion of an example composite tube 201. Figure 2B With Figure 2A Same orientation. This example further illustrates the shape of the hollow body of the first elongated member 203. As can be seen in this example, the first elongated member 203 forms a plurality of hollow bubbles in its longitudinal cross-section. Therefore, in this specification, the term "bubble" refers to the cross-sectional shape of a turn or circle of the first elongated member 203. A portion 209 of the first elongated member 203 overlaps the adjacent sheath of the second elongated member 205. The inner portion 211 of the first elongated member 203 forms the wall of the lumen 207.

[0151] The hollow body structure of first elongated member 203 contributes to the soundproofing properties of composite tube 201. In at least one embodiment, the outer diameter of first elongated member 203 is greater than the outer diameter of second elongated member 205. The bubble-shaped structure forms a cushion. Thus, the fluid (gas or liquid) filled bubble-shaped first elongated member 203 can suppress the noise generated when composite tube 201 is dragged over the edge of an object such as a table or nightstand. In this way, composite tube 201 can be quieter than a one-piece solid body bellows.

[0152] The hollow body structure of the first elongated member 203 also contributes to the insulating properties of the composite tube 201. An insulating composite tube 201 is desirable because, as explained above, it prevents heat loss. This can enable the composite tube 201 to deliver gas from a heated humidifier to a patient while maintaining the confined state of the gas with minimal energy consumption.

[0153] It was discovered that having gaps 213 between adjacent turns of the first elongated member 203, that is, between adjacent bubbles, unexpectedly improves the overall insulating properties of the composite tube 201. Therefore, in certain embodiments, adjacent bubbles are separated by gaps 213. In addition, certain embodiments that include implementations that provide gaps 213 between adjacent bubbles increase the thermal transfer resistivity (R value) and, therefore, reduce the thermal transfer conductivity of the composite tube 201. It was also discovered that such a gap configuration increases the flexibility of the composite tube 201 by allowing for shorter radius bends. A triangular second elongated member 205 or a T-shaped second elongated member 205, such as Figure 2B As shown in , can help maintain the gap 213 between adjacent bubbles. Otherwise, in some embodiments, adjacent bubbles are in contact. For example, adjacent bubbles can be bonded together.

[0154] Figure 2C Shows Figure 2B 205. As shown, the portion 209 of the first elongated member 203 that overlaps the adjacent sheath of the second elongated member 205 is characterized by the extent of the bonding area 217. A larger bonding area increases the resistance of the tube to delamination at the interface of the first elongated member and the second elongated member. Additionally or alternatively, the shape of the beads and / or bubbles can be adapted to increase the bonding area 217. For example, Figure 2D A relatively small binding area on the left hand side is shown. Figure 5B Also shows a smaller binding area. Figure 2E With ratio Figure 2D The binding area shown in FIG is much larger than that shown in FIG, due to the size and shape of the beads. Figure 5A and Figure 5CLarger binding areas are also shown. Each of these figures will be discussed in more detail below. It should be understood that although Figure 2E , Figure 3 and Figure 5C The configuration in may be preferred in certain embodiments, but other configurations, including Figure 2D , Figure 5B Configurations in other variations may be used in other embodiments.

[0155] Figure 2D A longitudinal cross section of the top end portion of another composite tube is shown. Figure 2D With Figure 2B This example further illustrates the shape of the hollow body of the first elongated member 203 and shows how the first elongated member 203 forms a plurality of hollow bubbles in its longitudinal cross-section. In this example, the bubbles are completely separated from each other by gaps 213. The generally triangular second elongated member 205 supports the first elongated member 203.

[0156] Figure 2H A longitudinal cross section of the top end portion of another composite tube is shown. Figure 2H With Figure 2B Same orientation.

[0157] exist Figure 2H In the example of FIG. 2 , the cross-sectional thickness of the inner portion 211 of the first elongated member 203 forming the lumen wall is less than the thickness of the outer portion 219. Since the first elongated member 203 has a D-shaped bubble profile, the outwardly facing portion of the first elongated member 203 has material gaps between adjacent turns of the second elongated member, which facilitates the movement and stretching of the composite tube 201 when it is bent into a ∩ shape. Figure 2H The configuration creates a thinner bubble near lumen 207, which allows inner portion 211 to be more easily compressed or "bundled" when composite tube 201 is bent into a ∩ shape. Therefore, certain embodiments include the following implementations: configurations in which the cross-sectional thickness of inner portion 211 is less than the cross-sectional thickness of outer portion 219 can increase the flexibility of composite tube 201 by allowing for shorter radius bends. In addition, certain embodiments include the following implementations: overall tube flexibility can be increased by providing first elongated member 203 with variable cross-sectional wall thickness. Desirably, the thickness of inner portion 211 is less than the thickness of outer portion 219.

[0158] In at least one example, the thickness of the inner portion 211 is at least 20% (or approximately 20%) less than the thickness of the outer portion 219. For example, in some embodiments, the thickness of the inner portion 211 is at least 30% (or approximately 30%) less, at least 40% (or approximately 40%) less, at least 50% (or approximately 50%) less, or at least 60% (or approximately 60%) less than the thickness of the outer portion 219. In some embodiments, the thickness of the inner portion 211 is 27% (or approximately 27%) less than the thickness of the outer portion 219. In some embodiments, the thickness of the inner portion 211 is 32% (or approximately 32%) less than the thickness of the outer portion 219. In some embodiments, the thickness of the inner portion 211 is 58% (or approximately 58%) less than the thickness of the outer portion 219. In some embodiments, the thickness of the inner portion 211 is 64% (or approximately 64%) less than the thickness of the outer portion 219.

[0159] The thickness of the outer portion 219 may be in the range of 0.14 mm (or about 0.14 mm) to 0.44 mm (or about 0.44 mm), such as 0.22 mm (or about 0.22 mm) or 0.24 mm (or about 0.24 mm). The thickness of the inner portion 211 may be in the range of 0.05 mm (or about 0.05 mm) to 0.30 mm (or about 0.30 mm), and preferably 0.10 mm (or about 0.10 mm) or 0.16 mm (or about 0.16 mm).

[0160] Reference again Figure 2H , the height of a single longitudinal cross-sectional bubble of first elongated member 203 (labeled H—H) can be greater than the width of a single longitudinal cross-sectional bubble of first elongated member 203 (labeled W—W). Since the greater height increases the size of the material voids in the outer wall of the bubble of first elongated member 203, this configuration can increase the flexibility of composite tube 201 by allowing shorter radius bends. Therefore, certain embodiments include the following implementations: overall tube flexibility can be increased by providing a first elongated member 203 having a longitudinal cross-sectional height that is greater than the longitudinal cross-sectional width. It should be understood that while this example configuration may be preferred in certain embodiments, other configurations and variations may be used in other embodiments as may be desired. For example, the height of the longitudinal cross-sectional bubble of first elongated member 203 can be less than its width.

[0161] In at least one embodiment, the bubble height (H—H) can be in the range of 1.2 mm (or about 1.2 mm) to 8.2 mm (or about 8.2 mm), such as 1.2 mm (or about 1.2 mm), 1.7 mm (or about 1.7 mm), 1.8 mm (or about 1.8 mm), 2.7 mm (or about 2.7 mm), 2.8 mm (or about 2.8 mm), 3 mm (or about 3 mm), 3.2 mm (or about 3.2 mm), 3.5 mm (or about 3.5 mm), 3.8 mm (or about 3.8 mm), 4 mm (or about 4 mm), 4.5 mm (or about 4.5 mm), 7.7 mm (or about 7.7 mm) or 8.2 mm (or about 8.2 mm). In at least one embodiment, the bubble width (W-W) can be in the range of 1.7 mm (or about 1.7 mm) to 8 mm (or about 8 mm), such as 1.7 mm (or about 1.7 mm), 3.2 mm (or about 3.2 mm), 3.5 mm (or about 3.5 mm), 4.0 mm (or about 4.0 mm), 4.2 mm (or about 4.2 mm), 5.2 mm (or about 5.2 mm), 5.5 mm (or about 5.5 mm), 6 mm (or about 6 mm), 7 mm (or about 7 mm), 7.5 mm (or about 7.5 mm) or 8 mm (or about 8 mm).

[0162] The relationship between the bubble height (H-H) and the bubble width (W-W) can be expressed as a ratio. A ratio of bubble height (H-H) to bubble width (W-W) equal to 0 has the worst flexibility. Flexibility increases as this ratio increases. In at least one embodiment, the ratio of the bubble height (H—H) to the bubble width (W—W) can be in the range of 0.15 (or about 0.15) to 1.5 mm (or about 1.5), such as 0.16 (or about 0.16), 0.34 (or about 3.4), 0.50 (or about 0.50), 0.56 (or about 0.56), 0.57 (or about 0.57), 0.58 (or about 0.58), 0.67 (or about 0.67), 0.68 (or about 0.68), 0.73 (or about 0.73), 0.85 (or about 0.85), 1.1 (or about 1.1) and 1.3 (or about 1.3).

[0163] It may be desirable for the outer profile of the bellows to be relatively smooth. Relative smoothness as used in this specification refers to the ridges between the first elongated member 203 and the second elongated member 205 along the length of the composite tube 201. A relatively smoother bellows has ridges that are flatter, more closely spaced, or otherwise less pronounced. A relatively smoother profile can advantageously reduce the noise made when the bellows is dragged over an object, such as the edge of a table or counter.

[0164] One example parameter for quantifying relative smoothness is the vertical difference between outer radial apex 221 of first elongated member 203 of composite tube 201 and outer radial apex 223 of second elongated member 205 (e.g., Figure 2H As the distance between the outer radial apex 221 and the outer radial apex 223 decreases, the composite tube 201 feels relatively smoother. In at least one embodiment, the vertical difference is in the range of 1 mm (or about 1 mm) to 4.6 mm (or about 4.6 mm), such as 1.0 mm (or about 1.0 mm), 1.1 mm (or about 1.1 mm), 1.3 mm (or about 1.3 mm), 1.4 mm (or about 1.4 mm), 1.6 mm (or about 1.6 mm), 1.9 mm (or about 1.9 mm), 2.0 mm (or about 2.0 mm), 2.3 mm (or about 2.3 mm), 2.4 mm (or about 2.4 mm), 3.0 mm (or about 3.0 mm), 3.3 mm (or about 3.3 mm) or 4.6 mm (or about 4.6 mm). It is also possible to quantify the relative smoothness as the vertical distance between the outer radial apex 221 of the first elongated member 203 of the composite tube 201 and the outer radial nadir point 225 of the second elongated member 205. For example, the vertical distance may be 1.5 mm (or about 1.5 mm).

[0165] Another example parameter for quantifying relative smoothness is the ratio of the vertical difference between radial apex 221 of first elongated member 203 and one radial apex 223 (or radial nadir 225) of second elongated member 205 of composite tube 201 to the maximum outer diameter of composite tube 201 (that is, from outer radial apex 221 to outer radial apex 221 on the opposite side of tube 201). As the maximum outer diameter increases, the vertical difference between outer radial apex 221 and outer radial apex 223 or nadir 225 has a smaller effect on relative smoothness. In at least one embodiment, the ratio is in the range of 0.04 to 0.18, such as 0.04, 0.05, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.16, 0.17 or 0.18 or thereabouts.

[0166] As another example, the distance between corresponding points from one turn to the next turn (that is, the pitch) can be selected to quantify the relative smoothness. In some embodiments, the pitch can be in the range of 2.1 mm (or about 2.1 mm) to 9.5 mm (or about 9.5 mm), such as 2.1 mm (or about 2.1 mm), 3.8 mm (or about 3.8 mm), 4.8 mm (or about 4.8 mm), 5.1 mm (or about 5.1 mm), 5.5 mm (or about 5.5 mm), 5.8 mm (or about 5.8 mm), 6.4 mm (or about 6.4 mm), 7.5 mm (or about 7.5 mm), 8.1 mm (or about 8.1 mm), or 9.5 mm (or about 9.5 mm).

[0167] The ratio of the pitch of the composite tube 201 to the vertical difference between the radial apex 221 of the first elongated member 203 and the radial apex 223 of the second elongated member 205 of the composite tube 201 can be selected to quantify the relative smoothness. In certain embodiments, the ratio is in the range of 1.3 (or about 1.3) to 4.8 (or about 4.8), such as 1.31 (or about 1.31), 1.76 (or about 1.76), 2.39 (or about 2.39), 2.42 (or about 2.42), 2.53 (or about 2.53), 2.71 (or about 2.71), 2.75 (or about 2.75), 3.26 (or about 3.26), 3.75 (or about 3.75), 4.13 (or about 4.13), 4.64 (or about 4.64) or 4.75 (or about 4.75).

[0168] The ratio of the pitch to the maximum outer diameter can also be selected to improve relative smoothness. In some embodiments, the ratio of the pitch to the maximum outer diameter of the tube can be in the range of 0.10 (or about 0.10) to 0.35 (or about 0.32), such as 0.11 (or about 0.11), 0.23 (or about 0.23), 0.28 (or about 0.28), 0.29 (or about 0.29), 0.30 (or about 0.30), 0.31 (or about 0.31), or 0.32 (or about 0.32).

[0169] As described above, the hollow portion of the first elongated member 203 can be filled with a fluid, i.e., a liquid or a gas. The first elongated member 203 can be substantially sealed to prevent a certain amount of fluid from being lost. The first elongated member 203 can also be open at one or both ends to allow continuous liquid or gas flow.

[0170] The gas can be air because of its low thermal conductivity (2.62 x 10 -2W / m·K) is desirable. It may also be advantageous to use a gas with a higher viscosity than air, since the higher viscosity reduces heat transfer under natural convection conditions. Thus, a gas such as argon (17.72 x 10 -3 W / m·K), krypton (9.43x10 at 300K) -3 W / m·K) and xenon (5.65x 10 -3 W / m·K) can increase insulating properties. Each of these gases is non-toxic, chemically inert, fireproof, and commercially available. The hollow portion of the first elongated member 203 can be sealed at both ends of the tube, causing the gas therein to be substantially stagnant. Alternatively, the hollow portion can be a secondary pneumatic connection, such as a pressure sample line for delivering pressure feedback from the patient end of the tube to a controller.

[0171] Examples of liquids may include water or other biocompatible liquids with high heat capacity. For example, nanofluids may be used. An example nanofluid with a suitable heat capacity includes water and nanoparticles of a substance such as aluminum.

[0172] In use, the fluid in the hollow portion of the first elongated member 203 can be configured to measure one or more properties of gas within the tube 201, the first elongated member 203, the second elongated member 205, and / or the lumen 207 of the tube 201. In at least one embodiment, the pressure of the gas moving along the lumen of the tube ("lumen gas") can be measured. A reference measurement of the pressure of the fluid in the hollow portion of the first elongated member 203 ("hollow fluid") is taken before the lumen gas begins to circulate. As the lumen gas begins to move through the tube 201, the pressure of the lumen gas will tend to cause a proportional rise in the pressure of the hollow fluid within the first elongated member 203. By comparing the measurements taken in use with the reference measurements, the pressure of the lumen gas within the tube 201 can be determined. In another embodiment, a hollow fluid is selected that changes one or more properties based on the thermal range of operation of the lumen gas within the tube 201. In this way, by measuring the properties of the hollow fluid, the temperature of the lumen gas can be determined. For example, a hollow fluid that expands with temperature may be used. In use, the temperature of the hollow fluid will tend to the temperature of the luminal gas flow. By then measuring the pressure of the hollow fluid, the temperature of the luminal gas can be determined. This may have particular benefits when the temperature of the luminal gas flow is difficult or undesirable to measure directly.

[0173] In at least one embodiment, the extrudate for forming the first elongated member 203 further includes a mineral filler. The extrusion method will be described in more detail below. Talc or hydrated magnesium silicate are suitable mineral fillers. In addition to talc, other suitable mineral fillers include calcium carbonate, magnesium calcium carbonate such as dolomite, barium sulfate, wollastonite, kaolin, and mica, each of which can be added alone or in combination. Suitable mineral fillers can also have a particle size of less than 10 μm (or about 10 mm), or less than 2.5 μm (or about 2.5 mm).

[0174] It has been found that adding mineral fillers to the plastic extruder reduces the stickiness of the resulting first elongated member 203. Stickiness refers to the tactile stickiness or tackiness of the first elongated member 203 material. A more sticky material feels stickier than a less sticky material. A more sticky material also tends to stick to more unwanted substances, such as dirt or hair, than a less sticky material. When bunching (and not bunching) around the periphery of the elbow, by reducing the degree to which adjacent bubbles stick (and not stick) to each other, it has been found that adding mineral fillers reduces the noise generated when the tube moves, bends, etc.

[0175] It has also been found that adding mineral fillers to the extrudate further reduces the noise generated when the first elongated member 203 is dragged over the edge of an object such as a table or nightstand. The mineral filler can help reflect the sound into the surrounding polymer so that the sound does not pass straight through. The improved sound reflection can also give the polymer phase more opportunities to absorb sound energy, and the mineral filler thus provides inherent sound attenuation. The mineral filler can also reduce the hardness of the plastic extrudate and thus improve the sound attenuation characteristics.

[0176] In certain embodiments, the range of mineral filler is 1.5 to 10 (or about 1.5 to about 10) weight percent of the total extrudate. In certain embodiments, the range of mineral filler is 1.5 to 5 (or about 1.5 to about 5) weight percent of the total extrudate. In certain embodiments, the range of mineral filler is 10 (or about 10) or less weight percent of the total extrudate. In certain embodiments, the range of mineral filler is 5 (or about 5) or less weight percent of the total extrudate. In certain embodiments, the range of mineral filler is 1.5 (or about 1.5) or more weight percent of the total extrudate.

[0177] exist Figure 2F In the embodiment, first elongated member 203 forms a plurality of hollow bubbles in its longitudinal cross section. In this example, there are a plurality of bubbles, and more specifically two adjacent envelopes of first elongated member 203 between the envelopes of second elongated member 205. Figure 2GThis configuration is shown in more detail in As described and shown elsewhere in this disclosure, certain configurations may allow for more than two, such as three, wraps of the first elongated member 203 between wraps of the second elongated member 205 .

[0178] Embodiments that include multiple adjacent wraps of first elongated member 203 between wraps of second elongated member 205 may be advantageous because overall tube flexibility is improved. As described below, second elongated member 205, which is substantially solid, is generally less flexible than first elongated member 203, which is hollow. Therefore, certain embodiments include realizations that overall tube flexibility may be improved by increasing the number of bubbles of first elongated member 203 between wraps of second elongated member 205.

[0179] Another advantage of the embodiment comprising multiple adjacent wraps of first elongate member 203 between wraps of second elongate member 205 is improved recovery from compression. It has been observed that samples having multiple bubbles between wraps of first elongate member 203 recover their shape faster after compression than samples having a single bubble between wraps of first elongate member 203.

[0180] Yet another advantage of the embodiment comprising a plurality of adjacent sheaths of the first elongated member 203 between the sheaths of the second elongated member 205 is improved crush resistance. Crush resistance is a mechanical property that plays an important role in the resilience of the tube in operation. Hospital environments can be harsh, as the tube can be crushed by the patient's arms or legs, bed frames, and other equipment. Example crush resistance properties will be discussed in more detail below.

[0181] Another advantage of a multi-bubble construction is that the construction confers the ability to hold or transport additional fluids. As explained above, the hollow portion of the first elongated member 203 can be filled with a gas. Multiple discrete bubbles or hollow portions can be filled with multiple discrete gases. For example, one hollow portion can hold or transport a first gas, and a second hollow portion can be used as a secondary pneumatic connection, such as a pressure sample line for delivering pressure feedback from the patient end of the tube to a controller. As another example, multiple discrete bubbles or hollow portions can be filled with a combination of liquids or a combination of liquids and gases. For example, a first bubble can hold or transport a gas, and a second bubble can hold or transport a liquid. Suitable liquids and gases are described above.

[0182] It should be understood that although Figure 2F and 2G The configuration in may be preferred in certain embodiments, but other configurations may be used in other embodiments as may be desired.

[0183] Second elongated member

[0184] Reference again Figure 2A and Figure 2B , the second elongated member 205 is also helically wound and is joined to the first elongated member 203 between the turns of the first elongated member 203. The second elongated member 205 can form at least a portion of the lumen 207 of the elongated tube. The second elongated member 205 acts as a structural support for the first elongated member 203.

[0185] The weight of a CPAP machine is typically in the range of 2 to 4 kg (or about 2 to 4 kg). Therefore, the breaking strength (the horizontal tensile load or force required to separate the first elongated member 203 from the second elongated member 205) of the composite tube 201 is desirably high enough to prevent separation in the event that a user attempts to use the composite tube 201 to lift a CPAP machine connected to the composite tube 201. Therefore, the breaking strength is preferably greater than 20 N (or about 20 N), and more preferably greater than 30 N (or about 30 N). In some embodiments, the breaking strength is in the range of 75 to 80 N (or about 75 to 80 N). The yield strength (the maximum stress that can be generated without causing plastic deformation) can be in the range of 55 to 65 N (or about 55 to 65 N). In some embodiments, when a lateral force of 2 N is applied, the composite tube 201 does not stretch (deflect horizontally) more than 0.5 mm (or about 0.5 mm).

[0186] In at least one embodiment, the second elongated member 205 is wider at its base (proximal to the lumen 207) and narrower at its top. For example, the shape of the second elongated member is generally triangular, generally T-shaped, or generally Y-shaped. However, any shape that conforms to the contour of the corresponding first elongated member 203 is suitable.

[0187] Preferably, second elongate member 205 is flexible to facilitate bending of the tube. Desirably, second elongate member 205 is less flexible than first elongate member 203. This improves the ability of second elongate member 205 to provide structural support to first elongate member 203. For example, the modulus of second elongate member 205 is preferably 30-50 MPa (or about 30-50 MPa). The modulus of first elongate member 203 is less than the modulus of second elongate member 205. Second elongate member 205 may be solid, or predominantly solid.

[0188] Fig. 6A A longitudinal cross section of the composite tube 201 is shown in a neutral position. Fig. 6Acentered on one turn or bubble of first elongated member 203 and two turns of second elongated member 205. First elongated member 203 and second elongated member 205 have radially outermost connection points 601. In this example, inner portion 211 of first elongated member 203 is thinner than outer portion 219 of first elongated member 203. In this example, second elongated member 205 also has a triangular cross-section. Lumen 207 is located below the base of first elongated member 203 and second elongated member 205. Figure 6B Shown in a bent position Fig. 6A The composite tube 201 is bent into a ∩ shape (eg Figure 6C ). Figure 6B Again, focus on one turn or bubble of the first elongated member 203 and two turns of the second elongated member 205. More specifically, Figure 6B The turns or bubbles of the first elongated member 203 are concentrated at the top of the ∩ shape, i.e., at the location of maximum bending. The radius of curvature of the composite tube 201 is limited by the length of the segment between adjacent outermost connection points 601 in the outer portion 219. If the composite tube 201 is bent beyond the minimum radius of curvature, the outer wall forms a Fig.6D The dimple 605 is shown in FIG.

[0189] A variety of polymers and plastics, including medical grade plastics, are suitable for the body of the second elongated member 205. Examples of suitable materials include: polyolefin elastomers, polyetheramide blocks, thermoplastic copolyester elastomers, EPDM-polypropylene blends, and thermoplastic polyurethanes. In certain embodiments, the first elongated member 203 and the second elongated member 205 can be made of the same material. The second elongated member 205 can also be made of a different color material than the first elongated member 203, and can be transparent, translucent, or opaque. For example, in one embodiment, the first elongated member 203 can be made of a transparent plastic, and the second elongated member 205 can be made of an opaque blue, black, or other color plastic.

[0190] The spirally wound structure including the flexible hollow body and the integral support can provide crush resistance while making the tube wall flexible enough to allow small radius bending without buckling, blocking or collapsing. Preferably, the tube can be bent around a metal rod with a diameter of 25 mm without buckling, blocking or collapsing, as defined in the test of increasing flow resistance by bending according to ISO 5367:2000(E).

[0191] This structure may also provide a smooth lumen 207 surface which helps to protect the tube from deposits and improves gas flow. It has been found that the hollow body may improve the insulating properties of the tube whilst enabling the tube to remain lightweight.

[0192] In some embodiments, the second elongated member 205 may be made of a material that absorbs water. For example, a water-absorbing sponge-like material may be used. In such embodiments, the second elongated member 205 may be connected to a water source, such as a water bag. In use, water will be delivered along at least a portion of the length of the second elongated member 205 (preferably substantially the entire length). As gas flows through the second elongated member 205, water vapor will tend to be acquired by the gas within the lumen 207, thereby humidifying the gas flow.

[0193] In some embodiments, one or more heating filaments 215 (e.g., Figure 2B ) can be controlled to vary the evaporation rate and thereby vary the level of humidification provided to the gas stream. Figure 2B Specifically shown is a heating filament 215, but it should be understood that the second elongated member 205 can encapsulate or contain one or more other conductive materials such as one or more filaments and specifically a sensor (not shown). Such conductive materials can be provided in the second elongated member 205 for heating or sensing the gas flow. The heating filament 215 can minimize the cold surface of condensation that may form on the humid air. The heating filament 215 can also be used to change the temperature profile of the gas in the lumen 207 of the composite tube 201.

[0194] exist Figure 2B In the example of the embodiment of the present invention, two heating filaments 215 are enclosed in the second elongated member 205, one on either side of the vertical portion of the "T". The heating filaments 215 include a conductive material such as an alloy of aluminum (Al) and / or copper (Cu) or a conductive polymer. Preferably, the material forming the second elongated member 205 is selected so that the material does not react with the metal in the heating filaments 215 when the heating filaments 215 reach their operating temperature. The filaments 215 can be spaced apart from the lumen 207 so that the filaments are not exposed in the lumen 207. At one end of the composite tube, the pairs of filaments can be formed into a connecting ring.

[0195] In at least one embodiment, a plurality of filaments are disposed in the second elongated member 205. These filaments can be electrically connected together to share a common track. For example, a first filament, such as a heating filament, can be disposed on a first side of the second elongated member 205. A second filament, such as a sensing filament, can be disposed on a second side of the second elongated member 205. A third filament, such as a grounding filament, can be disposed between the first filament and the second filament. The first filament, the second filament and / or the third filament can be connected together at one end of the second elongated member 205.

[0196] Figure 2E A longitudinal cross section of the top end portion of another composite tube is shown. Figure 2EWith Figure 2B Same orientation. Figure 2E In the example of Figure 2B The filaments 215 in the tube are spaced further apart from each other. It has been found that increasing the space between the heating filaments can improve the heating efficiency, and certain embodiments include such an implementation. The heating efficiency refers to the ratio of the amount of heat input into the tube to the amount of energy output or recoverable from the tube. In general, the greater the energy (or heat) emitted from the tube to the ambient atmosphere, the lower the heating efficiency. In order to improve the heating performance, the heating filaments 215 can be spaced equidistantly (or substantially equidistantly) along the tube hole. Alternatively, the filaments 215 can be positioned at the end of the second elongated member 205, which can provide simpler manufacturing.

[0197] Next reference FIG. 7A to FIG. 7G , these figures show example configurations of the second elongated member 205. Fig. 7A A cross section of a second elongate member 205 is shown, the shape of the second elongate member being similar to Figure 2B In this example embodiment, the second elongated member 205 does not have a heating filament. Other shapes of the second elongated member 205 can also be utilized, including variations of the T-shape as described below and triangular shapes.

[0198] Figure 7B Another example second elongated member 205 is shown, which has a T-shaped cross-section. In this example, the heating filaments 215 are embedded in the cutouts 701 on either side of the vertical portion of the "T" in the second elongated member 205. In some embodiments, the cutouts 701 can be formed in the second elongated member 205 during the extrusion process. Alternatively, the cutouts 701 can be formed in the second elongated member 205 after extrusion. For example, a cutting tool can form the cutouts in the second elongated member 205. Preferably, the cutouts are formed by the heating filaments 215 when they are pressed or pulled (mechanically fixed) into the second elongated member 205 shortly after extrusion, while the second elongated member 205 is relatively soft. Alternatively, one or more heating filaments can be mounted (e.g., attached, bonded or partially embedded) on the base of the elongated member so that the filament or filaments are exposed in the lumen of the tube. In such embodiments, it may be desirable for the filament or filaments to be insulated to reduce the risk of fire if flammable gases, such as oxygen, pass through the lumen.

[0199] Figure 7C Another example second elongated member 205 is shown in cross section. The second elongated member 205 has a generally triangular shape. In this example, heating filaments 215 are embedded on opposite sides of the triangle.

[0200] Fig.7D Another example second elongated member 205 is shown in cross section. Second elongated member 205 includes four grooves 703. Grooves 703 are indentations or grooves on their cross-sectional profile. In some embodiments, grooves 703 can be conducive to forming cutouts (not shown) for embedding filaments (not shown). In some embodiments, grooves 703 are conducive to positioning of filaments (not shown), which are pressed or pulled into these grooves and are thereby embedded in second elongated member 205. In this example, the four start grooves 703 are conducive to placing up to four filaments, such as four heating filaments, four sensing filaments, two heating filaments and two sensing filaments, three heating filaments and one sensing filament, or one heating filament and three sensing filaments. In some embodiments, the heating filaments can be located on the outside of the second elongated member 205. The sensing filaments can be located on the inside.

[0201] Fig. 7E Another example second elongate member 205 is shown in cross section. The second elongate member 205 has a T-shaped profile and a plurality of grooves 303 for placement of heating filaments.

[0202] Figure 7F Another example second elongated member 205 is shown in cross-section. Four heating filaments 215 are encapsulated in the second elongated member 205, two on either side of the vertical portion of the "T". As explained in more detail below, the filaments are encapsulated in the second elongated member 205 because the second elongated member 205 is extruded around the filaments. No cuts are formed to embed the heating filaments 215. In this example, the second elongated member 205 also includes a plurality of grooves 703. Because the heating filaments 215 are encapsulated in the second elongated member 205, the grooves 703 are not used to help form the cuts for embedding the heating filaments. In this example, the grooves 703 can help separate the embedded heating filaments, which makes it easier to peel off the individual cores when, for example, terminating the heating filaments.

[0203] Figure 7G Another example second elongated member 205 is shown in cross section. The second elongated member 205 has a generally triangular shape. In this example, the shape of the second elongated member 205 is similar to Figure 7C The shape is similar to that of , but four filaments 215 are enclosed in the second elongate member 205, all of which are centered in the bottom third of the second elongate member 205 and arranged along a generally horizontal axis.

[0204] As explained above, it may be desirable to increase the distance between the filaments to improve heating efficiency. In some embodiments, however, when the heating filament 215 is incorporated into the composite tube 201, the filament 215 can be positioned relative to the center of the second elongated member 205. The central positioning improves the stability of the reused composite tube, in part because such positioning reduces the possibility of filament breakage during repeated flexing of the composite tube 201. The central filament 215 can also reduce the risk of fire hazards because the filament 215 is covered with multiple layers of insulation and can be removed from the gas path.

[0205] As explained above, some examples illustrate appropriate placement of filaments 215 in the second elongated member 205. In the aforementioned examples including more than one filament 215, the filaments 215 are generally aligned along a horizontal axis. Alternative configurations are also applicable. For example, two filaments can be aligned along a vertical axis or along a diagonal axis. Four filaments can be aligned along a vertical axis or along a diagonal axis. The four filaments can be arranged in a cross-shaped configuration, wherein one filament is disposed at the top of the second elongated member, one filament is disposed at the bottom of the second elongated member (adjacent to the lumen of the tube), and two filaments are disposed on opposite arms on a "T"-shaped, "Y"-shaped, or triangular base.

[0206] size

[0207] Tables 3 and 4 show some example dimensions of the medical tubes described herein and some ranges of these dimensions. These dimensions refer to the transverse cross-section of the tube. In these tables, the lumen diameter represents the inner diameter of the tube. The pitch represents the distance between two repeated points measured along the axial direction of the tube, that is, the distance between the tips of the vertical portion of the adjacent "T" shape of the second elongated member. The bubble width represents the width of a bubble (maximum outer diameter). The bubble height represents the height of a bubble from the lumen of the tube. The bead height represents the maximum height of the second elongated member from the lumen of the tube (e.g., the height of the vertical portion of the "T" shape). The bead width represents the maximum width of the second elongated member (e.g., the width of the horizontal portion of the "T" shape). The bubble thickness represents the thickness of the bubble wall.

[0208] Table 3

[0209]

[0210] Table 4

[0211]

[0212] In another example embodiment, the medical tube has the approximate dimensions shown in Table 5.

[0213] Table 5

[0214] feature Dimensions (mm) Pitch 6.4 Bubble Width 5.5

[0215] The thickness of the bubble at the top farthest from the lumen (outer wall thickness) 0.22 The thickness of the bubble adjacent to the lumen (inner wall thickness) 0.16

[0216] In another example embodiment, the medical tube has the approximate dimensions shown in Table 6.

[0217] Table 6

[0218]

[0219] Preferably, the lower limits of the ranges of Table 6 correspond to each other, and the upper limits of the ranges of Table 6 correspond to each other.

[0220] The embodiments of Tables 5 and 6 may be particularly advantageous for obstructive sleep apnea applications.

[0221] Table 7, Table 8, and Table 9 provide example ratios between tube dimensional characteristics of the tubes described in Table 3, Table 4, and Table 6, respectively.

[0222] Table 7

[0223] ratio baby aldult Lumen diameter: pitch 2.3∶1 2.4∶1 Pitch: Bubble Width 1.1∶1 1.1∶1 Pitch: Bead Width 2.2∶1 3.1∶1 Bubble Width: Bead Width 2.0∶1 2.9∶1 Lumen diameter: bubble height 3.9∶1 5.1∶1

[0224] Lumen diameter: bead height 12.2∶1 12.0∶1 Bubble height: bead height 3.1∶1 2.3∶1 Lumen diameter: bubble thickness 27.5∶1 90.0∶1

[0225] Table 8

[0226]

[0227]

[0228] Table 9

[0229] ratio value Lumen diameter: Pitch 3.4:1 Pitch: Bubble Width 0.93:1 Pitch: Bead Width 2.2:1 Bubble Width: Bead Width 1.7:1 Lumen diameter: bubble height 5.4:1 Lumen diameter: bead height 10.8:1 Bubble height: Bead height 1.7:1 Lumen diameter: the thickness of the bubble at the top farthest from the lumen 71.7:1 Lumen diameter: thickness of the bubble adjacent to the lumen 172:1

[0230] Variable pitch and / or variable diameter The foregoing description discloses various constant pitch and constant diameter configurations. However, certain embodiments may incorporate variable pitch and / or variable diameter.

[0231] Variable pitch may be desirable because it may better allow the heat delivered to the gas stream to vary along the length of the tube. The ability to control where in the tube the heat is delivered may be used to control or reduce rain wash effects within the tube. For example, a tube end temperature set point may be implemented for given conditions that are insufficient to prevent rain wash effects within the tube, particularly at or near the inlet of the tube where the gas temperature may be close to the dew point temperature (high relative humidity). Certain embodiments include the following implementations: Redistributing the heat source to concentrate the heat source near the inlet of the tube can help ensure greater axial concentration of heat Q(z) [W / m] in this area, where z is the axial placement of the tube starting from the device end.

[0232] Fig. 8A An example composite tube 201 with a variable pitch is shown. In this example, the tube 201 has a smaller pitch proximal to the device end 801. Therefore, the heating filaments 215 in this area will be more densely spaced, thereby achieving more heating and greater and more accurate temperature control at that portion of the tube 201. The tube 201 has a larger pitch at the patient end 803. The larger spacing between the heating filaments 215 can allow the gas to reduce temperature when it is close to the patient. This can prevent the patient from receiving too hot gas and can reduce the formation of rain wash effect. Figure 8B Shows Fig. 8A Other temperature profiles are possible and can be customized to achieve a specific desired effect.

[0233] The geometry of the tube 201 also affects the mechanical properties of the tube. By increasing the size of the bubble of the first elongated member, the flexibility of the tube 201 will increase. Conversely, a smaller bubble size will produce a more rigid area of ​​the tube 201. By varying the flexibility and rigidity, the mechanical properties of the tube 201 can be tailored. By varying the diameter of the tube 201, it is possible to have a smaller diameter near the patient interface, which can increase patient comfort, improve aesthetics, and reduce invasiveness of the interface.

[0234] Additional Features

[0235] Tables 10-13 show some example properties of a composite tube (labeled "A") having a heating filament incorporated inside the second elongated member as described herein. For comparison, the properties of a Fisher & Paykel Model RT100 disposable bellows (labeled "B") having a heating filament helically wound inside the bore of the tube are also presented.

[0236] The resistance to flow ratio (RTF) was measured according to Annex A of ISO 5367:2000(E). The results are summarized in Table 10. As can be seen below, the RTF of the composite pipe is lower than that of the type RT100 pipe.

[0237] Table 10

[0238]

[0239] The condensate or "rain wash" in the tube refers to the weight of condensate collected per day at a gas flow rate of 20 L / min and at a room temperature of 18°C. Humidified air was continuously flowed through the tube from the chamber. The tube weight was recorded each day before the test and each day after the test. Three consecutive tests were performed, with the tube dried between each test. The results are shown in Table 11 below. The results show that the rain wash effect in the composite tube is significantly lower than that of the model RT100 tube.

[0240] Table 11

[0241]

[0242] The power demand refers to the power consumed during the condensation test. In this test, the ambient air is kept at 18°C. A humidified chamber (see, e.g. Figure 1 The humidification chamber 129 in the tube is powered by an MR850 heating base. The heating filaments in the tube are independently powered by a DC power supply. Different flow rates are set, and the temperature of the chamber is maintained at 37°C at the chamber output. The DC voltage of the circuit is then changed to produce a temperature of 40°C at the circuit output. The voltage required to maintain the output temperature is recorded, and the resulting power is calculated. The results are shown in Table 12. The results show that composite tube A uses significantly more power than tube B. This is because tube B uses a spiral heating filament in the tube bore to heat the gas from 37°C to 40°C. The composite tube does not heat the gas quickly because the heating filament is located in the wall of the tube (embedded in the second elongated member). Instead, the composite tube is designed to maintain the gas temperature and prevent rain wash effects by maintaining the tube bore temperature above the dew point of the humidified gas.

[0243] Table 12

[0244] Flow rate (L / min) 40 30 20 Tube A, required power (W) 46.8 38.5 37.8 Tube B, required power (W) 28.0 27.5 26.8

[0245] Vertical deflection can be used to quantify the flexibility of the composite pipe. Vertical deflection can be tested, for example, using a three point bend test. A first 300 mm long sample of pipe A and a second 300 mm long sample of pipe B were tested separately on the flexibility fixture. Fig. 9A A schematic diagram of the front side top cross section of the resilient clamp is shown in FIG. The clamp 901 uses a 25-mm rod 903 with a fixed mass of 120 g to apply force to each tube 201, and the rod is positioned between two rollers 905 and 907. The rollers are spaced 150 mm apart. The force applied by the rod 903 is about 1.2 N (0.12 kg x 9.81 m / s 2 ). Fig. 9B A detailed front side top cross-sectional view of rollers 905 and 907 is shown in FIG. Both rollers 905 and 907 have Fig. 9B The same dimensions as shown in . An Instron 5560 testing system instrument was used to measure load and extension. Each tube sample was tested three times; the extension of the tube under the applied load was measured to obtain the respective average stiffness constants. The average stiffness constants for tube A and tube B are reproduced in Table 13.

[0246] Table 13

[0247] Tube Stiffness(N / mm) A 0.028 B 0.088

[0248] Tube weight can be very important, especially for CPAP applications. If the patient bears less weight near the patient's face, the patient will become more comfortable during sleep. The lighter composite tube 201 will not pull the patient's head in a specific direction like a heavier tube. In order to ensure the comfort of the patient, it may be stipulated that the total mass or weight in the area near the patient end of the composite tube 201 must be less than a specified value. In some embodiments, the mass of the tube closest to the patient end 300mm is less than 24g (or about 24g). It is desirable that the mass of the tube closest to the patient end 300mm is less than 16g (or about 16g). In some embodiments, the mass of the tube closest to the patient end 300mm is less than 15g (or about 15g). It may also be stipulated that the total mass of the composite tube is less than a specified value. In some embodiments, the tube mass is less than 130g (or about 130g). It is desirable that the tube mass is less than 120g (or about 120g). In some embodiments, the tube mass is less than 100g (or about 100g).

[0249] The following discussion will now describe additional characteristics associated with a composite tube 201 having two bubbles between the sheaths of the second elongated member 205 as described above.

[0250] A first sample tube having a length of 300 mm and including two bubbles between the sheaths of the second elongated member 205, and a second sample tube having a length of 300 mm and including one bubble between the sheaths of the second elongated member 205 were each tested on the spring fixture 901 described above. The vertical deflection was measured using the positioning of a fixed weight relative to the vertical support 909 of the spring fixture, see FIG. 9C to FIG. 9F Photos.

[0251] Fig. 9C A front perspective view of a second sample under test in fixture 901 is shown. Fig.9D A rear perspective view of a second sample under test in fixture 901 is shown. Fig.9E A front perspective view of a first sample under test in fixture 901 is shown. Fig.9F A rear perspective view of the first sample under test is shown in fixture 901. FIG. 9C to FIG. 9F As shown in Fig.9E and Fig.9F The vertical deflection of the second sample shown in Fig. 9C and Fig.9D Specifically, the vertical deflection of the second sample is 3 mm, while the first sample is much more flexible, with a vertical deflection of 42 mm.

[0252] Use an Instron instrument such as Fig. 10AFour tube samples were tested for crush resistance using the assembly shown in the photo shown in FIG. 1. A cylinder 1001 was inserted 16 mm from the top of the tube at a rate of 60 mm / min. The Instron instrument has a load cell to accurately measure the force applied to the part versus the extension. The load versus extension ratio was plotted as shown in FIG. Fig. 10B as shown in .

[0253] By placing the best matching line with Fig. 10B The compression stiffness of each sample was obtained by fitting the data of and calculating its gradient. The calculated compression stiffness of each sample is shown in Table 14A. In Table 14A (and elsewhere in this disclosure), the name "double bubble" refers to a tube sample that includes two bubbles between the sheaths of the second elongated member 205 when the sample is observed in a longitudinal section. The name "single bubble" refers to a tube sample that includes a single bubble between the sheaths of the second elongated member 205 when the sample is observed in a longitudinal section. The average compression stiffness (measured in N / mm) represents the average maximum force per unit width that does not produce compression.

[0254] Table 14A

[0255] sample Compression stiffness (N / mm) average value

[0256]

[0257] As shown in the aforementioned table, the single bubble tube has an average compression stiffness of 3.86 N / mm, while the double bubble tube has an average compression stiffness of 3.21 N / mm. In other words, the double bubble tube has a compression resistance that is about 16.8% lower than the single bubble tube. However, it has been observed that the compression stiffness per unit thickness of the double bubble tube is about 165% of the value of the single bubble tube, as shown in Table 14B below.

[0258] Table 14B

[0259]

[0260] In other words, when the outer bubble thickness is taken into account, the double bubble tube is about 65% more resistant to crushing than the single bubble tube variant. Figure 2F and Figure 2G Similar to the bubbles shown in FIG, the tested bubbles in the double bubble configuration were taller than they were wide, which resulted in more material in their vertical planes. Therefore, it is believed that this unexpected improvement in the crush resistance per unit thickness of the bubble can be attributed to the additional vertical network between the beads acting in the crush direction.

[0261] Tensile tests were also performed on single bubble tube samples and double bubble tube samples. The length of the two samples was 230 mm and they were extended by 15 mm at a rate of 10 mm / min. The force required to extend the samples was measured. The results are shown in Table 14C.

[0262] Table 14C

[0263] sample Peak force at 15mm extension (N) Double Bubble 17.60 Single Bubble 54.65

[0264] As shown in Table 14C, the double bubble tube is significantly more extensible in the axial (longitudinal) plane. It is believed that this increase in longitudinal extensibility is due to the single bubble tube having more material between the beads acting in the axial plane.

[0265] Thermal properties

[0266] In an embodiment of a composite tube 201 incorporating a heating filament 215, heat can be lost through the walls of the first elongated member 203, resulting in uneven heating. As explained above, one method of compensating for these heat losses is to apply an external heat source to the walls of the first elongated member 203, which helps regulate the temperature and counteract the heat losses. However, other methods for optimizing thermal properties may also be used.

[0267] Reference again FIG. 5A to FIG. 5C , these figures illustrate example configurations of bubble height (ie, the cross-sectional height of first elongate member 203 measured from the surface facing the inner lumen to the surface forming the largest outer diameter) to improve thermal properties.

[0268] The size of the bubble can be selected to reduce heat loss from composite tube 201. In general, increasing the height of the bubble increases the effective thermal resistance of tube 201 because a larger bubble height allows first elongated member 203 to hold more insulating air. However, it has been found that at a certain bubble height, changes in air density can cause convection within tube 201, thereby increasing heat loss. Also, at a certain bubble height, the surface area becomes so large that heat loss through the surface outweighs the benefit of the increased height of the bubble. Certain embodiments include these implementations.

[0269] The radius of curvature and curvature of the bubble can be used to determine the desired bubble height. The curvature of an object is defined as the inverse of the radius of curvature of the object. Therefore, the larger the radius of curvature of an object, the smaller the curvature of the object. For example, the radius of curvature of a flat surface is ∞, and therefore the curvature is 0.

[0270] Figure 5A A longitudinal cross section of the top end portion of the composite tube is shown. Figure 5AAn embodiment of the composite tube 201 is shown in which the bubble has a large height. In this example, the bubble has a relatively small radius of curvature and thus has a large curvature. Also, the height of the bubble is about three to four times higher than the height of the second elongated member 205.

[0271] Figure 5B A longitudinal cross section of the top end portion of another composite tube is shown. Figure 5B An embodiment of the composite tube 201 is shown in which the top of the bubble is flat. In this example, the bubble has a very large radius of curvature, but has a small curvature. Also, the height of the bubble is approximately the same as the height of the second elongated member 205.

[0272] Figure 5C A longitudinal cross section of the top end portion of another composite tube is shown. Figure 5C An embodiment of a composite tube 201 is shown in which the width of the bubble is greater than the height of the bubble. In this example, the radius of curvature of the bubble and the curvature are Figure 5A and Figure 5B and the center of the radius of the upper portion of the bubble is outside the bubble (with Figure 5A The turning points on the left and right sides of the bubble are approximately in the middle (in height) of the bubble (as opposed to the bottom of the bubble, such as Figure 5A Also, the height of the bubble is approximately twice the height of the second elongated member 205, so that the bubble height is Figure 5A and 5B Between the heights shown.

[0273] Figure 5A The structure of the tube minimizes heat loss. Figure 5B The structure makes the heat loss of the tube the highest. Figure 5C The heat loss of the structure is Figure 5A and Figure 5B However, in Figure 5A The large external surface area and convective heat transfer in the construction lead to inefficient heating. Figure 5A –5C’s three bubble arrangements determine Figure 5C The actual meaning of this thermal efficiency is that when the same heat energy is input into these three tubes, Figure 5C The configuration is such that the temperature rise along the length of the tube is maximum. Figure 5C The bubbles are large enough to increase the amount of insulating air, but not large enough to cause significant convective heat losses. Figure 5B The construction has the worst thermal characteristics, i.e. Figure 5B The construction is such that the temperature rise along the length of the tube is minimal. Figure 5AThe structure has medium thermal characteristics and makes its temperature rise higher than Figure 5C The structure is low.

[0274] It should be understood that although Figure 5C The configuration may be preferred in some embodiments, but other configurations, including Figure 5A , Figure 5B The configurations shown, as well as other variations, may be used in other embodiments.

[0275] Table 15 shows Figure 5A , Figure 5B and Figure 5C The height of the bubble, the outer diameter of the tube, and the radius of curvature of these configurations are shown in each.

[0276] Table 15

[0277] Tube (picture) 5A 5B 5C Height of bubble (mm) 3.5 5.25 1.75 Outer diameter(mm) 21.5 23.25 19.75 Curvature radius (mm) 5.4 3.3 24.3

[0278] Table 16A shows the Fig.11A , Fig. 11B and Fig. 11C The height, outer diameter and further configured radius of curvature of the bubble shown in FIG.

[0279] Table 8A

[0280] Tube (picture) 10A 10B 10C Height of bubble (mm) 6.6 8.4 9.3 Outer diameter(mm) 24.6 26.4 27.3 Curvature radius (mm) 10 8.7 5.7

[0281] It should be noted that, in general, the smaller the radius of curvature, the tighter the tube can be bent about itself without causing the bubble to collapse or "buck". Fig.11D shows a tube bent beyond its radius of curvature (specifically, it shows Fig.11A The tube is bent with a radius of curvature of about 5.7 mm), thereby causing flexure of the bubble wall. Flexure is generally undesirable because it detracts from the appearance of the tube and can impair the thermal properties of the tube.

[0282] Therefore, in some applications, a configuration with increased bending properties (such as Figure 5A or Figure 5B ) may be desirable despite having less efficient thermal characteristics. In some applications, it has been found that a tube having an outer diameter of 25 mm to 26 mm (or about 25 mm to about 25 mm) provides satisfactory performance. It should be understood that although in Figure 5A Hehe Figure 5B The configuration in may be preferred in certain embodiments, but other configurations, including Fig.11A The configurations shown in -11D and other variations may be used in other embodiments.

[0283] Reference again FIG. 5C to FIG. 5F , these figures show example positioning of heating elements 215 having similar bubble shapes to improve thermal characteristics. The positioning of heating elements 215 can change the thermal characteristics within composite tube 201.

[0284] Figure 5C A longitudinal cross section of the top end portion of another composite tube is shown. Figure 5C An embodiment of a composite tube 201 is shown in which a heating element 215 is positioned in the center of the second elongated member 205. This example shows the heating elements 215 close to each other and not close to the bubble wall.

[0285] Figure 5D A longitudinal cross section of the top end portion of another composite tube is shown. Figure 5D An embodiment of a composite tube 201 is shown, wherein Figure 5C In comparison, the heating elements 215 are spaced furthest from each other in the second elongated member 205. These heating elements are closer to the bubble wall and provide better thermal regulation within the composite tube 201.

[0286] Figure 5E A longitudinal cross section of the top end portion of another composite tube is shown. Figure 5E An embodiment of composite tube 201 is shown in which the top ends of heating elements 215 are spaced apart from one another on the vertical axis of second elongate member 205. In this example, heating elements 215 are equidistantly adjacent to each bubble wall.

[0287] Fig. 5F A longitudinal cross section of the top end portion of another composite tube is shown. Fig. 5F An embodiment of a composite tube 201 is shown in which a heating element 215 is spaced apart at the opposite end of the second elongated member 205. The heating element 215 is close to the bubble wall, especially with respect to the Figure 5C –5E in comparison.

[0288] exist Figure 5C –5F shows four filament arrangements, determine Fig. 5F has the best thermal characteristics. Because they have similar bubble shapes, the heat losses of all tube configurations are similar. However, when the same amount of heat energy is input into the tube, Fig. 5F The filaments are constructed so that the temperature rise along the length of the tube is maximum with respect to the temperature of the bulk gas within the tube. Figure 5D The configuration has suboptimal thermal characteristics and causes the temperature rise along the length of the tube to be the second largest. Figure 5C The performance of the construction was the third best. Figure 5E The configuration has the worst performance and causes the temperature rise along the length of the tube to be the smallest when the same amount of heat is input.

[0289] It should be understood that although Fig. 5F The configuration may be preferred in some embodiments, but other configurations, including Figure 5C , Figure 5D , Figure 5E The configurations shown, as well as other variations, may be used in other embodiments.

[0290] Next reference FIG. 12A to FIG. 12C , these figures show example configurations for stacking first elongated members 203. It has been found that in certain embodiments, heat distribution can be improved by stacking multiple bubbles. These embodiments may be more beneficial when internal heating filaments 215 are used. Fig. 12A A longitudinal cross section of the top end portion of another composite tube is shown. Fig. 12A A cross section of a composite tube 201 is shown without any stacking.

[0291] Fig. 12B A longitudinal cross section of the top end portion of another composite tube is shown. Fig. 12B Another example composite tube 201 with stacked bubbles is shown. In this example, two bubbles are stacked on top of each other to form a first elongated member 203. Fig. 12A In comparison, the total bubble height remains constant, but the pitch of the bubble is Fig. 12A And, Fig. 12B The embodiment in FIG. 2 has only a slight reduction in air volume. The stacking of bubbles reduces natural convection and heat transfer in the gaps between bubbles 213 and reduces overall thermal resistance. The heat flow path in the stacked bubbles is increased, making it easier to distribute heat through the composite tube 201.

[0292] Fig. 12C A longitudinal cross section of the top end portion of another composite tube is shown. Fig. 12C Another example of a composite tube 201 having stacked bubbles is shown. In this example, three bubbles are stacked on top of each other to form a first elongated member 203. Fig. 12A In comparison, the total bubble height remains constant, but the pitch of the bubble is Fig. 12A One third of the Fig. 12B The embodiment in FIG. 2 has only a slight reduction in the amount of air. The stacking of the bubbles reduces the natural convection and heat transfer in the gaps between the bubbles 213.

[0293] Reference Fig.13, showing further possible characteristics of second elongated member 205. Second elongated member 205 includes one or more coaxial cables 1301 having a conductor 1303 surrounded by an insulating layer 1305, a shielding layer 1307, and a jacketing layer 1309. In some embodiments, one or more cables 1301 may be a multiaxial cable, i.e., multiple conductors 1303 of which are arranged in an insulating layer 1305. In this way, a single assembly containing multiple wires (including heating wires and / or sensing wires) may be used in second elongated member 205, thereby simplifying the assembly and providing some protection against RF interference and the like (via shielding layer 1307).

[0294] In some embodiments, one or more data transmission cables may be included in the second elongated member 205. The data transmission cables may include fiber optic cables. In at least one embodiment, a single fiber optic cable is included in the second elongated member 205 and is used in a passive mode. In a passive mode, at a first end of the cable, a light source and a light sensor are provided. At the second end, a reflector is provided. In use, the light source provides some light with certain characteristics to the reflector. The reflector then reflects the light to the light sensor, and the reflected light can be analyzed to determine the characteristics of the light. The reflector can be adapted to change the characteristics of the reflected light according to a characteristic of the system. For example, the reflector can be used to monitor condensation within the interface. The reflector can include a material that changes color, for example, according to the presence of condensation at the second end. The reflector can alternatively or additionally include a material that changes color, etc. according to the humidity level (relative humidity or absolute humidity) and / or gas temperature at the second end; and / or gas composition such as inhaled O2 or exhaled CO2.

[0295] Reference again Figure 2B In some embodiments, a fluid (gas or liquid) flow can flow through the space within the first elongated member 203. In such embodiments, it is desirable that at least a portion of the first elongated member 203 is formed of a breathable material. Breathable is used herein to mean significantly permeable to water vapor and substantially impermeable to liquid water and bulk gas flow. Suitable breathable materials include an activated perfluorinated polymer material having extremely hydrophilic properties such as or hydrophilic polyester block copolymers such as Other suitable materials include EVAQUA TM and EVAQUA 2 TMPolymers commercially available from TURN® catheters (Fisher & Paykel Healthcare Ltd., Auckland, New Zealand). Suitable materials are further described in PCT Publication WO 2011 / 077250, filed December 22, 2010, published June 30, 2011, and in U.S. Patent No. 6,769,431, filed May 8, 2001, published August 3, 2003.

[0296] The flow through the first elongated member 203 can be used to dry or humidify the gas flow through the lumen 207 of the tube 201 as needed. Conversely, the flow through the lumen 207 of the tube 201 can be used to dry or humidify the gas flow through the first elongated member 203 as needed. Exhaled respiratory gas can be carried through the first elongated member 203. As another example, a liquid such as liquid water can be carried. As another example, a humidified or saturated gas flow can be carried. As another example, a dry gas flow or a compressed ambient air flow can be carried. In the aforementioned embodiment, the first elongated member 203 can be open at both ends to promote fluid flow through the first elongated member 203. One end of the first elongated member 203 can be connected to a suitable source as needed, such as a source of exhaled respiratory gas, liquid water, humidified gas, dry gas, or compressed air. The other end can be connected to a suitable outlet or allowed to discharge to the atmosphere.

[0297] For example, refer to Figure 2B , the portion 211 of the first elongated member 203 that forms the lumen 207 of the tube 201 can be formed of a breathable material as described above. The outward-facing portion 219 of the first elongated member 203 (facing the ambient atmosphere and away from the lumen) can be formed of an impermeable material, that is, a material that is obviously impermeable to water vapor, liquid water, or a large amount of gas flow, as described elsewhere in this disclosure. In use, some humidification fluid (such as water) can pass through the space formed by the first elongated member 203. Because the humidification fluid is heated (for example, heated by the heating filament 215 disposed in the second elongated member 205), a portion of the humidification fluid will tend to evaporate. The water vapor can then pass through the breathable portion 211 into the large amount of gas flow passing through the lumen 207, thereby humidifying the large amount of gas flow. In this embodiment, the combination of the humidification fluid, the first elongated member 203 and the heating filament 215 can provide a means for humidifying the gas flow in the lumen 207, so that the system can omit a separate humidifier.

[0298] As another example, a gas stream may flow through the space within the first elongated member 203. For example, exhaled respiratory gas may be carried. Figure 2B , first elongate member 203 or at least outwardly facing portion 219 of first elongate member 203 is made of a breathable material as described above. In this way, as exhaled gas moves along the length of first elongate member 203, it tends to dry the gas at a relative humidity of about 100% at the patient end to reduce the humidity level at the contralateral end.

[0299] Coextrusion is a suitable method for forming a first elongated member 203 comprising a portion (211 or 219, depending on the desired application) formed from a breathable material and a portion (219 or 211, depending on the desired application) formed from an impermeable material.

[0300] In addition, although certain of the foregoing embodiments have been described with reference to a single first elongated member 203 comprising a breathable portion and an impermeable portion, it should be understood that the desired results (such as humidifying the gas flow within the tube cavity 207) can also be achieved using multiple first elongated members 203. Fig. 12B , Fig. 12C , Fig.37A and Fig.37B A suitable embodiment is shown in .

[0301] Fig.37A A cross section of a tube including two first elongated members is shown. The first first elongated member 203a is disposed proximal to the lumen 207 of the tube. The second first elongated member 203b faces the ambient atmosphere and faces away from the lumen 207. The interior of the first first elongated member 203a forms the lumen 207 wall. The first first elongated member 203a can define a conduit for a humidifying fluid such as liquid water. The first first elongated member 203a can be formed of a breathable material. Since the humidifying fluid is heated (for example, heated by a heating filament 215 disposed in the second elongated member 205), a portion of the humidifying fluid will tend to evaporate. The water vapor can then pass through the wall of the first first elongated member 203a into the large amount of gas flow passing through the lumen 207, thereby humidifying the large amount of gas flow. In such an embodiment, the combination of the humidification fluid, the first elongated member 203a and the heating filament 215 can provide a means for humidifying the gas flow within the lumen 207, so that the system can omit a separate humidifier. It should be understood that Fig.37A The dimensions shown are not necessarily drawn to scale. Fig. 12B As shown in FIG. 1 , the first elongated member 203a can be relatively large, and the second elongated member 203b can be relatively small. It should also be understood that the heating filament 215 does not have to be contained in the second elongated member 205. For example, Fig. 12BAs shown in , the second elongated member may be omitted. The heating filament 215 may, for example, be housed in a portion of the second first elongated member 203b proximal to the first first elongated member 203a.

[0302] Fig.37B Also shown is a cross section of a tube including two first elongated members. A first first elongated member 203a is disposed proximal to the lumen 207 of the tube. A second first elongated member 203b faces the ambient atmosphere and away from the lumen 207. An inner portion of the first first elongated member 203a forms a portion of the wall of the lumen 207. An inner portion of the second first elongated member 203b also forms a portion of the wall of the lumen 207. As described above with reference to Fig.37A As discussed, the first elongated member 203a can define a conduit for a humidifying fluid such as liquid water, and the combination of the humidifying fluid, the first elongated member 203 and the heating filament 215 can provide a means for humidifying the gas flow within the lumen 207, so that the system can omit a separate humidifier. Again, it should be understood that Fig.37B The dimensions shown are not necessarily drawn to scale. Fig. 12B As shown in FIG. 1 , the first elongated member 203a can be relatively large, and the second elongated member 203b can be relatively small. It should also be understood that the heating filament does not have to be contained in the second elongated member. For example, Fig. 12B As shown in , the second elongated member can be omitted. The heating filament can be accommodated in a portion of the second first elongated member 203b proximal to the first first elongated member 203a, for example. Fig.14A –14E and Fig.15A -15E, shows some variations of the composite tube 201 configuration adapted to provide increased lateral extension in the composite tube 201. Fig.15A –15E shows Fig.14A – A stretched state of the composite tube shown in Figure 14E.

[0303] include Fig.14A , Fig. 14B and Fig.14E Certain embodiments of the implementation of the tube shown in include a second elongated member 205 having a shape that enhances the stretching capability. Fig.14A In the embodiment, the second elongated member 205 is substantially oblate, and the height of its profile is substantially the same as that of the first elongated member 203. Fig.15A As shown in , this enables the second elongate member 205 to deform outwardly to at least twice the width compared to the stationary second elongate member 205. Fig. 14B and 14EIn the embodiment, the second elongated member 205 is formed to have an accordion-like shape. Fig. 15B and Fig.15E ), the second elongated member 205 can therefore accommodate the increased amount of stretch.

[0304] exist Fig. 14C and Fig.14D In the embodiment, the first elongate member 203 has a shape that can be deformed outwardly, thereby increasing its lateral extension (e.g., at Fig. 15C and Fig.15D ).

[0305] Medical circuit

[0306] Next reference Fig.16 , which shows an example medical circuit according to at least one embodiment. The circuit includes one or more composite tubes as described above, i.e., for the inspiratory tube 103 and / or the expiratory tube 117. The characteristics of the inspiratory tube 103 and the expiratory tube 117 are the same as those described above for Figure 1 The inspiratory tube 103 has an inlet 109 communicating with the humidifier 107, and an outlet 113 through which humidified gas is provided to the patient 101. The expiratory tube 117 also has an inlet 109 for receiving exhaled humidified gas from the patient, and an outlet 113. Figure 1 As described, outlet 113 of exhalation tube 117 may exhaust exhaled gases to atmosphere, to ventilator / blower device 105, to an air scrubber / filter (not shown), or to any other suitable location.

[0307] As described above, heating filaments 215 may be placed in the inspiratory tube 103 and / or the expiratory tube 117 to reduce the risk of rain wash effects in the tubes by maintaining the tube wall temperature above the dew point temperature.

[0308] Components of the blowing system

[0309] Laparoscopic surgery (also known as minimally invasive surgery (MIS) or keyhole surgery) is a modern surgical technique in which operations within the abdomen are performed through smaller incisions (usually 0.5 to 1.5 cm) than the larger incisions required for conventional surgery. Laparoscopic surgery includes operations in the abdominal or pelvic cavities. During laparoscopic surgery using insufflation, it may be necessary to humidify the insufflated gas (usually CO2) before it is delivered to the abdominal cavity. This can help prevent "dehydration" of the patient's internal organs and can reduce the amount of time required for post-operative recovery. The insufflation system typically includes a humidifier chamber in which a certain amount of water is maintained. The humidifier typically includes a heater plate that heats water to produce water vapor, which is delivered to the incoming gases to humidify the gases. The gases are transported out of the humidifier using water vapor.

[0310] Next reference Fig.17 , which shows an insufflation system 1701 according to at least one embodiment. The insufflation system 1701 includes an insufflator 1703 that generates a flow of insufflation gases at a pressure above atmospheric pressure for delivery into the abdominal or peritoneal cavity of a patient 1705. The gases enter a humidifier 1707 that includes a heater base 1709 and a humidifier chamber 1711, wherein the chamber 1711 is in contact with the heater base 1709 in use, such that the heater base 1709 can provide heat to the chamber 1711. In the humidifier 1707, the insufflation gases pass through the chamber 1711 such that they become humidified to a suitable humidity level.

[0311] System 1701 includes a delivery catheter 1713 connected between a humidifier chamber 1711 and the peritoneal cavity or surgical site of a patient 1705. The catheter 1713 has a first end and a second end, the first end being connected to the outlet of the humidifier chamber 1711 and receiving humidified gas from the chamber 1711. The second end of the catheter 1713 is placed in the surgical site or peritoneal cavity of the patient 1705, and the humidified insufflation gas travels from the chamber 1711 through the catheter 1713 into the surgical site to inflate the surgical site or peritoneal cavity and expand them. The system also includes a controller (not shown) that regulates the humidity level supplied to the gases by controlling the power supplied to the heater base 1709. The controller can also be used to monitor the water in the humidifier chamber 1711. The smoke exhaust system 1715 is shown to be drawn from the body cavity of the patient 1705.

[0312] The smoke evacuation system 1715 can be used in conjunction with the insufflation system 1701 described above, or can be used with other suitable insufflation systems. The smoke evacuation system 1715 includes an exhaust or gas branch 1717, an exhaust assembly 1719, and a filter 1721. The exhaust branch 1717 is connected between the filter 1721 and the exhaust assembly 1719, and is positioned in or near the surgical site or peritoneal cavity of the patient 1705 in use. The exhaust branch 1717 is a self-supporting tube (i.e., the tube can support its own weight without collapsing) with two open ends: an operating site end and an outlet end.

[0313] At least one embodiment includes the realization that the use of a composite tube as conduit 1713 can deliver humidified gas to a surgical site of patient 1705 with minimal heat loss of the humidified gas.

[0314] Coaxial tube

[0315] The coaxial breathing tube may also include a composite tube as described above. In the coaxial breathing tube, the first gas space is the inspiratory limb or the expiratory limb, and the second gas space is the other of the inspiratory limb or the expiratory limb. A gas passage is provided between the inlet of the inspiratory limb and the outlet of the inspiratory limb, and a gas passage is provided between the inlet of the expiratory limb and the outlet of the expiratory limb. In one embodiment, the first gas space is the inspiratory limb and the second gas space is the expiratory limb. Alternatively, the first gas space may be the expiratory limb and the second gas space may be the inspiratory limb.

[0316] Next reference Fig.18 , which shows coaxial tubes 1801 according to at least one embodiment. In this example, coaxial tubes 1801 are provided between a patient 1801 and a ventilator 1805. Exhaled gas and inhaled gas each flow in an inner tube 1807, or in a space 1809 between the inner tube 1807 and an outer tube 1811. It will be understood that the outer tube 1811 may not be precisely aligned with the inner tube 1807. In addition, "coaxial" refers to one tube being located inside another tube.

[0317] Due to heat transfer, the inner tube 1807 can carry inhaled air in the space 1813 therein and exhaled air in the space 1809 between the inner tube 1807 and the outer tube 1811. This air flow configuration is indicated by arrows. However, the opposite configuration is also possible, in which the outer tube 1811 carries inhaled air and the inner tube 1807 carries exhaled air.

[0318] In at least one embodiment, inner tube 1807 is formed from a corrugated tube, such as Fisher & Paykel Model RT100 disposable tube. Outer tube 1811 may be formed from a composite tube as described above.

[0319] Using coaxial tube 1801, ventilator 1805 may not notice the leak in inner tube 1807. This leak may short-circuit patient 1801, meaning that patient 1801 will not get enough oxygen. This short circuit can be detected by placing a sensor at the patient end of coaxial tube 1801. This sensor can be located in patient end connector 1815. The short circuit closer to ventilator 1805 will continue to make patient 1801 rebreathe the amount of air close to patient 1801. This will increase the concentration of carbon dioxide in the inhalation airflow space 1813 close to patient 1801, which can be directly detected by CO2 sensor. This sensor can include any number of such sensors currently available on the market. Alternatively, this rebreathing can be detected by monitoring the temperature of the gas at patient end connector 1815, where a temperature rise exceeding a predetermined level indicates that rebreathing has occurred.

[0320] In addition to the above, in order to reduce or eliminate the formation of condensate in the inner tube 1807 or the outer tube 1811, and in order to maintain the temperature of the gas flowing through the coaxial tube 1801 at a substantially uniform temperature, a heater, such as a resistive heating filament, can be provided in the inner tube 1807 or the outer tube 1811, and the heater is arranged in the gas space 1809 or 1813, or in the wall of the inner tube 1807 or the outer tube 1811 itself.

[0321] Nasal cannulas and other patient interfaces

[0322] Next reference Fig.19A , which shows a composite tube 201 used with a nasal cannula patient interface 1901. In this example, the patient interface 1901 is positioned on the face of a patient 1903 using a head cap 1905 secured around the back of the head of the patient 1901. The patient interface includes a cannula body 1907 and a delivery tube 1909. The composite tube 201 as described is in communication with the delivery tube 1909 to supply inhaled gas to the patient interface 1901.

[0323] In the past, delivery tubes 1909 have been used to decouple the weight of heated breathing tubes from patient interface 1901. Previously used delivery tubes 1909 consisted of a length of flexible tubing. It is important that the delivery tubes 1909 are lightweight so that the mass of the delivery tubes 1909 does not pull the patient interface 1901 off the patient's face. Heated tubes are substantially bulkier and heavier than unheated tubes. Therefore, previously used delivery tubes 1909 are unheated. In order to achieve satisfactory flexibility, previously used delivery tubes 1909 also have poor insulation properties. In the absence of good insulation and heating, the rain wash effect in the delivery tubes 1909 is a problem. Therefore, the delivery tubes 1909 are kept as short as possible to minimize the rain wash effect. However, the shorter length cannot always prevent the weight of the heated breathing tube from pulling the patient interface 1901 off. Therefore, previously used delivery tubes have multiple disadvantages.

[0324] The composite tube 201 described herein provides good insulation while maintaining good flexibility and light weight. Therefore, in some embodiments, the delivery tube 1909 can be a composite tube 201. The composite tube 201 can provide improved insulation properties that are superior to the delivery tubes previously known in the art. In addition, the length of the delivery tube can be longer and provide better decoupling of tube drag. The delivery tube 201 of the composite tube 201 can optionally have a heating filament (not shown) in the second elongated member (not shown). The heating filament (if present) can provide heat input. Alternatively, these heating filaments can provide structural support for the second elongated member when not powered.

[0325] The length of the delivery tube 1909 of the unheated composite tube 201 can be greater than the length of a normal unheated extension while still maintaining the same or less amount of heat loss due to the better insulating properties of the composite tube 201. The increased length of the delivery tube 1909 is beneficial in preventing patient movement from causing a pull off of the tube connection. The increased extension length will also allow for better head movement without compromising patient comfort.

[0326] Furthermore, certain embodiments include the realization that eliminating the separate delivery tube 1909 can have a variety of benefits discussed below. Fig.19B As shown in , the delivery tube 1909 and the composite tube 201 may desirably be a single component that extends to the cannula body 1907.

[0327] In a typical patient interface 1901, the heating tube (replacing Fig.19AThe composite tube 201 of FIG. 19 supplies the inhaled gas to the unheated delivery tube 1909. The temperature of the inhaled gas may experience significant heat loss (e.g., 20° C. or more or thereabouts) along the length of the unheated delivery tube 1909. To compensate, the temperature at the patient end of the heated tube is maintained above the desired temperature for actual delivery to the patient 1901. In addition, as the temperature within the delivery tube 1909 drops, condensation may occur as a rain wash effect. It is recognized that if Fig.19B As shown in , extending the heated composite tube 201 to the cannula body 1907 instead of the delivery tube 1909 can reduce the input energy requirements because the patient end of the composite tube 201 can be kept at a lower temperature. This configuration can also reduce the rain wash effect by eliminating the unheated delivery tube 1909 from the patient interface.

[0328] Desirably, the composite tube 201 can be tapered. In at least one embodiment, the patient end portion of the composite tube 201 is tapered to fit the entrance of the cannula body 1907. In at least one embodiment, the diameter of the length of the composite tube 201 near the patient end is smaller than the diameter of the rest of the composite tube 201. For example, the length of the composite tube 201 near the patient end can be in the range of 50 to 300 mm (or about 50 to 300 mm). The smaller diameter tube near the patient end can advantageously reduce the weight of the tube near the cannula body.

[0329] The composite tube 201 may include a temperature sensor (not shown) near at least the patient end of the composite tube 201. In addition to or in place of the temperature sensor, the composite tube 201 may also include another sensor (not shown) near at least the patient end of the composite tube 201. For example, the composite tube 201 may include a pressure sensor (not shown) near at least the patient end of the composite tube 201. The pressure sensor may be particularly advantageous for CPAP control and nasal high flow therapy. When the composite tube 201 and the delivery tube 1909 are a single component, this or these sensors are close to the nostrils of the patient 1903, which can provide more accurate information related to the delivered gas. The example patient-end sensor configuration is described in more detail below.

[0330] The unitary construction is also desirable because it can reduce wiring on the patient 1901. If the cannula body 1907 is equipped with one or more sensors or other electrical components, it is necessary to provide an electrical connection to the cannula body 1907. If the composite tube 201 and the delivery tube are a unitary component, the electrical wires can extend along the composite tube 201 to the patient end of the composite tube 201 at the cannula body 1907 as described above. A separate electrical connection to the cannula body 1907 is not required.

[0331] As described above, a single configuration can incorporate a variable pitch composite tube 201. In tubes with no or little unheated extension, the cannula body 1907 where the sensing element will be located will continue to be heated. These tubes require a reduction in the tube end temperature to ensure delivery of 37°C saturated gas. This is because, in general, the tube end temperature is set to be much higher than 37°C to compensate for heat losses in the unheated extension. However, a configuration without an unheated extension is more likely to encounter condensation at the device end. Redistributing heat to the area proximal to the device end of the tube will help promote T gas >T dew , and thus reduce the occurrence of condensation without delivering excessively high tube end temperatures.

[0332] It should be understood that although Fig.19B The configuration in may be preferred in certain embodiments, but other configurations, including Fig.19A The configuration shown in may be used in other embodiments.

[0333] The composite tube 201 of the present disclosure may also be combined with and / or used with other patient interfaces, such as a full-face mask 2001 ( Fig. 20A ), nose mask 2003( Fig. 20B ), and nasal / pillow masks 2005( Fig. 20C ). As described above, the composite tube 201 can act as the delivery tube 1909 or eliminate the need for a delivery tube entirely.

[0334] clean

[0335] Return again Figure 2A In at least one embodiment, the material used for the composite tube can be selected to handle different cleaning methods. In some embodiments, high-level disinfection (about 20 cleaning cycles) can be used to clean the composite tube 201. During the high-level disinfection process, the composite tube 201 is pasteurized at about 75°C for about 30 minutes. Next, the composite tube 201 is soaked in 2% glutaraldehyde for about 20 minutes. The composite tube 201 is removed from the glutaraldehyde and immersed in 6% hydrogen peroxide for about 30 minutes. Finally, the composite tube 201 is removed from the hydrogen peroxide and soaked in 0.55% o-phthalaldehyde (OPA) for about 10 minutes.

[0336] In other embodiments, sterilization (about 20 cycles) can be used to clean the composite tube 201. First, the composite tube 201 is placed in autoclave steam for about 30 minutes at about 121°C. Next, the temperature of the autoclave steam is raised to about 134°C for about 3 minutes. After autoclaving, 100% ethylene oxide (ETO) gas is surrounded around the composite tube 201. Finally, the composite tube 201 is removed from the ETO gas and immersed in about 2.5% glutaraldehyde for about 10 hours.

[0337] The composite tube 201 can be made of a material that can withstand repeated cleaning processes. In some embodiments, part or all of the composite tube 201 can be made of, but not limited to, styrene-ethylene-butylene-styrene block thermoplastic elastomer, such as Kraiburg TF6STE. In other embodiments, the composite tube 201 can be made of, but not limited to, thermoplastic polyester elastomer, polyurethane, or silicone.

[0338] Manufacturing method

[0339] Next reference FIG. 21A to FIG. 21F , these figures illustrate example methods for making composite tubes.

[0340] First go to Fig.21A In at least one embodiment, a method of manufacturing a composite tube includes providing a second elongated member 205 and helically wrapping the second elongated member 205 around a mandrel 2101, wherein opposite edge portions 2103 of the second elongated member 205 are spaced apart on adjacent wraps, thereby forming a second elongated member spiral 2105. In some embodiments, the second elongated member 205 can be directly wrapped around the mandrel. In other embodiments, a sacrificial layer can be provided on the mandrel.

[0341] In at least one embodiment, the method further includes forming second elongated member 205. Extrusion is one suitable method for forming second elongated member 205. The second extruder can be configured to extrude second elongated member 205 at a specific bead height. Thus, in at least one embodiment, the method includes extruding second elongated member 205.

[0342] like Fig.21BAs shown in , extrusion can be advantageous because it can allow heating filament 215 to be encapsulated in second elongated member 205 as second elongated member 205 is formed, for example using an extruder having a cross-head extrusion die. Therefore, in certain embodiments, the method includes providing one or more heating filaments 215, and encapsulating heating filaments 215 to form second elongated member 205. The method can also include providing second elongated member 205 having one or more heating filaments 215 embedded or encapsulated in second elongated member 205.

[0343] In at least one embodiment, the method includes embedding one or more filaments 215 in the second elongated member 205. For example, Fig. 21C As shown in , filament 215 can be pressed into (pulled into or mechanically positioned in) second elongated member 205 to a specific depth. Alternatively, cuts can be made in second elongated member 205 to a specific depth, and filament 215 can be placed in these cuts. Preferably, the pressing or cutting is performed shortly after extruding second elongated member 205, and second elongated member 205 is soft.

[0344] like Fig.21D and Fig.21E As shown in, in at least one embodiment, the method includes providing a first elongation member 203, and spirally wrapping the first elongation member 203 around a second elongation member spiral 2105, so that multiple portions of the first elongation member 203 overlap with adjacent sleeves of the second elongation member spiral 205, and a portion of the first elongation member 203 is arranged adjacent to the core shaft 2101 in the space between the sleeves of the second elongation member spiral 2105, thereby forming a first elongation member spiral 2107. Fig.21D An example method is shown in which a heating filament 215 is encapsulated in the second elongate member 205 prior to forming the second elongate member helix. Fig.21E An example method is shown in which heating filament 215 is embedded in second elongate member 205 as second elongate member spiral 2105 is formed. An alternative method of incorporating filament 215 into the composite tube includes encapsulating one or more filaments 215 between first elongate member 203 and second elongate member 205 in the region where first elongate member 203 and second elongate member 205 overlap.

[0345] As described above, at least one embodiment includes a tube having a plurality of wraps of first elongate member 203 between wraps of second elongate member 205. Thus, in certain embodiments, the method includes providing first elongate member 203 and helically wrapping first elongate member 203 around second elongate member spiral 2105 such that a first side portion of first elongate member 203 overlaps the wraps of second elongate member spiral 2105 and a second side portion of first elongate member 203 contacts a portion of an adjacent side of first elongate member 203. A portion of first elongate member 203 is disposed adjacent mandrel 2101 in a space between the wraps of second elongate member spiral 2105, thereby forming first elongate member spiral 2107 including a plurality of wraps of first elongate member 203 between the wraps of second elongate member 205.

[0346] In at least one embodiment, first elongated member 203 is wrapped multiple times in multiple turns of second elongated member 205. Fig.22A An example schematic diagram of the resulting longitudinal cross section is shown in . Any suitable technique, such as heat melting, adhesion or other attachment mechanism, can be used to fuse the adjacent sheaths of the first elongated member 203. In at least one embodiment, adjacent molten or softened bubbles can be contacted together and thereby bonded while hot and subsequently cooled with an air jet. The adjacent sheaths of the first elongated member 203 in a softened state can also be bonded together by winding them on a mandrel and cooling them.

[0347] In at least one embodiment, first elongated member 203 is wrapped one or more times in multiple turns of second elongated member 205, and one or more bubbles between multiple turns of second elongated member 205 are further collapsed into additional discrete bubbles using appropriate techniques, such as heat treatment. Fig. 22B An example schematic diagram of the resulting longitudinal cross section is shown in FIG. Fig. 22B As shown in , one bubble of the first elongated member 203 can be collapsed into two or three or more discrete bubbles using any suitable technique, such as mechanical force applied by an object or force applied by a directed air jet. Fig. 22C Another example schematic diagram of the resulting longitudinal cross-section is shown in FIG. In this example, the central portion of the bubble is collapsed so that the top of the bubble is combined with the bottom of the bubble to form two discrete bubbles separated by a flat bottom portion. Then, portions of the adjacent sides of the two discrete bubbles are combined to form a structure including three discrete bubbles.

[0348] The above-mentioned alternative of combining one or more heating filaments 215 with the composite tube has advantages over the alternative of having heating filaments on the gas path. Having one or more heating filaments 215 outside the gas path will improve performance because these filaments will heat the tube wall where condensation is most likely to form. By moving the heating filaments out of the gas path, this construction reduces the risk of fire in a high oxygen environment. This feature also reduces performance because it reduces the heating efficiency of the heating filament to the gas passing through the tube. However, in some embodiments, the composite tube 201 includes one or more heating filaments 215, which are placed in the gas path. For example, the heating filaments can be placed on the lumen wall (tube hole), such as in a spiral structure. An exemplary method for arranging one or more heating filaments 215 on the lumen wall includes bonding, embedding or otherwise forming a heating filament on the surface of the second elongated member 205, so that the lumen wall is formed during assembly. Thus, in certain embodiments, the method includes positioning one or more heating filaments 215 on the lumen wall.

[0349] Regardless of whether the heating filaments 215 are embedded or encapsulated in or disposed on the second elongated member 205, or otherwise placed in or on the tube, in at least one embodiment, the pairs of filaments can form a connecting ring at one end of the composite tube to form a loop.

[0350] Fig.21F Shows Fig.21E , focusing on the top portion of mandrel 2101 and the top portions of first elongated member spiral 2107 and second elongated member spiral 2105. This example shows second elongated member spiral 2105 having a T-shaped second elongated member 205. When the second elongated member is formed, heating filament 215 is embedded in second elongated member 205. Fig.21F The right side of FIG. 1 shows the bubble profile of the first elongate member spiral as described above.

[0351] The method may also include forming first elongated member 203. Extrusion is one suitable method for forming first elongated member 203. Thus, in at least one embodiment, the method includes extruding first elongated member 203. First elongated member 203 may also be manufactured by extruding two or more portions and bonding them together to form a single piece. As another alternative, first elongated member 203 may also be manufactured by extruding segments that create a hollow shape when formed or bonded adjacently during the helical tube forming process.

[0352] The method may also include supplying a gas at a pressure greater than atmospheric pressure to one end of the first elongated member 203. The gas may be, for example, air. Other gases may also be used, as explained above. Supplying a gas to one end of the first elongated member 203 may help maintain the shape of an open hollow body as the first elongated member 203 is wrapped around the mandrel 2101. The gas may be supplied before the first elongated member 203 is wrapped around the mandrel 2101, while the first elongated member 203 is wrapped around the mandrel 2101, or after the first elongated member 203 is wrapped around the mandrel 2101. For example, an extruder having an extrusion die / tip combination may supply or introduce air into the hollow chamber of the first elongated member 203 as the first elongated member 203 is extruded. Therefore, in at least one embodiment, the method includes extruding the first elongated member 203 and supplying a gas at a pressure greater than atmospheric pressure to one end of the first elongated member 203 after extrusion. A pressure of 15 to 30 cm H2O (or about 15 to 30 cm H2O) has been found to be suitable.

[0353] In at least one embodiment, the first elongated member 203 and the second elongated member 205 are spirally wound around the mandrel 2101. For example, the first elongated member 203 and the second elongated member 205 may come out of the extrusion die at an elevated temperature of 200°C (or about 200°C) or above, and then they are applied to the mandrel a short distance later. Preferably, the mandrel is cooled to a temperature of 20°C (or about 20°C) or below, such as nearly 0°C (or about 0°C) using a water jacket, a cooler and / or other suitable cooling method. After 5 (or about 5) spiral wraps, the first elongated member 203 and the second elongated member 205 are further cooled by a cooling fluid (liquid or gas). In one embodiment, the cooling fluid is air emitted from a ring, where the airflow surrounds the mandrel. After cooling and removing the components from the mandrel, a composite tube is formed, which has a lumen extending along the longitudinal axis and a hollow space around the lumen. In this embodiment, there is no need to use an adhesive or other attachment device to connect the first elongated member and the second elongated member. Other embodiments may also utilize an adhesive or other attachment device to bond or otherwise connect the two members. In another embodiment, after extruding and placing the heated filaments, the second elongated member 205 may be cooled to freeze the location of the heated filaments. Then, when applied to the mandrel, the second elongated member 205 may be reheated to improve bonding. Example methods for reheating include using a local heating device, a heating wheel, etc.

[0354] The method may also include forming the paired heating filaments or sensing filaments into a connecting loop at one end of the composite tube. For example, the ends of the two heating filaments or sensing filaments may be stripped from the second elongated member 205 and then formed together into a connecting loop, such as by tying, bonding, welding, adhering, fusing, etc. As another example, during the manufacturing process, the ends of the heating filaments may be detached from the second elongated member 205 and then formed into a connecting loop when the composite tube is assembled.

[0355] Reference Fig.23A -23H, an alternative method of forming the tube 201 involves an extrusion tool 2301 having a set of flow paths extending along it. The extrusion tool 2301 can be used to form the tube, such as Figure 23G and Fig.23H . As shown, a tube produced using an extrusion tool 2301 may include a plurality of first elongated members 203 extending generally along the longitudinal axis of the tube. In some embodiments, the extrusion tool 2301 includes a body 2310 and a central extension 2320. In some embodiments, the body 2310 and the extension 2320 are generally cylindrical. The body 2310 may include one or more flow paths 2312 to enable molten plastic or another material to flow through the body 2310 from an input end 2314 to an output end or extension end 2316. In some embodiments, these flow paths have a substantially conical longitudinal cross-section (i.e., wider at the input end 2314 where the molten plastic first enters, and narrower near the extrusion end 2316). These flow paths may have different configurations to produce tubes 201 with different profiles. For example, in Fig.23C and Fig.23D The flow path configuration at the output or extension end 2316 shown in FIG. 2 can produce a tube 201 having an end view feature such as Fig.23A as shown in . Fig.21B Shows Fig.23A The end view of the tube of FIG. 201 includes a second elongated member 205, which may include a heating filament 215 disposed between adjacent bubbles or between the first elongated members 203. In use, the tool 2301 may be adapted to rotate so as to guide the helical formation of the tube 201. Fig.23F As shown in , the central extension 2320 can couple the extrusion tool 2301 to an extruder 2330. The bearing 2322 disposed between the central extension 2320 and the extruder 2330 can enable the central extension 2320 and the body 2310 to rotate relative to the extruder 2330. The rotation speed of the tool 2301 can be adjusted to change the pitch or helix angle of the first elongated member 203. For example, a faster rotation speed can produce a smaller helix angle, such as Figure 23GSlower rotation speeds can produce larger helix angles, such as Fig.23H as shown in .

[0356] As mentioned above Fig. 8A and Figure 8B As discussed, certain embodiments may include a composite tube having a variable pitch. In manufacturing such embodiments, a mandrel 2101 and a control system are preferably provided that can change the effective pitch (i.e., "ropes") of the first elongated member 203 and the second elongated member 205. This can be achieved, for example, by controlling the ratio of the stranding speed to the advancement speed of the mandrel 2101 while maintaining a constant tangential speed at a critical dimension (i.e., the pitch center diameter of the rope groove). The pitch center diameter determines the middle of the pitch center passing through the rope groove. This value depends on the speed. It can therefore also be predicted that if the pitch center diameter is different from that expected, the speed can be adjusted to return the pitch center diameter to the desired value. Changing the effective pitch can also be achieved, for example, by controlling the ratio of the stranding speed to the advancement of the mandrel 2101 while maintaining a constant rotational speed of the spiral composite tube 201 thus formed. By controlling the stranding speed, any changes in the output of the extrudate can be compensated.

[0357] Another method for making a variable pitch composite tube 201 uses an integrated system where the extrusion speed and the mandrel 2101 advancement speed are uniformly varied. For example, in this mode, the stranding speed can remain the same, but the advancement of the mandrel 2101 when enabled will require slowing the extrusion speed to match the extrudate output with the tangential speed of the spiral tube 201 thus formed.

[0358] Another method for making variable pitch composite tube 201 moves the angle of incidence of second elongated member 205 and first elongated member 203 to change the pitch of tube 201. In these embodiments, the extruder can be on a chute, such as a turntable, that will allow the angle to be changed, with the center of rotation at the point where second elongated member 205 and first elongated member 203 meet mandrel 2101. This method can allow for a pitch change of 3-5 mm (or about 3-5 mm) at most.

[0359] Next reference FIG. 24A to FIG. 24F, these figures show transverse cross-sections of tubes comprising a single tubular element having a first elongated member or portion 203 and a second elongated member or portion 205. As illustrated, the second elongated portion 205 is integral with the first elongated portion 203 and extends along the entire length of the single tubular element. In the illustrated embodiment, such a single tubular element is an elongated hollow body having a relatively thin wall in its transverse cross-section, which partially defines a hollow portion 2201, and also having two reinforcing portions 205 of relatively greater thickness or relatively greater stiffness on opposite sides of the elongated hollow body adjacent to the relatively thin wall. After the elongated hollow body is helically wound, these reinforcing portions form a portion of the inner wall of the lumen 207, such that these reinforcing portions are also helically positioned between adjacent turns of the elongated hollow body.

[0360] In at least one embodiment, the method includes forming an elongated hollow body including a first elongated portion 203 and a reinforcing portion 205. Extrusion is a suitable method for forming the elongated hollow body. FIG. 24A to FIG. 24F A suitable cross-sectional shape of the tubular element is shown in FIG.

[0361] The elongated hollow body can be formed into a medical tube as explained above, and the discussion above is incorporated by this reference. For example, in at least one embodiment, a method of making a medical tube includes helically wrapping or winding the elongated hollow body around a mandrel. This can be done at an elevated temperature so that the elongated hollow body is cooled after being helically wound to bond adjacent turns together. Fig. 24B As shown in , the opposite side edge portions of the reinforcement portion 205 can touch on adjacent circles. In other embodiments, the opposite side edge portions of the second elongated member 205 can overlap on adjacent circles, such as Fig.24D and Fig.24E The heating filament 215 may be incorporated into the second elongated member as explained above and as shown in FIG. FIG. 24A to FIG. 24F For example, heating filaments may be provided on opposite sides of the elongated hollow body, e.g. Fig.24A Alternatively, the heating filament may be provided on only one side of the elongated hollow body, e.g. Fig.24E Any of these embodiments can also be combined with sensing the presence of a filament.

[0362] Placement of chamber end connectors with electrical connections

[0363] Next reference Fig.25A , shows an example flow chart for attaching a connector to the end of a tube configured for use in connection with a humidifier. For example, as described above with reference to Figure 1As described above, the inlet 109 of the air intake pipe 103 is connected to the humidifier 107 via the port 111 . Fig.25A The example flow chart of can make an inlet 109 that can be physically and electrically connected to the humidifier 107.

[0364] In this example, seal 2503 is inserted into seal housing 2501. Fig.25B The seal insertion behavior is also shown in more detail in FIG. The seal housing 2501 is made of a molded plastic. The open end is sized and configured for connection to the humidifier. The seal 2503 may be an O-ring, such as Fig.25B . The O-ring is suitable for a double ring surface structure, including thicker concentric ring surfaces connected by thinner snares. In this example, the O-ring is molded from a single elastic material, such as rubber or silicone. Seal 2503 is located in a compliant protuberance in seal housing 2501. Seal 2503 is designed to seal the outer surface of the port of the humidifier chamber. Seal 2503 can deflect or extend along the outer surface of the port. In other words, the double O-ring structure includes an inner O-ring and an outer O-ring connected by a flange. The outer O-ring will be sealed in the connector, and the inner O-ring can deflect along the flange portion and squeeze the outer surface of the port. In this positioning, the horizontal plane extending through the central axis of the inner O-ring and the horizontal plane extending through the central axis of the outer O-ring can be in different planes.

[0365] Go to again Fig.25A In the example of FIG. 25A , a printed circuit board (PCB) is inserted into a compliant dock on the seal housing 2501. Fig.25C The PCB insertion behavior is shown in more detail in Fig.25C In the embodiment of the present invention, an assembly 2505 including a PCB and PCB electrical connectors is inserted into a compliant portion on a seal housing 2501. Various PCBs of suitable size and configuration may be used. Various PCB electrical connectors may also be used. For example, the PCB electrical connector may be a straight-through connector or a bidirectional connector. The PCB includes four connection pads adapted to receive four conductive filaments enclosed in a second elongated member of the tube. However, if the second elongated member contains more than four or less than four conductive filaments, the PCB may be configured to receive a suitable number of conductive filaments.

[0366] Go to again Fig.25A , and as Fig.25DAs shown in more detail in , the seal retainer 2507 is clamped on an open end of the seal housing 2501, wherein the seal 2503 is located on the compliant ridge. The seal retainer 2507 is clamped in place to compress the seal 2503, and thereby form a liquid-resistant connection and a gas-resistant connection between the seal housing 2501 and the seal retainer 2507. In this example, the seal retainer 2507 is made of a molded plastic. In this example, the seal retainer 2507 also includes a protrusion, the size and shape of which match the PCB. The protrusion is used to support and protect the more flexible and fragile PCB. However, in some embodiments, the protrusion can be omitted. The resulting assembly including the seal housing 2501, the seal 2503, the PCB and the PCB connector assembly 2505, and the seal retainer 2507 is referred to as the connector tube assembly 2515.

[0367] Go to again Fig.25A In the example of FIG. 25, the tube is prepared for connection to the connector tube assembly 2515. Fig.25A As shown and in more detail Fig.25E As shown in FIG. 25, in step 2511, a portion of the second elongated member at one end of the tube is separated from the first elongated member. Then, in step 2513, a certain length of the separated second elongated member is peeled off to reveal four conductive filaments (or the number of conductive filaments contained in the second elongated member). Fig.25F Step 2513 is shown in more detail in FIG.

[0368] like Fig.25A As explained in Figure 25G As shown in more detail in FIG, the portion of the tube having the stripped length of the second elongated member is inserted into the connector tube assembly 2515. Figure 25G In the embodiment, the second elongated member 205 has a curved shape to accommodate the positioning of the PCB connector assembly 2505. The PCB connector assembly 2505 can also be sized and positioned to reduce or eliminate the curved shape, such as by moving the PCB connector assembly further toward the connector end. Fig.25A and Fig.25H As shown in step 2517 of , the four conductive filaments are inserted into the four connection pads of the PCB. Then, as Fig.25A and Fig.25I As shown in , a solder bead 2519 is placed on each filament-connection pad connection to secure the filament to the connection pad and ensure a good electrical connection between each filament and its corresponding connection pad.

[0369] In some embodiments, the aforementioned step of placing the solder bead 2519 may be omitted. Fig.26A-26E shows an example connector assembly configuration that does not require welding to connect the filaments to the connector assembly.

[0370] Fig.26A A connector assembly 2601 is shown including a clip housing 2603 and a circuit connector 2605. The second elongated member 205 stripped to a length 2607 exposes a heating filament 215 that can be inserted into a clip 2609 within the clip housing 2403. Each clip 2609 is electrically conductive. Suitable materials for the clips 2609 include, for example, aluminum, copper, and gold. The clips 2609 hold a heating filament 215 without the need for solder. Electrical conductors 2611 can extend between each clip 2609 and the circuit connector 2605.

[0371] Fig.26B A top view of connector assembly 2601 is shown, showing clip 2609 positioned in clip housing 2603 .

[0372] Fig.26C Clip 2609 is shown in more detail. Clip 2609 includes folded portion 2613, retaining tab portion 2615, flange portion 2617 and extension portion 2619. A heating filament (not shown) is inserted into flange portion 2617 so that folded portion 2613 receives and retains the heating filament. The shape of flange portion 2617 helps insert the heating filament and guide the heating filament to the appropriate position. However, flange portion 2617 can have a straight shape if desired. Flange portion 2617 can also have another suitable shape, such as a partial flange. The folded portion has a capture portion 2621 that conforms to retaining tab portion 2615. Retaining tab portion 2615 is angled so that a heating filament can slide over retaining tab portion 2615 in one direction and enter into folded portion 2613. Retaining tab portion 2615 also captures the heating filament to prevent it from accidentally falling off from folded portion 2613. The extension portion 2619 is conductive and conducts electrical current from the heating filament to and / or through the clip housing 2603.

[0373] Fig.26D yes Fig.26C , and shows the positioning of the tab portion 2615 and the capture portion 2621 in more detail. Fig.26E It is shown how the clip 2609 is positioned in the clip housing 2603. The clip housing 2603 is shown transparently to demonstrate the positioning of the extension 2619.

[0374] Reference again Fig.25A, in order to ensure that all the workpieces of the connector tube assembly 2515 are securely fixed to each other, a layer of glue 2521 is then applied. Glue is a broad term and refers to a material used to combine, fix or attach other materials. When the glue is liquid or semi-solid, it can be sticky or tacky to the touch. When the glue dries or otherwise cures to a solid state, the glue can be sticky or non-tacky or non-tacky to the touch. The glue can be a resin, such as an epoxy resin, or an elastomer (thermosetting or thermoplastic). Using TPE materials can be advantageous because they are generally flexible and can adapt to torsion, bending or non-crushing pressure.

[0375] exist Fig.25J An example method for applying glue 2521 is shown in FIG. In this method, a two-block mold is provided. In this example, the mold is made of a metal such as aluminum or stainless steel, but any suitable material may be used. For example, the mold may be made of The invention relates to a PTFE module. One module is configured to accommodate the protruding PCB and PCB connector assembly 2505 of the connector tube assembly 2515 and the adjacent tube, and the other module is configured to accommodate the opposite part of the tube and the connector tube assembly 2515. The tube is placed in the conforming mold so that the modules are superimposed on the top of another. A liquid glue is introduced into the inlet hole of the mold and the glue is hardened. Then, the mold is removed to expose the glued tube-connector assembly 2523, which includes a hardened glue layer 2521 covering the PCB and is combined between the tube and the connector tube assembly 2515. The glue layer can cover the PCB and all the soldered connections on the PCB. In this way, this glue layer can protect the PCB and its connections from corrosion. In other words, the glue plays at least three roles: sealing the connector and the conduit, keeping the PCB in place and potting the PCB; the glue layer forms a pneumatic seal, a mechanical bond, and a PCB potting. Additionally, the glue layer can act as an electrical insulation barrier, for example, by preventing moisture and liquids from reaching the electrical components and creating a conductive path to the user of the device.

[0376] Return again Fig.25A , the tube-connector assembly 2523 is then in a state for final assembly. Figure 25K As shown in more detail in FIG. 2 , the first clamshell 2525 and the second clamshell 2527 snap together around the tube-connector assembly 2523 such that a portion of the PCB connector remains exposed. Figure 25K The first clamshell 2523 and the second clamshell 2527 shown in FIG. 2 are the top clamshell and the bottom clamshell, respectively.

[0377] Fig.27AAn alternative clamshell design is shown in FIG. 27E , where a first clamshell 2525 and a second clamshell 2527 are left and right clamshells, respectively. The clamshells 2525 and 2527 are partly ( Figure 25K or Fig.27A –27E) can be made of molded plastic or any other suitable material. The clamshell 2525, 2527 portion ( Figure 25K or Fig.27A –27E) for further protection of the tube-connector assembly 2523 ( Fig.25A and Fig.25J ) and maintain the tube-connector assembly in a bent position which, in use, encourages condensate to return to the humidifier device. Figure 25L As shown in , the final assembly can be easily snapped into a humidifier, with compliant electrical connections near the connection port.

[0378] Although the foregoing manufacturing method is described with reference to a flow chart, the flow chart merely provides an example method for attaching a connector to the end of a tube configured to be connected to a humidifier in use. The method described herein does not imply that the steps have a fixed order. It also does not imply that any one step is required to practice the method. The embodiments can be practiced in any order, and combinations are also possible.

[0379] Alternative device-side connector placement

[0380] Next reference Fig.28A -28F, these figures show a connector that can be used for a medical circuit with wires passing through it. Connector 2801 includes a cutout 2802, which in some embodiments is 30 mm (or about 30 mm) across. In some embodiments, on one end of cutout 2802 is an L-shaped arm 2803 that partially extends outward from connector 2801 and is partially parallel to the longitudinal axis of connector 2801.

[0381] Arm 2803 may have one or more electrical conductors 2804 embedded therein. Conductor 2804 may be made of copper or brass or another suitable conductive material and may be formed as a flat L-shaped piece that extends substantially along the length of arm 2803.

[0382] The connector 2801 may further include an inner portion 2805 adapted to be substantially located inside a portion of the tube 201 , and an outer portion 2806 adapted to substantially surround a portion of the tube 201 .

[0383] A portion of the second elongated member 205 is stripped away to reveal one or more filaments 215 embedded therein. Preferably, about 5 mm of the filaments 215 are exposed. The connector 2801 is then attached to the tube 215 so that the inner portion 2805 is located within the tube 201 and the outer portion 2806 is located around the tube 201. Preferably, the connector 2801 is oriented so that the exposed ends of the filaments 215 are located at or near the cutout 2802.

[0384] The exposed ends of the filaments 215 are then electrically and / or physically connected to the conductor 2804. This can be accomplished by soldering the ends to the conductor 2804 or any other method known in the art.

[0385] A member 2807 may be inserted or molded on top of connector 2801 and optionally at least a portion of tube 201 to facilitate attachment between connector 2801 and tube 201. Member 2807 may be a hard material or a soft material, such as a soft rubber or elastomer.

[0386] In some embodiments, a generally L-shaped elbow 2808 may be placed over the assembly. The elbow 2808 may provide some additional strength to the connection and may provide a predetermined bend in the tube 201 (such that the connector 2801 may be easily positioned on the body of the tube 201 at an angle of approximately 90° to the body).

[0387] Next reference Fig.29A -29L, these figures show another connector 2901 that can be used in a medical circuit with wires passing through it. Fig.29A , connector 2901 allows the composite tube to be connected to a device such as a CPAP device (not shown). The L-shaped arm 2903 of the connector 2901 carries an electrical terminal, which engages with the complementary electrical terminal of the device to allow the transmission of electrical signals or electrical energy between the device and the composite tube. In the arrangement shown, the electrical terminal of the connector 2901 is a plug 2905 that conforms to the receiving seat or port of the device. However, if desired, this arrangement can also be reversed. In this example, the plug is electrically connected to the electrical contact 2906 for establishing an electrical connection with the composite tube. Here, the electrical contact 2906 is molded into the connector 2901. The connector 2901 further includes a filament rack 2907 also molded into the connector 2901. The connector 2901 also includes a cutout 2902, which in some embodiments spans 30mm (or about 30mm).

[0388] like Fig.29B and Fig.29CAs shown in FIG. 1 , a portion (e.g., a 10-mm portion) of the second elongated member 205 is stripped to reveal a smaller length of one or more filaments 215 embedded therein. Preferably, about 5 mm or 10 mm of the filaments 215 are exposed.

[0389] like Fig.29E , connector 2901 is then attached to tube 215 such that inner portion 2909 of connector 2901 is located within tube 201 and outer portion 2911 of connector 2901 is located around tube 201. Preferably, connector 2901 and composite tube 201 are oriented such that the exposed ends of filaments 215 are located at or near cutout 2902 and filaments 215 are aligned to meet near contact point 2906.

[0390] like Fig.29F As shown in , the heating filaments 215 are positioned below the filament rack 2907 so that each heating filament 215 is positioned above the contact point 2906.

[0391] like Figure 29G As shown in FIG. 2 , a solder bead 2913 is placed on each heating filament 215 at a corresponding contact point 2906. The combination of the connector 2901 and the composite tube 201 is labeled herein as a connector-tube assembly 2917. Fig.29H As shown in , the molding tool core 2915 is inserted into the connector 2901. Fig.29I As shown in , the connector-tube assembly 2917 and the core 2915 are placed in the injection molding tool 2919. Fig.29J In the embodiment of the present invention, a molding material 2921 is molded on the cutout (not shown) to combine the connector 2901 and the composite pipe 201. Suitable molding materials 2921 include plastics and rubbers. The connector-tube assembly 2917 and the core 2915 are removed from the injection molding tool (not shown), such as Figure 29K as shown in .

[0392] like Figure 29L As shown in FIG, core 2915 is removed, thereby providing composite tube 201 with device end connection 2901. Fig.29AThe method of –29J allows the plug 2903 to be electrically connected to the heating filament and / or one or more other electrical components (not shown) of the composite tube 201. Preferably, the heating circuit of the device provides electrical energy to the heating filament of the composite tube 201 so that the heating filament can provide thermal energy to the humidified air flow passing through the composite tube 201. As discussed herein, such an arrangement can prevent or limit condensation within the composite tube 201. In addition, or alternatively, the plug 2903 and the device port can provide other electrical signals to be communicated between the device and the composite tube 201, such as data signals. For example, a sensor at the patient interface end of the composite tube 201 can provide data on one or more parameters of the air flow (e.g., temperature, humidity level) for use by the control system of the device. Any other desired electrical signal can also be transmitted.

[0393] The foregoing methods of attaching a connector to a composite pipe are provided by way of example. The methods described do not imply that the steps have a fixed order. They also do not imply that any one step is required to practice the methods. The embodiments can be practiced in any order, and combinations are also practiceable.

[0394] Placement of patient-side connector with electrical connections

[0395] Next reference Fig. 30A -300, these figures show an example connector 3000, which is used to connect one end of the tube 201 to a patient interface (not shown). The end of the connector 3000 connected to the patient interface is indicated by reference numeral 3001.

[0396] Fig. 30A A side perspective view of connector 3000 is shown.

[0397] like Fig. 30B As shown in FIG. 30F , connector 3000 includes PCB assembly 3003 and insert 3005 , which when assembled together are collectively referred to as insert assembly 3007 , and cover 3009 . Fig. 30B –30D and Fig.30F Each shows a general Fig. 30A The view corresponds to a side perspective view. Fig.30E A side top view is shown.

[0398] Insert 3005 and cover 3009 are preferably molded plastic parts. Insert 3005 can serve one or more purposes, including providing a receiver for tube 201, providing a suitable conduit for gas flow path, providing a housing for PCB assembly 3003, and providing a housing for sensors (not shown) such as thermistors. Cover 3009 protects and covers the relatively fragile PCB assembly 3003, and protects the connection between tube 201 and insert 3005. Fig.30D and 30E As shown in FIG, the end of the insert 3005 inserted into the tube 201 (i.e., the end opposite the end 3001) can be angled, which can help insert into the tube 201. However, in some embodiments, the end opposite the end 3001 can be blunt or tapered.

[0399] like Fig.30D As shown in , desirably, the insert includes a stop portion 3006a. The stop portion 3006a can facilitate the correct placement of the tube 201 relative to the insert 3005. The stop portion 3006a can also be used to protect the PCB assembly 3003 from directly contacting the tube 201. Fig.30E An alternative configuration is shown in FIG. Fig.30E In the embodiment, the stop portion 3006b is formed as a spiral or helical component such as a spiral or helical rib. This configuration is advantageous because the shape will compensate for the helically wound tube 201, thereby providing a secure connection between the insert 3005 and the tube 201.

[0400] Fig.31A and Fig.31B Another alternative configuration is shown in FIG. In these figures, the stop portion 3006c is formed as a spiral or helical component such as a spiral or helical rib. Again, this configuration is advantageous because the shape will provide a better fit to the helically wound tube 201 ( Fig.31B ) to compensate, thereby providing a secure connection between the insert 3005 and the tube 201. In this configuration, the stop portion 3006c includes a directional stop feature structure 3101. Fig.31B As shown in FIG, the surface of the directional stop feature 3101 is tapered so that the directional stop feature 3101 resembles a fish fin. The shape of the directional stop feature 3101 can pinch, grasp or otherwise hold the second elongated member 205 of the tube 201. The directional stop feature 3101 can therefore be used to better hold the tube 201 in the correct position by preventing the tube 201 from moving and / or rotating.

[0401] return Fig.30E , the patient end 3001 of the insert 3005 is larger than Fig.30DThe patient end of the device is shown in the figure and explains how the dimensions can be modified for different applications (e.g., connection to an infant or adult patient interface).

[0402] Figure 30G A cross section of the connector 3000 is shown and generally corresponds to Fig. 30A Same side perspective view. In some embodiments, an insulating gap, such as an air gap, is present between the tube 201 and the insert 3005 to protect the sensor (discussed above) from thermal radiation from one or more heating filaments in the tube 201, which can induce sensor errors at low flow rates. Figure 30G In the embodiment of the present invention, such gaps will appear above and below the sensor portion 3017. Alternatively, in some embodiments, the insert 3005 is formed so that the air bubbles are encapsulated in the insert 3005. For example, the insert 3005 can include a porous plastic.

[0403] Fig. 30H A cross section of the insert assembly 3007 is shown and generally corresponds to Fig.30D Side perspective view of . Fig. 30I An alternative cross-section of the insert assembly 3007 is shown and generally corresponds to Fig.30E These figures show more details regarding the relative placement of the tube 201, the insert assembly 3007 and / or the cover 3009.

[0404] like Figure 30G -30I, a generally annular capture structure 3013 comprises two molded rings extending radially outward from the body of the insert 3005. The molded rings conform to a notch 3011 which comprises a molded ring extending radially inward from the cover 3009. The notch 3011 and capture structure 3013 retain the cover 3009 on the insert 3005.

[0405] Fig.32A and Fig.32B 3005. An alternative configuration of a capture structure 3013 is shown in . Again, the capture structure 3013 is generally annular and includes two molded rings extending radially outward from the body of the insert 3005. A plurality of anti-rotation protrusions 3201 extend vertically between the rings. In this example, there are four protrusions 3201 evenly spaced (e.g., at 90° intervals) around the circumference of the capture structure 3013. The protrusions 3201 engage with compliant notches (not shown) in the cap and prevent the cap from rotating on the insert assembly. Fig.32CAnother alternative configuration of a capture structure 3013 is shown in FIG. 32D. Again, the capture structure 3013 is generally annular and includes two molded rings extending radially outward from the body of the insert 3005. Anti-rotation notches 3203 are provided between these rings. In this example, there are four notches 3203 evenly spaced (e.g., at 90° intervals) around the circumference of the capture structure 3013. These notches 3203 engage with compliant protrusions (not shown) in the cap and prevent the cap from rotating on the insert assembly.

[0406] Figure 30G -30I further shows that the PCB assembly 3003 includes a PCB 3015, a sensor portion 3017, and a positioning portion 3019. The PCB assembly 3003 is positioned so that in use, the sensor portion 3017 is within the fluid flow path passing through 3005.

[0407] The sensor portion 3017 includes one or more sensors such as temperature sensors. The sensors are preferably positioned on a protruding portion of the sensor portion 3017. Suitable temperature sensors include thermistors, thermocouples, resistance temperature detectors, or bimetallic thermometers.

[0408] The PCB 3015 completes the heating and / or sensing circuitry of the composite tube 201 .

[0409] The locating portion 3019 improves stability and helps position the PCB assembly 3003 during the manufacturing process. However, the locating portion 3019 may be omitted in some embodiments.

[0410] Fig. 30I It is also shown that the PCB assembly 3003 can be further stabilized in the insert 3005 by recessing at least a portion of the PCB 3015 and / or the locating portion 3019 on the outer surface of the insert 3005. Fig.30N The recessed structure is also shown in FIG.

[0411] Figure 30G The configuration of -30I has several advantages. For example, certain embodiments include implementations where placing the sensor portion 3017 within the fluid flow path facilitates accurate measurement regardless of flow rate, ambient temperature, etc. Additionally, certain embodiments include implementations where fluid leaks due to poor user setup of the circuit are less likely to occur than with configurations having a separate sensor attached to a connector.

[0412] Additionally, some embodiments include the following implementations: Since the PCB assembly 3003 spans the entire width of the insert 3005, the PCB assembly 3003 can be used to extend the connection line throughout the tube 201. As described below, Fig.33A-33D shows a design of a PCB assembly 3301 that enables the connection line to be spread throughout the tube, and the corresponding figure shows both sides of the PCB assembly 3301. The concept of spreading the connection line throughout the tube 201 is described below with reference to Fig.34 , which is further discussed in the context of an intermediate connection between two tube 201 sections.

[0413] First go to Fig.33A and 33B , the PCB assembly 3301 includes connection pads 3303, 3305 for heating filaments and / or sensor connections. The connection pads 3303, 3305 are configured to be on opposite sides of the PCB assembly 3303 to facilitate their connection to the helically wound heating filaments.

[0414] PCB assembly 3301 includes sensor connection pads 3307 for the sensor. The sensor can be coupled to the diode via signal connection pads 3309 on PCB assembly 3301. As shown, PCB assembly 3301 includes gaps 3311 configured to thermally insulate the sensor from other electrical components and tracks. In some embodiments, gaps 3311 can be filled with an insulating material to further thermally isolate the sensor connected to sensor connection pads 3307. In addition, PCB assembly 3301 can be configured to position the sensor to be spaced apart from other active and / or passive electrical components such as protruding features 3313.

[0415] PCB assembly 3301 includes a power connection pad 3315 for a diode that is electrically coupled to the heater filament via a conductive track on PCB assembly 3301. Power connection pad 3315 may be electrically and thermally coupled to a heat sink 3317 to help dissipate heat, thereby reducing or minimizing the impact on the accuracy of the temperature reading of the thermistor coupled to sensor connection pad 3307.

[0416] Fig.33C and 33D Shows Fig.33A and Fig.33B The PCB assembly 2901 is located through the above for Fig. 30A -30O discussed insert 2605 or below for Fig.34 The appropriate position of the intermediate connector 3403 is discussed.

[0417] Thus, in at least one embodiment, a respiratory conduit segment such as insert 2605 or intermediate connector 3403 includes a lumen extending along a longitudinal axis, and a wall surrounding the lumen, the lumen defining a gas flow path when in use; and a PCB assembly 3301, the PCB assembly including a printed circuit board, and further including a first portion extending through the lumen along a diameter or chord line, such that a portion of the printed circuit board assembly substantially divides at least a portion of the flow path into two, the first portion being overmolded by an overmolding composition, a second portion adjacent to the first portion protruding outwardly from the wall in a direction away from the lumen, the second portion including one or more connectors on the printed circuit board Pad 3303, the one or more connection pads are configured to receive one or more metal wires from a first component, a third portion adjacent to the first portion protrudes outward from the wall in a direction away from the tubular cavity and in a direction opposite to the second portion, the third portion includes one or more connection pads 3305 on the printed circuit board, the one or more connection pads are configured to receive one or more metal wires from a second component different from the first component, and one or more conductive tracks on the printed circuit board are electrically coupled to the one or more connection pads of the second portion and the one or more connection pads of the third portion, and are configured to provide an electrical connection between the first component and the second component.

[0418] The first component and the second component may each be a breathing tube. Alternatively, the first component may be a breathing tube and the second component may be, for example, a patient interface.

[0419] Return again Figure 30G In the example of FIG. 30I, the sensor portion 3017 is mounted or formed so that the sensor portion 3017, the PCB 3015 and the positioning portion 3019 form an integral body. For example, the sensor portion 3017, the PCB 3015 and the positioning portion 3019 can be mounted to each other using a suitable method such as welding. The sensor portion 3017, the PCB 3015 and the positioning portion 3019 can be integrally formed of a suitable material such as a circuit board substrate.

[0420] Sensor portion 3017 may be electrically connected to PCB 3015 using a suitable technique such as circuit printing. For example, the electrical connection may include conductive tracks such as copper tracks. To electrically connect the conductive filaments in the second elongated member of tube 201 to the connection pads of PCB assembly 3003, the above-described method for electrically connecting the conductive filaments in the second elongated member of tube 201 to the connection pads of PCB assembly 3003 may be used. Fig.25E –25I shows a process similar to that described. Additional electrical components such as diodes (not shown) may be positioned on either side of the PCB 3015 inside and / or outside the gas path. Positioning the diodes outside the gas path is discussed above with reference to the sensor connection pads 3307 and signal connection pads 3309, and as Fig.33A –As shown in Figure 33B.

[0421] Return again Figure 30G –30I example, the PCB assembly 3003 can be mounted within the insert 3005 using, for example, an overmolding method known in the art. A material having a thermal conductivity in the range of 0.03–0.6 W / m·K or thereabouts, such as polypropylene (thermal conductivity 0.1–0.22 W / m·K) can be used to overmold at least a portion of the overmolded portion. The use of a material with low thermal conductivity can advantageously reduce interference from the surrounding environment during sensor measurements due to the material's poor ability to conduct heat from the sensor portion 3017 to the insert 3005 wall. Certain embodiments include the following implementations: Overmolding a single PCB assembly 3003 allows for more consistent sensor placement than overmolding a single sensor. Additionally, certain embodiments include the following implementations: Overmolding a sensor placed within the center of the tube can make the sensor less sensitive to radiation effects.

[0422] like Figure 30G As shown in FIG. 30I , the PCB assembly 3003 spans the width of the insert 3005 and is supported by opposing walls of the insert 3005. Because the PCB assembly 3003 is supported on opposing sides of the insert 3005, the PCB assembly 3003 can be relatively thin (i.e., having a smaller thickness and a smaller width than a PCB with one support on a tube). The thin profile can facilitate fluid flow by providing less resistance to flow than a thicker profile.

[0423] The overmold around the sensor portion 3017 is preferably configured to reduce resistance to the fluid flowing around the sensor portion 3017. The overmold may have an aerodynamically efficient tapered shape such as an airfoil shape, for example a bird wing shape, a fully tapered torpedo shape (such as a Figure 30G and Fig. 30H ), or a partially tapered bullet shape with a blunt edge (as Fig. 30I ). These tapered shapes promote fluid flow. In addition, when placed in a fluid stream, these tapered shapes reduce turbulence and eddies at the trailing edge of the tapered shape, which can cause unwanted cooling of the humidified gas and the formation of condensation. Condensation formation can lead to inaccurate measurements and unwanted temperature drops in the gas delivered to the patient. Thus, the tapered shape can facilitate more accurate readings. In addition, the tapered shape can reduce the collection of condensation that does form and also reduce the accumulation of patient secretions by promoting flow out.

[0424] The tapered shape may also be selected to reduce turbulence by reducing the formation of eddies in the flow and increase the likelihood that the flow will remain laminar.

[0425] The distance between the tapered shape and the inner wall of the insert 3005 is preferably selected to allow more space. In at least one embodiment, the distance between the tapered shape and the inner wall of the insert 3005 is at least 10% (or about 10%) or at least 30% (or about 30%) of the inner diameter, such as 33% (or about 33%) or 40% (or about 40%). In at least one embodiment, the distance between the tapered shape and the inner wall of the insert 3005 is greater than 2 mm (or about 2 mm). Allowing more space reduces the likelihood that condensate will be trapped in the space.

[0426] The overmold helps to read a more even temperature. There is some temperature deviation across the insert 3005, with higher temperatures toward the center of the insert 3005 and lower temperatures along the walls of the insert 3005. Asymmetric temperature profiles, where the highest temperatures are offset from the centerline of the insert 3005, are particularly common for curved tubes 203. The overmold has a larger surface area than the sensor portion 3017 of the PCB assembly 3003, and the overmold material spreads the heat so that the sensors of the sensor portion 3017 measure a more even temperature across the flow path.

[0427] Fig. 30J An end view of the connector 3000 taken along the width of the connector is shown, as viewed toward the tube (not shown) from the patient end portion 3001 of the connector 3000. In this view, the overmolded tapered shape housing the PCB assembly 3003 (not shown) is generally centered. Figure 30K An alternative configuration is shown. In this view, the tapered shape is offset from the center line. Fig. 30J and Figure 30K As shown in , the joint 3018 between the inner wall of the insert 3005 and the overmolded conical shape that accommodates the PCB assembly can optionally have multiple fillets to reduce fluid disturbances and reduce the area of ​​fluid accumulation. The fillet of the joint 3018 can be, for example, a radius of 1 mm (or about 1 mm).

[0428] Figure 30L Shown in more detail Figure 30K Since the sensor 3020 protrudes outward from the PCB assembly 3003, the offset configuration can improve accuracy by placing the sensor 3020 closer to the centerline. In addition, the offset configuration may also be desirable because the PCB assembly 3003 can be accommodated in one side of the molding tool during manufacturing, thereby simplifying the manufacturing process.

[0429] Figure 30MA longitudinal cross section of the insert assembly 3007 is shown, showing additional details of the PCB assembly 3003. A sensor 3020 is placed in the flow path. The sensor 3020 can provide temperature and / or gas flow information, thereby allowing conditions near the patient interface to be assessed. The sensor 3020 is preferably positioned near the edge of the protruding portion of the sensor portion 3017. The thickness of the overmold proximal to the sensor 3020 is preferably thinner than the thickness of the overmold around the rest of the PCB assembly 3003, such as Fig.30O Reducing the overmold thickness improves heat transfer to facilitate more accurate temperature measurement.

[0430] Reference again Figure 30M , conductive track 3021 electrically connects sensor 3020 to PCB 3015. (It should be noted that Figure 30M The sensor 3020 is not specifically shown in the figure; instead, the structure labeled 3020 indicates the general location of the sensor. The structure labeled 3020 shows the two conductive pads that the sensor will cross. For illustration purposes, the structure is labeled as sensor.) The through hole 3023 allows the component to contact the required conductive layer. Fig.30N An alternative construction of PCB assembly 3003 is shown. Fig.30N In the embodiment of the present invention, the conductive track 3021 has a tortuous path. It has been recognized that increasing the length of the conductive track 3021 within the flow path allows the temperature of the conductive track 3021 to more accurately reflect the temperature within the flow path, thereby reducing the impact of the environment on the sensor 3020 through the conductive track 3021. Preferably, there is an increased copper surface area near the sensor 3020. The increased copper helps to accurately detect the temperature around the sensor 3020 area.

[0431] In some embodiments, the conical shape can extend upstream along the gas path toward the source of the gas flow. This configuration promotes more accurate measurements by ensuring that the sensor 3020 protrudes into the fluid flow when the fluid passes through the overmolding portion before cooling. This configuration can also promote more accurate measurements by reducing the "stem effect". All contact temperature sensors have a stem effect. When the probe is immersed in the fluid flow, a heat conduction path is generated through the probe's stem. In the case where the ambient temperature is colder than the temperature of the measured fluid flow, the heat is conducted away from the probe tip via the probe's stem to the external atmosphere. This causes the sensing tip to read a lower temperature than the actual surrounding fluid. Moreover, in the case where the ambient temperature is hotter than the temperature of the measured fluid flow, the heat is conducted from the external atmosphere toward the probe tip via the probe's stem. This causes the sensing tip to read a higher temperature than the actual surrounding fluid. The conical shape configuration reduces the stem effect by making the sensor 3020 protrude from the portion of the sensor portion 3017 that connects the PCB 3015 and the positioning portion 3019 (i.e., away from the "stem"). In some embodiments, the tapered shape extends at least 6 mm (or approximately 6 mm) upstream from the portion of the sensor portion 3017 that connects the PCB 3015 and the positioning portion 3019.

[0432] In some embodiments, the tapered shape can extend downstream away from the source of the gas flow. This configuration can be advantageous, for example, when the design of the overmolded PCB assembly 3003 significantly changes the average downstream fluid properties, making it desirable to be able to accurately measure the fluid properties leaving the tube.

[0433] The heating filaments in the second elongated member (not shown here but described above) can be connected to a PCB 3015 which can provide termination points to complete the heating filament circuit. The PCB 3015 can also be used to provide additional termination points to provide power to additional heating filaments in secondary tubes, such as in a segmented inspiratory manifold configuration used with a humidification system, the segmented inspiratory manifold having connections configured to couple the heating filaments in two sections to the sensor. Fig.33A –33D discusses a suitable PCB assembly construction.

[0434] Return again Figure 30M, this configuration eliminates the need to have a separate power line extending to the heating filament. This configuration further ensures that the heating filament extends along the tube 203 and terminates at approximately the same position on the tube 203 as the sensor 3020. Therefore, this configuration minimizes the temperature drop from the end of the heating filament to the sensor 3020. This configuration can also reduce the temperature drop from the end of the heating filament to the second heating filament in the other section of the tube. This configuration can also be used to cover the connector of the heating sensor 3020, thereby reducing the heat lost to the cold environment and further improving the accuracy of the temperature measurement.

[0435] While the foregoing describes placement of one or more sensors at the patient end of tube 201 , it should be appreciated that such sensor configurations may be employed along any portion of the fluid path of tube 201 .

[0436] For example, Fig.34 A portion of a segmented inspiratory limb 3401 for use with a respiratory humidification system is shown, the segmented inspiratory limb 3401 comprising a first segment 3401a and a second segment 3401b, and having an intermediate connector 3403 configured to couple a first heating wire 3405a to a second heating wire 3405b, and a first temperature sensor 3407a to a second temperature sensor 3407b in the corresponding segments 3401a and 3401b. Coupling the two segments 3401a and 3401b may include mechanically coupling the segments to form a single conduit through which humidified gas may be delivered to a user, wherein mechanically coupling the segments 3401a and 3401b may electrically couple the corresponding heating wires 3405a, 3405b and the corresponding temperature sensors 3407a, 3407b through the intermediate connector 3403. Fig.33A and Fig.33B The PCB assembly 3301 shown in FIG. Fig.34 Used together with the intermediate connecting piece 3403.

[0437] Return again Fig.34, the segmented inspiratory limb 3401 may include a structure 3409 forming a lumen through which humidified gas can pass. Structure 3409 may include paths formed within the walls of structure 3409, which are configured to accommodate heating wires 3405a or 3405b so that the heating wires 3405a or 3405b are protected from the influence of the humidified gas traveling through the lumen and / or covered by an outer surface of structure 3409 so that the heating wires are not exposed. For example, structure 3409 can be a composite tube in which the heating wire paths are coils molded into the tube as described above. Structure 3409 can include any type of suitable material and can include insulating materials and / or flexible materials. In some embodiments, the structure 3409 and the intermediate connector 3403 may be configured such that when the first segment 3401a and the second segment 3401b are mechanically coupled, the heating wires 3405a and 3405b are wrapped around the intermediate connector 3403 in a manner so as to be electrically coupled to the intermediate connector 3403. In some embodiments, the first segment 3401a and / or the intermediate connector 3403 may exclude any flying leads for connecting to the second segment 3401b, thereby facilitating the connection of the second segment 3401b to the first segment 3401a.

[0438] The structure 3409 at the complementary ends of the first segment 3401a and the second segment 3401b can be configured to accommodate the intermediate connector 3403. Therefore, the intermediate connector 3403 can be internal to the suction leg 3401. In some embodiments, the complementary ends of the first segment 3401a and the second segment 3401b can be configured to protect the intermediate connector 3403 from the humidified gas traveling through the suction leg 3401. In some embodiments, the intermediate connector 3403 is internal to the suction leg 3401 and is protected from the humidified gas in the conduit, thereby reducing or eliminating exposure of the electrical connections on the intermediate connector 3403.

[0439] In some embodiments, the first heating wire 3405a may include two wires 3411 and 3413, and the second heating wire 3405b may include two wires 3415 and 3417. The two wires 3411 and 3413 in the first segment 3401a may be electrically coupled to each other via an electrical component 3419, wherein the electrical coupling creates an electrical path through the wire 3411, at least a portion of the electrical component 3419, and the wire 3413. Similarly, the two wires 3415 and 3417 in the second segment 3401b may be electrically coupled to each other via the electrical component 3419, and / or electrically shorted together at the end of the segment 3401b opposite the intermediate connector 3401b, such as via a patient-end connector (not shown). By coupling the wires 3415 and 3417 of the second section 3401b at the intermediate connector 3403, electrical connections at the patient end of the inspiratory limb 3401 are reduced or eliminated, which may reduce cost, system complexity, and / or patient risk.

[0440] The intermediate connector 3403 can be configured to allow a single controller such as a humidifier controller to control the power provided to the heating wires 3405a, 3405b. In some embodiments, the humidifier controller controls the heating wires 3405a, 3405b, and there is no additional control function on the intermediate connector 3403. For example, the intermediate connector 3403 may include a passive component without any logic circuit, wherein the passive component directs power to the heating wires 3405a and / or 3405b according to the selection of the controller. This can allow the intermediate connector 3403 to be designed using relatively inexpensive components, and can reduce the complexity of the design.

[0441] In some embodiments, the heating of the two sections 3401a and 3401b can be accomplished using a maximum of four metal wires in each section 3401a, 3401b. For example, in the first section 3401a, the four metal wires may include a first heating wire 3411, a second heating wire 3413, a signal temperature sensing wire 3419, and a return temperature sensing wire 3421. In the second section 3401b, the four metal wires may include a first heating wire 3415, a second heating wire 3417, a signal temperature sensing wire 3423, and a return temperature sensing wire 3425. By coupling the second heating wires 3415, 3417 to the first heating wires 3411, 3413 at the connection point 3427, and by coupling the second temperature sensing wires 3423, 3425 to the first temperature sensing wires 3419, 3421 at the connection point 3427, the controller can be configured to independently provide power to the first heating wire 3405a and the second heating wire 3405b, and independently read temperature sensor data from the temperature sensors 204a and 204b without having to include more than four wires in either section 3401a or 3401b. In some embodiments, the control of the heating wires 3405a and 3405b and the reading of the temperature sensors 3407a and 3407b can be accomplished using less than four wires in each segment (for example, using three wires or using two wires) or more than four wires in each segment (for example, using five wires, using six wires, using seven wires, using eight wires, or using more than eight wires).

[0442] The intermediate connector 3403 may include an electrical component 3419 configured to allow the controller to selectively control the heating wires 3405a, 3405b. The controller may be configured to control the heating of the inspiratory branch 3401 using two modes, wherein the first control mode includes providing power to the heating wire 3405a in the first section, and the second control mode includes providing power to the heating wires 3405a and 3405b in the first section 3401a and the second section 3401b. Therefore, the controller may be configured to independently control the heating wire sections. This capability allows the controller to control the heating of the inspiratory branch 3401 by controlling only the heating of the inspiratory branch according to the first control mode when the second section 3401b does not exist, thereby allowing the respiratory humidification system to be used in various situations without having to modify the controller or humidification device. In some embodiments, these control modes may include a mode in which power is transmitted only to the heating wire 3405b in the second section 3401b. In some embodiments, the controller includes a power supply that provides current. The first control mode and the second control mode can be based at least in part on the voltage supplied by the power supply, wherein a positive voltage or a positive current can trigger the first control mode, and a negative voltage or a negative current can trigger the second control mode. In some embodiments, the power supply provides rectified AC or DC power to the heating wires 3405a, 3405b, and the change in rectification or polarity triggers a change in the control mode. By switching the control mode, the control of heating in the breathing circuit can be completed with any power supply that can switch the polarity of the output signal. In some embodiments, the amount of power supplied to the heating wires 3405a, 3405b can be adjusted by adjusting the duty cycle of the power applied to the heating wires 3405a, 3405b. For example, pulse-width modulation (PWM) can be used to start the heating wires 3405a, 3405b, and the duty cycle of the PWM signal can be adjusted to control the power transmitted. In another example, the amount of power supplied to the heating wires 3405a, 3405b can be adjusted by controlling the amplitude of the power signal.

[0443] The intermediate connection 3403 may include an electrical component 3421 configured to allow the controller to selectively read the temperature sensors 3407a, 3407b. The selective reading may be accomplished by using a current source, wherein applying a positive current across the wires 3419 and 3421 as a whole may cause the controller to measure a temperature-related signal from the first temperature sensor 3407a, and applying a negative current across the wires 3419 and 3421 as a whole may cause the controller to measure a temperature-related signal from the second temperature sensor 3407b or from both the first temperature sensor 3407a and the second temperature sensor 3407b. The controller may use the readings from the temperature sensors 3407a, 3407b to adjust the power provided to the heating wires 3405a, 3405b using, for example, pulse-width modulation. A first temperature sensor 3407a can be positioned near the junction or intersection of the first section 3401a and the second section 3401b to provide the controller with the temperature of the gas entering the second section 3401b, which can correspond to entering an incubator or other such area with a different ambient temperature. A second temperature sensor 3407b can be positioned at the patient end of the second section 3401b to provide the controller with the temperature of the gas delivered to the patient, or the temperature before the final workpiece such as a Y-shaped workpiece before the patient. The controller can use these temperature readings to adjust the power provided to the heating wires 3405a, 3405b so as to maintain the temperature of the gas at the patient end of the inspiratory manifold 3401 at a target or suitable temperature. The target or suitable temperature can vary, at least in part, depending on the application and environment in which it is used, and can be about 37°C, about 40°C, at least about 37°C and / or less than or equal to about 38°C, at least about 36.5°C and / or less than or equal to about 38.5°C, at least about 36°C and / or less than or equal to about 39°C, at least about 35°C and / or less than or equal to about 40°C, at least about 37°C and / or less than or equal to about 41°C, or at least about 39.5°C and / or less than or equal to about 40.5°C. In some embodiments, the second temperature sensor 3407b can be positioned within the incubator but not attached to the breathing circuit. By measuring the temperature within the incubator, the temperature of the second segment 3401b can be calculated.

[0444] The controller can independently control the amount of power delivered in the first control mode and the second control mode as described herein. Based at least in part on feedback from temperature sensors 3407a and / or 3407b, the controller can independently adjust the power delivered in the first control mode and the second control mode so that the heater power ratio between the first section 3401a and the second section 3401b changes.

[0445] In some embodiments, the first temperature sensor 3407a is positioned within the gas flow within the suction manifold 3401. In some embodiments, the intermediate connector 3403 or the first section 3401a may include a mechanical component that reduces turbulence in the gas flow passing through the first temperature sensor 3407a, which can improve the accuracy of the reading of the temperature sensor 3407a. In some embodiments, the mechanical component that reduces turbulence (e.g., a cross-shaped member feature structure within the suction duct) also fixes the temperature sensor 3407a within the gas flow. In some embodiments, the intermediate connector 3403 and the mechanical component are configured to thermally isolate the temperature sensor 3407a from the electrical components on the intermediate connector 3403.

[0446] In some embodiments, the intermediate connector 3403 includes Fig.34 34. Additional connection points in addition to the connection point 3427 shown in FIG. The additional connection points can be used to integrate additional functionality into the breathing circuit, such as, for example, integrating a memory device (PROM), a microcontroller, additional circuits, etc.

[0447] Furthermore, the composite tube 201 may be an inhalation tube or an exhalation tube.

[0448] Placement of spiral connectors

[0449] Next reference Fig.35A -35E, these figures show the connector not being electrically connected to the PCB. However, as will be appreciated by those skilled in the art, the connector can be equivalently adapted to be electrically connected to the PCB. The connector is suitable for connection to, for example, a patient interface or a humidifier. It is particularly suitable for use as a patient-end connector and / or a device-end connector in an obstructive sleep apnea environment.

[0450] A spiral terminated molded insert 3501 is provided. The end of the insert 3501 opposite the spiral end is molded for insertion or attachment to a humidifier port, and / or a patient interface port, and / or any other desired component. The insert 3501 can be a hard material such as a hard plastic, for example polypropylene.

[0451] like Fig.35C As shown in , the helical end of the insert 3501 is screwed onto the compliant coils of the tube 201. In this example, the helical coils of the insert 3501 are sized and configured to fit into the coils of the first elongated member 203 of the tube 201.

[0452] It should be noted that if a tube has one or more electrodynamic wires, an electrical connection can be provided on at least a portion of the insert 3501. When installing the insert 3501, the electrical connector is preferably aligned with the wires to facilitate electrical connection. The connection can then be secured using solder or the like.

[0453] Member 3503 may be inserted or molded on top of insert 3501 and optionally at least a portion of tube 201 to facilitate attachment between insert 3501 and tube 201. Member 3503 may be a hard material or a soft material, such as soft plastic, rubber, or PTFE, such as polypropylene. In some cases, insert 3501 (or at least the spiral end of insert 3501) provides sufficient lateral crush resistance to enable high pressure molding techniques to be used, where pressures may exceed the lateral crush resistance of tube 201 without insert 3501. Member 3503 may also advantageously provide a soft surface to grip when inserting or removing the tube into or from a component.

[0454] The foregoing method of attaching a connector to a spirally wound pipe is provided by way of example. The method described herein does not imply that the steps have a fixed order. It also does not imply that any one step is required to practice the method. The embodiments can be practiced in any order, and combinations are also practiceable.

[0455] Placement of Alternative Patient-End Connections

[0456] Next reference Fig.36A –36K. Fig.36A and Fig.36B A patient end connector 3601 without electrical connections is shown. The connector 3601 has a patient end 3603 having a medical taper of a standard size suitable for use with a patient interface. The tube end 3605 of the connector 3601 is suitable for connection to the composite tube 201 as described below. The connector 3601 is preferably a pre-molded component formed of a suitable material such as plastic, rubber or PTFE.

[0457] like Fig.36C and Fig.36D As shown in FIG. 1 , a portion (e.g., a 10-mm portion) of the second elongated member 205 is stripped to reveal a smaller length of one or more filaments 215 embedded therein. Preferably, about 5 mm or 10 mm of the filaments 215 are exposed. Fig.36D As shown in FIG, filaments 215 are twisted together and optionally secured, such as by welding, to create a closed loop.

[0458] Then go to Figure 36G, the tube end 3605 of the connector 3601 is inserted into the tube 201, and the twisted filament 215 is placed under the retaining ring 3607. The retaining ring 3607 reduces the movement of the filament 215 during the molding process. The retaining ring 3607 also advantageously aligns the rotational pitch of the composite tube 201 with the connector 3601, which in turn promotes proper alignment of the tube 201 in the mold. The combination of the connector 3601 and the composite tube 201 is labeled herein as a connector-tube assembly 3609.

[0459] like Fig.36H As shown in , the molding tool core 3611 is inserted into the connector 3601. Fig.36I As shown in , the connector-tube assembly 3609 and core 3611 are placed in an injection molding tool 3613. Fig.36J In the embodiment of the present invention, a molding material 3615 is molded on the joint area between the composite tube 201 and the connector 3601, thereby bonding the composite tube 201 and the connector 3601. Suitable molding materials 3615 include plastics and rubbers. The connector-tube assembly 3609 and the core 3611 are removed from the injection molding tool (not shown), such as Figure 36K The core 3611 is removed, thereby providing the composite tube 201 with a patient end connector 3601 .

[0460] The foregoing method of attaching a connector to a composite pipe is provided by way of example. The described method does not imply that the steps have a fixed order. It also does not imply that any one step is required to practice the method. The embodiments can be practiced in any order, and combinations are also practiceable.

[0461] The foregoing description of the present invention includes preferred forms of the present invention. Modifications may be made to the present invention without departing from the scope of the present invention. The content to which the present invention relates will be apparent to those skilled in the art as many changes in structure and distinct embodiments and applications of the present invention will themselves not depart from the scope of the present invention as defined in the appended claims. The disclosure and description herein are entirely illustrative and are not intended to be limiting in any sense.

[0462] Throughout this specification and claims, the terms "comprises," "comprising," and the like should be construed in their inclusive sense, ie, in the sense of "including but not limited to," unless the context clearly requires otherwise.

[0463] Although the present invention has been described by way of example and with reference to possible embodiments thereof, it should be understood that various modifications or improvements may be made thereto without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. In addition, where reference has been made to specific components or the entirety of the present invention having known equivalents, these equivalents are incorporated herein as if individually set forth.

[0464] Any discussion of the prior art throughout this specification should in no way be considered as an admission that this prior art is widely known or forms part of the common general knowledge in the field anywhere in the world.

Claims

1. A connector assembly for a breathing tube for delivering humidified gas to a patient, the connector assembly comprising: a connector including a lumen extending along a longitudinal axis and a wall surrounding the lumen, the lumen defining a gas flow path through the connector for humidifying gas; and A circuit board assembly is fixed on a wall, and the circuit board assembly comprises: an electrical contact configured to couple to at least two wires of the breathing tube; a circuit board comprising one or more conductive tracks; a segmented portion extending into the lumen and dividing at least a portion of the airflow path and including a sensor portion disposed within the airflow path and including at least one sensor, at least a portion of the segmented portion and the sensor being overmolded with the overmolding composition; a wiring portion including an electrical contact, the wiring portion being adjacent to the segmentation portion and projecting outwardly from the wall in a direction away from the lumen; The one or more conductive tracks are configured to electrically connect the electrical contact to the at least one sensor, the one or more conductive tracks within the airflow path having a serpentine or tortuous path; Wherein, the circuit board assembly is configured such that the electrical contact points are located outside the air flow path.

2. The connector assembly of claim 1, wherein the circuit board assembly passes through the wall to allow the electrical contacts to be coupled to at least two wires of the breathing tube outside of the airflow path. 3 . The connector assembly according to claim 1 , wherein the wiring portion is disposed within a cover configured to cover and protect the wiring portion of the circuit board assembly.

4. The connector assembly of claim 3, configured to connect to a breathing tube, and wherein the cover is further configured to cover and protect the connection of the connector to the breathing tube.

5. The connector assembly of claim 1, wherein the circuit board assembly is configured to separate the at least one sensor from other active and / or passive electrical components. The connector assembly according to claim 1 , wherein the sensor portion extends from the split portion. The connector assembly of claim 6 , wherein the sensor portion comprises a tapered shape.

8. The connector assembly of claim 7, wherein the sensor portion comprises an airfoil shape, a bird wing shape, a torpedo shape, or a bullet shape so as to be aerodynamically efficient.

9. The connector assembly of claim 1, wherein the thinnest portion of the overmold composition is proximate an edge of the sensor portion.

10. The connector assembly of claim 1, wherein at least one sensor is a temperature sensor. The connector assembly of claim 10 , wherein the temperature sensor is a thermistor.

12. The connector assembly according to claim 1, comprising a positioning portion adjacent to the dividing portion, the positioning portion protruding outwardly from a wall of the connector in a direction away from the lumen and opposite to the wiring portion.

13. The connector assembly of claim 1, wherein the circuit board assembly includes at least one diode located on the circuit board, the diode being electrically coupled to the at least one sensor.

14. The connector assembly of claim 1, wherein the circuit board assembly is a printed circuit board assembly and the circuit board is a printed circuit board.

15. The connector assembly according to claim 1, wherein the circuit board includes a dividing portion and a wiring portion.

16. A breathing tube for delivering humidified gas to a patient, the breathing tube comprising: A first connector assembly, located at the first end, comprising at least two electrical conductors; A second connector assembly, located at a second end opposite the first end and comprising: a connector including a first lumen extending along a longitudinal axis and a wall surrounding the lumen, the first lumen defining a gas flow path through the connector for humidifying gas; and A circuit board assembly is fixed on a wall, and the circuit board assembly comprises: an electrical contact configured to couple to at least two wires of the breathing tube; a circuit board comprising one or more conductive tracks; a segmented portion extending into the lumen and dividing at least a portion of the airflow path and including a sensor portion disposed within the airflow path and including at least one sensor, at least a portion of the segmented portion and the sensor being overmolded with the overmolding composition; a wiring portion including an electrical contact, the wiring portion being adjacent to the segmentation portion and protruding outwardly from the wall in a direction away from the lumen; The one or more conductive tracks are configured to electrically connect the electrical contact to the at least one sensor, the one or more conductive tracks within the airflow path having a serpentine or tortuous path; wherein the circuit board assembly is configured such that the electrical contacts are located outside of the airflow path; An elongated body comprising: a second lumen defining a gas flow path along its length and in fluid communication with the first connector assembly and the second connector assembly such that the first connector assembly, the second connector assembly, and the elongated body form a gas flow path for the humidified gas between the first end and the second end of the breathing tube; The at least two conductive wires include at least two heater wires, the at least two conductive wires are helically wound along their lengths, and are configured to be electrically coupled to the at least two electrical conductors of the first connector assembly.

17. The breathing tube of claim 16, wherein the circuit board assembly penetrates the wall to allow the electrical contacts to be coupled to at least two wires outside of the airflow path.

18. The breathing tube of claim 16, wherein the wiring portion is disposed within a cover configured to cover and protect the wiring portion of the circuit board assembly.

19. The breathing tube of claim 18, wherein the cover is further configured to cover and protect a connection between the connector of the second connector assembly and the elongated body.

20. The breathing tube of claim 16, wherein the circuit board assembly is configured to separate the at least one sensor from other active and / or passive electrical components.

21. The breathing tube of claim 16, wherein the sensor portion extends from the segmented portion.

22. The breathing tube of claim 21, wherein the sensor portion comprises a tapered shape.

23. The breathing tube of claim 22, wherein the sensor portion comprises an airfoil shape, a bird wing shape, a torpedo shape, or a bullet shape so as to be aerodynamically efficient.

24. The breathing tube of claim 16, wherein the thinnest portion of the overmold composition is proximate an edge of the sensor portion.

25. The breathing tube of claim 16, wherein at least one sensor is a temperature sensor.

26. The breathing tube of claim 25, wherein the temperature sensor is a thermistor.

27. The breathing tube of claim 16, comprising a locating portion adjacent the segmenting portion, the locating portion projecting outwardly from a wall of the connector in a direction away from the lumen and opposite the wiring portion.

28. The breathing tube of claim 16, wherein the circuit board assembly includes at least one diode located on the circuit board, the diode being electrically coupled to the at least one sensor.

29. The breathing tube of claim 16, wherein the circuit board assembly is a printed circuit board assembly and the circuit board is a printed circuit board.

30. The breathing tube of claim 16, wherein the circuit board comprises a segmented portion and a wiring portion.

31. The breathing tube of claim 16, wherein the elongated body comprises a smooth lumen surface.

32. The breathing tube of claim 16, wherein the elongated body comprises a first elongated member and a second elongated member, and the at least two wires are embedded or encapsulated in the second elongated member.

33. The breathing tube of claim 32, wherein the first elongated member comprises a helically wound hollow body and the second elongated member is disposed between adjacent turns of the hollow body.

34. The breathing tube of claim 33, wherein the second elongated member is configured to act as a structural support or reinforcement portion of the elongated body.

35. The breathing tube of claim 16, wherein at least two of the wires comprise sensing wires.

36. The breathing tube of claim 35, wherein the circuit board assembly completes a heating circuit of the breathing tube formed by the heating wires and / or a sensing circuit of the breathing tube formed by the sensing wires.

37. The breathing tube of claim 16, wherein the first connector assembly is configured to removably connect the breathing tube in use to a respiratory assistance device or a humidification device to form a pneumatic and electrical connection.

38. The breathing tube of claim 16, wherein the first connector assembly is configured to removably connect the breathing tube in use to a flow generator, wherein the at least two wires terminate in at least two electrical conductors of the first connector assembly.

39. The breathing tube of claim 37, wherein: When the first connector assembly is coupled to the respiratory assistance apparatus or the humidification device, the at least two electrical conductors electrically couple the at least one sensor to the at least one controller of the respiratory assistance apparatus or the humidification device.

40. The breathing tube of claim 16, wherein the second connector assembly is configured to at least pneumatically connect the breathing tube in use to the patient interface.

41. The breathing tube of claim 16, wherein the tube is a suction catheter.

42. A respiratory assistance device for delivering humidified gas to a patient, comprising: A breathing tube according to any one of claims 16 to 41; and At least one of the following: an air source configured to provide an air flow; and A humidifier is configured to humidify a gas flow received from an air source in use, the humidifier comprising a humidification chamber containing a volume of water or other suitable liquid, the humidification chamber comprising an inlet and an outlet coupleable to the air source.

43. A breathing assistance apparatus as claimed in claim 42, comprising a humidifier, and wherein the breathing tube is removably coupleable to the outlet of the humidification chamber.

44. A breathing assistance apparatus according to claim 42, wherein the gas source comprises a ventilator or a blower.

45. A breathing assistance apparatus according to claim 42, comprising at least one controller configured to control the humidifier and / or the gas source.

46. ​​A breathing assistance apparatus according to claim 42, wherein the first connector assembly is configured to removably connect the breathing tube in use to an air source or a humidifier to form a pneumatic and electrical connection.

47. A breathing assistance apparatus as claimed in claim 42, comprising a patient interface, and wherein the second connector assembly is configured to removably connect a breathing tube in use to the patient interface.

48. A breathing assistance apparatus according to claim 47, wherein the patient interface is a nasal cannula comprising: delivery tube; Cannula body; and A head cap that is secured to the back of the patient's head.

49. A breathing assistance apparatus as claimed in claim 48 wherein the delivery tube is in fluid communication with the breathing tube to supply humidified gas to the patient.

50. A breathing assistance apparatus as claimed in claim 48 wherein the delivery tube is unheated.

51. A breathing assistance apparatus as claimed in claim 48 wherein the delivery tube and the breathing tube are an integral component extending to the cannula body.

52. A breathing assistance apparatus according to claim 47, wherein the apparatus is configured to provide nasal high flow therapy.

53. A breathing assistance apparatus according to claim 42, comprising a connector configured to be removably connected to the first connector component of the breathing tube in use to form a pneumatic and electrical connection.

54. A breathing assistance apparatus according to claim 53, wherein: The at least two electrical connectors of the first connector assembly are disposed on electrical terminals of the first connector assembly, and the connector of the respiratory assistance device comprises complementary electrical terminals configured to engage with the electrical terminals of the first connector assembly.

55. A breathing assistance apparatus as claimed in claim 53, wherein the connector of the breathing assistance apparatus comprises a pneumatic inlet configured to be removably connected to the connector of the first connector assembly in use.

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