Disposable anti-fog airway adapter
First Claim
1. An endotracheal airway adapter for use in a respiratory airstream of a patient in proximity of the patient'"'"'s mouth during quantitative measurement of the concentration of respiratory constituents of the patient using a respiratory analyzer having infrared transmission and detection devices disposed in a housing which receives said airway adapter, said airway adapter comprising:
- a substantially tubular portion comprised of a material which is slightly deformable and has oppositely disposed openings in a width-wise direction thereof which lie in an optical path between said infrared transmission and detection devices when received by said housing;
a pair of thin plastic windows respectively disposed over said oppositely disposed openings of said tubular portion so as to form a substantially airtight seal and so as to be a predetermined distance from each other during said quantitative measurement of the concentration of respiratory constituents of the patient using said infrared transmission and detection devices, said windows passing infrared energy from said infrared transmission device to said detection device; and
a non-toxic anti-fog surfactant which treats said windows so as to prevent fogging of said windows when said windows are placed in the respiratory airstream of the patient.
14 Assignments
0 Petitions
Accused Products
Abstract
A disposable anti-fog airway adapter for use with a mainstream respiratory gas analyzer which provides a measurement of a patient'"'"'s inhaled and exhaled gases. The airway adapter includes windows that are constructed of a thin, low heat capacity plastic that rapidly equilibrates to the temperature of the warm moist gases in the patient breathing circuit. In addition, the inside of the windows is also coated with an anti-fog surfactant either by laminating an anti-fog film with the window plastic prior to attaching the window to the airway adapter body or by first attaching the window to the airway adapter body and then applying the surfactant to the airway adapter after the window film is bonded in place so that the surfactant coats the entire inside of the adapter. The surfactant functions to increase the critical wetting tension of the surface it covers so that water on the window spreads into a uniform thin layer which does not absorb very much infrared energy and thus does not significantly reduce the signal strength. "Instant on" operation is accomplished because no heater and the like is necessary to warm up the windows to maintain them at an elevated temperature to prevent fogging. Numerous techniques are also provided for adhering the windows to the airway adapter body so that a substantially airtight seal may be obtained.
77 Citations
23 Claims
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1. An endotracheal airway adapter for use in a respiratory airstream of a patient in proximity of the patient'"'"'s mouth during quantitative measurement of the concentration of respiratory constituents of the patient using a respiratory analyzer having infrared transmission and detection devices disposed in a housing which receives said airway adapter, said airway adapter comprising:
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a substantially tubular portion comprised of a material which is slightly deformable and has oppositely disposed openings in a width-wise direction thereof which lie in an optical path between said infrared transmission and detection devices when received by said housing; a pair of thin plastic windows respectively disposed over said oppositely disposed openings of said tubular portion so as to form a substantially airtight seal and so as to be a predetermined distance from each other during said quantitative measurement of the concentration of respiratory constituents of the patient using said infrared transmission and detection devices, said windows passing infrared energy from said infrared transmission device to said detection device; and a non-toxic anti-fog surfactant which treats said windows so as to prevent fogging of said windows when said windows are placed in the respiratory airstream of the patient. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An endotracheal airway adapter for use in a respiratory airstream of a patient in proximity of the patient'"'"'s mouth during quantitative measurement of the concentration of respiratory constituents of the patient using a respiratory analyzer having infrared transmission and detection devices disposed in a housing which receives said airway adapter, said airway adapter comprising:
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a substantially tubular portion comprised of a material which is slightly deformable and has oppositely disposed openings in a width-wise direction thereof which lie in an optical path between said infrared transmission and detection devices when received by said housing; an anti-fog film including a thin plastic layer impregnated with a non-toxic anti-fog surfactant, said anti-fog film containing a pair of thin plastic windows formed therein and disposed such that when said anti-fog film is wrapped around said tubular portion said respective thin plastic windows are disposed over said respective oppositely disposed openings of said tubular portion so as to form a substantially airtight seal and so as to be a predetermined distance from each other during said quantitative measurement of the concentration of respiratory constituents of the patient using said infrared transmission and detection devices, said windows passing infrared energy from said infrared transmission device to said detection device; and a thin copper layer disposed between said anti-fog film and said tubular portion so as to distribute heat from said infrared transmission device over the surface of said tubular portion.
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17. A method of forming an endotracheal airway adapter having anti-fog windows for use in a respiratory airstream of a patient in proximity of the patient'"'"'s mouth during quantitative measurement of the concentration of respiratory constituents of the patient using a respiratory analyzer having infrared transmission and detection devices disposed in a housing which receives said airway adapter, comprising the steps of:
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respectively disposing a pair of thin plastic windows over oppositely disposed openings of a substantially tubular portion comprised of a material which is slightly deformable and has said oppositely disposed openings in a width-wise direction thereof which lie in an optical path between said infrared transmission and detection devices when received by said housing, said pair of thin plastic windows and said oppositely disposed openings forming a substantially airtight seal and said pair of thing plastic windows being a predetermined distance from each other during said quantitative measurement of the concentration of respiratory constituents of the patient using said infrared transmission and detection devices, said windows passing infrared energy from said infrared transmission device to said detection device; and treating said windows with a non-toxic anti-fog surfactant so as to prevent fogging of said windows when said windows are placed in the respiratory airstream of the patient. - View Dependent Claims (18, 19, 20, 21, 22, 23)
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Specification