US2121311A - Respiration apparatus - Google Patents

Description

June 21, 1938.

E. E. W. ANDERSON ET AL RESPIRATION APPARATUS Filed A ril 1, 1935 the respiratory action. The respiration muscles pressed. to ether.

sion must be compensated for by increasing the Patented June21, 1938 UNITED STATES PATENT OFFICE aEsPmA'moN APPARATUS Emil Einar Wilhelm Anderson and Georg Karl Vilhelm Johanson, Lidingo, Sweden, assign'ors to Svenska Aktiebolaget Gasaccumulator, Stockholm, Sweden, a corporation of Sweden Application April 1, 1935, Serial No. 13,996'

In Sweden April 5, 1934 16 Claims. (Cl. 128--29) Our invention relates to artificial respirators, branch conduit must be forced down before the and especially to apparatus of this type which is exhaling gas can escape. suitable for maintaining respiration during sur- In this kind of apparatus the inhalation is gical operations on the lungs of a patient. effected in such a way that the patient reduces Broadly, there are two types or kinds of resthe pressure in the lungs by means of the respiration apparatus, the first being employed to piration muscles to such an extent that gas from revive persons who are apparently dead, and the the apparatus flows thereinto. second being used for sustaining respirationdur- Both these types of respiration apparatus are, ing operations. however, of no use for more complicated opera- In the respiration apparatus used to revive pertions on lungs, especially for operations -in which sons who are apparently dead, an injector is used, the chest is entirely or partly cut open so that the pressure and suction sides of which, respecthe respiration muscles do not function satisfactively, are connected alternately with the inhaltorlly or even do not function at all, ing conduit'. Apparatus of this kind consequently Successful use of the foregoing type of respiraoperates so that air or oxygen gas is forced into tion apparatus is possible only if the operation the lungs up to a definite pressure, whereupon alfects but one of the lungs and only if such the gas is sucked out until a pressure somewhat operation may be rapidly performed. It the opbelow atmospheric pressure is obtained. 'I'hereeration is of longer duration it is probable that upon, the cycle is repeated. the patient will die because the respiration pro- The apparatus hitherto used for sustaining resceeds at greatly reduced efficiency. This is bepiration during operations has relied on the in-- cause the opened lung does no work, but serves haling muscles of the patient continuing to work as an equalizer for the other lung, so that only and the patient himself doing all or most of the one-half of the gas inhaled by the other lung respiration. Respiration apparatus of this kind consists of fresh air, while the other half consists supplies the gas to the lungs in a continual curof consumed air from the lung being operated rent, but when the patient exhales, means are upon. In the most complicated cases when both provided for passing the gas through a branch the pleural sacs must be opened,there is pracconduit. A resistance to flow is placed in this tically no chance of the patient surviving. In branch conduit or at the outlet thereof, so that such cases the second of the above mentioneda predetermined pressure is necessary for flow types of respiration apparatus is wholly useless to take place therethrough. because the motive power required is furnished This is necessary on account of the nature of by the respiration muscles of the patient. The first type of respiration apparatus cannot be used in this case either, as it works at a neutral respiration pressure level, and hence, as soon as the pleural sacs are opened, the lungs shrink.

One of the objects of our present invention is to provide a respiration apparatus in which the inhalation is effected by forcing gas into the lungs during a period of increasing elastic tension oi. the lungs, and the exhalation is effected by letting gas out during a period of decreasing elastic tension of the lungs. In both cases, however, a positive minimum pressure, adjustable from case to case, is maintained which allows an exhalation from the patient without relying on his own respiration action.

A further object of our invention is the provision of apparatus of the above type in which do not influence the lungs directly, but act upon the pleural sacs so that these expand or are Hence, there arises a partial vacuum or an excess of pressure between the pleural sac and the lung which results in inhalation or exhalation from the lung in order to equalize the pressure. The lung therefore lies more or less as an expanded elastic bladder within the pleural sac. The elastic tension in the lung is normally equal to to mm. of water column. In order to prevent the lung from shrinking or collapsing when the. chest is opened during an operation, the lung's own tenrespiration pressure level an amount corresponding to the above elastic tension of the lung. I

Usually the positive respiration pressure is produced by submerging the outlet of the branch conduit a suitable depth below the surface of a liquid so that the column of the liquid from the surface down to the outlet of the exhalation or the period of the artificial respiration is not scious reaction of the patient against a wrong periodicity.

Further objects and advantages of our invention will be apparent from the following description, considered in connection with the accompanying drawing which forms part of this specification and which is a cross-sectional view of a preferred embodiment of our invention.

In the figure, reference character I indicates a cylinder containing gas, such as oxygen. A pressure reducing valve 2, pressure governor 3 and an equalizer 4 are interposed in the conduit leading from this cylinder. The, gas contained in cylinder is under high pressure and valve 2 is a standard reducing valve for reducing the pressure of the gas passing therethrough. Pressure governor 3 is provided with valve mechanism controlled by a spring-pressed diaphragm and serves to maintain the pressure of the gas on the discharge side thereof at a constant value. Equalizer 4 comprises a chamber having an appreciable volumetric capacity bounded by a spring-pressed diaphragm and serves as a surge chamber to prevent sudden fluctuations in pressure which might occur too rapidly to be equalized by pressure governor 3. From the equalizer 4 a supply conduit 5 leadsto the main valve chamber 1 of the apparatus, a throttle valve 6 being interposed in the conduit. The valve chamber 1 contains an inhalation valve 8 and an exhalation valve 9, the valve members of which are connected with each other by means of a spindle |2 to which is also connected a quick action mechanism arranged in the pressure chamber Ill. Mechanism may consist of any pressure responsive snap action device and, as shown, comprisestwo levers connected to each other, the outer ends of said levers being connected to fixed points on the walls of chamber I0. One of these levers 49 includes a spring 50, interconnected between its two parts, the other lever 5| being connected to the spindle I2 and by means of spring 52 to the diaphragm 53, this latter being under pressure from spring 54. If the pressure in chamber I is increased, diaphragm 53 will slowly move against pressure of spring 54, thereby increasing the tension of spring 52. At a certain pressure this tension is equal to the component along the spindle |2 of the pressure from spring 50. Upon further increase of pressure in chamber lit-the tension in spring 52 will cause lever to move upwardly, therebycausing the angle between the levers to approach 180 and giving rise to a very rapid decrease of the said component of pressure from spring 50. The diaphragm 53 being balanced by springs 52 and 54 during this movement also moves upwardly, thus maintaining tension in spring 52. The spindle |2 therefore suddenly will snap to its highest position. The reverse is true upon a reduction in pressure. It will thus be apparent that valves 8 and 9 have no intermediate positions, but are either fully open or closed. Between the valve chamber 1 and the pressure chamber ID a check valve I3 is arranged- I8 by means of a conduit H, the chamber between the valve 8 and the wall I8 is connected with the supply conduit 5, and the chamber between the wall l6 and the valve 9 is connected with the exhalation valve housing 20 by means of a conduit l9. Both the inhalation valve housing l8 and the exhalation valve housing 20 are each divided into valve chambers 2| and 22, respectively, and diaphragm chambers 23 and 24, respectively. The tensions of the diaphragms are provided by springs 25 and 26, respectively. Spindles 21 and 28, respectively, connect the diaphragms with a second inhalation valve 29 and a second exhalation valve 30, respectively.

The inhalation valve chamber 2| is connected by means of the inhalation conduit 3| with the respiration mouth piece 32 and by this with the lungs, as schematically outlined at 33. From the inhalation conduit 3| a pressure equalizer conduit 34 communicates with'the diaphragm chamber 24 of the exhalation valve 20. Exhalation conduit 35 connects the valve chamber 22 of the exhalation valve 20 with the respiration mouth piece 32, and a pressure equalizer conduit 36 establishes communication between conduit 35 and the diaphragm chamber 23 of the inhalation valve I8.

An electric heater 3'! is arranged in connection with inhalation conduit 3|, and may also effect the gasification of narcotics in a reservoir 38. The temperature is measured by the thermometer 39. If desired, the inhaling gas may be moistened in the container 40. The level of respiration is read off on the manometer 4|, arranged in one of the pressure equlizer conduits, for instance in the conduit 36.

The device works in the following way. Assume that all valves are in the positions shown in the figure. The gas flows from the cylinder through the reducing valve 2, the pressure governor 3, the equlizer 4 and the conduit 5 with the throttle 6 to the chamber above the wall IS. The valves 8 and 29 being open, the gas continues through the conduit H, the valve chamber 2|, the conduit 3| and the mouth piece 32 to the lungs 33, which during a period of increasing elastic tension caused by their expansion, are filled with 5 fresh gas. The pressure of fluid being delivered to the lungs is transmitted to the diaphragm chambers 23 and 24 by means of the pressure equalizer conduits 36 and 34. A relatively small pressure increase causes the valve 30 to be opened by the diaphragm connected therewith. At first, however, this has no effect, as the valve 9 is still closed.v When the maximum pressure of the lung has been attained, the valve 29 is closed by its diaphragm.

The closing of valve 29 causes the pressure in the chamber above the wall I6 to increase very rapidly, and the gas, after having attained a certain pressure, flows into the pressure chamber I!) through the valve l3. After a short time, for instance 6 of a second, the valve spindle I2 is suddenly moved upwardly, thus closing the valve 8 and opening the valve 9.

The exhalation period now begins, the consumed gas leaving the lungs 33 through the mouth piece 32, the conduit 35 and the valves 30 and 9. By closing the valve 8, the gas supply to the pressure chamber III has been cut oil. Thereafter, the gas will be slowly discharged from this chamber through the conduit l4 and the throttle I5. A short time after the exhalation period has begun the valve 29 is opened due to the reduced pressure in diaphragm chamber 23, but this, how- 40 able for this purpose.

reached, and the exhalation periodstops. The

. valve 29 and the valve 30 are now in their proper positions for the start of the next'respiration cycle, and this begins immediately, when the pressure in the pressure chamber ID has fallen sumciently for the mechanism I I to move spindle l2 downwardly to open valve 8 and close valve 9. The respiration cycle is now repeated in the .same manner as above described.

It will be seen that the frequency of the periods may be regulated by adjusting throttle l5 the maxlmum pressure at theend of the inhalation period can be arbitrarily regulated by adjusting spring 25. In a corresponding way the positive. minimum pressure, which stops the exhalation period, may be adjusted by means of the spring 26. Normally, a relatively smallamount of gas is delivered between these two positions and consequently the movements of the lungs are relatively small, which is necessary in order not to disturb the physician in his operation. The apparatus, as above described, is

therefore not suitable as a reviving apparatus, partly for the reason that it causes too small respiration movements of the lungs, and partly on account of its respiration level being unsuit- However, the apparatus can-be easily adjusted so as to serve for reviving purposes. Two handles 42 and 43 are arranged inconnection with the inhalation valve l8 and the exhalation valve 20, respectively. By

means of the handle 42 an additional spring 44 may be rendered effective by means of which the maximum pressure may be increased to a value suitable for reviving apparatus. The handle 43 is arranged to lock the valve 3|] in o en 0 position so that the exhalation is unimpeded.

If the respiration muscles of. the patient are able to function even to an insignificant degree,

the patient unconsciously reacts against a wrong 3 respiration periodicity by movements that couri- 55f teract the normal period of the respiration of the apparatus. The respiration apparatus is Q sensitive to such re-synchronizing impulses. For this purpose, a valve 46, auxiliary to the exhala- Ition valve 30, is provided. These two valves are oiliconnected witheach other and with the diaphragm 45 by means of a lever 41 so arranged gthat inward movement of the diaphragm first completely closes valve 30, provided that the valve 30 is not locked, without actuating valve 65 46, but further movement of the diaphragm rapidly opensvalve 46. In case the valve 30 is' locked, and'the apparatus is working as a reviving apparatus, the diaphragm 45 immediately opens valve 46. The valve 46 is arranged in a 70 conduit 48, which connects the pressure cham- 75 apparatus, a vacuum is produced in the lungs 33 which is transmitted by the conduit 3| and the equalizer conduit 34 to the diaphragm chamber 24. This vacuum causes the diaphragm -46 to move inwardly sufficiently to open the valve 46.

Either the exhalation period of the apparatus has already been stopped by the normal closing of the valve 30 or this valve is closed by the 'movement of the diaphragm caused by the attempted inhalation. The pressure chamber III is immediately emptied by the opening of valve 46 and the mechanism II closes the valve 9 and opens valve 8, thereby starting a normal inhalation period. The re-synchronizing has, in this manner, been eifected.

If the re-synchronizing takes place during a period of inhalation of the apparatus by an attempted exhalation of the patient, the conduit 35 and the pres-sureequalizer conduit 36 transmit an immediate excess of pressure to the diaphragm chamber 23, which causes the valve 29 to close. A corresponding excess of. pressure is transmitted by the conduit 31 and the pressure equalizer conduit 34 to the diaphragm chamber '24 of the valve housing 20. The valve 30 is immediately opened thereby, and the valve 46, should it have been opened, is closed. In this way the passage between the pressure chamber i0 and the atmosphere at valve 46 is closed (throttle i5 remains open), and the valves 8 and 9 are moved to their proper position for the beginning of an exhalation period. Thus, in this case, a complete resynchronizing has been e1- fected.

While we have shown and described one preferred embodiment of our invention, it is to be understood that this has been done for purposes of illustration only, and that the scope of our invention is not to be limited thereby, but is to be determined by the appended claims viewed in the light of the prior art.

What we claim is:

1. In a respiration apparatus, means for stepping an inhalation period at a maximum positive pressure, means for stopping an exhalation period at a minimum positive pressure to thereby constantly maintain positive pressure in said ap-- paratus while said apparatus is in use, and pressure responsive means for actuating said means.

2. In a respiration apparatus, a valve for stepping an inhalation period, means for closing said valve responsive to a maximum positive pressure, a valve for stopping an exhalation period, and means for closing the last-mentioned valve responsive to a minimum positive pressure to thereby constantly maintain positive pressurein said apparatus while said apparatus is in use.

3. In a respiration apparatus, a mouthpiece, an inhalation conduit connected to said mouthpiece, an inhalation valve in said conduit, a first diaphragm for actuating said valve, an exhalation conduit connected to said mouthpieceyan exhalation valve in said exhalation conduit, and a second diaphragm for actuating said exhalation valve, said first diaphragm being responsive to an increase in pressure in said mouthpiece to close said inhalation valve and said second diaphragm being responsive to an increasein pressure in said mouthpiece to open said inhalation valve, each of said diaphragms acting independently or the other.

4. In a respiration apparatus, a mouthpiece, an inhalation conduit connected to. said mouthpiece, an inhalation valve in said conduit, a first diaphragm for actuating said valve, an exhalation ,conduit connected to said mouthpiece, an exunder pressure, a mouthpiece, an inhalation conhalation valve in said exhalation conduit, and a second diaphragm for actuating said exhalation valve, both of said diaphragms being subjected directly to fluid pressure, said first diaphragm being responsive to an increase in pressure in said exhalation conduit to close said inhalation valve and said second diaphragm being responsive to an increase in pressurein said inhalation conduit to open said exhalation valve.

5. In a respiration apparatus, a mouthpiece, an inhalation conduit connected to said mouthpiece, an inhalation valve in said conduit, a first diaphragm for actuating said valve, an exhalation conduit connected to said mouthpiece, an exhalation valve in said exhalation conduit, a second diaphragm for actuating said exhalation valve, each of said diaphragms acting independently of the other to actuate the respective valves independently, said first diaphragm being responsive to an increase in pressure in said mouthpiece to close said inhalation valve and said second diaphragm being responsive to an increase in the pressure in said mouthpiece to open said exhalation valve, and means for controlling the frequency of the actuation of said valves by said diaphragms.

6. In a respiration apparatus, a mouthpiece, aninhalation conduit connected to said mouthpiece, an inhalation valve in said conduit, a first diaphragm for actuating said valve, an exhalation conduit connected to said mouthpiece, an exhalation valve in said exhalation conduit, a second diaphragm for actuating said exhalation valve, said first diaphragm being responsive to an increase in pressure in said mouthpiece to close said inhalation valve and said second diaphragm being responsive to an increase in pressure in said mouthpiece to open said exhalation valve, and means operative upon an. increase in pressure Within said mouthpiece for controlling the frequency of the actuation of said valves by said diaphragms.

'1. In a respiration apparatus, a source of gas under pressure, a mouthpiece, an inhalation conduit connecting said source with said mouthpiece, a first inhalation valve and a second inhalation valve in said conduit, an exhalation conduit connecting said mouthpiece with the atmosphere, a first exhalation valve and a second exhalation valve in said exhalation .conduit, means for closing said first inhalation valve in response to an increase in pressure in said mouthpiece, means for opening said first exhalation valve in response to an increase in pressure in said mouthpiece, and means operative upon an increase in the pressure within said mouth piece for simultaneously closing said second inhalation valve and opening said second exhalation valve.

8. In a respiration. apparatus, a source of gas duit connecting said source with said mouthpiece, a first inhalation valve and a second inhalation valve in said conduit, an exhalation conduit connecting said mouthpiece with the atmosphere, a first exhalation valve and a second exhalation valve in said exhalation conduit, means for closing said first inhalation valve in response to an increase in pressure in said mouthpiece, means for opening said first exhalation valve in response to an increase in pressure in said mouthpiece, means forming ,a pressure chamber connected to said inhalation conduit between said first and. second inhalation valves, a one-way valve opening from said inhalation conduit into said chamber, throttling means connecting said chamber with the atmosphere, and means responsive to an increase in pressure in said chamher for simultaneously closing said second inhalation valve and opening said second exhalation valve.

9. In a respiration apparatus, a source of gas under pressure, a mouthpiece, an inhalation conduit connecting said source with said mouthpiece, a first inhalation valve and a second inhalation valve in said conduit, an exhalation conduit connecting said mouthpiece with the atmosphere, a first exhalation valve and a second exhalation valve in said exhalation conduit, means for closing said first inhalation valve in response to an increase in pressure in said mouthpiece, means for opening said first exhalation valve in response to an increase in pressure in said mouthpiece, means forming a pressure chamber connected to said inhalation conduit between said first and second inhalation valves, a one-way pressure responsive valve opening from said inhalation conduit into said chamber, said first inhalation valve being arranged to close at a lower pressure than is required to open said oneway valve, throttling means connecting said chamber with the atmosphere, and means responsive to an increase in pressure in said chamher for simultaneously closing said second inhalation valve and opening said second exhalation valve.

10. In a respiration apparatus, a valve for stopping an inhalation period, means for closing said valve responsive to a maximum positive pressure, a valve for stopping an exhalation period, and means for closing the last-mentioned valve responsive to a minimum positive pressure, either of said means being adiustable so as to be operative at different pressures. 11. In a respiration apparatus, a valve for stopping an inhalation period, a spring-pressed diaphragm for closing said valve responsive to a maximum positive pressure, additional spring means, means for rendering said additional spring means operative to increase the value of the pressure at which said diaphragm responds to close said valve, a valve for stopping an exhalation period, and means for closing the last-mentioned valve responsive to a minimum positive pressure.

12. In a respiration apparatus, a valve for stopping an inhalation period, means for closing said valve responsive to a maximum positive pressure, a valve for stopping an exhalation period, means for closing said valve responsive to a minimum positive pressure, and means for maintaining the last mentioned valve open against the action of the second-mentioned means.

13. In a respiration apparatus, a valve for stopping an inhalation period, a spring-pressed diaphragm for closing said valve responsive to a maximum positive pressure, additional spring means, means for rendering said additional spring means operative to increase the value of the pressure at which said diaphragm responds to close said valve, a valve for stopping an exhalation period, means for closing the last-mentioned valve responsive to a minimum positive pressure, and means for maintaining said last-mentioned valve open against the action of the last-mentioned means.

14. In a respiration apparatus, a source of gas under pressure, a mouthpiece, an inhalation cn piece, an inhalation valve in said conduit, an

exhalation conduit'connecting said mouthpiece exhalation valve,

with the atmosphere,an exhalation valve in said exhalation conduit, a pressure chamber, means responsive toa normalincrease in pressure in said mouthpiece for admitting gas under pressure to said chamber, means responsive-to an increase in pressure in said chamber for simultaneously closing said inhalation valve and opening said exhalationvalve, and means responsive to an abnormal reduction of pressure in said mouthpiece for reducing the pressure in said chamber. I

15. In a respiration apparatus, a source of gas under pressure, a mouthpiece, aninhalation conduit connecting said source with said mouthpiece, a first inhalation valve and a. second inhalation valve in said conduit, an exhalation conduit connecting said mouthpiece with the atmosphere, a. first exhalation valve and a second exhalation valve in said exhalation conduit, a first diaphragm for closing said first inhalation valve 35 chamber to the atmosphere, a valve in the last-v mentioned conduit, and means operatively connecting said second diaphragm with the lastmentioned valve for opening said last mentioned valve in response to an abnormal reduction of pressure in said mouthpiece. 7

16. In a respiration apparatus, a source of gas under pressure, a mouthpiece, an inhalation conduitv connecting said source with said mouthpiece, a first inhalation valve and a second inhalation valve in said conduit, an exhalation conduit connecting said mouthpiece with the atmosphere, a first exhalation valve and a second exhalation valve in said exhalation conduit, a first diaphragm for opening said first inhalation valve in response to a normal decrease of pressure in said mouthpiece, a pressure chamber, means responsive to a normal increase of pressure in said mouthpiece for admitting gas under pressure to said chamber, means responsive' to an increase of pressure in said chamber for simultaneously closing said second inhalation valve and opening. said second exhalation valve, a conduit connecting said chamber to the EMIL EINAR WILHELM ANDERSON. GEORG KARL JOHANSSON.

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