US2103144A

US2103144A - Apparatus for giving anesthetics

Info

Publication number: US2103144A
Application number: US732349A
Authority: US
Inventors: Carre Jean
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-07-18
Filing date: 1934-06-25
Publication date: 1937-12-21
Anticipated expiration: 1954-12-21
Also published as: BE403851A; FR43977E; FR44189E; GB426171A; FR758560A; DE662253C

Description

Dec. 21, '1937. J CARR 2,103,144"

" APPARATUS Fon GIVING ANESTHETICS I Filed June 25, 19:54 '2 shams-'sheetr 1 m. man

Dec. 21, 1937. J. CARRE A 2,103,144

APPARATUS FOR GIVING ANESI/'HETICS I i y Filed June 25, 1934 v2 Sheets-Sheet-Z 115 .n ,fm/m05 kan Clfre Patented Dec. 21, 1937 j UNITED- fs'rATEgs y f y .21034144 j I. i .l i 1 i, i. PPARATUS FOR GIVING I Jean Carr, Leers, Y

Application June z5, 1934. serial :No.mm f In Fance July 18, 1933 i i s claims. (o1. ras-isi) i l ture and carbon dioxide which is breathed out during the anesthesis. Also the known methods and apparatus do not in any special way permit of increasing the partial pressure of the anesthetic, and cf bringing the proportion thereof in the mixl ture rapidly to a maximum. Also, by not taking into account the fact that theconsumption of oxygen varies according to the degree oi anesthesis, these known methods and apparatus do not provide for an addition of oxygen in the anesthetic mixture which is proportional tothe quantity required bythe patient, `such quantity being also proportional tothe volume of water vapour and carbon dioxide breathed-out of the 1ung8 K i One object oithisinventionis considerably to increase the proportion of anesthetic inthe mixture given to the patient. Another Objectis to provide means for supplying automatically.- or semi-automatically to lthe mixture a quantity of oxygen proportional vto the quantity of carbon dioxide and moisture expelled; thek said means will preferably consist. of oxygen generators and avoid the useof high pressure bottleswhich arek heavy and cumbersome. Another object of this invention `is to provide means for having a ready reserve of air expelled from the lungs and containing a big proportion of carbon dioxide; such reserve is used, in case of necessity, avoiding the use of carbon dioxide pressure bottles. 4.0 Stili another object of the invention is to have in the apparatus a determined direction of iiowv oi.' gas which diners iroxnthe usual -ow .of gases in known apparatus. The direction oi the ow of gases in the apparatus according to the inven- 45 tion is studied in view to permit of: (I) expelling the air contained in the apparatus v.before .starting an operation; (1I) obtaining in a receptacle taneously reduce the concentration of anesthetic 55 in the mask. The mixture of gases being effected at the entrance 'ofv thel maskQand not in areceiver of the gases breathed out as in some known devices,` the actionof the anesthetic is either increased or diminished 'at the very instant the patient requires such action.; On the lcontrary 5 yin most known devices the patient is obliged to breathe, the atmosphere contained k,in a Areceiver before any modicationpin the anesthetic as required by thestate ofthe patient can be eiectively obtained. This can be acause of serious trouble 10 with someanesthetics. l y g In the appended drawings rvariousforms of construction of the Vapparatus according to this invention have been illustrated: Fig. 1 is a 'schematical view of a iirstr form .of l5 the apparatus.' ,r j

Fig. 2 shows a mask for giving anesthetics in connedatmosphere; 'f

Fig.` 8 is -asectional viewof afcontrolftapfor distributingtheanesthetic, ij

Fig. 9 is a schematical plan view of asiinplied apparatus for short anesthesis;

Fig. 1o isa" view to Fig. 9 of the ppaf' :iov

rams 111111181 oprationjthereof,v

Fig; 111s a plan View oiga similarfapparat-iis,v

but for-somewhat longeranesthesis.

Theapparatus according toj Fig. '1 essentially' comprises a mask I of very gasftight construe# 35 g tion, a pipe 2' for breathing `ouiafa -,valve l, a. v

bag-reservoir 4 for theatmosphere breathedout. a cock '5 admitting into bag-reservoir 4, pipe" t and suitable'cocks'Tandiorregulating'the flow r of the gas tobebreathed. L Thevalvesand the l pipes are established v to oerftheminimum re' sistance to the breathing: S is Aa rese`rvoir jcon stituted by onefor several cartridges' o r the like containing a chemical which givesiorthfoxygen by the action of water vapourlandcarbondioxidell* The chemical or chemicals contained `in the reservoir 9 are such that theiquantity of. QXygen produced, whichis in proportion' with the carbon l dioxide and' water'vapouif j`absorbed, "is iny sum-"f cient but.. not in excessive Aquantity"for receiving the breath-oi! the patient. y A: separate reservoirV l0 containing chemicals 'whichjsupply oxygen in case o! yneed byf the controlled action,v of 'water supplied `drop, by drop through apparatus Il. is

also provided'. jvaives' lz 'and il. anda cockiil ss make it possible to expel all the air from the apparatus before utilization. A reservoir Il for the anesthetic mixed in the breathed atmosphere is provided. I 8 designates a similar reservoir for the anesthetic in case the ilrst one is quite used up. A second bag-reservoir II provides for keeping in reserve an atmosphere containing a strong 'proportion Vof carbon dioxide in case the latter becomes insufficient in quantity in the mixture for breathing. A cock I8 controls the bag-reservoir I1. Another cock I9 suitably mounted permits of letting the patient breath independently of the apparatus at a moments notice if required. The apparatus functions as follows:` First the operator gathersin the bag I 'I a reserve of carbon dioxide. To this end the cock I8 is opened and cock l closed. The cocks Land 8 are operated so as to insulate from the circuit the oxygen re-` generator 9, the atmosphere being` directed through the return pipe 6'. The simultaneous operation of the cocks l and 8; such that cock 'I is open vwhen cock 8 is shut andy inversely, may be effected by means of a single handle 20 shown on Fig. 1. By means of the reservoirill a quantity of oxygen .is produced. 'suilicient for filling the bagJ I'I. The patient is made to breathe into the bag I'I, and as soon as the concentration of carbo'nldioxide in the atmosphere breathed in and outv is such that the respiration becomes ample and quick, the cock i8 is closed at the end of an expiration, and the cock Sis opened. -The bag I'I now contains an atmosphere with a high proportion of carbon dioxide which may be useful later. f

The operator then proceeds to produce in the apparatus an anesthetic atmosphereaspure as possible, by expelling all the airv or oxygen which the apparatus contains. -This-result kis obtained by opening the .exhaust cock .I4 and .sending through the apparatus acurrent-of anestheticV from the 'reservoir I5. By the pressure of the anesthetic gas the valve ,I3 is `closed against'its useat andthecurrent of gasl expels all the air from the pipesand mask. Y Y,

The bag`4 is filled ,withgaa then emptied by hand pressure, and filled again. `The current of anesthetic 'gas expels the air,from`V pipes 8 and throllgh the valve I2, and cock I4 lthe cocks I and are then operated in orderto send` the current of anesthetic gas tlnough the oxygen regen--v erator 9, the air from which. is expelled through valveIZ and cook Il. 4The air thus bei'ng'expelled from the apparatus, Vthe cook I4 ismanually closed andvalve I 2 is automatically kclosed and the anesthesis can be'gin. g v

, When air is breathed out, thevalve 3 is lifted.

The anesthetic goes intoY the bag reservoir 4, the

` breathes in, thevalve 3 is closed whilst valveslland i3 are open, the .exhaust pipe I4 being closed..

' produced by this apparatus is added tothe oxygen of oxygen. i Y

matically regenerated in the course of respiration.

cock 5 of which is opened. When thepatlent The ratmosphere, which is breathed ,in passes through cock 8 and apparatus 9where in some chemicals produce oxygen by the action of the steam and carbon dioxide of'vthe expired atmosphere. These products, steam. and ycarbon dioxide, are replaoedby a proportional volume Therefore the oxygen is auto- If the quantity ofV oxygen obtained-through the apparatus 9 is notsumcient, the apparatus III maybe used working in the manner described by admitting water from the reservoirII the oxygen produced by regenerator 9. The volume of oxygen produced from 9 alone or with the help of III must maar be Just sumcient'to maintain the respiration. The

f I8 of thebag I'IV isv kept closed. When agfurther quantity of atmosphere'is expired the valve 3 opens whilst valves I2 and I3 are closed and the operation is continued as aforesaid.

If'th'e proportion of oxygen is still too much theexplred atmosphere, the handle ZII is operated so as to divert more' or less of the at mosphere through the pipe 8' instead of the apparatus 8.

.If the quantity of carbon dioxide is insufflcient in the atmosphere to be breathed in, one may use the carbon dioxide mixed lwith oxygen contained in the bag-'reservoir II by opening the cock I 8. This operation will rarely be necessary asthe bag reservoir 4 always 'containsa certain proportion of carbon dioxide when'fthe pipe 8f is correctlyused as aforesaid.

If the anesthesis becomes too seriousone may -let the patient breathe fresh air through cock I8. When the bag-reservoir 4 becomes empty on account of the absorption oiane'stheticv by the lungs, a fresh quantity of the gas may `be yintroduced by the reservoir I5,.and when the latter becomes exhaustedfthereservoir I6 maybe used without disconnecting I5. The theticl by the patient decreaseswith vthe progress of the anesthesis to become null Vwhen the anesthesis is complete.A u k y'I'he apparatus which has been described with referecetofFig. 1 can be used with any-anesthetic whichis not modified bythe contact with the chemicals used `for regeneratingtheoxygen, for` instance withl nitrogen prot'oxide, ethylchloride, and the'like.AVV V f If the concentration of nitrous oxide inthe inhaled atmosphere i's toog'reat, it-produces saturation .of the blood-whichrenders :the anesthesia by setting apparatus IIl--in a'ct on to add pure oxygen to the anesthetic.

The method ofgiving'anesthetics as described above is eifectedin a confined atmosphere yand consequentlya perfectly gastight mask must ybe used, of a typeillustrated by'way of Aexample inFigs. 1 and 2. Themask illustrated byI Fig. 1 comprises al pneurnatieal` tirev or pad 2 I which ensures gas-tight contact around the mouth and nose of the patient, a chin-pieceZZ, and straps 23 suitably disposed and tensioned for maintaining the whole mask wellappliedonthe face ofthe patient. which permits of examining theminthe'course of the operation. f v

. The'mask illustrated inFig. 2 covers entirely the face of the patient and'is attached by straps 24; it comprises eye-holes Hand a chin-piece 26. A finger tube 2l opened at its The eyes ofthe patient remain free,`

end Z8 .allows ,thef 'surgeon to examine the eyesl'v absorption of the anes- V in.k

consequentlyk if the anesthesis tends to Fig. 3 illustrates an oxygen regenerating apparatus which does not contain the chemicals in cartridges but has the advantage o! allowing easy renewal of the chemicals used for producing oxygen from carbon dioxide and water, after each operation. The apparatus shown in perspective view comprises a box 28 containing elements 38 oi cylindrical 4or parallelopipedic shape, 'made of successive layers. These elements are impregrated with the oxygen regenerating product. The sides 3l and 32 of the box are left empty to allow easy lling pf the elements 38. When the apparatus has been charged, the side panels 33 and 34 are tted in, the two other sides of the box 28 being xed, and thetop and bottom sides of the .box being formed ofwire xgauze for .the flow of gas. The'box 28 is fitted inside a casing 35, which comprises tworemovable covers31, one

Y on each side', eachcover having a filtering layer on a table or horizontal support'48; the diierent parts of the apparatus are indicated by the same reference numerals as in Fig. 1-.

The apparatus illustrated by Figs. 5 to 8 is devised specially forthe use of nitrogen protoxide, with the use of'oxylithas oxygen regenerating agent. Oxylith. as here referred to, as achemical oxygenating agent, is an alkaline peroxide having the property oi' disengaging or'evolving oxygen under theaction of carbonio acid and the water vapor contained in the atmosphere exhaled by an individual. Among'such alkaline peroxides may be mentioned activated sodium peroxide, potassium and sodium trioxide and potassium and sodium pentoxide, all of which are capable of use after the oxygenating power has been reduced. Thesechemical agents absorb the carbonio ac id and water vapor contained in the exhaled atmosphere and then evolve suiiicient oxygen, to maintain respiration, but not to such -great extent as' to reduce the anesthetic proportion in the mixture inhaled.

The apparatus comprises a supporting cradle 8l. secured to the edge of the operation table 82.

The cradle l8| has a shape. adapted to receive the oxylith cylinder or reservoir 83. At one end ofthe cylinderis connecteda pipe 84, by means of a winged-nut 8 5. -At the other end of the cylinder v83 is connected the pipe 88 by means of the winged-nut 81. A collar 88 xed to 'orintegral with the cradle 8l carries the central pipe. 88 leading to a gas-tight mask. The pipe 88 leads from a three-way cock 18 which is illustrated in detail and in cross-section-in Fig. 8. 'Ihecock 1l is connected on the one side to the pipe 84 .and on the -other side to theA pipe 88.

A bottle 1i of nitrogen protoxide is connected to the central pipe 88 by means oi the connection 12 andwinged nut 13. A bottle 14 containing a bag reservoir, and additional oxygen producing apparatus of Fig. 1.

tion of anesthetic. `gauze wire or similar material and disposed 'in This bottle is .here shown Y three-way'cock 18. lA bag-reservoir` 18 i'or the reserve of ,anesthetic is connected'to pipe 84. A

cock 88 opening into the air,.and valves 8| and 82,v are provided-for expellingthe air from the apparatus and for obtaining an'high concentra- The three-way cock 'lofiuustrated separately in Fig. 8 comprises'a` cylindrical casting 83 at thebottom of which isconnected pipe '88..l Inside the' casting 83' fits a plug 84 which is milledon a portion. of its circumference to leave v.only the` solid part 88 extending nearthebottom of the casting. The casting 83 comprises, in two places of the circumference thereof, periorations88 and 81. Two chambers 8 8 and 88 formed in... the`jwa ll of the casting receive the ends of .pipes .84 and 88. -An axial pin 88 and a'handle8l a'reprovi'ded` for operating the cock. By appropriatelyturning the plug the

perforations

88 and 81 can be gradulally opened 'or closed. It will, oifcoursebe understood that' each of the valves 1 and'8 ofFig. 1 may be arranged andconstructed in the form dis- -`closed in Fig. 8. whereby graduated opening of'one oi."V said valves accompanies the corresponding graduated closing of the other, and vice versa.

This apparatus'functions as follows: the operator first makes certain that there visin the appa: ratus an anesthetic atmosphere which is as pure a's possible, by expelling the air or oxygen from the apparatus. This result is obtained by opening the exhaust pipe 88 and sending a flowof protoxide gas through theapparatus. The valve 82 is closed by the. pressure of the gas andthecock `18 is operated so as to close pipe84.- The flow of .gas expels the air from the tube 88 andthegmask. The cock 18 is then operated so as to yclose the pipe 88, but to open pipe- 84 and -the ilow of gas expels the air from by-pass11-and pipe 8 4. The

bag 18 is'lled with gas, then `emptied-by hand Y pressure, and vfilled again. The gas passes through the oxygen regeneratingcylinder. 83 to expel-thc f air therefrom andthrough the pipe l88 from which the air escapes by the valveliand the exhaust pipe 88 which can then beclosed.. The anesth'esisv thevalve 18 opensf'and illls the bag 18; by inspiration the valve 181s closed, whilst the `valves 8l. and 82 are open, the cockk88`being of course closed. The-atmosphere from `the bag 18 passes from the pipe'84 into' thereservoir 83 wherein thev chemical producesoxygenirom the'carbon di-' oxide and water ofthe atmosphere breathed out.

The volume of oxygen thus produced-is ina cer-H tain proportion with the volume of carbon `dioxide and vapour breathed out. The `regeneraltion of oxygen is effected automatically. y.The recomposed breathing atmosphere returns into 'the mask through the pipe 88, valves-8Iand82', cock 18 and pipe 88. By afurther expiration, valve 8 2l closes whilst valve 18 opensr and the same ope" eration is performed. .I i' the quantity of oxygen producedl in the reservoir 83 is insumcient, one

must use `the mixture ofoxygen andcarbon di-V oxideicontained in reservoir 14, and determine the proportionsfproperly.

If the quantity of oxygen from the reservoirv 83 becon`1es too highin proportionto the protox-f f ide,cock..18 is turned soas to close partially or 75 totally the pipe 88. In this manner part of the aspired atmosphere or the whole ot it does not pass through the reservoir `63. In this latter case the atmosphere is breathed out into the reservoir 19 through the pipe 04 and is breathed in again directly through the cock 10 and the` pipe 69 without passing through the reservoir 63 or thepipe 60. By simply turning the handle 9| one may control the openings of pipes 64 and 60, and the action of the reservoir 63 for obtaining a smaller or higher proportion of oxygen, and inversely of carbon dioxidel in the anesthetic.

If on the other hand the proportion of carbon dioxide in the anesthetic atmosphere is insilill-l cient, one may use the reserve of carbon dioxide and'oxygen contained in bottle 14, or simply reduce the proportion of oxygen. l

If the anesthesis becomes too deep, one may open communication with the outer atmosphere near the mask, or else one may dilute theprotoxide of nitrogen in the mixture by vopening the cock the air which thus breathed in dilutes the protoxide. 0

The apparatus illustrated by Figs. 9 to 1v1 is devised specially for short anesthesis, such asis required for instance for extracting a tooth, inclsing an abscess, and the like. Although this apparatus is destined to be used specially with nitrogen protoxide and oxylith with other chemicals or not, one may also use same with other anesthetics such-as ethyl chloride, and the like.

For these anestheses of short duration, it is required to obtain complete anesthesia, by means of a high concentration of anesthetic in the atmosphere to be breathed, the anesthesis being stopped as soon as this result is obtained. The maintaining of the anesthesis not being required in this case, the parts of the apparatus designed to' prolong the anesthesis can be dispensed with. Namely, the members (bags, bottles) for having a reserve of carbon dioxide and of oxygen and the circuit with the valves may be dispensed with. However, with this apparatus can be used sparklets of nitrogen protoxide, oxygen and carbon dioxide which allow to prolong slightly the anesthesis if required. The pipes are made asshort as possible, and

the dead space, which corresponds to the volume of gas remaining after each expirationY between the lips of the patient and the oxygen regenerator, is almost null; the purification of the gas is suflicient at each breath vwithoutV the use of the complete circuit with valves. The apparatus thus simplified for giving anesthetics for a little while is therefore of reducedweight and volume, and easily portable.

The apparatus of Figs. 9; and 10 essentially comprises: a mask `92-with` pneumatic pad 93 and rings for attaching the mask against the face, a short p ipe 95 connecting the mask with a three-way cock 96 having an opening 91 to the free air. 'Ihe plug of the cock 96 comprises a full portion 99 and a hollowed portion 9 8; the operation of the cock is eifected by a handle or wheel or any equivalent'means. A tube |00 connects the cock 98 to the oxygen regenerating cartridge |0| which functions for a few minutes. To the tube |00 is connected asmall tube |02l having a threaded end on which can be adapted a bottle |03 of the sparklet type, containingy nitrogeh protoxide. The sparklet is shown with the nozzle disposed in the middle of the cylindrical body which 'facilitates the manipulation thereof. 'I'he oxygen regenerating cartridge |0| communicates on the one lside with the tube |00 and on toxide, contains no air.

, I5, to a bag-reservoir the other with the bag-reservoir |04Afor anestheticy atmosphere.

f The oxygen regenerating cartridge which is here shown for oxylith, contains a central vdisc f `ment obliges the gas passing through the cartridge ,to come well into contact with the oxygen regenerating product, and ensure maximum eiliciency. Wire 'gauze or filters of glass-wool or a of asbestos-woolretain the chemical kinside the cartridge. fThe cartridge |0| having been,'.in course of manufacture, filled with nitrogen pro- The vbag reservoir |00 is `emptied, before being adapted f on the -apparatus.

This apparatus operates as follows: the cock es is tumedso as to close the tube lan: the

sparklet is then screwed on andthe nitrogen `protoxide fills the lbag |04 through the cartridge 0|; the cock iis'in the position illustrated by Fig-.9. The mask is applied against the face of the patient. At this stage only the cock 96 still lcontains air.Y To commence the operation of giving the anesthetic, the operator turns the cock in the direction of the arrow Fig. 9. By this operation there is a point 'when the plug closes the pipe 95 and leaves open the tube |00 Vand the opening 91, asis illustrated in Fig. 1l. During the very short time that this position occurs, the protoxide of nitrogen, still under pressure in the bag |04, expels the air from the tube |00 and from the cock through the opening 91. The plug being turned further in the same direction the pipe 95 is opened whereas the opening 91 is closed.l This position is maintained for giving the anesthetic and is illustrated by Fig.` 10. The reservoir-bag |044 is thereby in communication lwith ythe mask. The gas breathed iny and breathed out has its ozygen regenerated by passing through the cartridge |0| in the manner aforesaid.

As soon as the anesthesislis complete, the operator ,takes the mask away from the face of the patient and immediately -performs the short, painful operation. Iftheanesthesis must be kept on for a short time, it will however be necessary to stop it as soon as the cartridge |0| is exhausted. If on the `other hand the quantity oi' carbon dioxide isinsufilcient the anesthesis must be stopped.

In the case of operations lasting somewhat longer than those contemplated forI this last describedl embodiment of the apparatus, one may use the same apparatus, but with' the help of extra gas bottles, as illustrated by Fig. 11 of the drawings. If the quantity of carbon dioxide, or of nitrogen protoxide, or of oxygen is insufflcient in the mixture, one may with this apparatus immediately usev an extra sparklet of bottle containing one of these gases respectively. With-reference to Fig. 11, a pipe of small gauge, |05, is connected to tube |00.y The pipe |05 leads to three branchments |06, ||0, H4, respectively leading toV three cocks |01, and respectively |08, H2, and IIS, and to a respective sparklet.` sparklet |09 sparklet- ||3 contains oxygen, and the third sparklet ||1 contains ycarbon dioxide. When these sparkletsare opened the respective bagreservoirs |00, H2, andy I I0 contain the respective gases. and by means of the respective cocks |01, III, and Hi these gases can be sent 'I'he first contains anesthetic. The second into the anesthetic apparatus according to the requirements and according to the required proportions. 'I'he additional sparklets,v cocks and bags are laid on a table near'to the main apparatus and under the immediate control of the operator.

If the sparklets have a needle valve instead of a tin capsule which has to be pierced, the individual reservoirs |08, H2, and H6 can be dispensed with, and the required quantity of carbon dioxide, nitrogen protoxide or of oxygen can be sent directly into the main reservoir |04.

Having now fully described my said invention, what I claim and desire to secure by Letters Patent, is:

1. An apparatus for giving anesthetics in a confined atmosphere, comprising in a closed circuit, successively in the direction of the ilow of gas: a main circuit and a shunt circuit, cocks in each circuit after the branchment of said shunt circuit, a common means for operating said two cocks whereby the one cock is closed when the other is opened, and whereby said cocks are opened and closed progressively, an oxygen regenerating apparatus in said shunted portion of the main circuit, an oxygen producing apparatus connected to said shunt circuit, a cock beyond the shunt circuit allowing communication with the free air, and placed immediately before a connection with a source of anesthetic under pressure, valves permitting the said determined direction of ilow of gas, a connection between the said closed circuit and the mask, and a cock for closing said last mentioned connection and for communicating said mask with the free air.

2. An apparatus for giving anesthetics in a confined atmosphere, comprising in a closed circuit, a connection, with a cock, to a bag-reservoir for a reserve of pure anesthetic atmosphere, a shunted portion of the main .circuit and a shunt circuit, cocks in each circuit after the branchment of said4 shunt circuit, a common means for operating said two cocks whereby the one cock is closed when the other is opened, and whereby said cocks are opened and closed progressively, an oxygen regenerating apparatus in said shunted portion of the main circuit, an oxygen producing apparatus connected to said allowing communication with the free air, a bag-reservoir for a reserve of expired atmosphere and sources .of anesthetic under pressure'connected to the main circuit immediately before the connection from the said main circuit to the mask, and means for closing said last mentioned connection and for communicatingsaid mask with the iree air.

3. An apparatus for-giving anesthetics in a confined atmosphere, including an air excluding mask, a single conduit leading therefrom, a

shunt circuit, a cock beyond the shunt circuit Y.

closed circuit conduit in communication with the single conduit remote from the mask, a controlv` valve in the single conduit operable to place the mask in communication with. the atmosphere or with the closed circuit conduit at will, automat-v ically opening valves in the closed conduit permitting gaseous ow in one direction only, an an-lv esthetic gas container in communication with the closed circuit, a manually controlled air vent valve in the'closed circuit beyond the containerin the direction oi gaseous now, an anesthetic gas reservoir in the closed conduit beyond the' air vent valve, and an automatically opening valve in the closed circuit -conduit between the air venty valve and anesthetic gas reservoir, whereby on opening the atmospheric` ventl valve and closing the control' valve the'anestheticfgas from the reservoir may be forced through the closed circuit conduit to clear the latter of air and to charge the anesthetic gas container, said anesthetic gas container being open to the ex- V halations of the patient in the use of the apparatus for giving anesthetics, a by-pass in the closed conduit beyond the anesthetic gas container in the direction of gas ow, and simultaneously -and oppositely acting valves controlling the cosed conduit and by-pa'ss conduit to direct the gas iiow wholly through the by-pass conduit, wholly through the closedvconduit, or partially through each, and an oxygen regenerat ing apparatus in the by-pass conduit, whereby upon opening the by-pass conduit oxygen is v automatically regenerated during the course of respiration in theuse of the apparatus.

JEAN CARR.