US3099278A - Automatic resuscitating pressure apparatus - Google Patents

Description

July 30, 1963 H. KEszLER ETAL AUTOMATIC REsUscTTATING PRESSURE APPARATUS Filed Dec. 29, 1959 IN VEN TOR. mm1 /mtr- 3,099,278 UTMATC RESUSCHATHNG PRESSURE APPARATUS Hugo Keszler, Prague, and .laroinir Bernreiter, Beroun,

Czechosiovairia, assignors to Chirana Praha, narodui podnik, Prague, Czechoslovakia Filed Dec. 29, 1960, Ser. No. 90,901 Claims priority, application Czechoslovakia `ian. 2S, 196@ 1t Ciairns. (Ci. 137-64) This invention relates to improvements in an automatic resuscitating pressure apparatus.

Resuscitating appliances are designed to operate either on the principle of what may be termed the external method, e.g. the so-cal-led iron lungs, or 4the internal rnethod in which the respiration mixture is alternately driven into the patients lungs during the inhaling period and sucked oli in the course of the exhaling period. The internal method can be either direct or indirect. According to the direct internal method .the patient is connected directly -to the apparatus while the indirect internal method is characterized `by a respiration bag controlled by the apparatus itself. The respiration bag, located in ya separate pressure chamber, is connected to the patients respiration system. This method is frequently used in anaesthetic appliances fitted with an equipment ior artificial respiration.

rthe appliances operating on the internal method Vare either of the volumetric type or of the pressure type. In apparatus of the volumetric type the inhalation is switched over to exhalation and vice versa after a definite volume of gas has been inhaled. in an apparatus of the pressurel type the switching-over action is related to the attainment of a certain overpress-ure or underpressure.

`l\-lowadays a great variety of automatic resuscitating pressure appliances based on both the direct and indirect method is in use. In all these appliances the inspiration overpressure and the expiration :underpressure `are yalternately exerted with the aid of one or two injectors.

When one injector only is provided the switch-over mechanism alternately opens and closes the communication between the suction or pressure side of the injector and the free atmosphere or the patients lungs respectively.` In other instances the yapparatus is designed so that the switch-over mechanism alternately controls only the communication Abetween the suction or pressure side of the injector and the patients lungs while the communication between the suction or pressure side of the injector and the free atmosphere is controlled by means of springloaded unidirectional valves. These valves serve at the same time as underpressure or overpressure safety means.

In case of two injectors the switch-over mechanism usually controls the admission of the driving 'ga-s (most irequently oxygen) to the nozzles of the injectors and further also the communication between the suction side of the expiration injector (better called `an ejector) or the discharge side of an inspiration injector and the lungs of the patient.

Usually, the switch-over mechanism is controlled by means of a bellows or-more frequently`by means of an elastic diaphragm or like. Some types of these devices enable the yartificial pulmonary ventilation or the respiration frequency corresponding to -a certain respiratory volume to be controlled by 'an increased o-r decreased intake of the ydrivin-g gas. Additionally some appliances are equipped with facilities for controlling the inspiration overpressure and the expiration underpressure which, however, can only be controlled in relation to one another so that the increasing inspiration over-pressure ycauses also the expiration underpressure to rise, whereby the respiratory volume is also increased to a certain extent.

All aforementioned devices 'show the common draw- 3,099,273 Patented July 30, 1963 back that the inspiration overpressure and the expiration underpressure cannot be `controlled independently each from the other. The ratio of inspiration to the expiration period likewise, cannot -be regulated. Moreover, if these devices operate with a mixture of :oxygen and atmospheric air, they cannot be used in unbreathable media.

rfhese drawbacks are of considerable importance since the `average position of the thorax and .the respiration volume in case of artificial pulmonary ventilation can only lbe correctly adjusted if both above mentioned pressure values `are controlled independently.

The control of the ratio of inspiration and expiration period is of great practical value in case of extended artificial respiration since it permits a proper adjustment of the optimum conditions for air circulation, any excessive heart eliort, which usually occurs at the occasion of `artiicial respiration, can be eliminated.

The ability of the automatic resuscitation apparatus -to be used also in unbreathable medium is rather important mainly in such instances where the delay caused by prolonged transport of the patient, which is yoften required in order -to reach a reasonably pure atmospheric 'air (eg. in mines, large factories, etc.) could c-ause irreparable harm to or even death of the person to which artificial respiration has to be applied.

The above mentioned types of resuscitation apparatus with spring-loaded unidirectional valves mounted in the suction and pressure channels through which the single injector communicates with free atmosphere, have the further drawback that the injector rnust in all cases overcome an increased resistance either at the suction or at the pressure side `so that the consumption of the driving 4gas is unnecessarily large and the operational time of the apparatus corresponding to a ygiven quantity of driving gas is relatively short.

Appliances with a single injector, when compared with those .equipped with two injectors, show `a further disadvantage, namely that bot-h the inhaled and exhaled mixture flows alternately through the injector and the disinfection of the injector is usually extremely difiicult cr--in most cases-almost impossible. Appliances of the double-injector type are, therefore, preferable from the point of View of hygiene.

The drawbacks inherent in the above mentioned appliances `are eliminated to ,a substantial degree by the irnproved automatic resuscitation pressure `apparatus according to the present invention, which apparatus is adapted to operate according to the internal direct and indirect method. The apparatus, operating with alternating positivo and negative pressure, is driven by compressed oxygen or air and comprises an injector for inspiration and an ejector' for expiration. in this resuscitation apparatus the inspiratory overpressure is controlled so that a valve combined with la unidirectional check valve directed into the space within a pressure responsive member, which governs a switch-over or trigger mechanism, controls the overpressure difference existing between said space and `a chamber connected directly to the patients respiration channels. Said pressure responsive member may consist of `a chamber having a flexible diaphragrnatic wall. Another valve, `also combined with a non-return check valve leading out of said space, controls the underpressure difference between said space and the chamber connected directly to the patients lungs-and thereby `also the expiratory underpressure. According to the present invention, Ithe ratio of the inspiratory period to the respiratory period is controlled by shortening or extending the expiratory time this being effected by partly opening or closing an orifice plate or other closure means mounted in the ejector outlet, whereby the output of the ejector is increased or reduced. All controls, described above, are fully independent from each other.

The fresh-air inlet of `our new apparatus is equipped with an 'easily dismountable connecting device, for example with a threaded socket, to which a gas, smoke or dust lil-Iter or also the mine self-rescue device can be connected so that the apparatus can be used also in an unbreathable medium.

According t-o another feature of our new apparatus the switch-over or trigger mechanism controls not only the valves for intake of the driving gas into the injector and into the ejector, but also a valve in the suction branch of the ejector and a valve in the pressure branch of the injector in such a way that during the expiratory period the suction side `of the ejector is open while during the inspiratory period the pressure side of the injector is open. Both the ejector and the injector operate, therefore, without undue resistance whereby the driving gas consumption is minimized. The valve at the suction side of the ejector simultaneously serves as an adjustable overpressure safety valve while the valve of the pressure side of the injector also operates as an adjustable underpressure safety device.

The underpressure safety Valve is `connected to the suction branch of the injector so that, if the appara-tus operates in :an unbreathable medium and if the `admissible underpressure is exceeded, air from the outer space is forwarded through the corresponding filter.

The use of a separate injector for inspiration and a separate ejector for expiration in our new apparatus is of special advantage not only from the hygienical point of view but also because both the injector and the ejector are provided with nozzles having internal diameters dependent on each other so that the injector supplies the respiration mixture with an optimum oxygen concentration, while the high economy of the expiration ejector remains unaffected.

The objects of our invention will be more fully understood from the following specification when read with the accompanying drawing showing an embodiment of the new apparatus.

In the drawing,

PIG. 1 shows -a vertical -axial section of the :apparatus adapted for clinical application the apparatus being illustrated in the expiration phase, and

FIG. 2 is `a partial section on line 2--2 of FIGURE 1.

The `apparatus as shown comprises a cylindrical housing formed by a lower bottom part 4 and an upper lid part 18. A partition 1 held by and between said two parts encloses with said lower part i a valve controlled first chamber 25 which is provided with a duct 5 connectable to the patients lungs to carry either exhaled waste symbolized in the drawing by the directional arrow 20 or breathable medium symbolized by the directional arrow 24.

The partition 1 supports a pressure sensitive flexible diaphragm 2 which encloses with said partition a seco-nd chamber 26 occasionally hereinafter referred to as the diaphragm chamber. The chambers 25 and 26 communicate over two check valves 28 and 29, which open in different directions; namely, the valve 28 into the chamber 25 and valve 29 into the chamber 26. Said check valves 23, 29 may cooperate with adjustable throttle valves such as needle valves 1liand 15, respectively, which will control the length of time required for compensation of the pressures in said two chambers.

An ejector 6 is located within the chamber 25. During the expiratory period driving gas such as compressed air or oxygen symbolized by the directional arrow 19 is introduced into the ejector through a pipeti over a controlled inlet valve 8. The ejector c includes :a suction duct 6 which communicates with the first chamber 25 over a spring loaded control valve 10 which opens into said duct and also acts as an automatically working safety valve when the pressure of the inspiratory mixture-symbolized by the directional arrow 2er-within the chamber 2S exceeds a desired limit. In case of such excessive pressures the valve 10 permits said mixture to escape into the outside through the check valve 16.

An injector 7 is located in the upper part of the housing. Driving `gas symbolized by the directional arrow 22 is introduced into the injector during the inspiratory period :through the branch pipe 3G over a controlled inlet valve 9. The injector includes a `suction duct 13 which is provided with a protective sieve 13 and sucks fresh air from outside. In the injector the fresh air is mixed with the driving gas 22 and this mixture symbolized by the directional arrow Z4, which serves as inspiratory mixture, leaves through an exhaust duct 7 into a conduit 24 leading into the said first chamber 25. The exhaust `duct 7' is separated from conduit 2d lby a spring loaded control valve 11 which automatically opens when during the expiratory period a desired lirnit of underpressure in chamber 25 is reached or exceeded this causing fresh air to flow from the suction duct 13 into the exhaust duct 7 through ythe check valve 17 located `in the shunt conduit 17.

During the expiratory period driving gas flows as indicated fby arrows 19 through the ejector 6 and sucks ex- Lhaled waste symbolized by the directional arrows 20 from the patients respiratory organs through duet 5 into the chamber 25 and from there through the suction pipe 6 into fthe ejector from which the mixture of exhaled Waste and driving gas symbolized by the directional arrow 21 is driven into the opening through the discharge pipe 6". The discharge orifice of this pipe is controlled by an adjustable cover or closure member 12 which by regulating the flow of the mixture 21 permits the expiration period to be lengthened or shortened as required.

During the expiratory period the inlet valve 8 and the control valve 10 are open and the inlet valve 9 and the control valve 11 are closed as shown in FIG. 1. At the end of the expiratory period lan underpressure arises in the lungs of the patient and in the communicating chamber 25, the check valve 28 opens and mixture Z4 of fresh air and driving gas assembled in the diaphragm chamber 26 yduring the preceding inspiratory period ilows into charnber 25. By adjustingly closing or opening the needle valve 14 the underpressure in the patients lung may be increased or decreased, respectively, relative to lthe underpressure `arising at the same time in the diaphragm chamber 26, this permitting a regulation of the expiratory underpressure.

The underpressure arising in the `diaphragm chamber 26 causes a depression of the diaphragm 2 whereby the trigger device 3 is actuated; its toggle anns 3' switch from the position shown in FIG. l into an upwardly directed position whereby the spindles of the valves 8 and 10 are lifted and fthe valves closed thus causing the ejector 6 to cease operation. When trigger device 3 switches to the upwardly directed position, the spindles of the valves 9 and 11 are lifted, whereby the inlet Valve 9 controlling the intake of the driving gas in the direction of arrow 22 into the injector 7 and the control valve 11 in the exhaust duct of the injector are opened. 'Ilhe driving gas 22 ilowing through the injector 7 draws fresh air symbolized by the directional arrow 23 through the duct 13 and sieve 13', and the mixture of fresh air and driving gas symbolized by the arrow 24 is pressed through conduit 24 into the chamber 25 and from 4there through the duct 5 into the patients lungs. The now increased pressure the chamber 25 causes the check valve 29 to open and the mixture of fresh air yand driving gas (24) ows into the diaphragm chamber 26; this ilow may be regulated by adjusting the needle valve 15 whereby overpressure in the patients lungs may be increased or decreased relative to the contemporary pressure the diaphragm chamber 26, this permitting a regulation of the inspiratory overpressure.

The increased pressure in the diaphragm chamber 26 causes the diaphragm 2 to rise from its `depressed position and the thereby actuated trigger device 3 returns into the position shown in FIG. 1 whereby the valves S and 1t) are again opened reactivating the ejector 6 and the valves 9 and 11 are automatically closed causing the injector 7 to cease operation. Thereafter the respiratory cycle `described above is re eated.

The valves 1t? and 11 also act as safety mems so that the valve 1d operates as an overpressure safety valve and the valve 11 as underpressure safety valve. Both valves are yseparately and independently adjustable. tlf the inspiration overpressure exceeds the given limit Value the valve 1i) automatically opens and the overpressure is relieved so that the inspiration mixture escapes into the atmosphere through the overpressure ilap valve 16. Irf, on the contrary, the given limit underprlessure is exceeded the valve 11 automatically opens and the atmospheric air is drawn in through the intake extension with the sieve 13 and through the underpressure flap valve 17.

The total per-minute pulmonary ventilation can be regulated by varying the quantity of driving gas which is admitted tinto the apparatus.

The intake `duct 13 may be provided with a threaded attachment 27 which permits a gas, smoke or dust iilter to be connected to the apparatus. Alteinatively, said duct 13 can be provided with an easily dismountable connecting device for 'applying a mine self-rescue equipment.

Into the outlet duct 5 of chamber Z5 either a mask or an extension for an endotracheal tube or a tracheotomic cannula can be inserted. To the duct 5 a T-piece for interconnecting Ihoses can also be joined. Such T-piece comprises two unidirectional check valves, one of them permitting the 'free passage of the gaseous mixture towards, and the other one fro-m the patient. One of two rubber hoses connects each check valve t the -mask tti-ngs. This arrangement reduces the dead space -to a minimum if the Iapparatus is permanently stored in a transport case or suspended from a stand or the like and if only a mask is applied to the patients face.

ln anaesthetic applications the outlet duct is connected to the pressure chamber which contains the respiration bag of the anaesthetic apparatus. Por rescue purposes, when the apparatus is attended by laymen, the throttle vdves 14 and 15 will not be fitted with hand operated knobs as shown in FIG. l but their spindles will be provided with grooves for inserting a screwdriver and the ends of said spindles will be protected by castel nuts. These nuts as well as adjustable closure means 12 are preferably secured against undesired manipulation.

While a specific embodiment of our invention has been shown and described in detail to illustrate the application of the principles of our invention, it will be well understood that the same may be otherwise embodied without departing from such principles.

We claim:

l. An automatic resuscitating apparatus of the injector type comprising in combination a separable housing spacedly arranged by means of a perforate partition, first and second check valve means in said partition, a first chamber in said housing on one side of said partition and including a passage open at one end into said first chamber and adapted to be connected at the other end to a breathing device, and a second chamber on the opposite side of said partition, said second chamber including a pressure sensitive member adapted to expand and contract in response to variations of gaseous pressure therein, said irst check valve means communicating ilow from said irst chamber to said second :chamber and said second check valve means communicating ilow from said second chamber to said first chamber, compressed gas inlet means and suction duct means communicable through an ejector means in said first chamber, said ejector means having an exhaust means opening through a wall of said irst chamber to atmosphere with said eX- haust means having an adjustable closure means to control the output of said ejector means, compressed gas inlet means and atmospheric air inlet means associated with an injector means and communicating with said first chamber, rst valve means for controlling compressed gas flow to said injector and ejector means, and second valve means controlling flow from said injector means to said first chamber and third valve means controlling tlow from said iirst chamber to said suction duct means of said ejector means, and trigger means carried by the pressure sensitive means and connected to said iii-st, second and third valve means for alternately controlling the first, second and third valve means to create inspiratory and expiratory pulsations of the resnscitating apparatus.

2. An apparatus according to claim 1 wherein the pressure sensitive member is arranged to be supported at its perimeter by the partition.

3. An apparatus according to claim 1, wherein the iirst, second and third valve means are provided with spindle portions which extend through apertures in the partition and said pressure sensitive member.

4. An apparatus according to claim 1, wherein adjustable throttle needle valve means are provided adjacent to the iirst chamber for cooperation with the check valve means.

References Cited in the iile of this patent UNITED STATES PATENTS 2,138,845 Erickson Dec. 6, 1938 2,845,061 Goodner July 29, 1958 2,893,381 Black July 7, 1959

Claims (1)

1. AN AUTOMATIC RESUSCITATING APPARATUS OF THE INJECTOR TYPE COMPRISING IN COMBINATION A SEPARABLE HOUSING SPACEDLY ARRANGED BY MEANS OF A PERFORATE PARTITION, FIRST AND SECOND CHECK VALVE MEANS IN SAID PARTITION, A FIRST CHAMBER IN SAID HOUSING ON ONE SIDE OF SAID PARTITION AND INCLUDING A PASSAGE OPEN AT ONE END INTO SAID FIRST CHAMBER AND ADAPTED TO BE CONNECTED AT THE OTHER END TO A BREATHING ADVICE, AND A SECOND CHAMBER ON THE OPPOSITE SIDE OF SAID PARTITION, SAID SECOND CHAMBER INCLUDING A PRESSURE SENSITIVE MEMBER ADAPTED TO EXPAND AND CONTRACT IN RESPONSE TO VARIATIONS OF GASEOUS PRESSURE THEREIN, SAID FIRST CHECK VALVE MEANS COMMUNICATING FLOW FROM SAID FIRST CHAMBER TO SAID SECOND CHAMBER AND SAID SECOND CHECK VALVE MEANS COMMUNICATING FLOW FROM SAID SECOND CHAMBER TO SAID FIRST CHAMBER, COMPRESSED GAS INLET MEANS AND SUCTION DUCT MEANS COMMUNICABLE THROUGH AN EJECTOR MEANS IN SAID FIRST CHAMBER, SAID EJECTOR MEANS HAVING AN EXHAUST MEANS OPENING THROUGH A WALL OF SAID FIRST CHAMBER TO ATMOSPHERE WITH SAID EXHAUST MEANS HAVING AN ADJUSTABLE CLOSURE MEANS TO CONTROL THE OUTPUT OF SAID EJECTOR MEANS, COMPRESSED GAS INLET MEANS AND ATMOSPHERIC AIR INLET MEANS ASSOCIATED WITH AN INJECTOR MEANS AND COMMUNICATING WITH SAID FIRST CHAMBER, FIRST VALVE MEANS FOR CONTROLLING COMPRESSED GAS FLOW TO SAID INJECTOR AND EJECTOR MEANS, AND SECOND VALVE MEANS CONTROLLING FLOW FROM SAID INJECTOR MEANS TO SAID FIRST CHAMBER AND THIRD VALVE MEANS CONTROLLING FLOW FROM SAID FIRST CHAMBER TO SAID SUCTION DUCT MEANS OF SAID EJECTOR MEANS, AND TRIGGER MEANS CARRIED BY THE PRESSURE SENSTITIVE MEANS AND CONNECTED TO SAID FIRST, SECOND AND THIRD VALVE MEANS FOR ALTERNATELY CONTROLLING THE FIRST, SECOND AND THIRD VALVE MEANS TO CREATE INSPIRATORY AND EXPIRATORY PULSATIONS OF THE RESUSCITATING APPARTUS.

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