US2185067A - Apparatus for self-administration of anesthetics - Google Patents

Description

' Dec. 26, 1939. -J. G. SHOLES APPARATUS FOR SELF-ADMINISTRATION OF ANESTHETICS Filed July 2, 1937 4 Sheets-Sheet 3 L WJ N m '5 ATTORNEYS Dec. 26, 1939. J; G. SHOLES 2, ,05

AISPARATUS FOR SELF-ADMINISTRATION OF ANESTHFJTICS Filed July 2, 193'? 4 Sheets-Sheet 4 INVENTOR BY C 170 AWN-UM ATTORNEYS Patented Dec. 26, 1939 v 7 2,185,067

E APPARATUS FOR SELF-ADMINISTRATION C -FANES'H IE'IICSv Justin'Q -ShoIes, Cleveland, Ohio, assignmto The Ohio Chemical and Manufacturing Company, Cleveland, :Ohio, a corporation of 'Ohio I I v Application July 2, 193-1, Serlai No. 151,569

V Y r 18 Claims. (01. 128-203) v This invention "relates'to'an apparatus adaptparticularly-in which such cessation of the flow ed tor use by. a patient in the self -administraof anesthetic is not in anyway dependent upon tion of gaseousjanesthtics, and more particua relaxation'by the patient, but will occur even larly to apparatus of that character for enabling should the patient convulsively grip the control a patient to induce or maintain a condition handieduring unconsciousness.

' which, is sometimes known" as analg'esia,'by In various-forms of apparatus previously prowhich is meantinsensibility'to pain without loss posed for permitting seli administration of anesof consciousness, asdisting'uished from'a'state oi thetic, a fundamental objection has beenthat anesthesia, in which the patient'is entirely un-' the cutting 'off of the flow of anesthetic, should conscious. Asaa'i' matter of convenience l shall, the patient administer an overdose-andlapse 10 at times, designate and refer to'apparatus of this into unconsciousnesais dependent upon the pacharacter as an"an'al gesor"-. I 1 tientshrelaxation of hisgrip', or of his pressure The 'apparatusisf also useful in theadministrauponsomeb'utton' or valve, or releasing a cord or tion of,anesthetics.-'byia physician, "in cases in handle, or'some other relaxation intended to be which a complete anesthesia isurequired, and, 1 3produced by the patients unconsciousness. A 15 more particularly, whenfa brief but complete serious difliculty with such apparatus, however, unconsciousness is desired. 5 U V has been that at least some patients'do not relax' An anesthetic commonly used in; such appa when'they become unconscious, but,maintain a ratus is nitrous oxid, ordinarily mixed in suitable convulsive 'grip,.pre'ssure or pull upon the apparaso proportions with air oryoxygen. -Although other tus, as the case may' be, so that; the flow of go suitable anesthetics may' alsobe used in-apparaanesthetic does not automatically cease, and tus according to my invention, under pertain there is the possibility that a dangerous or even conditions,--for 'e'xafnple. cyclopropane under fatal overdose of anesthetic may be administered proper circumstances -the" 'following descripbefore the patients condition isno'ticed-by the l5 tlon will bemadewith'r'eference;telnitrousoxid physician.- I I by way' 'o exampleg' The terms gas- -oranes'- It has heretofore been proposed to provide thetidgasasused-hereafter should be 'underapparatus in, whichthe continued delivery of stood {to include'vaporsl as well .as gases, when anesthetic to the patient requires some purposetheformer aree'mployei' I p vful effort on the part of thelatter, but in most 7 go In varioussituationslwhicharise inzthe prac .such' apparatus there has beenan undesirable tice of medicine, surgery, or: dentistry it is def time relation involved in the shutting off of the sirable thatanbilgsia induced'onmaintained' ,;flow oi anesthetic, after the patient" became unby the patient self-administration 'oifith'e anes 'cons'cio'usfaccording to which some. predeterthetic, so that"the arnoimt thereofmay be, con,-

fmin'ed quantity'oi'fanesthetic could nevertheless trolled by the patient; and regulatedmtt iol'di rlgbe delivered to the patient after that time,.or" to the time of occurrence aindamoun't *ofy'the j the flow of anesthetic could be continued for a ain. Ant, example :15: in dentistry in which the given'time after the patient became unconscious. patient may 'adrni'nisterI anesthetic; to himself In m copending application Serial Number when drilling or otherpainful operation occurs; 115,327, filed De e ber 11,1936, now t 0- 40 in amount dependingj upon the severity of' the 9, for Self-administration of gaseous 40 pain. My inventionmay, however, be used-also, anesthetics, I'described an apparatus designed to in'casesof'chi1dbirth,,in setting fractures, in a overcome this 'diillcultm and, "in certain of its variety of instances of minor, surgery such as aspects, the invention of the present application dressing wounds,- and under, .othersuitable cir is an improvement thereon. r I

cumstances. 7 A further object of the present invention is to 45 An object ofthe present. invention is to proprovide a safe and simple apparatus which overvide an apparatus f or. .u'sefin the sel'frinduction comes both the foregoing. and other "dimculties of analgesia by a patient,-whi'ch' is at once safe encountered with previous types of apparatus; and simplefand more particularly by the use of which has relatively few I and simple working which a patientfcannot administentohimself an parts to get out of orderyand which isv so-ar- 5o overdose or any dangerous quantity. of anesthetic, ranged that there can beno continued delivery It isalso an object of thefpresent invention of gas from the storage cylinder or receptacle to to produce such an apparatus injwhich flow of the patient after the patient becomes unconthe anesthetic will automatically cease if the scious;

56 pat lapses into unconsciousness, n m e A still further object of the invention is to provide such an apparatus in which a master control'by the doctor, dentist or other. operator may be provided, so that the administration of the anesthetic may be supervised by him, and may, if desired, be discontinued, and pure air or oxygen be administered by him, at his discretion, without control by the patient. Such control by the physician or other attendant is desirable because the effect of gas upon different patients cannot always be predicted, and cases may arise in which the patient would be inclined to administer an overdose to himself. According to the present invention, this is under the control of the physician or attendant, and the gas may be shut off and air or oxygen sub- .stituted by the latter, should he consider it' advisable to do so. I

My apparatus is also valuable and eflicient for inducing brief anesthesia such as is required for lancing abscesses, removing skin blemishes or in an emergency, as for reducing or setting fractures and performing other brief operations last- I The method employed r ing only a few minutes. requires the physician or his assistant to compress and release the control handle or grip to a point at which the patient sinks into deep anesthesia for a sufficient length of time to permit the brief operation.

The use of my apparatus with anesthetic gas gives greater safety to the patient than administering chloroform; ether or ethyl chloride, which are commonly used in case of an emergency, but which place the patient in a state of anesthesia for an indefinite or uncontrolled length of time. With my apparatus the patient revives promptly, as soon as the physician or his assistant ceases to compress and release the control handle or grip, but recovery may be made even more prompt by administering pure oxygen in the manner hereafter to be described.

Other features and objects of the invention will appear from the following description.

' I shall now describe, by way of illustration, the

principle of my apparatus, and the best mode in which I have contemplated applying that, principle, constituting what is at present the preferred form of the apparatus now known to me, in greater detail in connection with the accompanying drawings. in which:

Figure 1 is an elevational view, partly broken away, of the preferred form 'of the complete apparatus assembled ready for use:

Fig, 2 is an-elevational view, mostly in crosssection, of the valve and gas control chamber assembly;

Fig. 3 is a detailed View, largely in section, of the reservoir portion of the apparatus employed for the admixture of air with the gas and for equalizing or stabilizing the flow of the thusmixed anesthetic to the mask;

Fig. 4 is a detailed sectional'view of the mask, on the line 44 of Figure 1; and v Fig. 5 is an elevation. partly in cross-section, of

a different form of apparatus, which may also be used, under certain conditions, instead of the apparatus shown in Figure 2, and which also formsa part of my invention.

Referring now to the drawings in greater detail, the apparatus comprises a suitable stand or support In which may be conveniently mounted on the casters II, for ready portability. At one side of the stand there is removably mounted a flask or cylinder I2 of compressed anesthetic gas-nitrous oxid in the case illustrated. This cylinder may be mounted, as shown, in the yoke or frame I3 where it is secured by the set-screw I4, and connects (through a wire gauze or filter, passing directly through the coupling and reducingvalve I8.

reducing valve I8, which may be adjusted by the physician, by means of the handle 20, to give any desired reduced pressure on the low-pressure side thereof, which reduced pressure is indicated by the low-pressure gauge 2|. Thus, for example, if gas from the cylinder I2 be admitted" to the high-pressure side of the reducing valve I8, by means of the valve I9, until the pressure builds up to say 1000 or 1500 pounds, then by suitable adjustment of the valve handle 20 the physician may regulate the reduced pressure to, say, 10 to pounds, as shown on the lowpressure gauge 2|.

A still further adjustment under the control or thephysician-or operator is furnished by the ad-,

ditional valve 22, located on the outlet side of the reducing valve I8. For example, this valve 22 may be a needle valve for controlling the rate of flow of the gas, and may be provided with an off" position, after which it progressively opens to permit more rapid flow of the gas, and is con-,

veniently marked light, medium and heavy on its dial, which designations signify respec-,

tively the strengthof the analgesia which the physician desires to have produced by the,respective rates of flow permitted by such respective settings of the needle valve.

Connected to the needle valve 22 is what I shall hereafter at times refer to, for convenience, as the control-valve-and-gas-chamber-assembly", or a gas control device, generically designated as 23. This comprises several parts, including a check valve 24 arranged at the inlet end of! the chamber 23. Also at the inlet end of the chamber 23 is a connection 25 to a reservoir and equalizing chamber 26. The latter maybe conveniently housed, as shown, inthe vertical portion of the stand I0, and may, for example, have a capacity of about 280 c. c. at one atmosphere pressure. The reservoir and equalizing chamber 26 is not connected to the pipe passing through the cross-head I5, but has itssole connection through the tube 25 to the valve and gas chamher 23. The endsof the chamber may/be closed by screw caps 23a and 2322. or in other suitable v manner permitting. access if necessary.

At the other end of the control valve chamber 23 is another check valve 21, constituting the outlet valve. Both" the inlet and outlet valves 24 and 21 are provided with springs, 28 and 29 respectively; tending to keep the valves closed. but both valves are capable of actuation, although never simultaneously, by the intermediately pivoted rocker arm30 carried by the transverse shaft 3|, journaled in the walls of the chamber 23. Actuation of the rocker arm 30 permits the alternate, \but never simultaneous, opening and closing. of the inlet and outlet checkyalves 24 and 21. V

Since the valves 24 and 21' may be similar in construction, I shall describe only valve 21 by way of example," It comprises the gas ducts 21a and 21b, valve seat 210' and valve head 21d, which is guided for vertical motion by the loosely-fitting" valve-stem 216. The valve head may also provided with a soft-rubber insert or seal 21 for making a tight closure against the valve seat. Both the weight of the valve head 21d and gas pressure above it. Upon releasing the grip 55" the pressure of the spring 29 keep the valve normally closed, and it can only be opened by a positive actuation of. the rocker arm 30, to exert pressure upon the lower end of the valve stem 21e. Gas outlet is through the duct 21g in the corrugated nipple 21h.

Referring to Figure 2, it will be seen thatthe openings of the valves 24 and 21, and arrangement of the rocker arm 30, is, such that one of the valves is always closed before the other one can be opened.

Actuation of the rocker arm 30 may be effected by the patient by means of the plunger or rod 32 (see Fig. 2) housed in the supplemental casing 33 threaded to the lower :side of the chamber 23. The plunger rod 32 isnormally maintained and biased in its downwardly extended position, as shown, by means of the spring 34. In this normal position of the rod 32, and consequently of the rocker arm 30, the inlet check valve 24 is maintained normally closed by its spring 28 and the weight of its valve 'head, as well as by the pressure of gas above the valve. The outlet check valve 21 is heldnormally open by the pressure of the rocker arm 30, urged by the spring 34. Thus gas flowing through the needle valve 22 can not enter the chamber 23, in the absence o1 the actuation now to be described.

The rocker arm 30 is actuated by means of the plunger rod 32through the intermediary of an enlarged plunger head or disc 35, bearing upon a similar cooperating plunger head or disc 36 shaft 31. The plunger of the Bowden cable may be extended longitudinally by the patient, by means of the handle-grip or patient control device 4|, in such manner that squeezing together 7 the two parts Ma and Nb of the handle grip 4| actuates the cable plunger 40a to force the rod 32 back against the pressure of the spring 34, and thus operate the rocker arm 30 to close the check valve 21 and thereafter open the check valve 24 against the spring 28 and against the upon the handle grip 4|, a suitable spring (not shown) located in barrel portion Me of the handle grip 4|, returns the handle grip to its normal position and retracts the plunger 40a and its.

button 4%, of the Bowden cable 40.

Thus in the normal position of the handle 4|,

the chamber 23 and its associated reservoir 26 are'not allowed to fill with gas; flow of gas passing through the needle valve 22, previously adjusted by the doctor, being cut off by valve 24. When the patient grips the handle 4|, its movement actuates the Bowden cable 40 and moves the rocker arm 30 against the spring 34 to first permit closing of the outlet valve 21, by means of its spring 29 and the weight of ;its head 21d, and then to open the inlet valve 24, by pressure of the right end of rocker arm 30 upon the valve stem 24e. Still the patient does not receive gas; but upon releasing the handle y'grip 4| the setting of the valves 24 and 21 is again reversed, and gas is allowed to flow to the patient, but only such amount as has been previously admitted to the chamber 23, and its associated reservoir, 'by the opposite setting of the valves. Thus the-patient receives no gasuntil he releases the handle grip 4|; when the apparatus is in its normal or rest position, the double action of gripping and releasing the handle 4| is necessary. before gas is received by the patient. In this way there can never be any continuous or steady flowof gas to the patient, whether the handle 4| is left normally open, or is continuously gripped, or is stationary in some intermediate position. Gas can only be made to flow by alternately gripping and releasing the handle 4|, and even then the gas flows only in measured doses equal to the contents of chamber 23 and its associated reservoir 26, and under the pressure previously set by the physician by the reducing valve l8, and further governed by the flow permitted by the needle valve22, also set by the physician. The chamber 23 and its valves thus constitutes what might be called a/gas lock or metering device, which permits only a predetermined volume of gas to pass through to the patient, for each. cycle of gripping and releasing the handle 4|, and whenever the handle 4| is kept stationary in any position,-open, closed or intermediate,'- the flow of gas automatically ceases at once.

Flow of gas to the patient is through the further apparatus now to'bedescribed (see Figs. 1, 3 and 4). The portion of this apparatus more particularly shown in Figure 3 (but also in Fig, 1) I shall sometimes refer to, for convenience, as a reservoir, or mixing chamber, since it serves to admit air to and mix it with the gas, and also serves to store the resulting mixture, generally under slight pressure.

Gas passes from the outlet check valve 21 through the rubber tube 42, attached to the corrugated nozzle 21h of the check valve 21, into the non-collapsible perforated rubber tube 43 (Fig. 3), This is suitably a corrugated tube of rubber of such-thickness as to be non-collapsible under the pressure to which it is subjected, and is pro vided with a series of holes 44 in its peripheral 45 wall. The inlet thereto is formed by the corrugated nipple 45, which permits inflow of gas,

while in the casing 46 surrounding the nipple there is also arranged a series of perforations 41,

covered on the inside by a light and flexiblerube-a ber disc or washer 48, thus forminga check valve-- from the parts 46, 41 and 4B. The perforations; 41 are open to the atmosphere on the outside, so] that any suction on the'non-collapsible rubber tube 43 draws air in through the check valve past the washer 48 and through the perforations 41.

Surrounding ,the perforated tube 43 is an expansible rubber bladder or balloon in the form of a bag 49, forming a reservoir and gas mixing and equalizing chamber for maintaining, under slight pressure, the mixture of gas and air which results from the arrangement just described, and for supplying it to the patient. This is done through the outlet check valve 50, provided with/ .a series of perforations 50a, opening into the tube 43, and a light rubber washer 5| arranged on I mouth, as desired. For dental work a nasal mask is preferred as shown. In that case, two inlets 55 and 5B 'intothe mask (Figs. 1 and 4) Ina/yen incide with the patients nostrils, for permitting him to inhale the air-gas mixture, and stillanother check valve 51 is arrangedon the outside I: v I

respectively, are'arranged at opposite ends of; a

of the mask to permit the patient to exhale.

This valve opens against the spring 58 upon eiihalation, but closes immediately the patient be-f gins to inhale, so that all inhalation is main gasmixture fromthe' reservoir 49. 1

An adjustablezcollar 5 9'(Fig. 1)- fitting overly I p but-suitably similar to. that 'of Flg. ;1) isrelaxed,

' thetwo rubber tubes 53 and normally held in place by .the spring catch and release button 60 condition, in the apparatus according to my-invention, the-flow of gas immediately ceases with out timing or other delay.

v A'difierenti'orm'ofgapparatusacc' rding to my invention is' shown in; Figure 5.: j struction the inlet and-outlet valves. I.0I and t-I02 cylindrical ga's-ancl-valve control -chamber I 03,-

which isprovidedwith a fixed partition {I04 inpermits the tubes 53 to' be'placed around the patients' head and the mask clamped .overlhis nose by sliding'of the collar 59 along the tubes 53, to provide a' comfortable adjustment.

A further safety feature'ofthe apparatus shown in Figure 1,,and consists offan oxygen' cylinder 6I, suitably mounted on'the stand I0,

and provided with a valve 62 controlled by the; physician, and connected to the rubber .tube' 63' connecting through the Y connection 64' to the tube 42, and thencethrough the; mixing chamber and reservoir-49, to -the mask 54. Thusshould' the physician observe any symptoms of distress or over-excitement in thepatie'nt, he has/only to" open the valve 62 and inject pure ox ygen into' the reservoir 49, where a slightjpressure of'pxygen termediate :the ends .Jthereof having seriesjof' perforations,-.,I05,- to permitpa'ssage oi gas.

When the-handle grip. (as "4| inot.shown in Fig. '5,

the valve' I 01 is" kept closed, as'shown, by the springfIIlIi, and gas' -,cannot;enterthe chamber this con- 1 I03. I If, "however. the handle 4| is gripped, its

Bowden' cable. (not shown. in 5 but similar to that, of ,Fig. 1). gactuatesthe rod I0I which, through-the.flexiblemubber or-other suitable diaphragm seal I08,and,head I09, pushes upon the loosely fitting discor plate IIO, 'thus-compressing the spring II and closing the valve I02 to.

, the outlet... This valve may consist; of the seat may be thusbuilt up, and oxygen immediately passes to the patient, thus, at once bringing the patient out of the anesthetic. "Ihe.valve62 is f preferably under the exclusive control of the physician.

:Ihe. operation of the form of apparatus shown in Figures 1 to 4 has been shown in detail by the foregoing description, but may be summarized as follows: r v

The physician first adjusts the valves I9, I8 7 and 22 to give the-desired pressure and flow of gas, then gives the handle grip 4I.-to the patient .and fitsthe mask or other suitable inhaling ap- .pliance over the patients nose, or, mouth, or

both, as desired, by adjusting the -tl1beS 53 ,and

collar 59, which is thereafterheld' in place' byits spring catch 60 Thus if the patient feels pain,

he has only to grip and then, release the handle 4I, thus permitting. gas to flow to thereservoir 49. In the meantime, the patient has, of course, I

been breathing air through the check valves 46, 41 and 48 at the inlet end, and 50 at the outlet end, of the reservoir or mixing'chamber 43, 49, thus inhaling from the reservoir 49 and exhaling through the check valve, 51'. Gripping and releasing the handle 41 injects gas'into the air in the reservoir 49 and gives a slight analgesic effect. Continued alternate gripping and re1easing.. of

the handle 4| continues'fto inject [gas into. the

reservoir 49', sothatai'rgas mixture is breathed,

guided by the additional perforated partition I I8, to abut, whenactuated, against the sliding pin. 1

but whenever-the patient feels-that he hasha'd J enough gas, or the pain ceases, he has only to stop working the handle 4] and gas will-instantly reversed. v i v I V t p t In this construction a reservoir and equalizing chamber may-be providedin the stand column-as V 102a,, gaspassage I021); and soft rubber, leather or other suitable seal I02c, set in. the' valve head -I02d. f The. plate I0 is mountedfupon rods lll; 7

and"I I.3' which pass through the partition I04 and; are,attached1at 'their-upper ends "to"the similar loosely fiting plate or discI I4. This in turn carries the rodor'plunger' I'I5 rigidly attachedthe'reto': Y This rod passes throughandis II6 for actuationpf the.check valve I01." Thus ,valve I02 is always closed it :valve' I'0I is open.

The perforationsjl05 in the partition I04 per- "mit the flow ofgas the-rethrough, and scout through nozzleT-I I1 to the reservoir and mask,

but due to thefinterrelation of valvesIOI and I02, there can nev'er' any continuous flow of gas to the mask, "whether the handle grip M be opened or'close'd. Onlyby continuousoperation of the? handle grip, alternately gripping and releasing ,it, can gas be made '-to flow to the. mask.

The purposeor the perforated. partition I I81is't to furnish asupportand guidewayior the plunger rod; II5, while the' fspri'ng. ,I, I9. maintains the plunger vH0 Qin' nQrmalIy r'etrac'ted position, as .j

:shown. Valve I02 jisf normally open, *also as "shown, and valve I 0 I, isfnormallyclosei'as shown.

Actuation of the handle grip first closes va'lve I02, then opens valve IOI. Upon relaxation of the handle grip'the process and setting of the valves I at 26 in Fig. 1',- and, for example, a' suitable capac-.

ity 'for this reservoirisapproximately 280. c, c. at 7 one atmosphere pressure. a

apparatus shown in Fig. 5 I-haveshown the needle In the construction as illustrated in the form of 1 valve 22 interposed' b'etween the chamber I03 and the reservoir 26; where'it may be-controlled by the physician. As before, a reducing valve I8 is pro- Y stop flowing, without any timed flow or metered after draws only pure air into the reservoir 49.

. An important advantage of this arrangement is that the-flow ofgas is immediately and auto-' matically shut. off when the patient ceas'esthe alternate gripping and releasing of handle, whether voluntarily or through lapsing into u'nconsciousness. Some patients may relaxfiwhen unconscious, while others are aptto maintain a convulsive grasp of the apparatus, but, in either v vidd between the gascylinder and the gas chamber I'.03., -with high and low pressure gauges I1 and 2t and a handle 20 under control of the physician,

all as before. 1- A copper gauze screen or filter (not shown), between the gas cylinder and the inlet side of the reducing valve, may also .be provided it desired; v

' 'Ifhe'detafled'operation of the form of apparatus shown in Figure 5 will be clear from the foregoing description, but may be summarized as follows:

. 'Whenthe valves and 22 have been. suitablyadjusted by the physician, valve I! is normally closed, and valve l02, to the mask or other inhaling appliance, is normally open. The patient thus breathes only air. Gripping of the handle 4! 'actuates the -Bowden cable 40 to push the plunger inward-thus first closing valve I02, and then opening valve I01. This admits gas to the chamber l03and the reservoir 26, but the patient still receives only air. Release of the 10 handle 4i reverses the setting of the valves NH tion of the apparatus of Fig. 5 are apparent from the detailed description already given, as well as from the description of Figures 1 to 4 inclusive.

When either form of the apparatus hereinabove described (that of Figures 1 and 2, or that of Figure 5) is employed for administering anesthesia,

as distinguished from inducing analgesia, as for producing brief anesthesia for minor operations or emergency work, as already described, the handle grip 4| is, of course,'utilized and controlled so by the physician or his assistant, in such manner that the desired anesthesia is produced for only the time during which it is actually required. This isa substantial advantage over earlier practice, as, for example, the administration of ether 5 for an emergency operation, which may produce unconsciousness for an uncontrolled or indefinite length of time.

The apparatus herein specifically illustrated and described are. the'best embodiments of my invention now known to me, but it is to be understood that the invention is not necessarily or specifically limited thereto, but may be carried out in other ways, without departure from its spirit, within the scope of the following claims.

I claim:

1. In an analgesic apparatus of the class described, adapted for the self-administration of anesthetic gas by a patient, and including a source of anesthetic gas, means for delivering the gas therefrom, and a mask for delivering the gas to the patient, the elements which comprise a gas control chamber provided with inlet and outlet valves so arranged and inter-related that both valves can never be opened at the same time, and operating mechanism under the control of the patient for alternately opening said valves to permit only a limited quantity of gas to flow to the patient, the arrangement and location of said valves and patient control means being such that gas can not flow to the patient while said patientcontrolled means is stationary in any position.

2. In an apparatus for use in the administration of an anesthetic, and having a source of anesthetic, an inhaling mask for the patient, and a reservoir connected with the mask and adapted to receive air from the atmosphere and deliver the same to the mask when the patient inhales, the elements which comprise a gas control valve mechanism having a plurality of valves through which gas must pass in series before reaching the patient, positively-acting mechanical means for automatically closing at least one of said valves before another of said valves can be opened, and means for opening said valves alternately and only while another of said valves is closed.

3. In'an apparatus for use in the administration of an anesthetic, and having a source of anesthetic, an inhaling appliance for the patient, and a reservoir connected with the inhaling appliance and adapted to receive air from the atmosphere and deliver the same to the patient when he inhales, the elements which comprise a gas control chamber and valve mechanism having at leasttwo valves through which gas must pass in series before reaching the patient, means for maintaining each of said valves normally'closed in the absence of actuation thereof, a rocker arm pivoted intermediate its ends and arranged to actuate said valves alternately only, the valves being actuated by the rocker arm from opposite sides of said pivot and the normal position of said rocker arm being such that it holds one valve open against its normal bias, while permitting the other valve to assume its normally closed position, and means for actuating said rocker arm to first close said open valve and then open said initially closed valve only While the initially open valve is maintained closed.

4. In an apparatus for use in the administration of an anesthetic, andhavinga source of anesthetic, an inhaling mask for the patient, and a reservoir connected with the mask and adapted to receive air from the atmosphere and deliver the same to the mask when the patient inhales, the elements which comprise a gas control chamber and valve mechanism having two valves through which gas must pass in series before reaching the patient, positively-acting mechanical means for automatically closing one of said valves before the other valve can be opened, means for opening said valves alternately, and an additional gas reservoir between said valves.

5. In an apparatus for permitting the selfadministration of anesthetic by a patient, and provided with a suitable source of anesthetic gas and an inhaling appliance for the patient, the features of novelty which comprise a master control under the exclusive control of a physician for limiting the maximum possible flow of gas to the patient, and a subsidiary control under the control of the patient for permitting limited flow of gas to the patient, subject to said master control, said subsidiary control comprising at least two valves through which gas must pass in series before it can reach the patient, said valves being so constructed and arranged that at least one of them is always closed and gas can not pass therethrough except upon positive actuation thereof, by the patient, and that passage of gas will be automatically cut off whenever said subsidiary control is in stationary condition.

6. In an apparatus for use in the selfadministration of anesthetic gas by a patient, said apparatus being provided with a source of anesthetic gas and an inhaling appliance for the patient, the elements which comprise a mixing chamber interposed between the inhaling appliance and the gas source and constructed and arranged to admit air from the atmosphere and mix the same with anesthetic gas from said source, a gas control device interposed between said gas source and said mixing chamber, means underthe control of the patient for permitting gas to pass through said control device only during positive actuation of said patient control means by the patient, and mechanism for shutting off further passage of gas through said gas control device whenever said patient-actuated control device is in stationary condition.

7. In an apparatus for use in the self-adminisof said patient control "means by the patient,

mechanism for shutting off further passage of gas throu h said gas control device whenever said patient-actuated control device is in stationary condition, and a source of oxygen and connection therefrom for permitting the physician to furnish oxygen to the patient at the discre tion of the physican and without control by-the patient.

8. In an apparatus of the class described, a gas reservoir and mixing chamber comprising, in combination, a chamber provided with a gas in let, a check valve for admitting air under the suction of inhalation by a patient, a second check valve for permitting the resulting mixture to be drawn out under the suction of inhalation, but closed by exhalation, to prevent the exhaled breath from mixing with the air-gas mixture in the reservoir, and a flexible reservoir in communication with said chamber between said ,check valves, for storing the air-gas mixture.

9. In an analgesor of the class described, and provided with an inhaling appliance for a patient, the features which comprise a collapsible reservoir connected with said inhaling appliance and provided with inlet and outlet check valves through which air is normally breathed by the patient, a connection to said reservoir from a gas control chamber; mechanism in said gas control chamber for permitting gas to pass therethrough only upon positive actuation thereof, and a control device adapted for operation by the patient and so connected to said gas control chamber that the patient can, at will, actuate the same, but only by positive mechanical movement of said control device, to inject a limited quantity of gas into said reservoir so that the patient inhales therefrom a mixture of air and gas instead of air only.

10, In an apparatus for use in the administration of an anesthetic, and having a source of anesthetic, an inhaling mask for the patient, and a reservoir connected with the mask and adapted to receive air from the atmosphere and deliver the same to the mask when the patient inhales, the novel elements which comprise a gas control valve mechanism having a plurality of valves through which gas must pass in series before reaching the patient, positively-acting mechanical control means for automatically closing one of said valves before another of said valves can be opened, and means for closing and opening said valves alternately in such manner that at least one of said valves is always closed.

11. In an apparatus for the administration of anesthetic gas, including a suitable source of anesthetic gas and an inhaling appliance fora patient, the features which comprise a master control valve, under the exclusive control of the attending physician, for limiting the possible flow of gas to the patient, and a subsidiary control means, also under the control of a physician, for permitting only a limited quantity of gas to flow to the patient, said subsidiary control gas to the patient can be immediately cut off I by the physician at will, bymaintaining said control valve in any stationary condition. I

12. In an apparatus for use in the: administration of anesthetic gas, and provided'with a suitable source of anesthetic gas and an inhaling appliance for a patient, the features which com- I prise primary means for limiting the flow of gas to the apparatus, and subsidiary means for administering limited quantities of gas to' the patient, said subsidiary means comprising a plurality of valves through which gas must pass in series before reachingthe patient, and actuating means for opening and closing said valves in such relation that at least oneof said valves is always closed in every position of said actuating means. I

13. In an apparatus for self-administration of anesthetic gas which comprises the combination with a gas chamber having an outlet for connection with a mask and an inlet for the anesthetic, a self-closing valve for the anesthetic inlet, and a movable member in the chamber, saidimovable'mernber being normally disengaged from said inletvalve but engageable therewith to open the same, manual means operable from a point outside the gas chamber to actuate said movable member within the chamber to open the anesthetic inlet valve, and a gas-tight flexible diaphragm sealing means interposed between said manualoperating means and the movable member within the gas chamber and hermetically sealing the gas chamber against escape of anesthetic gas into the atmosphere, while permitting actuation of the anesthetic valve by said external operating means.

14. A gas-and-air mixing and reservoir device for use in administration of anesthetics, comprising a pair of inter-communicating chambers, of which 'one is larger than the other, and the larger at 'least partially surrounds and encloses the smaller, said inner chamber being substantially non-collapsible in character and said outer chamber being flexible and expansible in character and adapted to receive and contain gas or gas-air mixture under moderate pressure; means associated with said inner chamber adapted for connection with a source of anesthetic gas; and means" also associated with said inner chamber and adapted. under suction of inhalation by apatient, to admit air to said reservoir, for mixture with the anesthetic gas.

15. A gas-and-air mixing and reservoir apparatus for use in administration of. anesthetics, comprising a pair of coaxial and interco rnmunicating chambers of which the outer encloses and surrounds at least a portion of the-inner, said inner chamber comprising a substantially noncollapsible, corrugated and perforated tube and said outer chamber comprising an expansible reservoir enclosing the perforated portion of said inner chamber and forming a substantially gastight seal at the ends thereof, means in com-- munication with said inner chamber for the admission to the interior of said reservoir of anesthetic gas from a suitable source, and means also in communication with said inner chamber for the admission to the interior of said reservoir of air from the surrounding atmosphere.

16. A gas control device for an apparatus for administration of anesthetic gas, comprising a gas chamber having inlet and outlet valves, means for maintaining said inlet valve in normally-closed position, means for maintaining said outlet valve in normally open. position, and actuating mechanism for operating said valves from outside said gas chamber, said actuating mechanism comprising, in combination, gas-tight sealing means for transmitting the actuating motion from outside to inside said gas chamber, and a reciprocating plunger operable by said transmission means, and interposed between said valves, said plunger being adapted to move along said gas chamber and actuate said valves in sequence; the proportions and dimensions of said plunger with respect to said valves and gas chamber being such that'the' -outlet valve is necessarily closed by motion of the plunger before the inlet valve can be opened and, conversely, upon a reciprocal motion of said plunger, the inlet valve is necessarilyclosed before the outlet valve can be opened.

17. A gas control device for an apparatus for administration of anesthetic gas, comprising a gasJchamber, having an inlet valve and an outlet valve through which gas-must pass in series in order to pass through said chamber, and operto its administratign to a patient, and having an inlet valve and means for maintaining the same in normally closed position, and an outlet valve and means for maintaining the same in normally closed position; a movable actuating member mounted for selective and alternative, but not simultaneous, actuation of said valves; biasing means operably associated with said ac-' tuating member for normally maintaining it in such position that said outlet valve is held open thereby and said inlet valve remains normally closed; and means operable from outside said gas chamber for moving said actuating member against its bias in such manner that said outlet valve is-first closed and said inlet valve is thereafter Opened, I

. JUSTIN G. SHOLES.

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