US1648547A - Method for producing an anaesthetic - Google Patents

Description

Nov. 8, 1927. 1,648,547

W. V. GOODFELLOW METHOD FOR PRODUCING AN ANESTHETIG Filed May 14. 1921 2 Sheets-Sheet 1 Nov. 8, 1927. 1,648,547

W. V. GOQDFELLOW METHOD FOR PRODUCING AN ANXESTHETIC Filed May 14. 1921 2 Sheets-Sheet 2 h we nz'ar Wa [fer V. 60 oafellom QM orngy.

Patented Nov. 8, 1927.

UN I T ED t WALTER V. GOODFELLO'W, 01 LOS ANGELES, CALIFORNIA;

mans on non. rnonucme an" ANES'IHETIC.

Application filed May 14, 1921.

My invention relates to and has for a principal object the provision of an improved process, or method, for producing an anaesthetic and for maintaining partial or.

complete anaesthesia when administered for ordinary purposes, where a general anaethetic is indicated.

It is well known that modern processes for producing and maintaining anaesthesia, while generally eflicient for producing the desired results, have many disadvantages which are a source of much discomfort and irritation to the patient and possible organic disorders, and when administered by present methods, the devices or mechanism by means of which the process is carried out are incapable of supplying a uniform amount of the anaethetic of satisfactory character. Because of this fact the state of anaesthesia is more or less varied in its extent and consequently a source of much concern and worry to the surgeons and frequent suffering on the part of the patient.

urthermore, unless and until a patient is completely under the influence of the anaesof present methods for adsame irritates the membranes of the'mouth, throat and lungs to such an extent that the patient is caused unnecessary suffering and discomfort which frequently delays the work of the surgeons. This irritation of the membranes intensifies the natural desires of the patient for momentary cessations in the administration of the anaesthetic, the irritation being due to the absence of moisture in the mouth and throat.

thetic, the use ministering the It is an object, therefore, of my invention to provide a method of producing and administering an anaesthetic which will maintain and deliver a uniform volume of the anaesthetic to the patient at all times during the use of the process in an operation, and in addition, to provide and mix with the anaesthetic a sufficient quantity of vapor, such as may be produced by the heating of a body of fluid to a temperature of about 120 degrees, whereby moisture may be administered with the anaesthetic so as to wholly or partially prevent the irritation of, the membranes which would otherwise occur, or at least to relieve and prevent discomfort to the patient, and shorten if not quite entirely obviate delays.

It will be readily understood by persons skilled in the art and use of anaesthetics that sulphurous ether and chloroform, which are Serial No. 469,572.

elements are readily use of my process without the attendant discomfort and irritation well known processes. In carrying out my process employ a specially designed apparatus including a container for supporting a quantity of fluid ether, chloroform or other fluid anaesthe tic in readiness for use, and a closed generating receptacleadapted to be partially filled with water or other suitable fluid into which the fluid anaesthetic is dis-, charged in a uniform and selected volume.

The water in said receptacle is heated to a temperature of about 120 degrees Fahrenheit, or to a temperature suiiicient to generate a vapor within the receptacle. thetic receptacle being in communication with the water receptacle, a suitable valve is interposed in the communicating passage for regulating the volume of the anaesthetic discharged into the generator rece tacle. The ether or chloroform being of lighter gravity than water and easily volatilized when the temperature is raised, will, when coming into contact with the volume of water immediately volatilize and unite vapor generated, and the admixture, which contains a sufficient amount of moisture will fill the space in the water receptacle above the level of the volume of water and may thereafter be drawn ofl by suitable means for use.

The temperature of the water may be automatically regulated by a thermostat and connected with an electric heating element provided for heating. the water.

The apparatus provided and the character of the process is such that positive control may at all times be had over the generation and volume of the anaesthetic administered to the patient, and the volume may be gradually increased or decreased from a normal quantity as each separate case may require, or a complete cessation of the anaesthetic may be instantly efi'ected.

In the accompanying drawings I have with the water produced by other its I illustrated a practical embodiment of a specially designed apparatus for carrying out the several steps of my process and reference is had thereto in the further consideration of my invention, which I will now more fully describe in connection with said drawings.

Fig. 1 is a view in vertical section of an apparatus adapted to carry out the purpose of my invention, illustrating a manner 1n which the anaesthetic is fed to a volume of Water or other fluid contained in a closed receptacle.

Fig. 2 is a plan view of the apparatus.

Fig. 3 is a view in bottom elevation thereof.

Fig. 4 is a view in sectional plan of the heating element.

Fig. 5 is a view in vertical section through a part of the apparatus as seen on the line 5-5 of Fig. 3, showing a thermostatic control device for regulating and maintaining a predetermined temperature.

In the apparatus shown, 7 indicates a closed fluid receptacle of hollow cylindrical form having an annular wall 8, a top closure 9, and a bottom closure 10. The bottom closure 10 is formed with an indented circular portion 11 leaving the bottom wall complete so that joints need not be employed that would tend to leak. Within the recess formed by the portion 11 is disposed a heating ele ment 12, shown particularly in Fig. 3, which is of usual construction and includes a mica plate 14, wound with resistance wire 15, so that upon a current passing through the resistance wire heat is generated to maintain an increased temperature of the fluid con tained within the receptacle. A closure wall 16 is provided below the heating element to protect it and is provided with a socket 16 formed integrally therewith. shown) of the resistance wire are connected to contacts 17 disposed within the socket. A fusible plug is inserted in the socket and establishes a circuit, serving to prevent excess heat being attained within the heating element.

The upper closure wall is provided with a socket member 18 formed with a passage 19 communicating with the space 20 in the receptacle. A translucent container 21, for the anaesthetic fluid is provided and is detachably mounted upon the receptacle by having its neck 22 inserted in the socket. A valve 23 for controlling the flow of anaesthetic fluid by gravity to the receptacle is provided and is formed with an extended stem guide 24.

A vertically disposed sternv 25 is provided formed with an end 26 tapering to a point 27 adapted to be inserted in the bore .of the valve. The stem extends upward through the interior of the translucent container through a closure 28 provided thereon and terminates in a knurled knob 29, which upon The ends (not being turned may be caused to advance or retract the pointed end of the stem relative to the valve to change the area of flow therethrough to control the frequency of the drops of anaesthetic fluid to the receptacle.

The closure wall of the container is provided with a vent opening 30, to allow air to enter to replace the fluid used. The vent is closed by means of a shutter 31 pivoted to the closure wall and is normally in a position to close the opening when the apparatus is not in use in order to prevent evaporation of the anaesthetic fluid.

The neck of the container is translucent so thatthe drops of fluid emanating from the valve are visible and the operator is aware of the amount of flow of the fluid and is thereby enabled to accurately control the flow by manipulation of the valve. To increase the visibility an electric lamp 32, connected parallel with the heating element is provided and will continue to illumine the neck of the container when the heating coil is not being energized. The lamp is provided with a protective tubular guard 32 depending into the receptacle and having its upper end disposed above the top closure wall thereof and provided with an opening '33 to direct and confine the light to a limited area in proximity to the valve where the drops of fluid form.

Inasmuch as the invention contemplates maintaining a volume of fluid in the receptacle at predetermined temperature an adjustable thermostat 3 1 is provided for opening and closing the circuit in which the heating element is interposed as will appear. The thermostat comprises essentially a circular casing 35 of shallow depth formed with an enclosed space 36. The space is divided by a fluid tight corrugated diaphragm 37 upon which rests a volume of volatile fluid such as ether or acetone, which fluids attain a vapor state of relatively high tension in an enclosed space at or slightly below normal body temperatures. The casing 35 is held within the receptacle a suitable distance from the bottom thereof by a vertically disposed tube 38 communicating with the space below the diaphragm. The tube is fixed to the bottom wall in alignment with an opening 39 provided therein, and a nonconductive stem 40 passes through the tube downward through the opening 39 and protrudes slightly therefrom, the other end of the stem being in contact with the under surface of the diaphragm. Upon the temperature of the fluid within the receptacle attaining a temperature suflicientto generate a pressure within the space above the diaphragm the expansion thereof will act to force the stem downward in a manner common to such thermostats.

The apparatus is provided with a hollow base 41 enclosing a space 42 within which loo ranged to convey current to are located wires 43, 44, and' 45 which are arthe heating element and the lamp. Two terminal posts 47 are provided for the purpose of attachment to an electric socket (not shown). The electric circuit carrying current through the heating element is formed by the wire 43 passing from one terminal post to the heating element which has the other end of' its resistance coil connected to the wire 44 of the circuit, which wire in turn is connected to the wire 45 through the fusible plug. In the circuit is interposed a circuit breaker 48 having a conductive member 49 pivoted as at 50 and adapted to be raised out of contact with a contact point 51 interposed in the circuit. A spring 52 rests against the conductive member to hold it yieldably in contact with the contact point. It is apparent that When a pressure is attained by the fluid in the thermostat the nonconductive stem will act on the conductive member to raise an end thereof out of contact with the contact point so that the circuit supplying current to the heating element is opened. By means of a screw 53 the tension of the spring may be varied so that ,the temperature attained by the fluid within the receptacle may be predetermined.

The operation of the anaesthetic generating apparatus is as follows: The anaesthetic container is partially filled with the desired anaesthetic fluid such as sulphurous ether or chloroform thru the opening in the closure wall thereof, the valve being closed during filling. The resistance wire of the specific heat of water is heating element is energized by connecting the terminal posts to a source of electricity, the receptacle being previously filled to about the level shown with a suitable fluid of higher boiling point than the anaesthetic fluid, such as water. The level of the fluid should be above the thermostat but below the outlet tube. As heat is generated by the heating element thefluid will increase in temperature to the predetermined degree, whereupon the thermostat will act to open the circuit to prevent the generation of additional heat. When this has occurred and it is desired to generate an anaesthetic vapor the valve is opened the proper degree as indicated by the frequency of the drops of fluid visible thru the translucent neck of the fluid container.

The highly volatile anaesthetic fluid dropping into the heated fluid in the receptacle will be turned practically instantly into a vapor. In fact it is found that fluids such as ether will vaporize almost instantly upon contact with the surface of a body of water maintained at or above 120 degrees Farenheit. It is apparent that inasmuch as the of the relatively large volume not appreciably altered by substaction of the latent and specific heatnecesin vapor from (not shown) connected to said receptacle.

Should globules of unvaporized fluid be carried thru the outlet tube 54, the reduced velocity of the vapor passing thru the receptacle 55 will result in the globules being deposited therein. The receptacle 55 is substantially larger in area than the tube 54,

and the outer end 56 of said tube is projected inwardly for a substantial distance into said receptacle, while the outer end of said receptacle is provided with an outlet 57 having a passage 58 therein which may be connected with a suitable flexible tube, not shown, for administering the anaesthetic.

Upon the water being reduced in temperature the thermostat will again close the circuit and supply additional heat thus maintaining a practically constant temperature. During the generation of the vapor the amount of anaesthetic fluid admitted to the generator may be controlled by manipulation of the valve. The proportions between the vapors from the two fluids may thus be altered and independently the amount of vapor formed by the fluid in the generator m y be increased by increasing the temperat re at which the thermostat acts to close the v circuit.

It will be observed from the foregoing that the anaesthetic vapor produced by the generator comprises the vapor from an anaesthetic fluid mixed with the vapor from a nonanaesthetizing fluid as water. Owing to the specific heat of the vapors, particularly that of the water vapor, the patient is not subject to quantities of cold air as in other methods now in use and the temperature of the vapors cannot decrease durin passage to the mask, it being understood t at saturated vapors maintain a constant temperature at constant pressure, the subtraction of heat from a saturated volume thereof mere? resulting in condensation of a part 0 the volume, leaving the remainder at the same temperature. In methods where air is employed it is not possible to so accurately control the temperature of the anaesthetic vapor. We have found in the employment of our method and apparatus that the vapor from a non-anaesthetizing fluid, such as water, when mixed with the vapor from an anaes thetic fluid tends to prevent irritation of the membranes of the patient and inasmuch as other methods.

While I have shown a specific embodiment of my apparatus for carrying out the im proved method, I do not limit myself to a specific apparatus for effecting the purpose of my invention, but may employ any suitable apparatus for generating an anaesthesia in" conformance with the method substan= tially as set forth in the appended claims, without departing from the spirit of my invention.

What I claim is:

1. The method of producing an anaesthetic vapor which consists in continuously heating a body of liquid in a closed chamber to a. uniform temperature, and introducing a fluid having anaesthetic properties to the chamber in regulated volume, for generating and delivering an anaesthetic vapor of uniform density and pressure for administration.

' 2. The method of producing an anaesthetic vapor which consists in generating heat in a chamber containing water, introducing an anaesthetic fluid into the heated chamber and on the surface of the water, whereby a vapor will be generated thereabove, and regulating the volume of anaesthetic fluid so introduced for varying the volume and pressure of the anaesthetic vapor produced according to requirements of administration and use.

WALTER V. GOODFELLOW.

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