Airco, Inc.

Wayne W Hay

A vaporizer interlock system is disclosed which is used in an anesthesia machine having two calibrated vaporizers for providing an anesthetic to a patient and further having a selector valve with three positions, two extreme positions where one of the two vaporizers is being utilized and a middle position where neither vaporizer is used. The system prevents opening of either vaporizer when the selector valve is in the middle position. Also, when the selector valve is moved to one of its extreme positions selecting one of the vaporizers, the other vaporizer is prevented from being moved from its 'off' position. The 'on' vaporizer must thereafter be placed in its 'off' position before the selector valve can be returned to its middle position. In addition, a quick disconnect means is shown for quickly attaching and detaching the vaporizers from the anesthesia machine.

Interlock system for anesthetic vaporizers

A manifold is described for use with anesthesia breathing circuits and which is adapted to receive exhaust anesthetic gases from the anesthesia breathing circuit for disposal thereof. The manifold is connectible to a vacuum system for such disposal and includes a needle valve which may be set to establish a desired flow of exhaust anesthetic gas to the vacuum system. Because the pressures (either positive or negative) within the manifold will also have an effect on pressures within the anesthesia breathing circuit from which the exhaust anesthetic gas is received, it is necessary to control the pressure inside the manifold within certain predetermined limits. Relief valves are thus provided and which relieve the pressure within the manifold at certain predetermined positive and negative limits. The relief valves are so arranged that both may be opened manually by a common member which is accessible exterior of the manifold and can readily be displaced by personnel. The displacement simultaneously opens both valves to free the same from sticking.

Evacuation manifold for medical anesthesia circuits

A selector valve for providing a choice of one of two vaporizers for use in administering an anesthetic to a patient is disclosed in connection with a manifold for receiving the vaporizers. The selector valve has three positions, wherein the user can utilize one of two vaporizers or place the valve in an off position when neither vaporizer is in the circuit providing a flow of gas to the patient. One of the features comprises a positive position means where the selector valve cannot inadvertently be placed in any position intermediate any two of the three positions so that only one of the three defined positions may be selected. Also, in the off position, leakage is prevented into the gas stream to the patient of anesthetic vapors from either of the vaporizers mounted to the manifold by closing both the inlet to and the outlet from both such vaporizers. Further, in the event one vaporizer is selected for use, the remaining vaporizer also has its inlet and outlet closed such that no inadvertent leakage of anesthetic vapor from the 'off' vaporizer can reach the path of gas proceeding through the 'on' vaporizer and selector valve to the patient. The means of connection and sealing means within the selector valve further are designed to insure that any seal leakage due to wear will cause the leaking anesthetic vapors to vent to atmosphere and not leak into one of the other active gas paths to the patient.

Selector valve for anesthesia machine

Anesthetic vaporizer of the flow-through type having a calibrated flow control valve unit for proportional distribution of the inlet gas between a vaporizing chamber and a main bypass passage to obtain a desired anesthetic concentration. A rotary, multiple-port valve with a multiplicity of laminar flow-type passages in parallel is operable in discrete steps for adding the anesthetic vapor from the chamber in predictable increments to a preset flow of the inlet gas for proportional gas division. An auxiliary gas bypass for temperature compensation has a cone-type valve with restricted opening controlled by a temperature responsive motor in the vaporizing chamber. A wick assembly in the anesthetic vaporizing chamber guides the chamber gas through a multiplicity of parallel passages formed by stacked sheets of absorbent and corrugated materials respectively, to obtain maximum vaporization of the anesthetic.

Calibrated anesthetic vaporizer

A valve is provided for use in an anesthesia breathing circuit and is located between the breathing bag or ventilator and the remaining parts of the circuit. The valve comprises a housing having an inlet connectible to the bag or ventilator and an outlet which is connectible to the remaining circuit. The valve has essentially two parallel flow paths for gas; in one path there is a check valve to allow gas to pass only in a direction away from the bag or ventilator, and in the other path is located a diaphragm valve which is spring biased to a closed position and is opened at a predetermined pressure in that path. The valve allows the retention at all times of a predetermined pressure within the patient circuit and thus the operator can select the lowest pressure which the patient's lungs will reach during ventilation to insure the lungs will always be expanded to more than their normal resting state. The position and operation of the present valve also achieves its desired result without introducing appreciable resistance against the patient's exhalation.

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Madison, WI, United States of America

Wayne W Hay