US3599634A

US3599634A - Valve device for anesthesia systems and respirators

Info

Publication number: US3599634A
Application number: US793267*A
Authority: US
Inventors: Soren H Englesson
Original assignee: Individual
Current assignee: SIXTEN ENGLESSON TEKNISK KONSULT AB
Priority date: 1968-02-01
Filing date: 1969-01-23
Publication date: 1971-08-17
Anticipated expiration: 1988-08-17
Also published as: DK117977C; NO118448B; GB1238411A; CH500721A; NL6901530A; BR6906032D0; FR2001112A1; DK117977B; NL147940B; SE318066B; DE1904222A1

Abstract

A valve device specifically for anesthesia systems and respirators, etc., comprising a check valve in a one-way system conveying breathing air to and from a patient as well as additional components, if desired, such as oxygen and/or anesthetic agent. The valve utilizes a balloon or bladder which releases the system air etc. to the outside through an appropriately designed balloon support when an overpressure occurs in the balloon as the result of excess pressure of said system air etc.

Description

United States Patent VALVE DEVICE FOR ANESTHESIA SYSTEMS AND RESPIRATORS l 1 Claims, 16 Drawing Figs.

U.S. Cl...; 128/l45.7, 128/188 lnt. Cl ..A61m 17/00 Field ofSearch 128/145],

202,145.5,l45.6,145.8, 188; 137/525,155,4 96; 25l/61.l

[56] References Cited UNITED STATES PATENTS 2,268,145 12/1941 Welty 128/202 2,737,176 3/1956 Fox l28/l45.8 2,907,322 10/1959 Hay 128/1456 3,286,710 11/1966 Bartlett 128/1455 Primary ExaminerRichard A. Gaudet Assistant Examiner-G. F. Dunne Attorney--Woodhams, Blanchard and Flynn ABSTRACT: A valve device specifically for anesthesia systems and respirators, etc., comprising a check valve in a one-way system conveying breathing air to and from a patient as well as additional components, if desired, such as oxygen and/0r anesthetic agent. The valve utilizes a balloon or bladder which releases the system air etc. to the outside through an appropriately designed balloon support when an overpressure occurs in the balloon as the result of excess pressure of said system air etc.

PATENTED Aum 7 19m 3599.634

SHEET 1 0F 5 Fig.1 (2) PRIOR ART PRIOR ART PATENTED AUG] 7197! SHEET 2 UF 5 Fig.1.

PRIOR ART PATENTED AUG 1 7:971

SHEET U [1F 5 VALVE DEVICE FOR ANESTHESIA SYSTEMS AND RESPIRATORS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention refers to apparatus and systems for administering anesthesia in surgery, and specifically to a valve device in a breathing apparatus included in such systems. The invention may also find application in such breathing apparatus as respirators etc.

2. Description of the Prior Art As is well known, anesthesia in connection with surgery has the purpose of providing the brain with a well-balanced dose of anesthetic. This is conveyed to the brain through the blood,

' which in turn is provided with the anesthetic by direct injection into the blood vessels (intravenous anesthetic) or by inhaling vaporized so-called inhaling anesthetics and diffusion of the latter to the blood in the lungs. In certain types of surgery it is necessary to make the patients musculature relax. This is achieved either by deeper anesthesia or by a muscle relaxing agent (for example curari) being injected into the blood vessels. The latter method necessitates artificial'respiration, asv the breathing musculature also will become paralyzed.

One of the tasks of the personnel administering anesthetics is to observe the blood circulation and the respiration. As is well known, the normal respiration has the purpose of providing the body' with oxygen and of eliminating carbon dioxide, which is expelled from the body through the lungs. The hygienic side of this includes making it necessary to ascertain that infections are not transferred from contaminated, i.e. unclean, anesthetic equipment.

The anesthetic systems that are in present day use operate well and reliably, but they are nevertheless subject to certain drawbacks. For one thing they require experience with respect both to their general manipulation and to the setting of valve devices included therein, which require uninterrupted attention. For another thing, cleaning and sterilizing their vital components are exceedingly laborious and time-consuming processes. After a completed administration of an anesthetic the equipment must be washed, dried and processed in an autoclave before it can be utilized for the next patient.

SUMMARY OF THE INVENTION The object of this invention is to provide a breathing apparatus for anesthetic systems, in which the drawbacks indicated above are reduced to a level that may well be accepted in practice or entirely obviated, by performing an important valve function in a novel manner and by means of a novel valve device. The object of the invention is achieved and a breathing apparatus that is easily handled and that operates reliably is provided by the valve device of the invention being given the features disclosed in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS A number of embodiments of the invention will now be described so as to illustrate the same with reference to the accompanying drawings, in which:

FIG. I is a diagrammatic illustration of a modern anesthetic system of conventional design.

FIGS. 2 and 3 illustrate the manner of operation of the system in accordance with FIG. 1 in inhaling and exhaling, respectively.

FIG. 4 is a diagrammatic cross section of a semiautomatic breathing bellows of the Air Shield type.

FIG. 5 is a cross section through the support means disclosed by the invention for a breathing balloon.

FIGS. 6 and 7 are cross sections along the lines Vl-VI and VII-VII, respectively, of FIG. 5, and FIG. 7a is a cross section corresponding to FIG. 7 but through a modified support means.

FIG. 8 is a cross section through an additionally modified design of the support means of FIG. 5.

FIG. 9 is a view, partially in section, along the line IX-IX of FIG. 10, through an additionally modified embodiment of the support means, and r p FIG. 10 is a cross section along the line X-X of FIG. 9.

FIG. 11 is a cross section through a second embodiment of I the invention and illustrates a support means for a breathing balloon provided with an internal discharge tube with a valve plate. I

FIG. 12 is a partial cross section along the line XII-XII of DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to facilitate the comprehension of the invention the principle design of a typical breathing apparatus in a modern anesthetic system and its mode of operation will be disclosed briefly by manner of introduction with reference to FIGS. 1-

4, respectively. Thus the breathing apparatus 10, see FIG. 1, comprises a channel system or a conduct system in communication with the patient and forming a one-way closed path of flow for the breathing gas mixture consisting of air, supplementary oxygen and anesthetic gases. The path of flow comprises a branch pipe 12, through which the gas is conveyed to and from the patient, respectively, over a close-fitting face mask or a so-called tracheal tube (a sterile rubber tube iritroduced .into the windpipe with a seal against its interior by means of an inflatable rubber sleeve). Two corrugated rubber tubes 14 extend from the branch pipe 12, and one of these, viz 14a, conveys the expiratory gas to an absorbing unit 16 containing calcium for absorbing carbon dioxide. The inlet side of said unit is provided with a check valve I8, and a similar check valve 20 is positioned behind the unit. From the latter check valve the gas is conveyed through the second rubber tube 14b back to the branch pipe 12. The conduit system joining the outlet of the absorbing unit 16 to the check valve 20 is provided with an outlet having a soft rubber balloon 24 (volume 24 liters, i.e. 2.24.4 quarts) connected thereto.

If the system is considered thus far, it will immediately be seen that the two check valves force the oxygen, to flow around in a closed circuit, constantly in the direction indicated by the arrows; When exhaling occurs, the gas will flow along the upper path (in accordance with FIG. I) and will pass the absorber l6 and will fill the balloon 24. In subsequent inhaling, the upper path will be blocked, and the gas will flow through the check valve 20 and the tube 14b back to the patient. A repeated cycle of this type with the breathing gas traveling between the lungs of the patient and the balloon 24 will naturally create a lack of oxygen concurrently with car- 7 gas mixture from the portioning means being conveyed to a 5 nipple or similar connection 28 in the conduit system 22 between the absorber l6 and the balloon 24 over a tube connection.

As the closed system continuously is supplied with an addition of gas, corresponding gas discharge of equal quantity must be provided so as to comply with the continuity principle without an overpressure occuring in the system. For instance,

this may be carried out by a spring actuated relief valve or leak valve, diagrammatically indicated at 30, being introduced into the communication between the upper rubber tube 14a and the check valve I8 at the inlet of the absorber. The overpressure valve 30 is set to a definite position so as to be opened in response to a slight overpressure occuring at the termination of the expiratory phase for expelling the appropriate amount of gas from the system for maintaining a continuous steady state.

FIGS. 2 and 3 diagrammatically illustrate an inhaling and exhaling sequence, respectively In inhaling, the valve 20, see

FIG. 2, is opened, and the breathing gas from the balloon 24 will flow together with a continuous addition from the external gas source through the connection 18 to the patient through the lower tubel4b and the branch pipe 12. Both the check valve 18 and the leak valve 30 are now closed. During the exhaling phase, see FIG. 3, the check valve 18 is opened, whereas valve is closed, and the gas will flow from the branch pipe 12 through the rubber tube 14a and the absorbing unit 16 to the balloon 24 for filling the latter. Towards the end of the exhaling a slight pressure increase will occur as the result of the counterpressure in the balloon24, and hence the leak valve will open and will release an excess quantity of the gas corresponding to the continuous external addition through the connection 18.

In modern breathing apparatus of the pertinent type it is also possible to perform overpressure breathing or artificial respiration when necessary, when the patient is not capable of breathing spontaneously. The breathing balloon 24 is then subjected to an external rythmic pressure applied either by the anesthetic administrator compressing it manually or with the assistance of mechanical or pneumatic means, thereby urging the gas contents of the balloon 24 into the lungs of the patient along the path shown in FIG. 2. When the balloon is released or unloaded, exhaling occurs, thereby inflating the balloon, thus maintaining the breathing. I

As has been mentioned above the relief valve 30 must be set to a definite position, particularly for providing an appropriate distribution of gas between on one hand the lungs of the patient'and on the other hand the valve itself for discharge during artificial respiration. This demands both skill and experience in the person administrating the anesthetic. Other relief valves of semiautomatic type have been proposed, and, in particular, the rubber balloon 24 has been replaced by'a corrugated rubber bellows, the movements of which control, a discharge valve or leak valve in different ways (for instance in known systems of the Air Shield type or the Spiropulsator type). As a final example of conventional methods FIG. 4 diagrammatically illustrates one of these breathing bellows of the Air Shield type.

A corrugated bellows 32 is positioned in a closed housing 34 having a bottom 36 provided with a circular neck portion 38, to which the bellows 32 is fastened as the figure illustrates. The neck portion 38 is provided with an inlet 40 to the bellows trol a leak valve device in which the balloon itself is included as a valve element that closes and opens discharge .flow channels from the balloon. This design provides some analogy to the bellows 32 accordance with FIG. 4 inasmuch as a gas discharge occurs at the end of an exhaling phase, but the simplification is extremely broad and there are no valve mechanisms nor movable components at all apartfrom the rythmically pulsating balloon.

For the purpose of the invention two individual portions of the balloon may be utilized, viz either its neck portion or the tip portion or end portion opposite thereto. FIGS. 5-10 illustrate some embodiments of the first type, whereas FIGS. 1 1- 13 show examples of utilizing the end portion of the balloon as valve means. 7

The designation 54 in FIG. 5 refers to a portion of the upper wall of a housing or protective cover having appropriate form and accommodating a breathing balloon 70. A balloon socket 58 is introduced into an aperture 56 in' the wall 54 and is detachably and sealingly affixed in the opening in a manner not disclosed in detail, for instance by means of a bayonet mount or similar. The socket 58 comprises a'substantially cylindrical device that is adapted to support the balloon 70, the neck portion 700 of which is provided with a bulge 70b along itsupper edge in conventional manner, with said bulge being received in a circumferential groove 59 at the upper part of the cylindrical portion of the socket 58 as illustrated in FIG. 5. Below the bulge 70b the neck portion 70a of the balloon follows close to the cylindrical socket 58, i.e. in relieved, nonextended condition the internal diameter of the neck portion very nearly conforms with the external diameter of the socket and therefore the balloon neck will surround and lightly contact the socket without substantial stretch. The

. neck 70a is slightly longer than the portion of the socket 58 situated below the balloon bulge and extends outside of this portion, subsequently expanding outwards.

The portion of the socket 58 enclosed by the balloon neck 70a is provided with a number of axial grooves 60, see FIGS. 5

and communicates with the patients lungs substantially in the connection 42. The portion of the bellows 32 opposite to the neck portion 38 is closed by means of an endpiece 44. One' end of a light chain 46 is fastened to said endpiece 44, and the other end of said chain is connected to an exhaling valve 48 having the form of a valve cone or valve hall 50 disposed to close an outlet 52 in the neck portion 38. as is diagrammatically indicated in FIG. 4. During exhaling, when the bellows 32 expands and the endpiece 44 withdraws from the neck portion 38, the chain.46 will be extended so as to remove the ball 50 from its seat and to release the excess of breathing gas through the outlet 52 towards the end of the exhaling. Hence, the exhaling valve 48 serves in the same manner as the leak valve 30 disclosed above.

In accordance with the basic principle of the invention a breathing balloon substantially of the type 24 illustrated in FIGS. l-3, respectively, is utilized in such manner that is movements, i.e. alternating expansion and contraction, conand 7, respectively, uniformly distributed along the circumference of the socket. The grooves 60 begin somewhat inside of the lower axial end of the socket, as seen in FIG. 5, and they terminate with their upper ends in a comparatively deep, circumferential groove or an annular groove 62 shortly below the balloon bulge groove 59. From the interior of groove 62 a number of channels 64 extend upwards through the socket 58 so as to terminate in theatmosphere outside of the balloon housing. A centrally located inlet channel 66 extends through the socket 58 from an upper tube or pipe connection 68, which only has been illustrated diagrammatically, to a lower, expanded channel portion 66a terminating in the interior of the balloon 70.

The groove system 60-62-64 together with the balloon neck 70a forms a check valve device, which in principle may be compared to the valve of a bicycle inner tube. When the patient exhales, the balloon 70 is filled and expanded in normal manner. Towards the termination of the exhaling-the balloon material is stretched and the neck portion 70a is also expanded so as to be displaced from the cylindrical socket 58, as indicated by dotted lines in FIG. 5, thereby opening a passage to the outside through the axial grooves 60, the annular groove 62 and the channels 64, so as to discharge the excess of gas this'way instead of through formerly used valves, particularly leak valves, for instance the valve 30 in accordance with FIGS. l3. The path of flow is indicated by dot-dashed arrows in FIG. 5.

Hence, in order to openthe discharge passage, a certain overpressure in the balloon is necessary, and the magnitude of this overpressure is primarily determined by how snugly the balloon neck encloses the socket and by the thickness of the balloon material. The design of the socket may also influence the opening pressure. FIG. 8 illustrates a modified design 58' of the socket, wherein its lower portion, which receives the balloon neck, has conical shape and is either convergent or (indicatedby dashed lines) divergent downwards. The balloon downwardly converging socket, axially extending the balloon as the result of inflating the same will contribute to displacing theneck from the socket.

The balloon socket may also have polygonal cross section or it may be provided with flattened portions in which the discharge grooves are formed, for instance as illustrated by the socket 63 of FIG. 7a. This socket has a hexagonal cross section with rounded corners, and grooves 61 have been formed in the six flat surfaces 65 as illustrated by the figure. The balloon neck 71 encloses the socket 63 lightly but sealingly, and with this design the necessary pressure increase in the balloon for displacing the neck of the latter from the socket so as to discharge gas will be still smaller. The conical sockets 58' in accordance with FIG. 8 may also be provided with flattened surfaces carrying the grooves 60'.

FIGS. 9 and 10 illustrate an additional modification 58" of the balloon socket This socket is designed in the same manner as socket 58, but it is provided with an additional number of axial grooves 72 in the envelope surface of the socket between the .valve grooves 60". The additional grooves 72 are somewhat wider and shallower than the grooves 60", and in contrast to the latter they begin at the lower end of the socket 5 8" and terminate shortly below the annular groove 62". In this case the balloon neck 70"a is preformed with inwardly directed folds'74, which are received in the grooves 72 with tolerances as illustrated in.FIG. 9 and 10,- respectively. The

purpose of these folds is to lower the opening pressure, i.e. the

overpressure in the balloon that is necessary for opening the discharge passage through the socket. :Therefore it is not necessary in this case that the material of the neck portion 70"a of the balloon be stretched so as to displace the rubber from the socket but merely that the folds 74 be straightened out to a greater or smaller extent. 7 7

FIGS. ll13 illustrate some examples of the second method of the invention as disclosed above for utilizing the breathing balloon as a valve device, specifically the portion thereof opposing its neck portion or end portion. In this case a balloon socket 76 is provided, which is introduced into an aperture in the upper wall 78 of a balloon housing. The lower or inner portion of the socket is designed in appropriate manner'and is provided with a bulge groove 77 for fastening the neck of a rubber balloon 80 provided with a bulge 80b. The inlet to the balloon consists of a nipple 82 being affixed in the side of the socket 76 and being' connected to the remainder of the breathing apparatus by means of a tubular connection that is not specifically illustrated. A discharge tube 84. thatis threaded externally at the top is centrally located in an opening. in socket 76 provided with internal threads and may be; adjusted vertically by rotating a knurled finger grip 86 provided at the upper end of the tube. The inner or lower end of the tube is slightly expanded and is provided with a fixed, somewhat curved valve disc 88 having apertures 90. The discharge tube 84 extends through the entire balloon 80and engages the end portion 80:: thereof, withthe balloon being maintained substantially extended by the tube so-that the end I portion 80a will cover the apertures 90and will lightly engage the curvedvalve disc 88. The arrangement should be clear from FIG. 11.

With 'exhaling, the balloon is expanded in normal manner, andwhen the balloon materialhas been stretched its'end portion 800 will disengage; the valve disc 88, thereby positioning the balloon 80 as illustrated by dashed lines in-FIG. 1'1 so that excess gas will be expelledthrough apertures 90 into tube 84 asindicated by the arrows. In order to offer less resistance at the-initial fillingthe balloon may appropriately have'the form of a flattened rubber bladder in its empty state in well-known manner, as illustrated by the cross section'of FIG. 12, and it may even be provided with a fold as illustrated at 800 in the same figure.

by a resilient counteracting component as is diagrammatically illustrated in FIG. 13. The counteracting component 94,

which is disposed adjustably in the bottom 79 of the balloon housing coaxially to the discharge tube 84, may for instance consist of a bowl 95 turned upside down and having an exter-- nally concave bottom which is shaped in conformance with the curved valve disc 88' and is lightly urged against the latter by a compression spring 96, the compression of which may be adjusted by means of a small knob 98, as may be seen from the figure without more specific description. In this case the balloon does not have to be maintained stretched for engagement against the valve disc 88 and instead it may be entirely loose and freein its empty state, with the exception of the actual end portion 80'a, which is maintained lightly urged against the valve disc 88' by the counteracting component 94 and covers the openings of said valve disc. The balloon may be ventilated more thoroughly by means of this supplementing counteracting component device, but the function is the same as in the embodiment of FIGS. 11 and 12, respective- Iy. I

In conclusion, FIGS. 14 and 15 illustrate how a breathing apparatus provided with the valve device of FIGS. 5 or 9, respectively, operates. With inhaling, see FIG. 14, the sequence will be substantially the same as is illustrated by FIG. 2. The breathing gas flows from the balloon 70 together with an addition from the connection 28 through the opening check valve 20, the lower, corrugated rubber tube 14b and through the branch pipe 12 to the lungs of the patient. In this operation the balloon neck tightly encloses the discharge grooves 60 (see FIG. 5) of the socket 58, and neither air nor other gas can penetrate from the outside this way. With exhal ing, see FIG. 15, the gas flows from the lungs of the patient through the branch pipe 12, the upper tube 14a, the opening check valve 18, the Co -absorber l6 and to the balloon 70. The latter expands, and in the final stage the lower part of its neck portion releases its engagement with the socket 58, with the excess gas flowing out through the latter, as has been disclosed previously. In FIG. 15 dashed lines illustrate a simple device by means of which the moment of opening the balloon valve may be influenced. An adjustable plate 102 is displaced upwards towards the balloon from the bottom 79 of the balloon housing and engages the lower end of the balloon. The higher the plate 102 is displaced, the earlier will the valve open.

respiration mentioned by way of introduction, i.e. whenthe patient cannot breath spontaneously, the balloon 7.0 is subjected to a rythmic external pressure which urges its contents to the lungs of the patient. In order to provide a' respirator, i.e.

an apparatus for pure breathing systems, the absorbingunit' 16' is disconnected and the patient is made to breath out'dire'ctly into the atmosphere by means of an appropriate exhaling valve-at his mouth. Concurrently, a partial vacuum-is created outside the balloon 70' so that atmospherical-air willbe'dr'awn An important advantage in the invention is that certain of-its embodiments, particularly those illustrated'as examples in FIGS. 5-l0,nrespectively, as the result of their simplicity are attractive as embodiments foruse one single time, i.e. theballoon and its associated socket may be manufactured as'aisimple unit in mass'production that'may be thrown away after'u'se.

For providing the overpressure breathing or artificial The invention is naturally not limited to the embodiments illustrated and described above, and it may be varied in additional respects within thescope of the basic conception of the invention.

1 claim:

1. In a breathing apparatus having a one-way closed flow circuit and a storage balloon'or bladder connected to the circuit for momentarily accumulating and storing herein the breathing gases discharged from a patient, means for adding a supplement, such as oxygen or an anesthetic agent, to the gases stored within the balloon, whereby said gases in the balloonare then supplied to the patient, said balloon including a neck portion having an opening therein and support means disposed within said opening for supporting said balloon, the

edge of said balloon as defined by said opening being in engagement with said support means, and said support means having opening means extending therethrough forproviding communication between said circuit and the interior of said balloon whereby breathing gases can be supplied to or withdrawn from said balloon, the improvement comprising:

relief means for permitting external discharge of excess gases from said balloon during expansion of the balloon when the pressure of the gases within the balloon exceeds a predetermined maximum; said relief means including discharge passage means formed in said support means for permitting discharge of said excessgases to a location external of said balloon, said I discharge passage means having an inner end adapted for communication with the interior of said balloon; and said balloon having a movable wall portion normally disposed in sealing engagement with a portion of said support means for preventing communication between the interior of said balloon and the' inner end of said discharge passage means whe'n'the pressure within said balloon is less than said predetermined maximum; whereby exceeding said predetermined maximum pressure during expansion of said balloon causes said, movable wall portion to move out of sealing engagement with said support means for permitting the excess gases to flow through said discharge passage means. I i I 2. An apparatus according to claim 8, wherein said support meansincludes a substantially cylindrical support member disposed within the neck portion of said balloon, and said discharge passage means including a discharge passage formed within. said support'member and extending substantially therethrough, the inner end of said discharge passage terminating at the outer periphery of said support member at a location which is spaced. from the inner end, of said support member, and said neck portion of said balloon being disposed in sealing engagement with said support member for closing the inner end of said discharge passage, when the pressure within said balloon is less than said predetermined maximum.

, 3, An apparatus according to claim 9, wherein said support member is provided with a flat surface, and said discharge passage comprises an elongated groove extending longitudinally of said flattened surface. I

4. An apparatus according to claim 9, wherein said support member includes a substantially. annularportion disposed adjacent the inner end thereof and positioned for sealing engagement .with the surrounding neck portion of said balloon, said annular portion being disposed inwardly from the inner end of said discharge passage for preventing communication between said discharge passage and the interior of said balloon when the pressure within sad balloon is below said predeterminedmaximum.

5. An apparatus according to claim 11, wherein said support I member has a portion having a substantially truncated conical configuration disposed within said neck portion of said balloon.

6. An apparatus according to claim 8, wherein said support means includes a substantially cylindrical support member disposed within and in sealing engagement with the neck portion of said balloon, said support member having a plurality of circumferentially spaced, longitudinally extending grooves formed in the periphery thereof, and the neck portion of said balloon having a plurality of inwardly extending,v axially directed folds normally disposed within said grooves for closing same to prevent flow of breathing gases therethrough when the pressure within said balloon is belowsaid predetermined maximum.

7. An apparatus according to claim 8, wherein said support means includes an elongated discharge member extending into the interior of said balloon, said discharge member having said discharge passage means extending therethrough, said discharge member having one end thereof positioned'adjacent an end portion of said balloon opposite from theneck portion thereof, with said end portion of said balloon being normally maintained in sealing engagement with said one end of said discharge member for preventing communication between the interior of said balloon and said discharge passage means whenever the pressure within said. balloon is less than said predetermined maximum.

8. An apparatus according to claim 14, further including resiliently urged engaging means disposed externally of said balloon and positioned for engagement with the end portion of said ballobn for normally resilientlymaintaining said end por-' tion in sealing engagement with said one end of said discharge member for preventing flow through the discharge passage means whenever the pressure within said balloon is less than said predetermined maximum. I

9. A breathing apparatus comprising a storage balloon havinga neck portion defining an opening into the interior of said balloon, and support means at least partially disposed within said opening and sealingly engaged by said neck portion for closing said opening, said support means having a flow passage extending therethrough for providing communication between the interior of said balloon and a location disposed externally of said balloon for permitting breathing gases to be supplied to and withdrawn from said balloon, the improvement wherein relief means are provided for permitting external discharge of excess gases from said balloon during expansion thereof when the pressure of the gases within the balloon exceeds a predetermined maximum, said relief means including discharge passage means formed in said support means for permitting discharge of said excess gases at a location externally of said balloon, said discharge passagemeans having an inner end adapted for communication with the interior of said balloon, and said balloon having a movable wall portion normally disposed in engagement with a portion of said support means for preventing communication between the interior of said balloon and the inner end of said discharge passage means when the pressure within the balloon is less'than said predetermined maximum, whereby exceeding said predetermined maximumpressuring during expansion of said balloon causes said movable wall portion to move out of sealing engagement with said support means for permitting the excess gases to flow through said discharge passage means.

'10. A breathing apparatus according to claim 16, wherein said support means includes a hublike support member disposed within and sealingly engaged by the neck portion of said balloon, and said discharge passage means including a discharge passage formed in said support member with the inner end of said discharge passage terminating adjacent the external periphery of said support member in the region surrounded by the neck-portion of said balloon whereby said neck portion normally prevents communication between said discharge passage and the interior of said balloon, a part of said neck portion being radially expandable so as to move out of sealing engagement-with said support member to permit gases within the interior of said balloon to flow through said discharge passage when the pressure within said balloon exceeds said predetermined maximum.

11. A breathing apparatus according to claim 16, wherein said support means includes an elongated tubular discharge member extending into the interior of said balloon, said discharge member having anend thereof disposed adjacent an end portion of said balloon opposite from said neck portion, said end portion of said balloon being normally disposed in sealing engagement with said end of said tubular discharge member for preventing communication between the interior UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 599 634 Dated August l7, 19 71 I. Inventor($) Soren Henrik Eng'lpqqnn It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 7, in line 42 "claim 8" should read --claim l---, in line 55 "claim 9" should read -claim 2---, in line 59 "claim 9" should read --claim 2--, in line 68 "claim 11" should read --claim 4-, and in line 72 "claim 8" should 4 read -claim l--.

Column 8 in line 8 "claim 8" should read --claim l-, in line 20 "claim l4" should read --claim 7-, in line 57 'claim 16" should read -claim 9-, and in line 72 "claim 16" should read ---claim 9 Signed and sealed this 21st day of March 1972.

(SEAL) AtteSt;

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents RM PO-105O (10- uscomm-Dc 60376-P69 U 5 GOVERNMENT PRINTlNG OFFICEI I969 O--35334

Claims

1. In a breathing apparatus having a one-way closed flow circuit and a storage balloon or bladder connected to the circuit for momentarily accumulating and storing herein the breathing gases discharged from a patient, means for adding a supplement, such as oxygen or an anesthetic agent, to the gases stored within the balloon, whereby said gases in the balloon are then supplied to the patient, said balloon including a neck portion having an opening therein and support means disposed within said opening for supporting said balloon, the edge of said balloon as defined by said opening being in engagement with said support means, and said support means having opening means extending therethrough for providing communication between said circuit and the interior of said balloon whereby breathing gases can be supplied to or withdrawn from said balloon, the improvement comprising: relief means for permitting external discharge of excess gases from said balloon during expansion of the balloon when the pressure of the gases within the balloon exceeds a predetermined maximum; said relief means including discharge passage means formed in said support means for permitting discharge of said excess gases to a location external of said balloon, said discharge passage means having an inner end adapted for communication with the interior of said balloon; and said balloon having a movable wall portion normally disposed in sealing engagement with a portion of said support means for preventing communication between the interior of said balloon and the inner end of said discharge passage means when the pressure within said balloon is less than said predetermined maximum; whereby exceeding said predetermined maximum pressure during expansion of said balloon causes said movable wall portion to move out of sealing engagement with said support means for permitting the excess gases to flow through said discharge passage means.

2. An apparatus according to claim 8, wherein said support means includes a substantially cylindrical support member disposed within the neck portion of said balloon, and said discharge passage means including a discharge passage formed within said support member and extending substantially therethrough, the inner end of said discharge passage terminating at the outer periphery of said support member at a location which is spaced from the inner end of said support member, and said neck portion of said balloon being disposed in sealing engagement with said support member for closing the inner end of said discharge passage when the pressure within said balloon is less than said predetermined maximum.

3. An apparatus according to claim 9, wherein said support member is provided with a flat surface, and said discharge passage comprises an elongated groove extending longitudinally of said flattened surface.

4. An apparatus according to claim 9, wherein said support member includes a substantially annular portion disposed adjacent the inner end thereof and positioned for sealing engagement with the surrounding neck portion of said balloon, said annular portion being disposed inwardly from the inner end of said discharge passage for preventing communication between said discharge passage and the interior of said balloon when the pressure within sad balloon is below said predetermined maximum.

5. An apparatus according to claim 11, wherein said support member has a portion having a substantially truncated conical configuration disposed within said neck portion of said balloon.

6. An apparatus according to claim 8, wherein said support means includes a substantially cylindrical support member disposed within and in sealing engagement with the neck portion of said balloon, said support member having a plurality of circumferentially spaced, longitudinally extending grooves formed in the periphery thereof, and the neck portion of said balloon having a plurality of inwardly extending, axially directed folds normally disposed within said grooves for closing same to prevent flow of breathing gases therethrough when the pressure within said balloon is below said predetermined maximum.

7. An apparatus according to claim 8, wherein said support means includes an elongated discharge member extending into the interior of said balloon, said discharge member having said discharge passage means extending therethrough, said discharge member having one end thereof positioned adjacent an end portion of said balloon opposite from the neck portion thereof, with said end portion of said balloon being normally maintained in sealing engagement with said one end of said discharge member for preventing communication between the interior of said balloon and said discharge passage means whenever the pressure within said balloon is less than said predetermined maximum.

8. An apparatus according to claim 14, further including resiliently urged engaging means disposed externally of said balloon and positioned for engagement with the end portion of said balloon for normally resiliently maintaining said end portion in sealing engagement with said one end of said discharge member for preventing flow through the discharge passage means whenever the pressure within said balloon is less than said predetermined maximum.

9. A breathing apparatus comprising a storage balloon having a neck portion defining an opening into the interior of said balloon, and support means at least partially disposed within said opening and sealingly engaged by said neck portion for closing said opening, said support means having a flow passage extending therethrough for providing communication between the interior of said balloon and a location disposed externally of said balloon for permitting breathing gases to be supplied to and withdrawn from said balloon, the improvement wherein relief means are provided for permitting external discharge of excess gases from said balloon during expansion thereof when the pressure of the gases within the balloon exceeds a predetermined maximum, said relief means including discharge passage means formed in said support means for permitting discharge of said excess gases at a location externally of said balloon, said discharge passage means having an inner end adapted for communication with the interior of said balloon, and said balloon having a movable wall portion normally disposed in engagement with a portion of said support means for preventing communication between the interior of said balloon and the inner end of said discharge passage means when the pressure within the balloon is less than said predetermined maximum, whereby exceeding said predetermined maximum pressuring during expansion of said balloon causes said movable wall portion to move out of sealing engagement with said support means for permitting the excess gases to flow through said discharge passage means.

10. A breathing apparatus according to claim 16, wherein said support means includes a hublike support member disposed within and sealingly engaged by the neck portion of said balloon, and said discharge passage means including a discharge passage formed in said support member with the inner end of said discharge passage terminating adjacent the external periphery of said support member in the region surrounded by the neck portion of said balloon whereby said neck portion normally prevents communication between said discharge passage and the interior of said balloon, a part of said neck portion being radially expandable so as to move out of sealing engagement with said support member to permit gases within the interior of said balloon to flow through said discharge passage when the pressure within said balloon exceeds said predetermined maximum.

11. A breathing apparatus according to claim 16, wherein said support means includes an elongated tubular discharge member extending into the interior of said balloon, said discharge member having an end thereof disposed adjacent an end portion of said balloon opposite from said neck portion, said end portion of said balloon being normally disposed in sealing engagement with said end of said tubular discharge member for preventing communication between the interior of said balloon and the interior of said tubular discharge member whenever the pressure within said balloon is less than said predetermined maximum.