US20040149284A1 - Humidified gases delivery apparatus - Google Patents

Humidified gases delivery apparatus Download PDF

Info

Publication number
US20040149284A1
US20040149284A1 US10/746,730 US74673003A US2004149284A1 US 20040149284 A1 US20040149284 A1 US 20040149284A1 US 74673003 A US74673003 A US 74673003A US 2004149284 A1 US2004149284 A1 US 2004149284A1
Authority
US
United States
Prior art keywords
tube
ptc
ribbon
conductors
material
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/746,730
Inventor
Daniel Smith
Hussein Kadhum
Malcolm Smith
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fisher and Paykel Healthcare Ltd
Original Assignee
Fisher and Paykel Healthcare Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to NZ50349500 priority Critical
Priority to NZ503495 priority
Priority to US09/808,567 priority patent/US6918389B2/en
Priority to US09/956,723 priority patent/US7588029B2/en
Application filed by Fisher and Paykel Healthcare Ltd filed Critical Fisher and Paykel Healthcare Ltd
Priority to US10/746,730 priority patent/US20040149284A1/en
Assigned to FISHER & PAYKEL HEALTHCARE LIMITED reassignment FISHER & PAYKEL HEALTHCARE LIMITED ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KADHUM, HUSSEIN, SMITH, DANIEL JOHN, SMITH, MALCOLM DAVID
Publication of US20040149284A1 publication Critical patent/US20040149284A1/en
Application status is Abandoned legal-status Critical

Links

Images

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/08Bellows; Connecting tubes ; Water traps; Patient circuits
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/10Preparation of respiratory gases or vapours
    • A61M16/1075Preparation of respiratory gases or vapours by influencing the temperature
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/10Preparation of respiratory gases or vapours
    • A61M16/1075Preparation of respiratory gases or vapours by influencing the temperature
    • A61M16/109Preparation of respiratory gases or vapours by influencing the temperature the humidifying liquid or the beneficial agent
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/10Preparation of respiratory gases or vapours
    • A61M16/1075Preparation of respiratory gases or vapours by influencing the temperature
    • A61M16/1095Preparation of respiratory gases or vapours by influencing the temperature in the connecting tubes
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/10Preparation of respiratory gases or vapours
    • A61M16/14Preparation of respiratory gases or vapours by mixing different fluids, one of them being in a liquid phase
    • A61M16/16Devices to humidify the respiration air
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/10Preparation of respiratory gases or vapours
    • A61M16/14Preparation of respiratory gases or vapours by mixing different fluids, one of them being in a liquid phase
    • A61M16/16Devices to humidify the respiration air
    • A61M16/161Devices to humidify the respiration air with means for measuring the humidity

Abstract

A gases transportation pathway for use in supplying a humidified gases stream to a patient includes regulated conduit heating. The regulated conduit heating may include a section of positive temperature coefficient material wherein the localised electrical resistance of the material is positively related to the localised temperature. The regulated conduit heating may be a layer of positive temperature coefficient material within the wall of the gases transportation pathway with at least a pair of conductors running the length of the pathway and in electrically conductive contact with the positive temperature coefficient material.

Description

    BACKGROUND TO THE INVENTION
  • 1. Field of the Invention [0001]
  • The present invention relates to apparatus for the delivery of humidified gases and in particular to conduits for humidified breathing circuits. [0002]
  • 2. Summary of the Prior Art [0003]
  • A number of methods are known in the art for supplying humidified gases to a patient requiring breathing assistance. Such prior art humidifiers generally comprise a source of pressurised air (or other mixture of gases), a humidification chamber including a source of water and a heating means to vaporise the water, and a conduit to convey the humidified gases to the patient or user. [0004]
  • For example U.S. Pat. No. 4,038,980 describes a “flash vaporisation” humidifier where water drips onto a low thermal mass heater to create respiratory humidity. It mentions “control means may be provided automatically to regulate the water supply rate in response to means sensing the relative humidity”, however they prefer a manual control of water flow rate. Thus it incorporates a humidity sensor and controls the water rate, as opposed to controlling the amount of electrical heating. [0005]
  • U.S. Pat. No. 5,092,326 also describes the use of a humidity sensor in a humidifier. It describes a high frequency ventilation system that incorporates a heated humidifier and a humidity sensor, where these are linked to a central microprocessor. Apparatus is disclosed to moisten a gas mixture supplied to the airway, and a microprocessor controls the amount of moisture supplied to the gas mixture. [0006]
  • U.S. Pat. No. 5,769,071 describes a humidifier incorporating a heat and moisture exchanger (HME), supply of water to the HME, heater element and humidity sensor. The humidity sensor can control humidity via water supply rate or temperature (via the heater element). The humidity sensor is described as being at the patient airway. [0007]
  • U.S. Pat. No. 5,988,164 describes a heated breathing tube system for use with a humidifier. This uses a relative humidity sensor (located near the patient) to control the amount of heating provided by the heated broathing circuit so that the gas is at a constant level of relative humidity. The heated breathing circuit may use either electrical heating, or heating via warm recirculating water in a tube. Also described is a method of control of the electric heater wire or heated water tube based on the output of relative humidity sensor. [0008]
  • The previously mentioned U.S. Pat. Nos. 4,038,980 and 5,769,071 both describe humidifiers where the humidification chamber is located close (proximal) to the patient. These have the disadvantage of introducing weight, heat and complexity near the patient which is inconvenient and could be painful to the patient. Of the cited prior art only U.S. Pat. No. 5,988,164 specifically describes the humidification chamber as being located remotely from the patient. [0009]
  • There are several disadvantages of the prior art systems using a humidification chamber located remotely from the patient. It is normally assumed that gases leaving such prior art humidifiers are saturated with water vapour (100% relative humidity). However there is no guarantee that the gases leaving such humidifiers are in fact saturated with water vapour. In certain circumstances (e.g. with the incoming air already warm), the gases leaving such humidifiers can be significantly less than 100% relative humidity. This is because the humidifiers are typically controlled to achieve a desired outlet gas temperature, which in some cases may not be much more than the incoming air. [0010]
  • Another drawback of the prior art systems is that condensation can occur in the (sometimes heated) conduits connecting the patient to the respiratory assistance equipment. This may occur if the temperature profile along such conduits is not even and allows some parts of the conduit to be colder than the gas at these points. [0011]
  • A third disadvantage of such prior art systems is that where the gas leaving the humidifier is at 100% relative humidity it must be heated immediately by some form of conduit heater or it may lose heat through the walls of the conduit otherwise condensation and therefore a drop in the amount of absolute humidity contained in the gas will result. [0012]
  • Another fourth disadvantage of the prior art systems is the need for a sensor very near to the patient, which adds to the weight and bulk of equipment at the patient's airway. [0013]
  • SUMMARY OF THE INVENTION
  • It is therefore an object of the present invention to provide apparatus for the delivery of humidified gases which goes some way to overcoming the above mentioned disadvantages. [0014]
  • Accordingly in a first aspect the present invention consists in a gases transportation pathway for transporting humidified gases to a patient, said pathway comprising: [0015]
  • an enclosing wall including at least a layer of positive temperature co efficient material wherein the localised electrical resistance of said material is positively related to the localised temperature, and [0016]
  • at least two electrical conductors running the length of said pathway and disposed in electrical contact with said positive temperature co efficient material. [0017]
  • To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting. [0018]
  • The invention consists in the foregoing and also envisages constructions of which the following gives examples.[0019]
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • One preferred form of the present invention will now be described with reference to the accompanying drawings. [0020]
  • FIG. 1 shows an example of an humidification system, with three basic parts [0021]
  • FIG. 2 is a plan view of a section of a ribbon of PTC material with an electrode embedded along each edge. [0022]
  • FIG. 3 is a plan view of a spirally configured heater element using the PTC ribbon of FIG. 2. [0023]
  • FIG. 4 is a plan view of a second form of spirally configured PTC ribbon heater element. [0024]
  • FIG. 5 is perspective view of a tube formed with a spirally wound PTC ribbon (without pre-embedded conductors) with longitudinally oriented conductors in the tube. [0025]
  • FIG. 6 is a plan view of a section of a ribbon of PTC material with a conductor embedded along one edge and second conductor embedded near the centre. [0026]
  • FIG. 7 is a plan view of a spiral forming arrangement performing a conduit using the ribbon of FIG. 6 (with the forming mandrel not shown). [0027]
  • FIG. 8 shows construction of a tube incorporating flexible PTC elements in a parallel wire configuration. [0028]
  • FIG. 9 shows a chamber combined with an unheated, well insulated delivery tube, [0029]
  • FIG. 10 shows construction of a tube incorporating flexible PTC elements in a parallel wire configuration, [0030]
  • FIG. 11 shows a humidifier configuration; using the tube in any one of FIGS. [0031] 8 to 10.
  • DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
  • FIG. 1 illustrates a typical respiratory humidification system, comprised of three parts: [0032]
  • 1) a humidification chamber located at a distance from the patient, which heats and substantially saturates gases flowing through it; [0033]
  • 2) a delivery system consisting of a flexible tube which carries humidified gases from the humidification chamber [0034] 1 to the gas outlet 5; and
  • 3) a heater base which heats the humidification chamber [0035] 1 and provides measurement and control functions.
  • The gas to be humidified flows into the chamber [0036] 1 from port 4 and leaves the delivery system 2 at gas exit port S. Gas from exit port 5 flows to a patient via a face mask or similar (not shown). Dry gases at the gas input 4 are heated and humidified by passing over the surface of hot water 6 in the chamber 1 so that they are substantially saturated with water vapour when they leave chamber 1 at exit port 10. Hot water 6 is heated by heater plate 9 and the amount of heating is controlled so that the gas reaches a predetermined temperature at exit port 10. Therefore the humidification chamber 1 acts to heat and humidify the medical gases so that they are substantially saturated at the output of chamber 1, and are at a predetermined temperature.
  • The gas delivery system [0037] 2 (also known as a delivery tube or breathing circuit) consists of a flexible tube 11 containing a heater 12. The gas from the humidification chamber 1 passes through the tube 11 and is heated by heater 12 to offset heat losses through the walls of tube 11.
  • The system as described has gas entering gas inlet [0038] 4 from a continuous flow gas source (not shown) and exiting the system through gas outlet 5. However the system is equally applicable where the gas source is a ventilator, which creates intermittent flow patterns to provide breaths to a patient. In this case gas outlet port 5 is connected directly to gas inlet port 16. The patient is connected to port 17 via an endotracheal tube, mask, mouthpiece or other patient interfaces (not shown). During patient inspiration dry gases from the ventilator enter the system at inlet port 4, pass through chamber 1, delivery system 2, pass through wye-piece 13 and reach the patient through port 17. During patent exhalation gases pass back through port 17, through wye-piece 13, tube 14 and leave through gas outlet port 18. Tube 14 may also be heated by heater 15 to prevent condensation.
  • One aspect of the present relates to removing the need for a sensor at the patient airway To remove this sensor safely, we must be certain that the gas entering the delivery tube has a safe level of temperature and absolute humidity, and that the surfaces inside the delivery tube do not exceed safe temperature levels. This implies a delivery tube that has a constant internal wall temperature. [0039]
  • It would be desirable, therefore, to have a heated delivery tube which self-regulates its temperature at a desired level. The heater could either be embedded in the wall of the delivery tube itself, or it could lie inside the lumen of the delivery tube, or it could be wrapped around the outside of the delivery tube. Such a heater could be made from positive temperature coefficient (PTC) material (such as “Winterguard” from Raychem Corp., Menlo Park, Calif. USA), so that the resistance of the heater increases if the heater is hot, resulting in reduced power. However the delivery tube may pass through more than one environment, or may have localised drafts present on certain parts of the tube. If the PTC elements are arranged in parallel, then the fill benefit of the PTC heater can be envisaged. If the PTC elements are arranged in parallel, then the cold portions of the tube will have a lower resistance, which will result in more heat being dissipated. Thus the tube will tend to regulate its own temperature. [0040]
  • FIG. 10 shows construction of a tube incorporating flexible PTC elements in a parallel wire configuration. The tube [0041] 48 is made of a flexible PTC material, which has two low resistive strip connections, 46 and 47, on either side of it. This allows each portion of the tube to consist of short conducting segments of tube connected in parallel between conductors 46 and 47. These segments are represented by dotted lines encircling the tube in FIG. 10. The conductors 46 and 47 are connected to adjustable voltage source 49, which may be AC or DC. The tube would have an outer layer (not shown) which provides electrical insulation and thermal insulation to the tube. Each longitudinal segment of the tube will be able to regulate its own temperature independently of the rest of the tube.
  • Although one specific PTC heated tube design has been envisaged and described, other PTC tube designs could be used. Some additional tube designs are d&scribed out below. It may also be of advantage to create a PTC tube that has a differing temperature profile along its length rather than a constant temperature profile. The PTC design could also be extended to incorporate PTC heaters in other parts of the patient breathing circuit, such as the flexible extension tube which is usually connected between the Y-piece (port [0042] 17 of FIG. 1) and the patient's endotracheal tube. A faker extension of the PTC tube concept would be into a self-heated and temperature controlled endotracheal tube.
  • The PTC tube described with reference to FIG. 10 allows us to create a humidifier which doesn't use any sensor at the patient airway. FIG. 11 shows a humidifier configuration using this tube. Gas enters humidification chamber [0043] 52 via inlet port 51 and is humidified by water 53, heated by heater plate 54. Absolute humidity sensor 55 controls the heater plate so that the gas passing sensor 55 is at a desired level of absolute humidity. PTC tube 56 is heated by an external voltage (not shown) so that the internal surface temperature is at a constant desired temperature, which is selected to be above the dewpoint of the gas. The gas which leaves tube 56 at outlet 57 will therefore be near the temperature of the tube, and containing the desired level of absolute humidity which was controlled by absolute humidity sensor 55.
  • A variation of the system shown in FIG. 11 would be to use a temperature sensor at position [0044] 55. Another variation of a tube with a constant internal wall temperature would a delivery tube with heated water or other fluid pumped through smaller conduits in the wall of the delivery tube. Since the heated fluid has a high specific heat relative to air, the temperature of the fluid remains fairly constant during passage through the delivery wall conduits.
  • Referring to FIGS. [0045] 2 to 8 further preferred forms of the present invention are described. These forms provide a heated delivery tube which self-regulates its temperature at a desired level. The heater may be embedded in the wall of the delivery tube itself, form the fabric of the tube or lie inside the lumen of the delivery tube. The heater of the present invention is formed from a positive temperature coefficient (PTC) material.
  • The resistance of a PTC material increases markedly once it reaches a threshold temperature, resulting in reduced power consumption and subsequent cooling. The delivery tube may pass through more than one environment, or may have localised drafts present on certain parts of the tube. [0046]
  • In one embodiment of the present invention the PTC heater is provided as an elongate structure laying within the lumen of the delivery tube. The construction according to a preferred embodiment is illustrated with respect to FIGS. [0047] 2 to 4. In particular the heater structure is formed from a ribbon 20 of PTC plastic material with conductors 21, 22 embedded in the plastic material adjacent the opposite edges thereof. In use the conductors are attached to a power supply to provide a voltage difference between the conductors and cause a current to flow between them depending on the resistance of the PTC material.
  • The ribbon may be provided in the tube as a single length of ribbon blindly terminated at one end and terminated with a power connector at the other end. This configuration is illustrated in FIG. 3 where the ribbon [0048] 20 is wound into a generally helical configuration and is terminated at one end with a blind connector 23. Termination of the other end at a power connector is not shown. In a alternative configuration the ribbon may be provided as a loop so that both ends terminate at the power connector with both ends of the positive electrode terminating at the positive pin and both ends of the negative or ground electrode terminating at the ground and negative pin. This configuration is depicted in FIG. 4, in which the ribbon 20 is provided in a generally double helical configuration. The conductors 21 and 22 have both ends terminating in the power connector 25 at one end of the heater structure. The ribbon 20 loops back upon itself at the other end 24 of the heater structure.
  • With the pair of conductors provided along opposite edges of the ribbon the PTC material offers an amorphous array of parallel current paths along the entire length of the ribbon. Where the internal conduit temperature is lower the heater structure will have a lower resistance and more current will flow producing a greater heater effect. Where the internal temperature in the conduit is higher the PTC material will have a higher resistance, choking off current flow and reducing heating in that region of the conduit. [0049]
  • In a fixer aspect of the invention the PTC material is arranged in a parallel circuit over the length of the tube and forming part of the wall itself the full benefit of using PTC heater can be obtained. At the cold portions of the tube the material will have a lower resistance, which will result in more heat being dissipated in that area. Thus the tube will tend to regulate its own temperature. [0050]
  • In particular if the PTC material is composed to provide a threshold temperature at or just above the preferred gases temperature (eg above the dew-point of the humidified gases) the PTC material will maintain itself at that threshold temperature (with some hysteresis fluctuation) and condensation on the conduit surface will be at least substantially eliminated. This provides effective condensation control then maintaining an elevated temperature for the humidified gases where condensation may still form on the cold wall surfaces. [0051]
  • PTC material behaviour is exhibited in a range of polymer compositions with electrically conductive fillers. The behaviour can be characterised by a general statement that “providing certain other conditions are fulfilled, the composition becomes electrically conductive when particles of electrically conductive filler form a continuous chain, penetrating the material from the point of entry of electric current to the place where it leaves the polymer material”. Polymer compositions containing electrically conductive filler can exhibit PTC properties due to the formation of a chain of filler particles that are close enough for current to flow at a certain temperature, generating heat which increases the temperature of the material until it reaches a phase transformation temperature. At the phase transformation temperature the crystalline polymer matrix changes to an amorphous structure. This change is accompanied by a small thermal expansion, forcing filler particles to move apart, breaking the conductive paths. Accordingly resistance rises sharply at this phase transformation temperature. As the material cools the small thermal conduction allows new conductive paths to form and current flow to resume. The rise and fall in temperature and the thermal contraction and expansion provides an inherent hysteresis in the cycle. [0052]
  • In producing a PTC material a number of factors have a bearing on the performance of the material. Particular factors include the quantity, type and particle size of the carbon black (or other conductive filler) used in the composite, the polymer that the carbon black binds with during mixing of the base materials and the process conditions such as temperature, pressure and time of mixing. It is important that the conductive filler particles are distributed evenly through the composite so that the composite exhibits uniform PTC behaviour. [0053]
  • For the present invention a PTC material having a phase transformation temperature not exceeding 40° C. is desired. One composition meeting these criteria has been developed and has the following composition: [0054]
  • 20% by weight carbon black powder having a surface area of 254 m[0055] 2/g and oil Di-Butyl- Phthalate absorption of 188 cm3/100 g. This powder is available as VULCAN XC-72 (powder) from Cabot Corporation.
  • 64% Ethylene-Vinyl-Acetate. This material is available as ELVAX (grade 40 w) from Dupont (E.I. du Pont de Nemours and Company), with a density of 965 kg per m[0056] 3, a melting point of 46° C. and melting index of 52.
  • 13.5% Plastomer. An example plastomer is available as EXACT 2M055 from ExxonMobil Corp, having a density of 882 kg/m[0057] 3, a melting point of 70° C. and a melting index of 3.
  • 2.5% Wax. [0058]
  • This material was uniformly mixed and extruded to form a PTC ribbon with embedded conductors using a segmented screw extruder. The composite performance showed an acceptable level of self regulation without the temperature exceeding 40° C. [0059]
  • There are many possible ways of producing a tube having a PTC wall material with a pair of conductors running the length of the tube to have all of the potential pathways through the PTC material operating in parallel. A number of preferred embodiments are now described. [0060]
  • With reference to FIG. 5 a smooth walled tube [0061] 140 is shown by way of a first example. The smooth walled 140 tube has a PTC plastic material extruded as a narrow and thin ribbon 141 and wound helically with overlapping edges of adjacent turns. The edges of adjacent turns bound firmly to one another, fusing together in their moulten state. A pair of conductors run 142, 143 longitudinally in the tube wall. The conductors are diametrically opposed; The conductors may be applied to either the internal or external surfaces of the molten PTC material during forming of the tube. To apply the conductors to the internal surface the conductors are applied longitudinally to the forming mandrel prior to laying the extruded PTC ribbon in place. Alternatively they may be applied directly to the outside of the PTC material while the material is still in a molten state. It would be appreciated that these conductors may also be applied helically rather than in a straight longitudinal direction, and that multiple conductors may be used.
  • Design of a PTC tube of this type involves selection of a wall thickness, a conductor gauge and a density of conductors in the PTC tube wall. The total resistance R (Ω) of the tube wall in its pre-threshold state will be a measure of the available power output for a given voltage. The available power output must be sufficient to offset the heat lose from the tube to its surrounding environment and (if the gases are entering the tube in a cooler state) to the humidified gases. The total resistance is proportional to the pre-threshold volume resistivity X (Ω m) of the material and to the average shortest path distance between the conductors of opposite plurality. The total resistance is also proportional to the inverse of the length L[0062] C (m) of the conductors and to the inverse of the wall thickness t (m) of the PTC material. Furthermore, typically there will be a pair of opposite and alternate paths for current to flow from a conductor of one polarity to the conductor of the other polarity, halving the total resistance. Thus the total resistance can be found from the formula: R = X w _ 2 L c t
    Figure US20040149284A1-20040805-M00001
  • where {overscore (w)}(m) is the average shortest length path between conductors. [0063]
  • Therefore for a given tube length and diameter the total cold resistance may be varied by varying the density of conductors (varying the average shortest path distance between conductors) or by varying the wall thickness. The density of conductors may be varied by adding additional conductors in parallel (eg: a second or more pair of conductors) or by disposing the conductors in a helical arrangement with decreasing pitch corresponding to an increased density. For a given tube diameter D (m) and tube length L[0064] t (m) then the average shortest path length can be found using the total conductor path length for a single polarity (half the total conductor length) by: w _ = π DL T 2 L c
    Figure US20040149284A1-20040805-M00002
  • The tube of FIG. 5 may be reinforced by applying a spiral bead, or by applying circumferential ribs to the outside of the tube, or by corrugating the tube, or by adding additional layers to the tube, particularly of a spiral ribbed or corrugated configuration, which would also provide additional external insulation from the ambient conditions. [0065]
  • A further construction is illustrated in FIGS. 6 and 7. FIG. 6 shows a pair of conductors [0066] 145, 146 extruded into a ribbon of PTC material. The first conductor 145 is disposed adjacent one edge of the PTC ribbon 147. The second conductor 146 is disposed adjacent the centre of the PTC ribbon 147. The exact location of the conductors within the PTC material is not critical, however the spacing between the conductors should be half of the pitch of winding the ribbon on to the former (eg: (width of ribbon—width of overlap between turns)÷2). For additional conductor density, additional pairs of conductors may be used. For lower conductor density the width of ribbon may be increased or alternatively a single conductor may be provided in the ribbon but two ribbons may be extruded and wound on to the former as a double helix.
  • Referring to FIG. 7 a manufacturing configuration is shown (without the rotating former, which may for example be a spiral pipeline mandrel available from OLMAS SRL of Italy). In this manufacturing configuration the PTC ribbon [0067] 147 is co-extruded with the embedded pair of conductors 145, 146 by a first extruder head 148. It is extruded directly on the former at a angle corresponding to the pitch of the former (the relationship between the advance and rotation speeds of tubes formed on it). The ribbon 147 is laid on the former so that the leading edge 149 of each new lap overlaps the trailing edge 150 of the immediately preceding turn. A reinforcing bead 162 is preferably extruded on to this overlap by an additional extruder head 161. The reinforcing bead 162 assists the bonding between overlapping turns of the ribbon as well as providing reinforcing against crushing of the formed tube.
  • Alternatively a conduit may be formed on a spiral pipeline mandrel with the reinforcing bead extruded to lie between the overlap of turns of the ribbon. This is particularly suited to where the ribbon is preformed and will not bond to itself without assistance. In this case contact may be provided between adjacent turns of the PTC ribbon along either side of the bead (for example by extended overlap) or the ribbon used may be have a conductor along each edge (as in FIG. 2). [0068]
  • FIG. 8 shows a further construction of a tube incorporating a parallel wire configuration The tube [0069] 158 is a flexible PTC material; which has two conductors built in,, it.
  • The tube [0070] 158 according to this construction may be a directly extruded tube with the conductors co-extruded into the tube wall, or alternatively the conductors may be added subsequent to forming the tube by direct application to the exterior of the tube as wires or as conductive ink.
  • The tube may have an outer layer (not shown) which provides electrical insulation and thermal insulation to the tube. [0071]
  • The tube may be corrugated by passing through a set of corrugating rollers, to provide flexibility and lateral reinforcing against crushing. [0072]
  • The PTC design could also be extended to incorporate PTC heaters in other parts of the patient breathing circuit, such as the flexible extension tube which is usually connected between the Y-piece (port [0073] 17 of FIG. 1) and the patient's endotracheal tube. A further extension of the PTC tube concept would be into a self-heated and temperature controlled endotracheal tube.
  • The tube with PTC wall material allows a humidifier to be used without any sensor at the patient airway. FIG. 9 shows a humidifier configuration using a PTC tube according to the embodiments of FIGS. [0074] 5 to 8. Gas enters humidification chamber 152 via inlet port 151 and is humidified by water 153, heated by heater plate 154. An absolute humidity sensor 155 controls the heater plate so that the gas passing sensor 155 is at a desired level of absolute humidity. PTC tube 156 is heated by an external voltage (not shown) so that the internal surface temperature is at a constant desired temperature, which is selected to be above the dewpoint of the gas. The gas which leaves tube 156 at outlet 157 will therefore be near the temperature of the tube, and containing the desired level of absolute humidity which was controlled by absolute humidity sensor 155.

Claims (5)

1. A gases transportation pathway for transporting humidified gases to a patient, said pathway comprising:
an enclosing wall including at least a layer of positive temperature coefficient material wherein the localised electrical resistance of said material is positively related to the localised temperature, and
at least two electrical conductors running the length of said pathway and disposed in electrical contact with said positive temperature coefficient material.
2. A gases transportation pathway as claimed in claim 1 wherein said wall includes at least one helically arranged ribbon of positive temperature coefficient material with adjacent turns of ribbon overlapping and fused to one another.
3. A gases transportation pathway as claimed in claim 2 wherein said conductors are arranged helically along said gases transportation pathway at least substantially constantly spaced from one another along the length of said gases transportation pathway.
4. A gases transportation pathway as claimed in claim 3 wherein at least a pair of said conductors are disposed within a said ribbon of positive temperature coefficient material, in constant position in relation to said ribbon.
5. A gases transportation pathway as claimed in any one of claims I to 4 wherein said positive temperature coefficient material has a phase transformation temperature between 35° C. and 40° C.
US10/746,730 2000-03-21 2003-12-26 Humidified gases delivery apparatus Abandoned US20040149284A1 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
NZ50349500 2000-03-21
NZ503495 2000-03-21
US09/808,567 US6918389B2 (en) 2000-03-21 2001-03-14 Breathing assistance apparatus
US09/956,723 US7588029B2 (en) 2000-03-21 2001-09-20 Humidified gases delivery apparatus
US10/746,730 US20040149284A1 (en) 2000-03-21 2003-12-26 Humidified gases delivery apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US10/746,730 US20040149284A1 (en) 2000-03-21 2003-12-26 Humidified gases delivery apparatus

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US09/956,723 Division US7588029B2 (en) 2000-03-21 2001-09-20 Humidified gases delivery apparatus

Publications (1)

Publication Number Publication Date
US20040149284A1 true US20040149284A1 (en) 2004-08-05

Family

ID=46278191

Family Applications (2)

Application Number Title Priority Date Filing Date
US09/956,723 Active 2021-05-20 US7588029B2 (en) 2000-03-21 2001-09-20 Humidified gases delivery apparatus
US10/746,730 Abandoned US20040149284A1 (en) 2000-03-21 2003-12-26 Humidified gases delivery apparatus

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US09/956,723 Active 2021-05-20 US7588029B2 (en) 2000-03-21 2001-09-20 Humidified gases delivery apparatus

Country Status (1)

Country Link
US (2) US7588029B2 (en)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030131844A1 (en) * 2001-12-04 2003-07-17 Kumar Matthew M. Inducing hypothermia and rewarming using a helium-oxygen mixture
US20040102731A1 (en) * 2000-10-16 2004-05-27 Blackhurst Michael Joseph Apparatus used for the humidification of gases in medical procedures
US20050267552A1 (en) * 2004-05-26 2005-12-01 Baylis Medical Company Inc. Electrosurgical device
US20070157929A1 (en) * 2005-12-23 2007-07-12 Draeger Medical Ag & Co. Kg Respirator with active dehumidification
US20080105257A1 (en) * 2006-11-08 2008-05-08 Resmed Limited Humidifier for respiratory apparatus
WO2008055307A1 (en) * 2006-11-08 2008-05-15 Resmed Ltd Humidifier for respiratory apparatus
US20080167646A1 (en) * 2004-05-26 2008-07-10 Baylis Medical Company Inc. Electrosurgical apparatus having a temperature sensor
US20080190427A1 (en) * 2005-05-26 2008-08-14 Matthew Jon Payton Breathing Assistance Apparatus
US20090110379A1 (en) * 2007-10-29 2009-04-30 Smiths Medical Asd, Inc. Pid coefficient adjustment for respiratory heater closed loop control
US20100206308A1 (en) * 2007-07-31 2010-08-19 Resmed Ltd Heating element, humidifier for respiratory apparatus including heating element, and respiratory apparatus
US20120060836A1 (en) * 2010-09-10 2012-03-15 Michael El-Shammaa Patient circuit for improved support delivery
US8511651B2 (en) 2011-03-29 2013-08-20 Smiths Medical Asd, Inc. Heater unit humidification chamber monitor
AU2013257505B2 (en) * 2006-11-08 2014-10-30 ResMed Pty Ltd Conduit for Use in a Respiratory Apparatus
DE102016110002A1 (en) * 2016-05-31 2017-11-30 BSH Hausgeräte GmbH Method for producing a corrugated hose for a household appliance, corrugated hose, device and household appliance

Families Citing this family (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7588029B2 (en) 2000-03-21 2009-09-15 Fisher & Paykel Healthcare Limited Humidified gases delivery apparatus
US6918389B2 (en) * 2000-03-21 2005-07-19 Fisher & Paykel Healthcare Limited Breathing assistance apparatus
US8550072B2 (en) 2000-03-21 2013-10-08 Fisher & Paykel Healthcare Limited Apparatus for delivering humidified gases
US7111624B2 (en) 2000-03-21 2006-09-26 Fisher & Paykel Healthcare Limited Apparatus for delivering humidified gases
US7120354B2 (en) 2000-03-21 2006-10-10 Fisher & Paykel Healthcare Limited Gases delivery conduit
EP1295621B1 (en) * 2001-09-19 2018-11-07 Fisher & Paykel Healthcare Limited Humidified gases delivery apparatus
US20030181857A1 (en) * 2002-03-22 2003-09-25 James Blake Insufflation device with integral heater control
US8536496B2 (en) * 2004-09-15 2013-09-17 Watlow Electric Manufacturing Company Adaptable layered heater system
CN101061752B (en) * 2004-09-30 2011-03-16 沃特洛电气制造公司 Modular layered heater system
JP4771711B2 (en) * 2005-02-15 2011-09-14 株式会社メトラン Humidifier for breathing circuit
WO2007069922A1 (en) * 2005-12-15 2007-06-21 Fisher & Paykel Healthcare Limited Breathing assistance apparatus
US7744068B2 (en) 2006-09-13 2010-06-29 Dristeem Corporation Insulation for a steam carrying apparatus and method of attachment thereof
US20090071478A1 (en) * 2007-09-17 2009-03-19 General Electric Company Ventilator
US8122882B2 (en) * 2007-10-29 2012-02-28 Smiths Medical Asd, Inc. Rainout reduction in a breathing circuit
KR100831077B1 (en) * 2007-12-14 2008-05-22 (주) 아모센스 Heater for preventing freezing burst of pipe using heating element having strip type surface and fabricating method thereof
DE102008039137B3 (en) * 2008-08-21 2010-02-11 Dräger Medical AG & Co. KG Ventilator with a breathing circuit
US9327092B2 (en) 2011-06-22 2016-05-03 Breathe Technologies, Inc. Ventilation mask with integrated piloted exhalation valve
US9038634B2 (en) 2011-06-22 2015-05-26 Breathe Technologies, Inc. Ventilation mask with integrated piloted exhalation valve
US9038635B2 (en) 2011-06-22 2015-05-26 Breathe Technologies, Inc. Ventilation mask with integrated piloted exhalation valve
US8844533B2 (en) 2011-06-22 2014-09-30 Breathe Technologies, Inc. Ventilation mask with integrated piloted exhalation valve
GB201114580D0 (en) 2011-08-23 2011-10-05 Armstrong Medical Ltd Humidified gas delivery system
GB201909316D0 (en) * 2012-11-14 2019-08-14 Fisher & Paykel Healthcare Ltd Zone heating for respiratory circuits
US9878121B2 (en) 2013-03-13 2018-01-30 Breathe Technologies, Inc. Ventilation mask with heat and moisture exchange device
CA2931618A1 (en) * 2013-11-26 2015-06-04 Dri-Steem Corporation Steam dispersion system
KR20170118695A (en) 2014-12-09 2017-10-25 플렉시케어, 인크. Systems and methods for heating and humidifying inspired gases during mechanical ventilation

Citations (92)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US485127A (en) * 1892-10-25 Island
US3243753A (en) * 1962-11-13 1966-03-29 Kohler Fred Resistance element
US3582968A (en) * 1968-12-23 1971-06-01 Texas Instruments Inc Heaters and methods of making same
US3584193A (en) * 1968-04-25 1971-06-08 Hans Badertscher Water vaporizers
US3695267A (en) * 1969-07-01 1972-10-03 Hans Hirtz Inhalator for moist air
US3766914A (en) * 1970-07-29 1973-10-23 H Jacobs High pressure resuscitating and ventilating system incorporating humidifying means for the breathing mixture
US3823217A (en) * 1973-01-18 1974-07-09 Raychem Corp Resistivity variance reduction
US3914349A (en) * 1973-04-23 1975-10-21 Sunbeam Corp Portable humidifier
US4013742A (en) * 1974-07-29 1977-03-22 Volker Lang Device for wetting and heating gases, preferably breathing gases in respirators
US4013122A (en) * 1975-05-05 1977-03-22 Richard William Long Diver's gas heater
US4038980A (en) * 1973-11-12 1977-08-02 Imre Fodor Air humidifiers
US4050823A (en) * 1974-09-05 1977-09-27 Dragerwerk Aktiengesellschaft Apparatus for continuously measuring the CO2 content in breathing gases
US4080576A (en) * 1976-01-08 1978-03-21 Sperry Rand Corporation Tow mode harmonic and nonharmonic phase detector
US4110419A (en) * 1975-04-18 1978-08-29 Respiratory Care, Inc. High-volume disposable and semi-disposable cartridge humidifier with self-contained cartridge sterilizing means, and related method
US4162370A (en) * 1977-06-24 1979-07-24 Automation Industries, Inc. Current carrying hose assembly
US4172105A (en) * 1979-02-15 1979-10-23 Respiratory Care, Inc. Pediatric cartridge humidifier
US4177376A (en) * 1974-09-27 1979-12-04 Raychem Corporation Layered self-regulating heating article
US4459473A (en) * 1982-05-21 1984-07-10 Raychem Corporation Self-regulating heaters
US4500480A (en) * 1982-08-23 1985-02-19 Respiratory Care, Inc. Pediatric cartridge humidifier
US4543474A (en) * 1979-09-24 1985-09-24 Raychem Corporation Layered self-regulating heating article
US4560498A (en) * 1975-08-04 1985-12-24 Raychem Corporation Positive temperature coefficient of resistance compositions
US4574188A (en) * 1982-04-16 1986-03-04 Raychem Corporation Elongate electrical assemblies
US4676237A (en) * 1985-01-29 1987-06-30 Boutade Worldwide Investments Nv Inhaler device
US4682010A (en) * 1983-03-07 1987-07-21 Safeway Products, Inc. In-line electric heater for an aerosol delivery system
US4684786A (en) * 1984-08-01 1987-08-04 Navistar International Corporation Electrically heated fuel pick-up assembly for vehicle fuel tanks
US4710887A (en) * 1984-08-21 1987-12-01 Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of National Defence Computer controlled constant concentration and size particulate general system
US4722334A (en) * 1985-07-16 1988-02-02 Transpirator Technologies, Inc. Method and apparatus for pulmonary and cardiovascular conditioning of racehorses and competition animals
US4753758A (en) * 1983-05-19 1988-06-28 Intertech Resources Inc. Respiratory humidifier
US4780247A (en) * 1985-09-18 1988-10-25 Shigeyuki Yasuda Method for controlling steady state exothermic temperature in the use of heat sensitive-electrically resistant composites
US4791966A (en) * 1982-04-20 1988-12-20 Hew-Kabel Heinz Eilentropp Kg Wrapped, elongated stock
US4808793A (en) * 1986-11-13 1989-02-28 Everhot Corporation Tankless electric water heater with instantaneous hot water output
US4829998A (en) * 1988-02-25 1989-05-16 Jackson Richard R Delivering breathable gas
US4840804A (en) * 1987-04-14 1989-06-20 Mitsubishi Chemical Industries Limited Method of dehydrating foods in melted erythritol
US4911157A (en) * 1988-01-07 1990-03-27 Pegasus Research Corporation Self-regulating, heated nebulizer system
US4911357A (en) * 1988-04-11 1990-03-27 Shibaura Electronics Company, Ltd. Humidity controller utilizing absolute humidity
US4921642A (en) * 1987-12-03 1990-05-01 Puritan-Bennett Corporation Humidifier module for use in a gas humidification assembly
US4941469A (en) * 1987-11-12 1990-07-17 Carmeli Adahan Portable ventilator apparatus
US5024894A (en) * 1988-11-02 1991-06-18 Academy Of Applied Science Method of producing silicon and similar wafers buffered for the deposition of metal oxide superconducting (MOS) polymer composites and the like by insulating metal oxides (IMO) suitable as substrates for MOS, and novel buffered wafers provided thereby
US5031612A (en) * 1990-04-24 1991-07-16 Devilbiss Health Care, Inc. System and method for delivering warm humidified air
US5062145A (en) * 1988-09-29 1991-10-29 Fisher & Paykel Limited Humidifying apparatus
US5092326A (en) * 1987-11-19 1992-03-03 Winn Bryan D Apparatus and method for a ventilator system
US5101820A (en) * 1989-11-02 1992-04-07 Christopher Kent L Apparatus for high continuous flow augmentation of ventilation and method therefor
US5121746A (en) * 1989-12-08 1992-06-16 Sikora John R Anaesthetic and respirator breathing circuit device
US5148801A (en) * 1990-03-23 1992-09-22 University Of Victoria Electronic heater-humidifier for hypothermia treatment
US5224923A (en) * 1990-03-26 1993-07-06 Air-Shields, Inc. Infant incubator
US5231979A (en) * 1992-02-14 1993-08-03 Puritan-Bennett Corporation Humidifier for CPAP device
US5336158A (en) * 1992-11-12 1994-08-09 Huggins Freddie L Pneumatic vacuum vibrator apparatus
US5346128A (en) * 1993-07-22 1994-09-13 Honeywell Inc. Humidity control system
US5362310A (en) * 1992-04-09 1994-11-08 Wisap Gesellschaft Fur Wissenschaftlichen Apparatebau Mbh Heating apparatus for insufflator
US5387604A (en) * 1990-08-29 1995-02-07 Merrell Dow Pharmaceuticals Inc. 1,4 benzodioxin derivatives and their use as serotonin 5HT1A agonists
US5388443A (en) * 1993-06-24 1995-02-14 Manaka; Junji Atmosphere sensor and method for manufacturing the sensor
US5392770A (en) * 1993-06-29 1995-02-28 Clawson; Burrell E. Tubing circuit systems for humidified respiratory gas
US5404729A (en) * 1991-12-27 1995-04-11 Nissan Motor Co., Ltd. Heat pump type air conditioner for automotive vehicle
US5454061A (en) * 1994-05-27 1995-09-26 Steward Plastics, Inc. Apparatus and method for making flexible tubing with helically wound heating conductor
US5482031A (en) * 1991-09-20 1996-01-09 Gibeck Respiration Ab Arrangement for connecting a patient to a respirator, and the use of a moisture-heat-exchanger in the arrangement
US5516466A (en) * 1994-10-27 1996-05-14 Armstrong International, Inc. Steam humidifier system
US5529060A (en) * 1991-05-22 1996-06-25 Fisher & Paykel Limited Humidifiers with control systems to prevent condensation
US5558084A (en) * 1991-10-04 1996-09-24 Fisher & Paykel Limited Humidifier with delivery tube condensation preventing structure and control
US5564415A (en) * 1995-06-07 1996-10-15 Lifecare International, Inc. Humidifier for a ventilator
US5588423A (en) * 1994-08-20 1996-12-31 Fisher & Paykel Limited Humidifier chamber
US5640951A (en) * 1994-03-15 1997-06-24 Fisher & Paykel Limited Humidifier conduit
US5705555A (en) * 1991-05-04 1998-01-06 Cabot Corporation Conductive polymer compositions
US5759149A (en) * 1993-12-17 1998-06-02 Hill-Rom, Inc. Patient thermal support device
US5769071A (en) * 1995-02-16 1998-06-23 Smiths Industries Plc Humidifier systems
US5873687A (en) * 1997-04-16 1999-02-23 Mori Seiki Co., Ltd. Tool unit with hydraulic feed passage
US5988154A (en) * 1997-10-31 1999-11-23 G.S. Blodgett Corporation Combination steamer and convection oven with double doors
US5991507A (en) * 1995-03-20 1999-11-23 Perycut-Chemie Ag Vaporizer
US5988164A (en) * 1995-07-31 1999-11-23 Paluch; Bernard Breathing circuits with humidity controls
US6050260A (en) * 1996-12-02 2000-04-18 Fisher & Paykel Limited Humidifier sleep apnea treatment apparatus
US6078730A (en) * 1995-11-13 2000-06-20 Fisher & Paykel Limited Heat respiratory conduit
US6090313A (en) * 1996-10-08 2000-07-18 Therm-O-Disc Inc. High temperature PTC device and conductive polymer composition
US6095505A (en) * 1998-07-15 2000-08-01 Pegasus Research Corporation Patient-end humidifier
US6125847A (en) * 1997-10-22 2000-10-03 Lin; Chung-Yuan Anesthetic applicator with a temperature humidity regulating capability
US6158431A (en) * 1998-02-13 2000-12-12 Tsi Incorporated Portable systems and methods for delivery of therapeutic material to the pulmonary system
US6167883B1 (en) * 1998-01-23 2001-01-02 Respiratory Support Products, Inc. Medical air hose internal flow heater
US6238598B1 (en) * 2000-08-11 2001-05-29 Fuzetec Technology Co., Ltd. Positive temperature coefficient (PTC) polymer blend composition and circuit protection device
US6311958B1 (en) * 1998-12-01 2001-11-06 Emerson Electric Co. Humidifier with detachable fan assembly
US6349722B1 (en) * 1997-06-17 2002-02-26 Fisher & Paykel Limited Respiratory humidification system
US6367472B1 (en) * 1996-05-29 2002-04-09 Dragerwerk Aktiengesellschaft Respiration humidifier
US6394084B1 (en) * 1996-07-16 2002-05-28 Respironics, Inc. Humidification unit, method of making same, and ventilatory system using such a humidification unit
US6397848B1 (en) * 1999-08-18 2002-06-04 Gc Corporation Mouthguard composition
US6398197B1 (en) * 1999-05-10 2002-06-04 Fisher & Paykel Limited Water chamber
US6440512B1 (en) * 1998-11-04 2002-08-27 The Goodyear Tire & Rubber Company Hose construction containing ternary blend of polymers
US6463925B2 (en) * 1999-11-22 2002-10-15 The United States Of America As Represented By The Secretary Of The Navy Hot water heater for diver using hydrogen catalytic reactions
US6474335B1 (en) * 1997-12-04 2002-11-05 Medisize B.V. Artificial respiration system
US20030059213A1 (en) * 2000-03-21 2003-03-27 Mackie Scott Robert Gases delivery conduit
US6543412B2 (en) * 2000-03-29 2003-04-08 Hitachi, Ltd. Intake air control device and internal combustion engine mounting the same
US6564011B1 (en) * 2000-08-23 2003-05-13 Fmc Technologies, Inc. Self-regulating heat source for subsea equipment
US6601776B1 (en) * 1999-09-22 2003-08-05 Microcoating Technologies, Inc. Liquid atomization methods and devices
US6718974B1 (en) * 2000-10-06 2004-04-13 Mallinckrodt, Inc. CPAP humidifier having sliding access door
US6918389B2 (en) * 2000-03-21 2005-07-19 Fisher & Paykel Healthcare Limited Breathing assistance apparatus
US7453043B2 (en) * 2006-02-15 2008-11-18 Ls Cable Ltd. Composition for manufacturing insulation materials of electrical wire and electrical wire manufactured using the same

Family Cites Families (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1167551A (en) 1965-12-01 1969-10-15 Texas Instruments Inc Heaters and Methods of Making Same
SU379270A1 (en) 1971-02-01 1973-04-20 Drug adapter
US4060576A (en) 1972-09-13 1977-11-29 Graham Cameron Grant Method and apparatus for vapor saturated gas delivery
DE3311811A1 (en) 1983-03-31 1984-10-04 Hirtz & Co Device for treating the airways with hot air
JPH0328243Y2 (en) 1984-04-02 1991-06-18
BE905330A (en) 1986-08-26 1986-12-16 Anthony Jean M Humidifier and heater for medical breathing appts. - is electrically regulated and is of hygienic modular construction
DE3629353C1 (en) 1986-08-28 1988-01-07 Draegerwerk Ag Ventilation device
EP0356000A3 (en) 1988-08-26 1992-05-20 The British Petroleum Company p.l.c. Breathing apparatus
BR9101157A (en) 1990-03-26 1991-11-05 Air Shields Wetting of incubator for newborns
IT1243853B (en) 1990-10-19 1994-06-28 Hospital Hi Tec S R L An apparatus for continuous alveolar positive pressure breathing.
DE4034611A1 (en) 1990-10-31 1992-05-07 Stiebel Eltron Gmbh & Co Kg Two=stage throughflow electric heater - has NTC resistance in second stage avoiding abrupt temp. rise on switching to higher flow rate
DE4244493A1 (en) 1992-01-18 1993-07-22 Eilentropp Hew Kabel
AU3713193A (en) * 1992-04-24 1993-10-28 Fisher & Paykel Limited Humidifier apparatus and/or gases distribution chambers and/or temperature probes for the same
JP2654887B2 (en) 1992-05-22 1997-09-17 将秀 大塚 Condensation sensor addition humidifier
US5544275A (en) 1993-03-17 1996-08-06 Applied Materials, Inc. Electrically heated fluid carrying conduit having integrated heating elements and electrical conductors
GB9309294D0 (en) 1993-05-06 1993-06-16 Smiths Ind Public Ltd Heaters and heated devices
US6024694A (en) 1995-09-25 2000-02-15 Hill-Rom, Inc. Humidifier for a thermal support apparatus
DE9409231U1 (en) 1994-06-07 1994-11-03 Madaus Schwarzer Medtech Ventilator for Sleep Medicine
JPH0861731A (en) 1994-08-24 1996-03-08 Matsushita Electric Ind Co Ltd Air supply and exhaust apparatus
JPH09234247A (en) 1995-12-27 1997-09-09 Nikkiso Y S I Kk Artificial respiratory apparatus and improved heating/ humidifying device
AUPO425496A0 (en) 1996-12-18 1997-01-16 William A Cook Australia Pty Ltd Medical humidifier
SE9803047D0 (en) 1998-09-09 1998-09-09 Siemens Elema Ab Humidity and bacterial barrier for medical components
EP2345449B1 (en) 1999-08-05 2019-05-01 ResMed R&D Germany GmbH Respiratory gas tube, connecting device therefor and connecting device structure
JP2001129091A (en) 1999-11-09 2001-05-15 Kofurotsuku Kk Medical oxygen concentrator
US7588029B2 (en) 2000-03-21 2009-09-15 Fisher & Paykel Healthcare Limited Humidified gases delivery apparatus
EP1326665B1 (en) 2000-10-16 2019-05-08 Fisher & Paykel Healthcare Limited Apparatus used for the humidification of gases in medical procedures
US6816669B2 (en) * 2001-06-08 2004-11-09 Algas-Sdi International Llc Vaporizer with capacity control valve

Patent Citations (94)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US485127A (en) * 1892-10-25 Island
US3243753A (en) * 1962-11-13 1966-03-29 Kohler Fred Resistance element
US3584193A (en) * 1968-04-25 1971-06-08 Hans Badertscher Water vaporizers
US3582968A (en) * 1968-12-23 1971-06-01 Texas Instruments Inc Heaters and methods of making same
US3695267A (en) * 1969-07-01 1972-10-03 Hans Hirtz Inhalator for moist air
US3766914A (en) * 1970-07-29 1973-10-23 H Jacobs High pressure resuscitating and ventilating system incorporating humidifying means for the breathing mixture
US3823217A (en) * 1973-01-18 1974-07-09 Raychem Corp Resistivity variance reduction
US3914349A (en) * 1973-04-23 1975-10-21 Sunbeam Corp Portable humidifier
US4038980A (en) * 1973-11-12 1977-08-02 Imre Fodor Air humidifiers
US4013742A (en) * 1974-07-29 1977-03-22 Volker Lang Device for wetting and heating gases, preferably breathing gases in respirators
US4050823A (en) * 1974-09-05 1977-09-27 Dragerwerk Aktiengesellschaft Apparatus for continuously measuring the CO2 content in breathing gases
US4177376A (en) * 1974-09-27 1979-12-04 Raychem Corporation Layered self-regulating heating article
US4110419A (en) * 1975-04-18 1978-08-29 Respiratory Care, Inc. High-volume disposable and semi-disposable cartridge humidifier with self-contained cartridge sterilizing means, and related method
US4013122A (en) * 1975-05-05 1977-03-22 Richard William Long Diver's gas heater
US4560498A (en) * 1975-08-04 1985-12-24 Raychem Corporation Positive temperature coefficient of resistance compositions
US4080576A (en) * 1976-01-08 1978-03-21 Sperry Rand Corporation Tow mode harmonic and nonharmonic phase detector
US4162370A (en) * 1977-06-24 1979-07-24 Automation Industries, Inc. Current carrying hose assembly
US4172105A (en) * 1979-02-15 1979-10-23 Respiratory Care, Inc. Pediatric cartridge humidifier
US4543474A (en) * 1979-09-24 1985-09-24 Raychem Corporation Layered self-regulating heating article
US4574188A (en) * 1982-04-16 1986-03-04 Raychem Corporation Elongate electrical assemblies
US4791966A (en) * 1982-04-20 1988-12-20 Hew-Kabel Heinz Eilentropp Kg Wrapped, elongated stock
US4459473A (en) * 1982-05-21 1984-07-10 Raychem Corporation Self-regulating heaters
US4500480A (en) * 1982-08-23 1985-02-19 Respiratory Care, Inc. Pediatric cartridge humidifier
US4682010A (en) * 1983-03-07 1987-07-21 Safeway Products, Inc. In-line electric heater for an aerosol delivery system
US4753758A (en) * 1983-05-19 1988-06-28 Intertech Resources Inc. Respiratory humidifier
US4684786A (en) * 1984-08-01 1987-08-04 Navistar International Corporation Electrically heated fuel pick-up assembly for vehicle fuel tanks
US4710887A (en) * 1984-08-21 1987-12-01 Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of National Defence Computer controlled constant concentration and size particulate general system
US4676237A (en) * 1985-01-29 1987-06-30 Boutade Worldwide Investments Nv Inhaler device
US4722334A (en) * 1985-07-16 1988-02-02 Transpirator Technologies, Inc. Method and apparatus for pulmonary and cardiovascular conditioning of racehorses and competition animals
US4780247A (en) * 1985-09-18 1988-10-25 Shigeyuki Yasuda Method for controlling steady state exothermic temperature in the use of heat sensitive-electrically resistant composites
US4808793A (en) * 1986-11-13 1989-02-28 Everhot Corporation Tankless electric water heater with instantaneous hot water output
US4840804A (en) * 1987-04-14 1989-06-20 Mitsubishi Chemical Industries Limited Method of dehydrating foods in melted erythritol
US4941469A (en) * 1987-11-12 1990-07-17 Carmeli Adahan Portable ventilator apparatus
US5092326A (en) * 1987-11-19 1992-03-03 Winn Bryan D Apparatus and method for a ventilator system
US4921642A (en) * 1987-12-03 1990-05-01 Puritan-Bennett Corporation Humidifier module for use in a gas humidification assembly
US4911157A (en) * 1988-01-07 1990-03-27 Pegasus Research Corporation Self-regulating, heated nebulizer system
US4829998A (en) * 1988-02-25 1989-05-16 Jackson Richard R Delivering breathable gas
US4911357A (en) * 1988-04-11 1990-03-27 Shibaura Electronics Company, Ltd. Humidity controller utilizing absolute humidity
US5062145A (en) * 1988-09-29 1991-10-29 Fisher & Paykel Limited Humidifying apparatus
US5024894A (en) * 1988-11-02 1991-06-18 Academy Of Applied Science Method of producing silicon and similar wafers buffered for the deposition of metal oxide superconducting (MOS) polymer composites and the like by insulating metal oxides (IMO) suitable as substrates for MOS, and novel buffered wafers provided thereby
US5101820A (en) * 1989-11-02 1992-04-07 Christopher Kent L Apparatus for high continuous flow augmentation of ventilation and method therefor
US5121746A (en) * 1989-12-08 1992-06-16 Sikora John R Anaesthetic and respirator breathing circuit device
US5148801A (en) * 1990-03-23 1992-09-22 University Of Victoria Electronic heater-humidifier for hypothermia treatment
US5224923A (en) * 1990-03-26 1993-07-06 Air-Shields, Inc. Infant incubator
US5031612A (en) * 1990-04-24 1991-07-16 Devilbiss Health Care, Inc. System and method for delivering warm humidified air
US5387604A (en) * 1990-08-29 1995-02-07 Merrell Dow Pharmaceuticals Inc. 1,4 benzodioxin derivatives and their use as serotonin 5HT1A agonists
US5705555A (en) * 1991-05-04 1998-01-06 Cabot Corporation Conductive polymer compositions
US5529060A (en) * 1991-05-22 1996-06-25 Fisher & Paykel Limited Humidifiers with control systems to prevent condensation
US5482031A (en) * 1991-09-20 1996-01-09 Gibeck Respiration Ab Arrangement for connecting a patient to a respirator, and the use of a moisture-heat-exchanger in the arrangement
US5558084A (en) * 1991-10-04 1996-09-24 Fisher & Paykel Limited Humidifier with delivery tube condensation preventing structure and control
US5404729A (en) * 1991-12-27 1995-04-11 Nissan Motor Co., Ltd. Heat pump type air conditioner for automotive vehicle
US5231979A (en) * 1992-02-14 1993-08-03 Puritan-Bennett Corporation Humidifier for CPAP device
US5362310A (en) * 1992-04-09 1994-11-08 Wisap Gesellschaft Fur Wissenschaftlichen Apparatebau Mbh Heating apparatus for insufflator
US5336158A (en) * 1992-11-12 1994-08-09 Huggins Freddie L Pneumatic vacuum vibrator apparatus
US5388443A (en) * 1993-06-24 1995-02-14 Manaka; Junji Atmosphere sensor and method for manufacturing the sensor
US5392770A (en) * 1993-06-29 1995-02-28 Clawson; Burrell E. Tubing circuit systems for humidified respiratory gas
US5346128A (en) * 1993-07-22 1994-09-13 Honeywell Inc. Humidity control system
US5759149A (en) * 1993-12-17 1998-06-02 Hill-Rom, Inc. Patient thermal support device
US5640951A (en) * 1994-03-15 1997-06-24 Fisher & Paykel Limited Humidifier conduit
US5454061A (en) * 1994-05-27 1995-09-26 Steward Plastics, Inc. Apparatus and method for making flexible tubing with helically wound heating conductor
US5588423A (en) * 1994-08-20 1996-12-31 Fisher & Paykel Limited Humidifier chamber
US5516466A (en) * 1994-10-27 1996-05-14 Armstrong International, Inc. Steam humidifier system
US5769071A (en) * 1995-02-16 1998-06-23 Smiths Industries Plc Humidifier systems
US5991507A (en) * 1995-03-20 1999-11-23 Perycut-Chemie Ag Vaporizer
US5564415A (en) * 1995-06-07 1996-10-15 Lifecare International, Inc. Humidifier for a ventilator
US5988164A (en) * 1995-07-31 1999-11-23 Paluch; Bernard Breathing circuits with humidity controls
US6078730A (en) * 1995-11-13 2000-06-20 Fisher & Paykel Limited Heat respiratory conduit
US6367472B1 (en) * 1996-05-29 2002-04-09 Dragerwerk Aktiengesellschaft Respiration humidifier
US6394084B1 (en) * 1996-07-16 2002-05-28 Respironics, Inc. Humidification unit, method of making same, and ventilatory system using such a humidification unit
US6090313A (en) * 1996-10-08 2000-07-18 Therm-O-Disc Inc. High temperature PTC device and conductive polymer composition
US6050260A (en) * 1996-12-02 2000-04-18 Fisher & Paykel Limited Humidifier sleep apnea treatment apparatus
US5873687A (en) * 1997-04-16 1999-02-23 Mori Seiki Co., Ltd. Tool unit with hydraulic feed passage
US6694974B1 (en) * 1997-06-17 2004-02-24 Fisher & Paykel Limited Respiratory humidification system
US6349722B1 (en) * 1997-06-17 2002-02-26 Fisher & Paykel Limited Respiratory humidification system
US6125847A (en) * 1997-10-22 2000-10-03 Lin; Chung-Yuan Anesthetic applicator with a temperature humidity regulating capability
US5988154A (en) * 1997-10-31 1999-11-23 G.S. Blodgett Corporation Combination steamer and convection oven with double doors
US6474335B1 (en) * 1997-12-04 2002-11-05 Medisize B.V. Artificial respiration system
US6167883B1 (en) * 1998-01-23 2001-01-02 Respiratory Support Products, Inc. Medical air hose internal flow heater
US6158431A (en) * 1998-02-13 2000-12-12 Tsi Incorporated Portable systems and methods for delivery of therapeutic material to the pulmonary system
US6095505A (en) * 1998-07-15 2000-08-01 Pegasus Research Corporation Patient-end humidifier
US6440512B1 (en) * 1998-11-04 2002-08-27 The Goodyear Tire & Rubber Company Hose construction containing ternary blend of polymers
US6311958B1 (en) * 1998-12-01 2001-11-06 Emerson Electric Co. Humidifier with detachable fan assembly
US6398197B1 (en) * 1999-05-10 2002-06-04 Fisher & Paykel Limited Water chamber
US6397848B1 (en) * 1999-08-18 2002-06-04 Gc Corporation Mouthguard composition
US6601776B1 (en) * 1999-09-22 2003-08-05 Microcoating Technologies, Inc. Liquid atomization methods and devices
US6463925B2 (en) * 1999-11-22 2002-10-15 The United States Of America As Represented By The Secretary Of The Navy Hot water heater for diver using hydrogen catalytic reactions
US20030059213A1 (en) * 2000-03-21 2003-03-27 Mackie Scott Robert Gases delivery conduit
US6918389B2 (en) * 2000-03-21 2005-07-19 Fisher & Paykel Healthcare Limited Breathing assistance apparatus
US7120354B2 (en) * 2000-03-21 2006-10-10 Fisher & Paykel Healthcare Limited Gases delivery conduit
US6543412B2 (en) * 2000-03-29 2003-04-08 Hitachi, Ltd. Intake air control device and internal combustion engine mounting the same
US6238598B1 (en) * 2000-08-11 2001-05-29 Fuzetec Technology Co., Ltd. Positive temperature coefficient (PTC) polymer blend composition and circuit protection device
US6564011B1 (en) * 2000-08-23 2003-05-13 Fmc Technologies, Inc. Self-regulating heat source for subsea equipment
US6718974B1 (en) * 2000-10-06 2004-04-13 Mallinckrodt, Inc. CPAP humidifier having sliding access door
US7453043B2 (en) * 2006-02-15 2008-11-18 Ls Cable Ltd. Composition for manufacturing insulation materials of electrical wire and electrical wire manufactured using the same

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8206337B2 (en) 2000-10-16 2012-06-26 Fisher & Paykel Healthcare Limited Apparatus used for the humidification of gases in medical procedures
US20040102731A1 (en) * 2000-10-16 2004-05-27 Blackhurst Michael Joseph Apparatus used for the humidification of gases in medical procedures
US9095668B2 (en) 2000-10-16 2015-08-04 Fisher & Paykel Healthcare Limited Apparatus used for humidification of gases in medical procedures
US10293121B2 (en) 2000-10-16 2019-05-21 Fisher & Paykel Healthcare Limited Apparatus used for the humidification of gases in medical procedures
US6983749B2 (en) * 2001-12-04 2006-01-10 Minnesota High-Tech Resources, Llc Inducing hypothermia and rewarming using a helium-oxygen mixture
US20030131844A1 (en) * 2001-12-04 2003-07-17 Kumar Matthew M. Inducing hypothermia and rewarming using a helium-oxygen mixture
US20050267552A1 (en) * 2004-05-26 2005-12-01 Baylis Medical Company Inc. Electrosurgical device
US20080167646A1 (en) * 2004-05-26 2008-07-10 Baylis Medical Company Inc. Electrosurgical apparatus having a temperature sensor
US20080190427A1 (en) * 2005-05-26 2008-08-14 Matthew Jon Payton Breathing Assistance Apparatus
US9839759B2 (en) 2005-05-26 2017-12-12 Fisher & Paykel Healthcare Limited Breathing assistance apparatus
US8893715B2 (en) * 2005-05-26 2014-11-25 Fisher & Paykel Healthcare Limited Breathing assistance apparatus
US8919343B2 (en) * 2005-12-23 2014-12-30 Dräger Medical AG & Co. KG Respirator with active dehumidification
US20070157929A1 (en) * 2005-12-23 2007-07-12 Draeger Medical Ag & Co. Kg Respirator with active dehumidification
US9440040B2 (en) 2006-11-08 2016-09-13 Resmed Limited Humidifier for respiratory apparatus
AU2013257505B2 (en) * 2006-11-08 2014-10-30 ResMed Pty Ltd Conduit for Use in a Respiratory Apparatus
US20080105257A1 (en) * 2006-11-08 2008-05-08 Resmed Limited Humidifier for respiratory apparatus
US9855398B2 (en) 2006-11-08 2018-01-02 Resmed Limited Humidifier for respiratory apparatus
CN103933651A (en) * 2006-11-08 2014-07-23 雷斯梅德有限公司 Conduit for use in a respiratory apparatus
WO2008055307A1 (en) * 2006-11-08 2008-05-15 Resmed Ltd Humidifier for respiratory apparatus
US20130239966A1 (en) * 2007-07-31 2013-09-19 Resmed Limited Heating element, humidifier for respiratory apparatus including heating element, and respiratory apparatus
US8459259B2 (en) * 2007-07-31 2013-06-11 Resmed Limited Heating element, humidifier for respiratory apparatus including heating element, and respiratory apparatus
US9327093B2 (en) * 2007-07-31 2016-05-03 Resmed Limited Heating element, humidifier for respiratory apparatus including heating element, and respiratory apparatus
US20100206308A1 (en) * 2007-07-31 2010-08-19 Resmed Ltd Heating element, humidifier for respiratory apparatus including heating element, and respiratory apparatus
US20090110379A1 (en) * 2007-10-29 2009-04-30 Smiths Medical Asd, Inc. Pid coefficient adjustment for respiratory heater closed loop control
US7983542B2 (en) 2007-10-29 2011-07-19 Smiths Medical Asd, Inc. PID coefficient adjustment for respiratory heater closed loop control
US20120060836A1 (en) * 2010-09-10 2012-03-15 Michael El-Shammaa Patient circuit for improved support delivery
US8511651B2 (en) 2011-03-29 2013-08-20 Smiths Medical Asd, Inc. Heater unit humidification chamber monitor
DE102016110002A1 (en) * 2016-05-31 2017-11-30 BSH Hausgeräte GmbH Method for producing a corrugated hose for a household appliance, corrugated hose, device and household appliance

Also Published As

Publication number Publication date
US7588029B2 (en) 2009-09-15
US20020124847A1 (en) 2002-09-12

Similar Documents

Publication Publication Date Title
AU778385B2 (en) A humidifier
CA2447915C (en) Respiratory humidification system
US5558084A (en) Humidifier with delivery tube condensation preventing structure and control
JP5100932B2 (en) Components of the breathing circuit
US10252017B2 (en) Conduit with heating element
JP5670621B2 (en) Humidifier for respiratory apparatus and respiratory apparatus for delivering a humidified flow of respiratory gas to a patient
JP4386595B2 (en) Humidifier
US7469719B2 (en) Limb for breathing circuit
AU702011B2 (en) Humidifier systems
CN101098726B (en) Nosepiece
US5031612A (en) System and method for delivering warm humidified air
JP3299261B2 (en) Artificial nose device
US7140367B2 (en) Conduit overheating detection system
US20020072700A1 (en) Method and apparatus for humidification and warming of air
US6662802B2 (en) Conduit with heated wick
TW470658B (en) Medical air hose having internal flow heater
DE4441380B4 (en) Line for heated, humidified breathing air
DE60020024T2 (en) ventilation system
US5988164A (en) Breathing circuits with humidity controls
CN103933651B (en) The conduit used in breathing equipment
AU679377B2 (en) Apparatus and method for making flexible tubing with helically wound heating conductor
US20060113690A1 (en) Humidification system
US6010118A (en) Medical humidifier
AU2002211121B2 (en) Improvements to apparatus used for the humidification of gases in medical procedures
JP2001061966A5 (en)

Legal Events

Date Code Title Description
AS Assignment

Owner name: FISHER & PAYKEL HEALTHCARE LIMITED, NEW ZEALAND

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SMITH, DANIEL JOHN;KADHUM, HUSSEIN;SMITH, MALCOLM DAVID;REEL/FRAME:015118/0621

Effective date: 20011019

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION