US3292623A

US3292623A - Respirator

Info

Publication number: US3292623A
Application number: US347092A
Authority: US
Inventors: Raymond W Warren
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-02-24
Filing date: 1964-02-24
Publication date: 1966-12-20
Anticipated expiration: 1983-12-20

Description

Dec. 20, 1966 R. w. WARREN 3,292,623

I RESPIRATOR Filed Feb. 24, 1964 /N VENTO/Z,

2/2 YMO/VD h! WAz/ZEN responsive to the pressure in the patients lungs.

United States Patent. O

3,292,623 RESPIRATOR Raymond W. Warren, McLean, Va., assignor to the United States of America as represented by the Secretary of the Army Filed Feb. 24, 1964, Ser. No. 347,092 1 Claim. (Cl. 128-203) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to me of any royalty thereon.

This invention relates to respirators and more particularly to novel pressure regulated device for cycling air to a persons lungs for breathing purposes through the patients mouth and nose.

Objects of this invention include the provision of a novel, lightweight, inexpensive, no moving part, respirator which can efiiciently cycle air through a victims lungs by raising the pressure above and below atmospheric pressure, and which will automatically adjust to the natural respiration of the patient.

The reasons for these objects may be readily appreciated by considering the usual emergency situation where a patient is unconscious, and has apparently stopped breathing. The person may be a victim of drowning, or a battle casualty in a military situation. In these situations speed is essential. Since applicants device is lightweight, inexpensive, and has no moving parts it may be widely distributed in the field at points of possible use. Since the respirator has no moving parts it will operate satisfactorily after years of disuse.

By raising and lowering the pressure above and below atmospheric, the maximum exchange of air to the patients lungs can be accomplished. Further, since the respirator will automatically adjust to any feeble breathing, there is no fighting between the respirator and the patient.

Applicants successful realization of the stated objects also makes this invention useful for persons with chronic respiratory disorders. In such cases the lightweight, compact features permit some patients to become at least partially ambulatory by using this respirator. Further, the automatic adjustment of the applicants novel respirator to the breathing of the patient is especially beneficial.

The stated objects of this invention, as well as other objects and features of this invention, are achieved through the use of a bistable, pure fluid element. One output channel of the element is a respiratory channel and the other channel is an exhaust channel. The respiratory channel contains pressure sensitive control means which is When the lung pressure has built up to a predetermined amount, the air supply in the respiratory channel is stopped, and simultaneously the patients lungs are exhausted through this same channel until a predetermined subatmospheric pressure is reached. When the subatmospheric pressure is reached, the control means causes air to again enter the respirator channel.

FIG. 1 is a plane view of an embodiment of applicants novel respirator.

FIG. 2 is a partial sectional view showing the laminar construction, and control adjustments.

In FIGURE 1 there is shown the respirator pump connected to a source of compressed air 11 with a mask 12 adapted to be applied over the face of a patient.

The respirator pump 10 is essentially a bistable, lockon type, fluid amplifier. It has a fluid jet-forming nozzle 14, an expirating channel 15, a respirating channel 16 and opposed

control nozzles

17 and 18.

The characteristic of this type of fluid device, as is well understood by those skilled in the art, is wall lockon. That is, a fluid jet formed in nozzle 14 and issuing from the nozzle 14a will become attached to, and lock on to either the wall 15a of expirating channel 15 or wall 16a of respirating channel 16. Attached to either the

wall

15a or 16a is a stable condition, and the fluid jet issuing from nozzle orifice 14a will remain attached until a control signal is received from

control nozzles

17 or 18.

In the respirating channel 16, there is a lung pressure sensing port 19. Connecting the lung pressure sensing port 19 and the control nozzle 18 is afluid feed-back path .21.

The control nozzle 17 is connected to atmosphere via channel 22 and an adjusting valve 23. Feed-back line 21 has a similar adjusting valve 24. One embodiment of valve 23 is shown in FIGURE 2, which also illustrates a preferred laminar construction for the respirator 10.

The respirator may be constructed by bonding an upper flat plate 26, which may be made of a clear plastic if desired, to a lower plate 27 which has the various channels and nozzles etched or machined on it, such as channel 22. The adjusting valve 23 may be merely a screw 28 idapted to be screwed into the channel 22 to close it o In operation, the mask 12 is placed over the face of the patient while the air supply 11 is turned on by means of a valve 31.

The air jet formed by nozzle 14 issuing from orifice 14a will instantaneously impinge upon splitter 30, then quickly become attached to either the

wall

15a or 16a. If it is desired to insure that the jet will initially flow into the respirator channel, the unit may be geometrically biased by placing the splitter 30 slightly to the right (toward nozzle 17) of the centerline of nozzle 14.

Assuming the air jet to be locked on the Wall 16a of respirator channel 16, air will flow into the mask 12 and thence into the patients lungs. As the air fills the patients lungs, the pressure in the respirator channel 16 increases. This increased pressure in 16 is detected and fed back into control nozzle 18 via port 19 and channel 21.

When the pressure at the nozzle 18 exceeds a predetermined amountsuificient to overcome the bias pressure at nozzle 17-the air jet is switched, attaches to wall 15a and issues from expirating channel 15.

Flow from the expirating channel entrains air from the respirating channel 16, lowering the pressure in this channel to below atmospheric. This lowered pressure in channel 16 helps to expel the air from the patients lungs.

The reduced pressure in channel 16 is felt by the port 19 and fed back to control nozzle 18 via channel 21. When the pressure nozzle 18 has reached a predetermined subatmospheric value, the pressure at nozzle 17, connected to atmosphere via channel 22, is sufficient to switch the air jet back into the channel 16, and becomes attached to the wall 16a. Air again fills the patients lungs, and the above described cycle is repeated.

As will be apparent to those skilled in the art, the frequency at which the respirator cycles can be adjusted by means of

control valves

23 and 24. That is, the dwell time, or time the air jet is in each

channel

15 or 16 may be adjusted to suit a patients natural respiratory rate by means of these

valves

23 and 24.

Opening valve 23 alone tends to raise the pressure at nozzle 17 increasing the time the air jet is in the respiratory channel 16. Conversely, closing valve 23 decreases the time the air jet is in the respiratory channel 16.

Closing valve 24 alone will tend to increase the time the fluid jet stays in respirator channel 16, and opening it tends to decrease the dwell time in respirator channel 16.

By properly adjusting the frequency of the respirator 10 to a value slightly longer than the patients natural breathing rate, respirator 10 can be used to assist a patient with a pulmonary disorder.. In this case. the patients arespirator control device connected to said source of 10 pressurized air and including a bistable fluid amplifier having an air jet nozzle, a respiratingchannel and expirating channel, said channels meeting and diverging from in front of said air jet nozzle, a control nozzle adjacent said jet nozzle, a closed feed-back path including a port communicating with said respirating channel and said control nozzle, said feed-back path having a variable valve therein, a biasing nozzle adjacent said air jet nozzle and opposite said control nozzle, said biasing means being in continuous communication with atmosphere and having means to modulate the communication of said a biasing nozzle and said atmosphere; and a mask attached to said respirator channel.

References Cited by the Examiner UNITED STATES PATENTS 2,536,435 1/1951 FOX 12s 2 9 3,001,539v 9/1961 Hurvitz 137 s1.5 3,185,166 5/1965 Hortonetal 137-81.5

OTHER REFERENCES Transactions American Society for Artificial Internal Organs: A Blood Pump Powered and Controlled by a 15 Fluid Amplification System, Barila et al., vol. VIII RICHARD A. GAUDET, Primary Examiner.

' C. F. ROSENBAUM, Assistant Examiner.