Medical tube and method of manufacturing

Abstract

The present disclosure relates to medical tubes and methods for making medical tubes. The tube can be a composite structure made of two or more different parts, which are spirally wound to form an elongated tube. For example, one of the parts can be a spirally wound elongated hollow body, and the other part can be an elongated structural part, which is still spirally wound between the coils of the spirally wound hollow body. However, the tube does not need to be made of different parts. For example, an elongated hollow body formed by a single material (e.g., extruded) can be spirally wound to form an elongated tube. The elongated hollow body itself can have a thin-walled portion and a relatively thick or harder reinforcement portion in cross section. The tube can be part of a variety of medical circuits or can be used for other medical purposes.

Description

[0001] This divisional application is a divisional application based on the invention patent application with Chinese invention patent application number 201710063274.9 (parent case original application number 201280038062.0), invention name “Medical Tube and Manufacturing Method” and application date May 30, 2012. Technical Field

[0002] The present disclosure relates generally to tubing suitable for medical use, and in particular to tubing suitable for use in medical circuits suitable for providing gas to and / or removing gas from a patient, such as for use in positive airway pressure (PAP), breathing masks, anesthesia, ventilators, and insufflation systems. Background Art

[0003] In a medical circuit, different components transmit warm and / or humid 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 heater-humidifier through an inhalation tube. As another example, a tube can deliver humidified gas (usually CO2) to the abdominal cavity in an insufflation circuit. This can help prevent "drying" of the patient's internal organs and can reduce the amount of time required to recover from surgery. Unheated pipes allow significant heat losses to become natural cooling. This cooling can cause unnecessary condensation or a "rain wash effect" to form along the length of the pipe that transmits warm, humid air. There is still a need for pipes that can isolate heat losses in medical circuits and improve temperature and / or humidity control. Summary of the invention

[0004] Medical tubes and methods for making medical tubes are disclosed herein in different embodiments. In some embodiments, the tube can be a composite structure that is formed by spirally winding two or more different parts to form an elongated tube. For example, one of the parts can be an elongated hollow body that is spirally wound, and the other part can be an elongated structural part that is also spirally wound between the coils of the spirally wound hollow body. In other embodiments, the tube does not need to be made of different parts. For example, an elongated hollow body formed of a single material (such as extrusion) can be spirally wound to form an elongated tube. The elongated hollow body itself can have a thin-walled portion and a relatively thick or harder reinforcement portion in a cross section. These tubes can become part of a variety of medical circuits or can be used for other medical purposes.

[0005] In at least one embodiment, a composite tube may include a first elongated member including a hollow body that is helically wound to at least partially form an elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall surrounding the lumen. A second elongated member that may be helically wound and connected 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 designations "first elongated member" and "second elongated member" do not necessarily indicate an order, such as an order in which the components are assembled. As described herein, the first elongated member and the second elongated member may also be portions of a single tubular element.

[0006] In various embodiments, the aforementioned components have one, some, or all of the following characteristics, as well as those described elsewhere in this disclosure.

[0007] The first elongated member can be a tube. The first elongated member can form a plurality of bubbles in a longitudinal section, and these bubbles have a flat surface on the cavity. Adjacent bubbles can be separated by a gap above the second elongated member, or will not be directly connected to each other. These bubbles can have perforations. The second elongated member can have a longitudinal section, which is wider on the proximal side of the cavity and narrower at the radially distant end of the cavity. Specifically, the second elongated member can have a longitudinal section, which is generally triangular, generally T-shaped or generally Y-shaped. One or more conductive wires can be embedded or encapsulated in the second elongated member. This or these conductive wires can be heating wires (or more specifically, resistive heating wires) and / or sensing wires. The tube can include multiple pairs of conductive wires, such as two or four conductive wires. Multiple pairs of conductive wires can form a connecting ring at one end of the composite tube. This or these conductive wires can be spaced apart from the cavity wall. In at least one embodiment, the second elongated member can have a generally triangular, generally T-shaped, or generally Y-shaped longitudinal cross-section, and one or more conductive filaments can be embedded or encapsulated in the second elongated member on opposite sides of the triangle, T-shape, or Y-shape.

[0008] In other applications, according to any or all of the aforementioned embodiments, the aforementioned components may become part of a medical circuit component, an inhalation tube, an exhalation tube, a PAP component, an insufflation circuit, a detection component, or a surgical component.

[0009] A method for making a composite tube is also disclosed. The resulting tube may have one, some, or all of the characteristics described above or described elsewhere in this disclosure. In at least one embodiment, the method includes providing a first elongated member, the 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 spirally wrapped around a mandrel, and the opposite side edge portions of the second elongated member are spaced apart on adjacent wraps, thereby forming a second elongated member spiral. The first elongated member is spirally wrapped around the second elongated member spiral, so that some portions of the first elongated member overlap with adjacent wraps of the second elongated member spiral, and a portion of the first elongated member is placed adjacent to the mandrel in the space between the wraps of the second elongated member spiral, thereby forming a first elongated member spiral.

[0010] In various embodiments, the aforementioned method may include one, several, or all of the following methods. The method may include supplying air at a pressure higher 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, thereby forming a composite tube having a cavity extending along the longitudinal axis and a cavity surrounding the cavity. The method may include forming the first elongated member. The method may include forming the first elongated member by extrusion with a first extruder. The method may include forming the second elongated member. The method may include forming the second elongated member by extrusion with a second extruder. The second extruder may be configured to encapsulate one or more conductive filaments in the second elongated member. The step of forming the second elongated member may include embedding conductive filaments in the second elongated member. The conductive filaments may be non-reactive with the second elongated member. The conductive filaments may include alloys of aluminum or copper or other conductive materials. The method may include forming a connecting ring of multiple pairs of conductive filaments at one end of the composite tube. The first extruder may be different from the second extruder.

[0011] A medical tube is also disclosed. In at least one embodiment, the tube includes an elongated hollow body that is helically wound to form an elongated tube having a longitudinal axis, a lumen extending along the longitudinal axis, and a hollow wall surrounding the lumen, wherein the elongated hollow body has a wall in cross section that defines at least a portion of the hollow body. The tube may further include a reinforcing portion that extends along the length of the elongated hollow body, the reinforcing portion being helically positioned between adjacent coils 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 stiffer than the wall of the elongated hollow body.

[0012] In various embodiments, the aforementioned tube has one, several or all of the following characteristics, as well as the characteristics described elsewhere in this disclosure. The reinforcing portion may be formed by the same piece of material that forms the elongated hollow body. The cross section of the elongated hollow body may include two reinforcing portions located on opposite sides of the elongated hollow body, wherein the spiral winding of the elongated hollow body is interconnected with adjacent reinforcing portions, so that the opposite edges of the reinforcing portion are in contact with the adjacent spiral coils of the elongated hollow body. The opposite side edges of the reinforcing portion may overlap with the adjacent spiral coils of the elongated hollow body. The reinforcing portion may be made of a piece of material separated from the material from which the elongated hollow body is made. The hollow body may form a plurality of bubbles in a longitudinal cross section, and the bubbles have a flat surface on the cavity. These bubbles may have perforations. The medical tube may also include one or more conductive wires embedded or encapsulated in the reinforcing portion. The conductive wire may be a heating wire and / or a sensing wire. The medical tube may include two conductive wires, one of which is embedded or encapsulated in each reinforcing portion. The medical tube may include two conductive wires positioned only on one side of the elongated hollow body. Pairs of conductive wires may form a connecting ring at one end of the elongated tube. The wire or wires may be spaced apart from the cavity wall.

[0013] In other applications, according to any or all of the aforementioned embodiments, the aforementioned tube may become part of a medical circuit component, an inhalation tube, an exhalation tube, a PAP component, an insufflation circuit, a detection component, or a surgical component.

[0014] A method of making a medical tube is also disclosed. In at least one embodiment, the method includes helically winding an elongated hollow body around a mandrel to form an elongated tube having a longitudinal axis, a cavity extending along the longitudinal axis, and a hollow wall surrounding the cavity, wherein the elongated hollow body has a wall in cross section that defines at least a portion of the hollow body, and two reinforcing portions located on opposite sides of the elongated body, the two reinforcing portions forming a portion of the wall of the cavity, the two reinforcing portions being relatively thicker or stiffer than the wall defining at least a portion of the hollow body. The method further includes interconnecting adjacent reinforcing portions such that opposing edges of the reinforcing portions contact adjacent turns of the elongated hollow body.

[0015] In various embodiments, the foregoing method may include one, several, or all of the following features or other features described elsewhere in this disclosure. Connecting adjacent reinforcement portions to each other may allow the edges of the reinforcement portions to overlap. The method may further include supplying air at a pressure higher than atmospheric pressure to one end of the elongated hollow body. The method may further include cooling the elongated hollow body so that adjacent reinforcement portions are connected to each other. The method may further include extruding to form the elongated hollow body. The method may further include embedding conductive filaments into the reinforcement portions. The method may further include forming a connecting ring of multiple pairs of conductive filaments at one end of the elongated tube.

[0016] For the purpose of summarizing 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 in accordance with any particular embodiment of the present invention. Therefore, the present invention may be embodied or implemented in a manner that achieves or optimizes one advantage or group of advantages taught herein without necessarily achieving other advantages that may be taught or suggested herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Now, according to the drawings, example embodiments that implement the various features of the disclosed systems and methods will be described. The drawings and the related descriptions are provided to illustrate the embodiments and not to limit the scope of the present disclosure.

[0018] Figure 1 A schematic diagram of a medical circuit incorporating one or more medical tubes is shown.

[0019] Figure 2A A side plan view showing a cross section of an example composite tube.

[0020] Figure 2B Shows similarity to Figure 2A Example of a composite tube. A longitudinal cross-sectional view of the top portion of one tube.

[0021] Figure 2C Another longitudinal cross-section illustrating a first elongated member in the composite tube is shown.

[0022] Figure 2D Another longitudinal cross section of the top portion of a tube is shown.

[0023] Figure 2E Another longitudinal cross section of the top portion of a tube is shown.

[0024] Figure 3A A cross section of a second elongate member in the composite tube is shown.

[0025] Figure 3B Another cross-section of a second elongate member is shown.

[0026] Figure 3C Another example second elongate member is shown.

[0027] Figure 3D Another example second elongate member is shown.

[0028] Figure 3E Another example second elongate member is shown.

[0029] Figure 3F Another example second elongate member is shown.

[0030] Figure 3G Another example second elongate member is shown.

[0031] Figure 4A An aspect of a method for forming the composite tube is shown.

[0032] Figure 4B A helically wound second elongate member is shown.

[0033] Figure 4C Another aspect of the method for forming the composite tube is shown.

[0034] Figure 4D Another aspect of the method for forming the composite tube is shown.

[0035] Figure 4E Another aspect of the method for forming the composite tube is shown.

[0036] Figure 4F Another aspect of the method for forming the composite tube is shown.

[0037] Figure 5A-5B Another example illustrating a single elongated hollow body that is helically wound to form a medical tube is shown.

[0038] Figures 5C-5F Other examples of single elongated hollow bodies that are helically wound to form medical tubing are shown.

[0039] Figure 6 An example medical circuit is shown in accordance with at least one embodiment.

[0040] Figure 7 An insufflation system according to at least one embodiment is shown.

[0041] Figure 8 is a schematic diagram of a coaxial tube according to one embodiment.

[0042] Fig.9A -C shows examples of shapes of the first elongated member that are configured to improve thermal efficiency.

[0043] Fig.9D -F shows an example of filament arrangements configured to improve thermal efficiency.

[0044] Fig. 10A -C shows an example of a first elongate member stack.

[0045] Fig.11A -D shows the curvature radius characteristics of the tube according to various embodiments.

[0046] Throughout the accompanying drawings, reference numbers are repeated to indicate consistency between referenced (or similar) elements. In addition, the first digit of each reference number indicates the figure in which the element first appears. DETAILED DESCRIPTION

[0047] The following describes, with reference to the accompanying drawings, details of several illustrative embodiments for implementing the apparatus and methods described herein. The present invention is not limited to these described embodiments.

[0048] A breathing circuit comprising one or more medical tubes

[0049] 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 usual and customary meaning to those of ordinary skill in the art (i.e., not limited to a special or customized meaning) and includes but is not limited to non-cylindrical passages. Certain embodiments may incorporate a composite tube, which may be generally defined as a tube comprising two or more parts, or specifically, in certain embodiments, comprising two or more components, as described in more detail below. Such a breathing circuit may be a continuous, variable, or dual-layer positive airway pressure (PAP) system or other form of respiratory therapy.

[0050] Gas can be Figure 1The dry gas is transmitted in a loop. The dry gas is transferred 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 moist gas) of the suction tube 103 via the port 111, thereby supplying moist gas to the suction tube 103. The suction tube is a tube configured to deliver respiratory gas to the patient, and can be made of a composite tube, which will be further described below. The gas flows through the suction tube 103, flows to the outlet 113 (the end for discharging moist gas), and then flows to the patient 101 through a patient interface 115 connected to the outlet 113.

[0051] The exhalation tube 117 is also connected to the patient interface 115. The exhalation tube is configured to allow the exhaled humidified gas to leave the patient. Here, the exhalation tube 117 returns the exhaled humidified gas from the patient interface 115 to the ventilator / blower 105.

[0052] In this example, the drying 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. In particular, the functions of the electronic controller 123 can be controlled by the electronic main controller 125, which responds to inputs from the main controller 125 and user-set predetermined desired values ​​(preset values) for pressure or fan speed through the dial 127.

[0053] The humidifier 107 includes a humidification chamber 129, which contains a certain amount of water 130 or other suitable humidification liquid. Preferably, after use, the humidification chamber 129 is removable from the humidifier 107. Removability can make the humidification chamber 129 easier to disinfect or place. However, the humidification chamber 129 portion of the humidifier 107 can be an integrated structure. The body of the humidification chamber 129 can be formed by a non-conductive glass or plastic material. But the humidification chamber 129 can also include conductive components. For example, the humidification chamber 129 can include a high thermal conductivity base (e.g., an aluminum base) that is in contact with or associated with a heating plate 131 on the humidifier 107.

[0054] The humidifier 107 may also include 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. For example, in response to input of a user-set humidity or temperature value via a user interface 133, as well as other inputs, the main controller 125 determines when (or to what level) to activate the heating plate 131 to heat the water 130 in the humidification chamber 129.

[0055] Any suitable patient interface 115 may be incorporated. Patient interface is a broad term and will be given its usual and customary meaning (i.e., not limited to a special or customary meaning) for those of ordinary skill in the art, and includes, but is not limited to, masks (e.g., tracheal masks, facial masks, and nasal masks), cannulas, and nasal pillows. A temperature probe 135 may be connected to the suction tube 103 near the patient interface 115, or to the patient interface 115. The temperature probe 135 detects the temperature near or on the patient interface 115. A heating wire (not shown) associated with the temperature probe may be used to adjust the temperature of the patient interface 115 and / or the suction tube 103 to increase the temperature of the suction tube 103 and / or the patient interface 115 to above the saturation temperature, thereby reducing the chance of unwanted condensation.

[0056] exist Figure 1 In the embodiment of the present invention, the exhaled moist gas is returned from the patient interface 115 to the ventilator / blower 105 via the exhalation tube 117. The exhalation tube 117 can also be a composite tube, which is described in more detail below. However, the exhalation tube 117 can also be a medical tube as previously known in the art. In either case, the exhalation tube 117 can have a temperature probe and / or a heating wire, as described above with respect to the inhalation tube 103, in combination with it to reduce the chance of condensation. In addition, the exhalation tube 117 does not need to return the exhaled gas to the ventilator / blower 105. Alternatively, the exhaled moist gas can be directly transferred to the surrounding environment or to auxiliary equipment, such as an air scrubber / filter (not shown). In some embodiments, the exhalation tube is omitted entirely.

[0057] Composite pipe

[0058] Figure 2A A side plan view showing a cross section of an example composite tube 201. In summary, composite tube 201 includes a first elongated member 203 and a second elongated member 205. Member is a broad term and is given its usual and customary meaning to those of ordinary skill in the art (i.e., not limited to a specific or customary meaning) and includes, but is not limited to, an integral part, an integral component, and a distinct component. Thus, although Figure 2A An embodiment consisting of two different components is described, and it should be understood that in other embodiments (for example, in the following Figures 5A-5D ), the first elongated member 203 and the second elongated member 205 can also represent areas formed by a single material in the tube. Therefore, the first elongated member 203 can represent the hollow portion of the tube, while the second elongated member 205 represents the structural support or reinforcement portion of the tube that can add structural support in the hollow portion. The hollow portion and the structural support portion can have a spiral configuration, as described herein. The composite tube 201 can be used to form the inhalation tube 103 and / or the exhalation tube 117 as described above, or a coaxial tube as described below, or any other tube as described elsewhere in this disclosure.

[0059] In this example, the first elongated member 203 includes a spirally wound hollow body that is used to at least partially form an elongated tube having a longitudinal axis LA-LA and a cavity 207 extending along the longitudinal axis LA-LA. In at least one embodiment, the first elongated member 203 is a tube. Preferably, the first elongated member 203 is flexible. In addition, the first elongated member 203 is preferably transparent, or at least translucent or semi-opaque. Optical transparency enables a caregiver or user to check for blockage or contamination of the cavity 207, or to confirm the presence of moisture. A variety of plastics, including medical grade plastics, are suitable for the body of the first elongated member 203. Examples of suitable materials include polyolefin elastomers, polyether block amides, thermoplastic copolyester elastomers, EPDM-polypropylene blends, and thermoplastic polyurethanes.

[0060] The hollow body structure of the first elongated member 203 provides insulation to the composite tube 201. As explained above, an insulated tube prevents heat loss, so an insulated tube 201 is desirable. In this way, the tube 201 can deliver gas from the heater-humidifier to the patient while maintaining the conditioned state of the gas with minimal energy consumption.

[0061] In at least one embodiment, the hollow portion of the first elongated member 203 is filled with gas. The gas may be air, which has a low thermal conductivity (2.62×10 -2 W / m·K at 300K) and is very low cost, so air is sufficient. It is also advantageous to use a gas that is more viscous than air, because the higher viscosity reduces convective heat transfer. Thus, for example, argon (17.72×10 -3 W / m·K, 300K), krypton (9.43×10 -3 W / m·K, 300K) and xenon (5.65×10 -3W / m·K, 300K) can increase the insulating properties. Among these gases, each gas is non-toxic, chemically inert, flame retardant, and commercially available. The hollow portion of the first elongated member 203 can be sealed at both ends of the tube so that the gas therein does not flow substantially. Alternatively, the hollow portion can be a secondary pneumatic connection, such as a pressure sampling tube for transmitting feedback from the patient end of the tube to the controller. The first elongated member 203 can optionally be perforated. For example, the surface of the first elongated member 203 can be perforated on the outward surface, opposite to the cavity 207. In another embodiment, the hollow portion of the first elongated member 203 is filled with a liquid. Examples of liquids can include water or other biocompatible liquids with high heat capacity. For example, nanofluids can be used. Example nanofluids with suitable heat capacity include water and nanoparticles of some substances (e.g., aluminum).

[0062] The second elongate member 205 is also helically wound and connected to the first elongate member 203 between adjacent coils of the first elongate member 203. The second elongate member 205 forms at least a portion of the lumen 207 of the elongate tube. The second elongate member 205 acts as a structural support to the first elongate member 203.

[0063] In at least one embodiment, the second elongated member 205 is wider at the bottom (adjacent to the cavity 207) and narrower at the top. For example, the second elongated member can be 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.

[0064] Preferably, the second elongated member 205 is flexible, which facilitates bending of the tube. It is desirable that the flexibility of the second elongated member 205 is less than the flexibility of the first elongated member 203. This improves the ability of the second elongated member 205 to provide structural support to the first elongated member 203. For example, the modulus of the second elongated member 205 is preferably 30-50 MPa (or about 30-50 MPa). The modulus of the first elongated member 203 is less than the modulus of the second elongated member 205. The first elongated member 205 can be solid or primarily solid. In addition, the second elongated member 205 can encapsulate or contain conductive materials, such as wires, and specifically heating wires or sensors (not shown). Heating wires can minimize cold surfaces on which humid air can form condensation. Heating wires can also be used to change the temperature profile of the gas in the cavity 207 of the composite tube 201. A variety of plastics, including medical grade plastics, are suitable for the body of the second elongated member 205. Examples of suitable materials include polyolefin elastomers, polyether block amides, thermoplastic copolyester elastomers, EPDM-polypropylene blends, and thermoplastic polyurethanes. In some 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 can be made of an opaque blue (or other color) plastic.

[0065] This spirally wound structure, which includes a flexible hollow body and an integral support, can provide crush resistance while allowing the tube wall to be flexible enough to allow these short radius bends without kinking, occlusion or collapse. Preferably, the tube can be bent around a metal cylinder with a diameter of 25 mm without kinking, occlusion or collapse, as defined in the test for resistance to rheological increase during bending in accordance with ISO 5367:2000 (E). This structure can also provide a smooth cavity 207 surface (tube hole), which helps to keep the tube free of sediment and improve airflow. It has been found that the hollow body improves the insulation of the tube while allowing the tube to remain light weight.

[0066] As explained above, the composite tube 201 can be used as an exhalation tube and / or an inhalation tube in a breathing circuit, or as a part of a breathing circuit. Preferably, the composite tube 201 is used at least as an inhalation tube.

[0067] Figure 2B Shows Figure 2A A longitudinal cross-sectional view of a top portion of an example composite tube 201. Figure 2B With Figure 2ASame orientation. This example further illustrates the hollow body shape of the first elongated member 203. As seen in this example, the first elongated member 203 forms a plurality of hollow bubbles in a longitudinal cross section. Portions 209 of the first elongated member 203 overlap with adjacent wraps of the second elongated member 205. Portions 211 of the first elongated member 203 form the wall (pore) of the cavity.

[0068] It was found that having gaps 213 between adjacent coils of the first elongated member 203 (i.e., between adjacent bubbles) unexpectedly improved the overall insulation of the composite tube 201. Therefore, in certain embodiments, adjacent bubbles are separated by gaps 213. In addition, certain embodiments include providing gaps 213 between adjacent bubbles to increase the heat transfer resistance (R value) and correspondingly reduce the thermal conductivity of the composite tube 201. It was also found that the configuration of this gap can improve the flexibility of the composite tube 201 by forming a bend with a shorter radius. As shown in FIG. Figure 2B As shown in , T-shaped second elongated member 205 can help maintain gap 213 between adjacent bubbles. Nevertheless, in some embodiments, adjacent bubbles are in contact. For example, adjacent bubbles can be bonded together.

[0069] One or more conductive materials may be placed in the second elongated member 205 for heating or sensing the airflow. In this example, two heating wires 215 are encapsulated in the second elongated member 205, one on each side of the vertical portion of the "T" shape. The heating wires 215 include a conductive material, such as an alloy of aluminum (Al) and / or copper (Cu), or a conductive polymer. Preferably, the material selected to form the second elongated member 205 is non-reactive with the metal in the heating wire 215 when the heating wire 215 reaches its operating temperature. The wires 215 can be spaced apart from the cavity 207 so that the wires are not exposed to the cavity 207. At one end of the composite tube, multiple pairs of conductive wires can form a connecting ring.

[0070] In at least one embodiment, multiple wires are placed in the second elongated member 205. These wires can be electrically connected together to share a common rail. For example, a first wire (e.g., a heating wire) can be placed on a first side of the second elongated member 205. A second wire (e.g., a sensing wire) can be placed on a second side of the second elongated member 205. A third wire (e.g., a grounding wire) can be placed between the first wire and the second wire. The first wire, the second wire, and / or the third wire can be connected together at one end of the second elongated member 205.

[0071] Figure 2C Shows Figure 2B217. As shown, a portion 209 of the first elongated member 203 overlaps an adjacent coating of the second elongated member 205, characterized by the extent of a bonding area 217. A larger bonding area improves the resistance of the tubes to delamination at the interface of the first and second elongated members. Additionally or alternatively, the shape of the bead and / or bubble can be adjusted to increase the bonding area 217. For example, Figure 2D A relatively small binding area on the left hand side is shown. Fig. 9B A smaller binding zone is also shown. In contrast, due to the size and shape of the beads, Figure 2E Has a binding area much larger than Figure 2D The binding region shown in . Fig.9A and 9C A larger binding region is also illustrated. Each of the figures will be discussed in more detail below. It should be understood that although Figure 2E , 9A , and 9C may be preferred in some embodiments, but including Figure 2D , 9B Other configurations and other variations may also need to be used in other embodiments.

[0072] Figure 2D A longitudinal cross-section of the top portion of another composite tube is shown. Figure 2D With Figure 2B This example further illustrates the hollow body shape of the first elongated member 203 and shows how the first elongated member 203 forms a plurality of hollow bubbles in a 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.

[0073] Figure 2E A longitudinal cross-section of the top portion of another composite tube is shown. Figure 2E With Figure 2B Same orientation. Figure 2B Compared with the silk 215 in Figure 2E In the example of the embodiment, the heating wires 215 are spaced farther apart from each other. It has been found that increasing the space between the heating wires can improve the heating efficiency, and certain embodiments include this implementation. The heating efficiency refers to the ratio of the heat input to the tube to the energy output or recoverable from the tube. In general, the more energy (or heat) dissipated from the tube, the lower the heating efficiency. In order to improve the heating performance, the heating wires 215 can be spaced equidistantly (or approximately equidistantly) along the hole of the tube. Alternatively, the wire 215 can be positioned at the end of the second elongated member 205, which can provide simpler manufacturing.

[0074] Next reference Figures 3A to 3G , these figures show example configurations for the second elongated member 205. Figure 3A A cross-sectional view of a second elongated member 205 is shown, the second elongated member 205 having a shape similar to Figure 2B In this example embodiment, the second elongated member 205 does not have a heating wire. Other shapes of the second elongated member 205 can also be used, including variations of the T-shape as described below and triangular shapes.

[0075] Figure 3B Another example of a second elongated member 205 having a T-shaped cross-section is shown. In this example, a heating wire 215 is embedded in a cutout 301 of the second elongated member 205 on either side of the vertical portion of the "T". In some embodiments, the cutout 301 can be formed in the second elongated member 205 during the extrusion process. Alternatively, the cutout 301 can be formed in the second elongated member 205 after the extrusion process. For example, a cutting tool can form the cutout in the second elongated member 205. Preferably, the heating wire 215 forms the cutout when it is pressed or pulled into (mechanically fixed) the second elongated member 205 shortly after the extrusion process. Alternatively, one or more heating wires can be mounted (e.g., adhered, bonded, or partially embedded) at the bottom of the elongated member so that the one or more wires are exposed to the lumen. In these embodiments, it is desirable to include the one or more wires in insulation to reduce the risk of fire when a flammable gas (e.g., oxygen) passes through the lumen.

[0076] Figure 3C Another example of a second elongated member 205 is shown in cross-section. The second elongated member 205 has a generally triangular shape. In this example, the heating wire 215 is embedded on opposite sides of the triangle.

[0077] Figure 3D Another example of the second elongated member 205 is shown in cross-sectional view. The second elongated member 205 includes four grooves 303. Groove 303 is a dent or groove in the cross-sectional profile. In certain embodiments, groove 303 can facilitate the formation of the incision (not shown) for embedding a silk (not shown). In certain embodiments, groove 303 promotes the positioning of silk (not shown), which is pressed or pulled in, and thus embedded in the second elongated member 205. In this example, four initial grooves 303 facilitate the placement of up to four silks, such as four heating wires, four sensing wires, two heating wires and two sensing wires, three heating wires and a sensing wire or a heating wire and three sensing wires. In certain embodiments, the heating wire can be located at the outside of the second elongated member 205. Sensing wire can be located inside.

[0078] Figure 3EAnother example of a second elongated member 205 is shown in cross-section. The second elongated member 205 has a T-shaped profile and a plurality of grooves 303 for placing the heating wires.

[0079] Figure 3F Another example of the second elongated member 205 is shown in a cross-sectional view. Four filaments 215 are enclosed in the second elongated member 205, two filaments on each side of the vertical portion of the "T" shape. As explained in more detail below, because the second elongated member 205 is extruded around these filaments, these filaments are enclosed in the second elongated member 205. No cut is formed to embed the heating filaments 215. In this example, the second elongated member 205 also includes a plurality of grooves 303. Because the heating filaments 215 are enclosed in the second elongated member 205, the grooves 303 do not facilitate the formation of the cuts for embedding the heating filaments. In this example, the grooves 303 can facilitate the separation of the embedded heating filaments, which makes it easier for the individual cores to be stripped, for example when the heating filaments are released.

[0080] Figure 3G Another example of a 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 3C , but four filaments 215 are enclosed in the second elongated member 205, all of which are centered on the bottom edge of the second elongated member 205 and are positioned along a generally horizontal axis.

[0081] As explained above, it is desirable to increase the distance between the filaments to improve heating efficiency. However, in some embodiments, when the heating filaments 215 are incorporated into the composite tube 201, the filaments 215 can be relatively centrally located in the second elongated member 205. Centralized positioning promotes robustness of the reused composite tubing, in part because such positioning reduces the likelihood of filament breakage during repeated bending of the composite tube 201. Because the filaments 215 are encased in an insulating layer and removed from the gas path, the centralization of the filaments 215 can also reduce the risk of fire hazards.

[0082] As explained above, some examples illustrate suitable placement of the wire 215 in the second elongated member 205. In the above examples including more than one wire 215, these wires 215 are generally aligned along the horizontal axis. Alternative configurations are also suitable. For example, two wires can be aligned along the vertical axis or along the diagonal axis. Four wires can be aligned along the vertical axis or along the diagonal axis. Four wires can be aligned in a cross configuration, with one wire placed at the top of the second elongated member, one wire placed at the bottom of the second elongated member (near the lumen), and two wires placed on the opposite arms of the "T" shape, "Y" shape, or triangular bottom.

[0083] Tables 1A and 1B show some preferred specifications of the medical tubes described herein, and some preferred ranges of these specifications. These specifications refer to the cross-section of the tube. In these tables, the cavity diameter represents the inner diameter of the tube. The spacing represents the distance between two repeated points measured axially along the tube, i.e., the distance between the tips of the vertical parts of the adjacent "T" shapes of the second elongated member. The bubble width represents the width (maximum outer diameter) of the bubble. The bubble height represents the height of the bubble from the lumen. The bead height represents the maximum height of the second elongated member from the lumen (i.e., the height of the vertical part of the "T"). The bead width represents the maximum width of the second elongated member (e.g., the width of the horizontal part of the "T"). The bubble thickness represents the thickness of the bubble wall.

[0084] Table 1A

[0085]

[0086] Table 1B

[0087]

[0088] Tables 2A and 2B provide example ratios between specifications of tube features for the tubes described in Tables 1A and 1B, respectively.

[0089] Table 2A

[0090] ratio baby aldult Cavity diameter: spacing 2.3:1 2.4:1 Spacing: Bubble Width 1.1:1 1.1:1 Spacing: Bead width 2.2:1 3.1:1 Bubble width: bead width 2.0:1 2.9:1 Cavity diameter: Bubble height 3.9:1 5.1:1 Cavity diameter: bead height 12.2:1 12.0:1 Bubble height: bead height 3.1:1 2.3:1 Cavity diameter: bubble thickness 27.5:1 90.0:1

[0091] Table 2B

[0092] ratio baby aldult Cavity diameter: spacing 2.3:1 2.4:1 Spacing: Bubble Width 1.1:1 1.1:1 Spacing: Bead width 2.2:1 2.2:1 Bubble width: bead width 2.0:1 2.1:1 Cavity diameter: Bubble height 3.9:1 4.5:1 Cavity diameter: bead height 12.2:1 10.6:1 Bubble height: bead height 3.1:1 2.4:1 Cavity diameter: bubble thickness 27.5:1 90.0:1

[0093] The following tables show some example properties of a composite tube (labeled "A"), described herein, having a heating wire integrated into the inside of the second elongated member. For comparison, the properties of a Fisher & Paykel model RT100 disposable bellows (labeled "B") having a heating wire helically wound inside the tube bore are also described.

[0094] The resistance to flow (RTF) was measured according to Annex A of ISO 5367:2000(E). The results are summarized in Table 3. As can be seen below, the RTF of the composite pipe is lower than the RTF of the model RT100 pipe.

[0095] Table 3

[0096]

[0097] The condensed water or "rainfall" in the tube refers to the weight of condensate collected each day at a gas flow rate of 20 L / min and a room temperature of 18°C. Humid air was continuously passed through the tube from a cavity. The tube weight was recorded before and after each day of testing. The tube was dried between each test, and three consecutive tests were performed with the dried tube. The results are shown in Table 4 below. The results show that the rainfall in the composite tube was significantly lower than the rainfall in the model RT100 tube.

[0098] Table 4

[0099]

[0100] The power requirement is the power consumed during the condensation test. In this test, the ambient air is maintained at 18°C. The humidified chamber (see e.g. Figure 1 The humidification chamber 129 in the tube is powered by the MR850 heater base. The heating wire in the tube is independently powered by a DC power supply. Different flow rates are set, and the chamber is maintained at 37°C at the chamber output. Then, the DC voltage of the loop is changed to produce a temperature of 40°C at the loop output. The voltage required to maintain the output temperature is recorded, and the power generated is calculated. The results are shown in Table 5. The results show that the composite tube A uses significantly more power than tube B. This is because tube B uses a spiral heating wire in the tube hole to heat the gas from 37°C to 40°C. The composite tube does not tend to heat the gas faster because the heating wire is in the tube wall (embedded in the second elongated member). On the contrary, the composite tube is designed to maintain the gas temperature and prevent rain washing by maintaining the tube hole temperature at a temperature higher than the dew point of the humid gas.

[0101] Table 5

[0102] 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

[0103] The flexibility of the tubes was tested by using a three-point bend test. The tubes were placed in a three-point bend test fixture and used with an Instron 5560 test system instrument to measure load and stretch. Each tube sample was tested three times and the stretch of the tube under the applied load was measured to obtain an average relative stiffness constant. The average stiffness constants for tube A and tube B are reproduced in Table 6.

[0104] Table 6

[0105] Tube Stiffness(N / mm) A 0.028 B 0.088

[0106] Manufacturing method

[0107] Next reference Figures 4A to 4F , these figures illustrate example methods for making composite tubes.

[0108] First turn Figure 4A In at least one embodiment, the method of making a composite tube includes providing a second elongated member 205, and helically wrapping the second elongated member 205 around a mandrel 401 with opposing side edge portions 403 of the second elongated member 205 spaced apart on adjacent wraps, thereby forming a second elongated member spiral 405. 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.

[0109] In at least one embodiment, the method further includes forming the second elongated member 205. Extrusion is a suitable method for forming the second elongated member 205. The second extruder can be configured to extrude the second elongated member 205 at a specified bead height. In at least one embodiment, the method further includes extruding the second elongated member 205.

[0110] like Figure 4B As shown in , extrusion can be advantageous because extrusion can cause the heating filament 215 to be encapsulated in the second elongated member 205 when the second elongated member 205 is formed (using an extruder with a cross-head extrusion die). Therefore, in certain embodiments, the method includes providing one or more heating filaments 215, and encapsulating the heating filaments 215 to form the second elongated member 205. The method can also include providing a second elongated member 205 having one or more heating filaments 215 embedded or encapsulated in the second elongated member 205.

[0111] In at least one embodiment, the method includes embedding one or more heating wires 215 into the second elongated member 205. For example, Figure 4C As shown, the wire 215 can be pressed (pulled in or mechanically positioned) into the second elongated member 205 to a specified depth. Alternatively, cuts can be made in the second elongated member 205 to a specified depth, and the wire 215 can be placed into these cuts. Preferably, the punching or cutting is completed a short time after the second elongated member 205 is extruded and the second elongated member 205 becomes soft.

[0112] like Figure 4D and 4E As shown in, in at least one embodiment, the method includes providing a first elongated member 203, and spirally wrapping the first elongated member 203 around a second elongated member spiral 405, so that a portion of the first elongated member 203 overlaps with an adjacent wrapping of the second elongated member spiral 405, and a portion of the first elongated member 203 is placed adjacent to the core shaft 401, in the space between the wrappings of the second elongated member spiral 405, thereby forming a first elongated member spiral 407. Figure 4DAn example method is shown in which a heating filament 215 is encapsulated within the second elongate member 205 prior to forming the second elongate member helix. Figure 4E An example method is shown in which a heating filament 215 is embedded in the second elongated member 205 as the second elongated member spirals. An alternative method of incorporating the heating filament 215 into the composite tube includes encapsulating one or more filaments 215 between the first elongated member 203 and the second elongated member 205 in the area where the first elongated member 203 and the second elongated member 205 overlap.

[0113] Compared with the alternative scheme of having a heating wire in the gas passage, the above-mentioned alternative scheme for incorporating one or more heating wires 215 into the composite tube has advantages. Because the wire heats the tube wall where condensation is most likely to form, having one or more heating wires 215 outside the gas passage improves performance, and this configuration reduces the risk of fire in a high oxygen environment due to moving the heating wire out of the gas passage. Since this feature reduces the efficiency of the heating wire to heating the gas passing through the tube, it also reduces performance. Nevertheless, in some embodiments, the composite tube 201 includes one or more heating wires 215 placed in the gas passage. For example, the heating wire can be placed in the cavity wall (tube hole), such as in a spiral configuration. The example method for placing one or more heating wires 215 on the cavity wall includes combining, embedding, or otherwise forming the heating wire on the surface of the second elongated member 205 so that the cavity wall is formed when assembled. Therefore, in some embodiments, the method includes placing one or more heating wires 215 on the cavity wall.

[0114] Regardless of whether the heating wire 215 is embedded or encapsulated in or placed on the second elongated member 205, or otherwise placed in or on the tube, in at least one embodiment, multiple pairs of wires can form a connecting ring at one end of the composite tube to form a loop.

[0115] Figure 4F Shows Figure 4E 4 shows a longitudinal cross-sectional view of an assembly shown in FIG, with emphasis on the top portion of the mandrel 401 and the top portions of the first elongated member spiral 407 and the second elongated member spiral 405. This example shows the second elongated member spiral 405 having a T-shaped second elongated member 205. As the second elongated member is formed, the heating wire 215 is embedded in the second elongated member 205. Figure 4F The right side of shows the bubble-shaped profile of the first elongated member spiral, as described above.

[0116] The method also includes forming the first elongated member 203. Extrusion is a suitable method for forming the first elongated member 203. Therefore, in at least one embodiment, the method includes extruding the first elongated member 203. The first elongated member 203 can also be manufactured by extruding two or more parts and connecting them to form a single part. As another alternative, the first elongated member 203 can also be manufactured by extruding a segment that can form a hollow shape when forming or bonding is performed immediately after the spiral tube forming process.

[0117] The method may also include supplying a gas at a pressure greater than atmospheric pressure to one end of the first elongated member 203. For example, the gas may be air. Other gases may also be used, as explained above. Because the first elongated member 203 is wrapped around the mandrel 401, supplying a gas to one end of the first elongated member 203 may help maintain an open hollow body shape. The gas may be supplied before the first elongated member 203 is wrapped around the mandrel 401, while the first elongated member 203 is wrapped around the mandrel 401, or after the first elongated member 203 is wrapped around the mandrel 401. For example, as the first elongated member 203 is extruded, an extruder having an extrusion die head / tip combination may supply or convey air into the hollow cavity of the first elongated member 203. 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.

[0118] In at least one embodiment, the first elongated member 203 and the second elongated member 205 are spirally wound around the mandrel 401. For example, the first elongated member 203 and the second elongated member 205 can be sent out from the extrusion die at an elevated temperature of 200°C (or about 200°C) or higher, and then sent to the mandrel after a short distance. Preferably, the mandrel is cooled to 20°C (or about 20°C) or lower, such as a temperature close to 0°C (or about 0°C) using a water jacket, a freezer, and / or other suitable cooling methods. 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 having a nozzle surrounding the mandrel. After cooling and removing the components from the mandrel, a composite tube is formed, which has a cavity extending along the longitudinal axis and a hollow space surrounding the cavity. In such an embodiment, no adhesive or other attachment mechanism is required to connect the first and second elongated members. Other embodiments may utilize adhesives or other attachment mechanisms to bond or otherwise connect the two members. In another embodiment, the second elongated member 205 may be cooled after extrusion and placement of the heating filament to freeze the position of the heating filament. The second elongated member 205 may then be reheated as it is fed to the mandrel to improve bonding. Example methods for reheating include using a localized heating device, heated rollers, and the like.

[0119] The method may also include forming a connecting loop of multiple pairs of heating or sensing wires at one end of the composite tube. For example, the end segments of the two heating or sensing wires may be released from the second elongated member 205 and formed into a connecting loop, such as by bundling, bonding, adhering, fusing, etc. The two wires are connected together. As another example, during the manufacturing process, the end segments of the heating wires may remain free from the second elongated member 205 and then formed into a connecting loop when the composite tube is assembled.

[0120] Medical tubing and method of manufacture using a single spirally wound tube

[0121] Next reference Figures 5A to 5F, these figures show cross-sectional views of a tube 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, the single tubular element is an elongated hollow body having a relatively thin wall in cross section that partially defines a hollow portion 501, wherein two reinforcing portions 205 have a greater thickness or 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 cavity 207, so that these reinforcing portions are also helically positioned between adjacent turns of the elongated hollow body.

[0122] In at least one embodiment, the method includes forming an elongated hollow body including a first elongated member 203 and a reinforcing portion 205. Extrusion is a suitable method for forming the elongated hollow body. Suitable cross-sectional shapes for tubular elements have been shown in Figures 5A to 5F middle.

[0123] As explained above, the elongated hollow body can form a medical tube, and the above discussion 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 cooling of the hollow body after helically winding can allow adjacent coils to connect together. Figure 5B As shown in , the opposite side edge portions of the reinforcing portion 205 can be in contact on adjacent spiral coils. In other embodiments, the opposite side edge portions of the second elongated member 205 can overlap on adjacent spiral coils, such as Figure 5D and 5E The heating wire 215 may be incorporated into the second elongated member as explained above and as shown in Figures 5A to 5F For example, heating wires may be provided on opposite sides of the elongated hollow body, e.g. Figures 5A-5D Alternatively, the heating wire may be provided on only one side of the elongated hollow body, e.g. Figure 5E-5F Any of these embodiments may also incorporate the presence of a sensing filament.

[0124] Medical circuit

[0125] Next reference Figure 6 , which shows an example medical circuit according to at least one embodiment. The circuit includes one or more composite tubes as described above, namely, the suction tube 103 and / or the exhalation tube 117. The characteristics of the suction tube 103 and the exhalation tube 117 are similar to those described above with respect to Figure 1The inhalation tube 103 has an inlet 109 that communicates with the humidifier 115, and an outlet 113 through which humidified gas is provided to the patient 101. The exhalation tube 117 also has an inlet 109 that receives humidified gas from the patient's exhalation, and an outlet 113. Figure 1 As described, outlet 113 of exhalation tube 117 may discharge exhaled gases to the atmosphere, to ventilator / blower 115, to an air scrubber / filter (not shown), or to any other suitable location.

[0126] As described above, the heating wire 601 may be placed in the inhalation tube 103 and / or the exhalation tube 117 to reduce the risk of rain wash effect in the tube by maintaining the tube wall temperature above the dew point temperature.

[0127] Components of the air blowing system

[0128] Laparoscopic surgery, also known as minimally invasive surgery (MIS) or laparoscopic surgery, is a modern surgical technique in which operations in the abdomen are performed through small incisions (usually 0.5 to 1.5 cm) compared to the larger incisions required in traditional surgery. Laparoscopic surgery includes operations in the abdominal cavity or pelvic cavity. During laparoscopic surgery with insufflation, it is desirable to humidify the insufflation gas (usually CO2) before it is introduced into the abdominal cavity. This can help prevent the patient's internal organs from "drying out" and can reduce the amount of time required to recover from surgery. The insufflation system typically includes multiple humidification chambers that contain an amount of water. The humidifier typically includes a heating plate that is used to heat water to produce water vapor, which is transferred to the incoming gas to humidify the gas. The gases are transmitted out of the humidifier with water vapor.

[0129] Next reference Figure 7 , which shows an insufflation system 701 according to at least one embodiment. The insufflation system 701 includes an insufflator 703 that generates an insufflation gas flow at a pressure higher than atmospheric pressure that can be delivered into the abdominal or peritoneal cavity of a patient 705. The gas enters a humidifier 707 that includes a heater base 709 and a humidification chamber 711, wherein the chamber 711 is in contact with the heater base 709 during use, so that the heater base 709 provides heat to the chamber 711. In the humidifier 707, the insufflation gas passes through the chamber 711 to humidify the gas to an appropriate humidity level.

[0130] System 701 includes a delivery circuit 713 connected between a humidification chamber 711 and the peritoneal cavity or surgical site of a patient 705. The circuit 713 has a first end and a second end, the first end being connected to the outlet of the humidification chamber 711 and receiving humidified gas from the chamber 711. The second end of the circuit 713 is placed at the surgical site or peritoneal cavity of the patient 705, and the humidified insufflation gas is passed from the chamber 711, through the circuit 713 and into the surgical site to insufflate and expand the surgical site or peritoneal cavity. The system also includes a controller (not shown) that regulates the amount of humidity supplied to the gas by controlling the power supplied to the heater base 709. The controller is also used to monitor the water in the humidification chamber 711. The smoke evacuation system 715 is shown to be drawn out of the body cavity of the patient 705.

[0131] The smoke evacuation system 715 may be used in conjunction with the insufflation system 701 as described above or may be used in conjunction with other suitable insufflation systems. The smoke evacuation system 715 includes a discharge or exhaust branch 717, a discharge assembly 719, and a filter 721. The discharge branch 717 is connected between the filter 721 and the discharge assembly 719 and, in use, is located at or adjacent to the surgical site or peritoneal cavity of the patient 705. The discharge branch 717 is a self-supporting tube (i.e., the tube is capable of supporting its own weight without collapsing) having two open ends: a surgical site end and an outlet end.

[0132] At least one embodiment includes the implementation of the use of composite tubing as a loop 713, which can deliver humidified gas to the surgical site of the patient 705 with minimal heat loss. This can advantageously reduce the overall energy consumption of the insufflation system because less heat input is required to compensate for heat loss.

[0133] Coaxial tube

[0134] The coaxial breathing tube may also include a composite tube as described above. In the coaxial breathing tube, the first gas space is an inhalation limb or an expiratory limb, and the second gas space is the other of the inhalation limb or the expiratory limb. A gas passage is provided between the inlet of the inhalation limb and the outlet of the expiratory 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 inhalation 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 inhalation limb.

[0135] Next reference Figure 7, which shows coaxial tubes 701 according to at least one embodiment. In this example, coaxial tubes 701 are provided between a patient 701 and a ventilator 705. Exhaled gas and inhaled gas each flow in one of the spaces 709 between the inner tube 707 or the inner tube 707 and the outer tube 711. It will be understood that the outer tube 711 can be strictly aligned with the inner tube 707. Of course, "coaxial" means that one tube is inside another tube.

[0136] For heat transfer reasons, the inner tube 707 can carry the inhaled gas in the space 713 therein, while carrying the exhaled gas in the space 709 between the inner tube 707 and the outer tube 711. This gas flow configuration is indicated by the arrows. However, the opposite configuration is also possible, in which the outer tube 711 carries the inhaled gas and the inner tube 707 carries the exhaled gas.

[0137] In at least one embodiment, the inner tube 707 is formed from a corrugated tube, such as a Fisher & Paykel model RT100 disposable tube. The outer tube 711 can be formed from a composite tube, as described above.

[0138] Using coaxial tube 701, ventilator 705 may not be aware of the leak in inner tube 707. Such leak can be a short circuit in patient 701, meaning that patient 701 will not have sufficient oxygen supply. Such short circuit can be detected by placing a sensor at the patient end of coaxial tube 701. This sensor can be located in patient end connector 715. A short circuit closer to ventilator 705 will cause patient 701 to continue to re-breathe the amount of air close to patient 701. This will cause the concentration of carbon dioxide to rise in the inhalation flow space 713 close to patient 701, which can be directly detected by CO2 sensor. Such sensor can include any one of a plurality of such sensors currently commercially available. Alternatively, this re-breathing can be detected by monitoring the gas temperature of patient end connector 715, wherein the temperature rises to an indication that re-breathing has occurred when it is higher than a predetermined level.

[0139] In addition to the above reduction or elimination of the formation of condensation within the inner tube 707 or the outer tube 711, and maintaining a substantially uniform temperature in the gas flowing through the coaxial tube 701, a heater (e.g., a resistive heating wire) may be provided within the inner tube 707 or the outer tube 711, placed within the gas space 709 or 713, or within the wall of the inner tube 707 or the outer tube 711 itself.

[0140] Thermal properties

[0141] In embodiments of the composite tube 201 incorporating the heating filament 215, heat losses may occur when passing through the walls of the first elongated member 203, resulting in uneven heating. As explained above, one way to compensate 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.

[0142] Next reference Figures 9A to 9C , these figures illustrate example configurations of bubble height (ie, the interface height of the first elongated member 203 measured from the surface facing the lumen to the surface forming the largest outer diameter) for improving thermal properties.

[0143] The size of the bubble can be selected to reduce heat loss from the composite tube 201. In general, because a larger bubble height allows the first elongated member 203 to contain more insulating air, increasing the bubble height increases the effective thermal resistance of the tube 201. However, it was found that at certain bubble heights, changing air density caused convection within the tube 201, thereby increasing heat loss. Moreover, at certain bubble heights, the surface area becomes larger so that the heat loss through the surface exceeds the benefit of the increased bubble height. Certain embodiments include these implementations.

[0144] 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 an object has, the less curved the object is. For example, a plane will have a radius of curvature of ∞, and therefore the curvature is 0.

[0145] Fig.9A A longitudinal cross-section of the top portion of the composite tube is shown. Fig.9A An embodiment of a composite tube 201 is shown in which the bubble has a large height. In this example, the bubble has a smaller radius of curvature and therefore has a large curvature. Moreover, the height of the bubble is approximately three to four times greater than the height of the second elongated member 205.

[0146] Fig. 9B A longitudinal cross-section of the top portion of another composite tube is shown. Fig. 9B An embodiment of a composite tube 201 is shown in which the bubble is flat at the top. In this example, the bubble has a very large radius of curvature, but a small curvature. Moreover, the bubble has approximately the same height as the second elongated member 205.

[0147] Fig. 9C A longitudinal cross-section of the top portion of another composite tube is shown. Fig. 9C An embodiment of a composite tube is shown in which the width of the bubble is greater than the height of the bubble. In this example, the radius of curvature and the curvature of the bubble are Fig.9A and Fig. 9BThe radius of curvature is between 1 and 2, and the radius center of the upper portion is outside the bubble (such as Fig.9A The inflection points on the left and right sides of the bubble are approximately in the middle (height direction) of the bubble (as opposed to the lower part of the bubble, such as in Fig.9A Moreover, the height of the bubble is about twice the height of the second elongated member 205, resulting in a bubble height of Fig.9A and Fig. 9B between the heights.

[0148] Fig.9A The configuration is such that heat losses from the tubes are minimal. Fig. 9B The configuration makes the heat loss of the tube the highest. Fig. 9C The heat loss of the configuration is Fig.9A and 9B However, Fig.9A The large surface area and convective heat transfer in the configuration can lead to inefficient heating. Figures 9A-9C Three bubbling arrangements are determined Fig. 9C It has the best overall thermal characteristics. When the same heat energy is input into these three tubes, Fig. 9C The configuration maximizes the temperature rise along the length of the tube. For increasing the volume of insulating air, Fig. 9C The bubbles are large enough, but not large enough to cause significant convective heat loss. Fig. 9B The configuration has the worst thermal characteristics, i.e. Fig. 9B The configuration minimizes the temperature rise along the length of the tube. Fig. 9C Compared with the configuration of Fig.9A The configuration has intermediate thermal characteristics and has a smaller temperature rise.

[0149] It should be understood that although Fig. 9C A configuration of may be preferred in some embodiments, but other configurations, including Fig.9A , 9B And other variations of configurations may also be used in other embodiments.

[0150] Table 7 shows the Fig.9A , 9B and the bubble height, outer diameter of the tube, and radius of curvature for the configuration shown in 9C.

[0151] Table 7

[0152] Tube (picture) 9A 9B 9C Bubble height (mm) 3.5 5.25 1.75 Outer diameter(mm) 21.5 23.25 19.75 Curvature radius (mm) 5.4 3.3 24.3

[0153] Table 7A shows the Fig.11A , 11B And the bubble height, outer diameter and radius of curvature of another configuration shown in 11C.

[0154] Table 7A

[0155]

[0156]

[0157] It should be noted that, in general, the smaller the radius of curvature, the tighter the tube can bend about itself without the bubble collapsing or "kinking". Fig.11D A tube is shown that is bent beyond its radius of curvature (specifically, it shows Fig.11A A tube bent with a radius of curvature of 5.7 mm) is used to induce kinks in the bubble wall. Kinks can detract from the appearance of the tube and impair the thermal properties of the tube, so kinks are generally undesirable.

[0158] Therefore, in some applications, it is desirable to have a configuration with increased bending properties (e.g. Fig.9A 9B), although these configurations have 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 a good balance between thermal efficiency, flexibility, and bending performance. It should be understood that although Fig.9A and 9B A configuration of may be preferred in some embodiments, but other configurations, including Figures 11A-11D and other variations may be used in other embodiments.

[0159] Next reference Figures 9C to 9F , these figures show example positioning of heating elements 215 with similar bubble shapes to improve thermal characteristics. The positioning of heating elements 215 can change the thermal characteristics within composite tube 201.

[0160] Fig. 9C A longitudinal cross-section of the top portion of another composite tube is shown. Fig. 9C An embodiment of a composite tube 201 is shown in which the heating element 215 is located 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 walls.

[0161] Fig.9D A longitudinal cross-section of the top portion of another composite tube is shown. Fig.9D An embodiment of a composite tube 201 is shown, wherein Fig. 9C In contrast, the heating elements 215 are spaced further apart 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.

[0162] Fig.9E A longitudinal cross-section of the top portion of another composite tube is shown. Fig.9EAn embodiment of the composite tube 201 is shown in which the heating elements 215 are spaced apart from one another at the top, at the vertical axis of the second elongated member 205. In this example, the heating elements 215 are equidistantly adjacent to each bubble wall.

[0163] Fig.9F A longitudinal cross-section of the top portion of another composite tube is shown. Fig.9F An embodiment of the composite tube 201 is shown in which the heating element 215 is spaced apart at opposite ends of the second elongated member 205. The heating element 215 is close to the bubble wall, especially Figures 9C-9E compared to.

[0164] exist Figures 9C-9F Among the four wire arrangements, determine Fig.9F has the best thermal characteristics. Due to their similar bubble shapes, all configurations experience similar heat losses from the tube. When the same heat energy is input to these tubes, Fig.9F The wire configuration maximizes the temperature rise along the length of the tube. Fig.9D The configuration has the second best thermal characteristics and provides the second largest temperature rise along the length of the tube. Fig. 9C The configuration is the third best. When the same amount of heat is input, Fig.9E The configuration has the worst performance and minimizes the temperature rise along the length of the tube.

[0165] It should be understood that although Fig.9F A configuration of may be preferred in some embodiments, but other configurations, including Fig. 9C , 9D , 9E and other variations may be used in other embodiments.

[0166] Next reference Figures 10A to 10C , these figures show example configurations for stacking the first elongated member 203. It has been found that by stacking multiple bubbles, in certain embodiments, heat distribution can be improved. These embodiments can all be more beneficial when an internal heating wire 215 is used. Fig. 10A A longitudinal cross-section of the top portion of another composite tube is shown. Fig. 10A A cross-sectional view of a composite tube 201 is shown without any stacking.

[0167] Fig. 10B A longitudinal cross-section of the top portion of another composite tube is shown. Fig. 10B 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. 10A Compared with the above, the total bubble height is maintained, but the bubble spacing is Fig. 10A And, Fig. 10BThe embodiment of the present invention only slightly reduces the air volume. The stacking of bubbles reduces the natural convection and heat transfer in the gaps between the bubbles 213 and reduces the overall thermal resistance. The increased heat flow path in the stacked bubbles can make it easier for heat to spread throughout the composite tube 201.

[0168] Fig. 10C A longitudinal cross-section of the top portion of another composite tube is shown. Fig. 10C Another example of a composite tube 201 with stacked bubbles is shown. In this example, three bubbles are stacked on top of each other to form a first elongated member 203. Fig. 10A Compared with the above, the total bubble height is maintained, but the bubble spacing is Fig. 10A One third of the Fig. 10B The embodiment in FIG. 21 is only a slight reduction in air volume. The stacking of bubbles reduces natural convection and heat transfer in the gaps between the bubbles 213.

[0169] clean

[0170] In at least one embodiment, the material used for the composite pipe can be selected to perform different cleaning methods. In some embodiments, high-level disinfection (about 20 cleaning cycles) can be used to clean the composite pipe 201. During high-level disinfection, the composite pipe 201 is subjected to pasteurization at about 75°C for about 30 minutes. Next, the composite pipe 201 is washed in 2% glutaraldehyde for about 20 minutes. The composite pipe 201 is taken out of glutaraldehyde and immersed in 6% hydrogen peroxide for about 30 minutes. Finally, the composite pipe 201 is taken out of hydrogen peroxide and washed in 0.55% o-phthalaldehyde (OPA) for about 10 minutes.

[0171] In other embodiments, sterilization (about 20 cycles) can be used to clean the composite tube 201. First, the composite tube 201 is placed in an autoclave steam at about 121°C for about 30 minutes. Next, the temperature of the autoclave steam is raised to about 134°C for about 3 minutes. After the autoclave treatment, 100% ethylene oxide (ETO) gas is surrounded by 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.

[0172] Composite tube 201 can be made of a material that can withstand repeated cleaning processes. In some embodiments, part or all of composite tube 201 can be made of materials including, but not limited to, styrene-ethylene-butylene-styrene block thermoplastic elastomer, such as Kraiburg TF6STE. In other embodiments, composite tube 201 can be made of materials including, but not limited to, hytrel, urethane, or silicone.

[0173] The above description of the present invention includes its preferred forms. Modifications may be made thereto without departing from the scope of the present invention. For those skilled in the art, many changes in structure and widely different embodiments and applications of the present invention to the content to which the present invention relates may demonstrate themselves without departing from the scope of the present invention as defined in the appended claims. These disclosures and descriptions are purely illustrative and are not intended to be limiting in any sense.

Claims

1. A composite tube for use in a medical circuit for supplying gas to a patient and / or removing gas from a patient, the composite tube comprising: 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 at least partially surrounding the lumen; as well as a second elongate member, the second elongate member being helically wound and connecting between adjacent coils of the first elongate member, the second elongate member forming at least a portion of the lumen of the elongate tube and comprising at least one conductive filament embedded or encapsulated in the second elongate member, wherein: the second elongate member serves as structural support and / or reinforcement for the first elongate member, The second elongated member is less flexible than the first elongated member, and the second elongated member is relatively thicker than a wall defining the first elongated member.

2. The composite tube of claim 1, wherein the first elongated member forms a plurality of bubbles in a longitudinal cross-section, wherein adjacent bubbles are separated by gaps above the second elongated member.

3. The composite tube of claim 1, wherein the second elongated member is solid or primarily solid.

4. The composite tube of claim 1, wherein the first elongated member forms a plurality of bubbles in a longitudinal cross-section, wherein the plurality of bubbles have a flat surface at the cavity.

5. The composite tube of claim 4, wherein adjacent bubbles are separated by gaps that allow for shorter radius bends.

6. The composite tube of claim 1, wherein the first elongated member has a flat surface at the lumen and a radius of curvature away from the lumen.

7. The composite tube of claim 1, wherein the second elongated member has a longitudinal cross-section that is wider proximal to the lumen and narrower radially distal to the lumen.

8. The composite tube of claim 1, comprising a plurality of said conductive filaments.

9. The composite tube of claim 1, comprising four of said conductive filaments.

10. The composite tube of claim 1, wherein the conductive filament pair forms a connecting loop at one end of the composite tube.

11. The composite tube according to any one of claims 1 to 10, wherein the at least one conductive filament comprises a heating filament and / or a sensing filament.

12. A method of making a composite tube for use in a medical circuit for supplying gas to a patient and / or removing gas from a patient, the method comprising: providing a first elongated member comprising a hollow body and a second elongated member, wherein the second elongated member comprises at least one conductive filament embedded or encapsulated in the second elongated member; helically wrapping the second elongated member about a mandrel, with opposing side edge portions of the second elongated member being spaced apart on adjacent wraps, thereby forming a second elongated member helix; and Helically wrapping the first elongated member around the second elongated member spiral such that portions of the first elongated member overlap adjacent wraps of the second elongated member spiral, and placing a portion of the first elongated member proximate the mandrel in a space between the wraps of the second elongated member spiral, thereby forming a first elongated member spiral, wherein: The second elongate member serves as structural support and / or reinforcement for the first elongate member, and The second elongate member is less flexible than the first elongate member.

13. The method of claim 12, wherein the second elongated member is relatively thicker than a wall defining the first elongated member.

14. The method of claim 12, comprising forming the second elongated member.

15. The method of claim 14, wherein forming the second elongated member comprises extruding the second elongated member with a second extruder.

16. The method of claim 15, wherein the second extruder is configured to embed or encapsulate the at least one conductive filament in the second elongated member.

17. The method of claim 16, wherein the at least one conductive filament is non-reactive with the second elongated member. The method of claim 16 , wherein the at least one conductive filament comprises aluminum or copper.

19. The method of claim 16, comprising forming the conductive filament pairs into a connecting loop at one end of the composite tube.

20. The method of claim 16, comprising forming the first elongated member.

21. The method of claim 20, wherein forming the first elongated member comprises extruding the first elongated member with a first extruder.

22. The method of claim 21, comprising forming the second elongate member by extruding the second elongate member with a second extruder, wherein the first extruder is different from the second extruder.

23. The method of any one of claims 12 to 22, wherein the at least one conductive filament comprises a heating filament and / or a sensing filament.

24. A tube for a medical circuit for supplying gas to a patient and / or removing gas from a patient, the tube for a medical circuit comprising: an elongated hollow body helically wound to form an elongated tube having a longitudinal axis, a cavity extending along the longitudinal axis, and a hollow wall at least partially surrounding the cavity, wherein the elongated hollow body has a wall in cross section defining at least a portion of the hollow wall; and a reinforcing portion extending along the length of at least one side of the elongated hollow body so as to be helically positioned between adjacent turns of the elongated hollow body; and at least one conductive filament, the at least one conductive filament being embedded or encapsulated in the reinforcing portion, wherein at least a portion of the reinforcement portion defines a portion of the cavity, and wherein: The reinforcement portion serves as structural support and / or reinforcement for the elongated hollow body, and The reinforcement portion is integrally formed with the elongated hollow body.

25. The tube for a medical circuit according to claim 24, wherein the flexibility of the reinforced portion is lower than that of the elongated hollow body and / or the reinforced portion is relatively thicker than a wall defining the elongated hollow body.

26. The tube for a medical circuit according to claim 24, wherein the elongated hollow body and the reinforcement portion provide a lumen having a smooth lumen surface.

27. The tube for a medical circuit according to claim 24, wherein the reinforced portion has a triangular longitudinal cross-section.

28. The tube for a medical circuit according to claim 24, wherein the helically wound and connected elongated hollow body and reinforcement portion provide crush resistance while being flexible enough to allow short radius bending in accordance with ISO 5367:2000(E) without kinking, occlusion or collapse.

29. The tube for a medical circuit according to claim 24, wherein a portion of the elongated hollow body overlaps an adjacent coil of the reinforcing portion.

30. The tube for a medical circuit according to claim 24, wherein the reinforcement portion is solid or predominantly solid.

31. The tube for a medical circuit according to claim 24, wherein the elongated hollow body forms a plurality of bubbles in a longitudinal section, wherein the plurality of bubbles have a flat surface at the cavity.

32. The tube for a medical circuit according to claim 31, wherein the bubble has perforations.

33. The tube for a medical circuit according to claim 24, wherein the elongated hollow body has a flat surface at the lumen and a radius of curvature away from the lumen.

34. The tube for a medical circuit according to claim 24, wherein the reinforced portion has a longitudinal cross-section that is wider proximal to the lumen and narrower radially distal to the lumen.

35. The tube for a medical circuit according to claim 24, comprising a plurality of said conductive wires.

36. The tube for a medical circuit according to claim 24, comprising four of said conductive wires.

37. The tube for a medical circuit according to claim 24, wherein the pair of conductive filaments form a connecting loop at one end of the tube.

38. The tube for a medical circuit according to claim 24, wherein the at least one conductive filament is spaced apart from the lumen wall.

39. A tube for a medical circuit according to claim 24, wherein the reinforcement portion has a substantially triangular, substantially T-shaped or substantially Y-shaped longitudinal cross-section, and at least two of the plurality of conductive filaments are embedded or encapsulated on opposite sides of the triangle, T-shape or Y-shape.

40. The tube for a medical circuit according to any one of claims 24 to 39, which is one or more of the following: a medical circuit component, an inhalation tube, an exhalation tube, a PAP component, an insufflation component, a detection component, and a surgical component.

41. A tube for a medical circuit according to claim 24 or any one of claims 26 to 39, wherein: The reinforcing portion is less flexible than the elongated hollow body and / or the reinforcing portion is relatively thicker than a wall defining the elongated hollow body, and The elongated hollow body forms a plurality of bubbles in a longitudinal cross-section, wherein adjacent bubbles are separated by gaps.

42. The tube for a medical circuit according to claim 41, wherein the gap allows for shorter radius bends.

43. The tube for a medical circuit according to claim 41, wherein In a cross section along the longitudinal axis, the gap extends between two adjacent turns of the elongated hollow body above the reinforcement portion.

44. The tube for a medical circuit according to claim 41, wherein In a cross section along the longitudinal axis, the gap is clear between two adjacent coils of the elongated hollow body above the reinforcement portion.

45. The tube for a medical circuit according to claim 24, wherein The reinforcement portion is disposed on one side of the elongated hollow body and connected to adjacent coils of the elongated hollow body.

46. ​​The tube for a medical circuit according to claim 24, wherein: The reinforcement portion includes a first portion and a second portion connected together.

47. The tube for a medical circuit according to claim 46, wherein The first portion and the second portion are disposed on a first side and a second side of the elongated hollow body, respectively.

48. A tube for a medical circuit according to any one of claims 24 to 39 or any one of claims 45 to 47, wherein The at least one conductive filament comprises a heating filament and / or a sensing filament.

49. A method of manufacturing a tube for a medical circuit for supplying gas to and / or removing gas from a patient, the method comprising: The invention relates to a method for forming an elongated tube having a longitudinal axis, a cavity extending along the longitudinal axis, and a hollow wall at least partially surrounding the cavity, wherein adjacent coils of the elongated hollow body and the reinforcing portion are connected together such that the reinforcing portion is helically positioned between adjacent coils of the elongated hollow body and at least a portion of the reinforcing portion defines a portion of the cavity, wherein: The reinforcement portion serves as structural support and / or reinforcement for the elongated hollow body, and The reinforcement portion is integrally formed with the elongated hollow body.

50. The method of claim 49, wherein the reinforcing portion is less flexible than the elongated hollow body and / or the reinforcing portion is relatively thicker than a wall defining the elongated hollow body.

51. The method of claim 49, wherein: In a cross section along the longitudinal axis, a gap extends between two adjacent turns of the elongated hollow body above the reinforcement portion.

52. The method of claim 49, comprising supplying air at a pressure greater than atmospheric pressure to one end of the elongated hollow body.

53. The method of claim 49, comprising cooling the reinforcement portion and the elongated hollow body.

54. The method of claim 49, wherein: The reinforcement portion is disposed on one side of the elongated hollow body and the connection includes connecting the reinforcement portion to adjacent turns of the elongated hollow body.

55. The method of claim 49, wherein the reinforcement portion comprises a first portion and a second portion and the connecting comprises connecting the first portion and the second portion.

56. The method of any one of claims 49 to 55, wherein the reinforcing portion comprises at least one conductive filament embedded or encapsulated therein, the at least one conductive filament comprising a plurality of the conductive filaments.

57. The method of claim 56, said plurality of said conductive filaments comprising four said conductive filaments.

58. The method of claim 56, wherein the plurality of conductive wires comprises a pair of conductive wires forming a connection loop at one end of the tube for the medical circuit.

59. The method of any one of claims 49 to 55, wherein the reinforcing portion comprises at least one conductive filament embedded or encapsulated in the reinforcing portion, the at least one conductive filament comprising a heating filament and / or a sensing filament.

Images