Breathing apparatus having an arrangement for artificial respiration

Oct. 28, 1969 □. q. a. johannisson 3,474,784

BREATHING APPARATUS HAVING AN ARRANGEMENT FOR ARTIFICIAL RESPIRATION

Filed Nov. 18, 1966

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United States Patent Office _Patented J?™’™ '

3,474,784

BREATHING APPARATUS HAVING AN ARRANGEMENT FOR ARTIFICIAL RESPIRATION

Dag Olof Alfred Johannisson, Lidingo, Sweden, assignor to AGA Aktiebolag, Lidingo, Sweden, a corporation of Sweden

Filed Nov. 18,1966, Ser. No. 595,393

Claims priority, application Sweden, Jan. 19, 1966, 663/66

Int. Cl. A62b 9/02, 7/00; A61h 16/00

U.S. CI. 128—145.7 8 Claims

ABSTRACT OF THE DISCLOSURE

A breathing apparatus adapted for artificial respiration has a feeding device such as rubber bag for feeding gas through a conduit to a three-way breathing valve, which responds to pressure differences so as to connect a patient alternately with the feeding device for an inspiration and with an expiration outlet for an expiration. Auxiliary valve means in the form of a pair of oppositely directed non-retum valves in the conduit separates the feeding device from the three-way valve, these non-return valves responding to predetermined pressure differences to open the conduit and permit flow to or from the three-way valve, depending upon the sense of the pressure difference. A manual control can hold one of the non-retum valves open so as to permit continuous flow therethrough.

The invention relates to a breathing apparatus having an arrangement for artificial respiration and comprising a reservoir for the breathing gas, a feeding device for feeding from the reservoir to the patient, a conduit leading from the feeding device and adapted to be connected to the breathing organs of a patient, and a multi-way breathing valve with an expiration conduit provided in the said conduit and responsive to pressure from the feeding device for opening and admitting breathing gas to the patient and simultaneously closing the expiration conduit, and which responds to breathing pressure from the patient to open the expiration conduit.

In an arrangement of this type, the feeding device may comprise a construction of the reservoir to make possible the delivery of gas from the same; for instance, the reservoir may be a rubber bag which can be compressed for feeding gas to the patient.

It may be desirable for the connection from the reservoir to the multi-way breathing valve not to be directly open but through an overflow valve, which, even if it does let the feeding pressure pass during artificial respiration, does not let pass the pressure with which gas is fed into the apparatus. If this arrangement were not provided, the last-mentioned feeding pressure, which is to fill the reservoir during the patient’s expiration, would reach the multi-way valve and the patient would have to overcome this feeding pressure in order to open the multi-way valve.

According to the invention, this disadvantage is obviated by means of an auxiliary valve arrangement provided in the conduit between the feeding device and the breathing valve and comprising an overflow valve which is adapted to open in response to pressure from the feeding device and clear the conduit leading to the patient.

However, providing such an overflow valve may in its turn lead to a difficulty owing to the fact that at the termination of an artificial inspiration there is a high residual pressure between the overflow valve and the patient, which would have to be overcome by the patient if he is to actuate the multi-way valve for an expiration. To obviate this, it is preferable to provide also a nonreturn valve making possible a passage in the opposite direction to that of the overflow valve, whereby the said pressure can be let off through the nonreturn valve and contribute to the filling of the reservoir. In this manner, the patient only has to overcome the inherent pressure of the multig way valve itself, which is of a negligible order of magnitude.

An embodiment of the invention is shown on the drawing.

The embodiment shown has a conduit 5 adapted to be IQ connected on one hand to a gas-source supplying oxygen or air and/or other gases, e.g. N₂O, with a predetermined pressure and on the other to the patient’s breathing organs.

Conduits 5 communicates with a rubber bag 37 serving 15 as a reservoir and leads to an auxiliary valve device 38 and from it on via a breathing valve to the patient.

Valve device 38 comprises a housing 39 having a valve chamber 40 with an overflow valve comprising a valve disc 41 therein, the valve disc being urged towards the 20 closing position by a spring 42 acting against a membrane 43. A central aperture is provided in valve disc 41 to cooperate with a smaller valve disc 44, which is also urged towards the closing position by a spring 45 acting against a stem 46 and valve disc 41.

A knob 47 is provided to be adjustable between two positions, the drawing showing the knob in its pusheddown position. Knob 47 is mounted on a shaft 48 having recesses 49 and 50 into which a spring-urged ball can snap so as to determine the two terminal positions to 30 which knob 47 can be adjusted. A lever 52 is pivotally mounted on housing 39 to be actuated through a spring around the outer part of shaft 48, to in turn control membrane 43.

In its pushed-down position, knob 47 determines by 35 means of lever 52 acting on the membrane an outer terminal position for membrane 43, whereby valve discs 41 and 44 are normally closed. In the outer position of knob 47, lever 52 pivots to move membrane 43 inwardly against stem 46, hence unseating valve disc 44 40 and establishing a continuous opening.

The breathing valve 51 is provided with an easily flexible thin valve disc 53, the edge of which seats on a larger valve seat, thereby closing off conduit 5. The central portion of disc 53 seats on a smaller valve seat ⁴⁵ formed by a tube 54. In the inactive position, disc 53 seats on both of the valve seats referred to; it is retained in position by pins 55 engaging tube 54.

Tube 54 has a wider portion 56, in which there is provided a valve disc 57 serving as a nonreturn valve for ⁵⁰ the patient’s expiration.

OPERATION

Auxiliary valve 38: the essential function of this arrangement is in connection with giving the patient artificial 55 respiration by means of a pressure on the rubber bag. By observing the rubber bag, it is possible to see if the patient’s spontaneous breathing ceases, for the bag normally moves in the rhythm of the patient’s breathing. If it is desired to give artificial respiration, the bag 37 is 60 compressed. Air is then forced out through auxiliary valve 38, the valve disc 41 of which is unseated by the pressure in conduit 5. The gas mixture flows through chamber 40 and under the edge of valve disc 53 to the patient. The pressure in conduit 5 then presses valve 65 disc 53 against tube 54. When the inspiration is completed, this pressure must be removed to make possible for the patient to breathe out through tube 54 and valve 57, since this expiration has to take place by means of the expiratory pressure acting on the peripheral part of 70 valve disc 53 so as to unseat it from the tube 54.

If this operation is to be possible, the pressure on the underside of valve disc 53, as was mentioned above, must

3,474,784 be removed. To this end valve disc 44 can move away from disc 41 and makes it possible for the gas to flow from conduit 5 back to rubber bag 37, thus relieving the residual pressure between breathing valve 51 and auxiliary valve 38.

When knob 47 is in the drawn-out position, membrane 43 acts against stem 46 to hold valve disc 44 open, and continuous flow of the gas mixture can take place.