US2288436A

US2288436A - Resuscitating device

Info

Publication number: US2288436A
Application number: US413405A
Authority: US
Inventors: Alvin M Cahan
Original assignee: Individual
Current assignee: Individual
Priority date: 1941-10-03
Filing date: 1941-10-03
Publication date: 1942-06-30
Anticipated expiration: 1959-06-30

Description

A. M. CAHAN 2,288,436

RESUSCITATING- DEVICE June 30, 1942.

Fild Oct. 5, 1941 2 Sheets-Sheet 1 49 mean 635 su 4 Y VACUUM wet ama- A 7' ED CIRCUIT F02 SOLENOID uM A'h/ June 30, 1942, A. MI CAHAN 2,288,436

RESUSCITATING DEVICE Filed 001;. s, 1941 2 Sheets-Sheet 2 ATTOKNE Y5.

I Y INVENTOR.

Patented June 36,1942

, UNITED STATES PATENT OFFICE 2,288,436 RESUSCITA'IING DEVICE Alvin M. Cahan, New York, N. Y.

Application October 3, 1941, Serial No. 413,405

' 12 Claims. (01.128-29) My present invention relates to a resuscitating device and while not limited thereto is especially adapted for use with any patientin whom there is respiratory failure, such as occurs in fourth stage anaesthesia, gas poisoning, morphine poiwere not prevented by positive pressure anaesthesia.

The fire hazard entailed in the use of such an apparatus in conjunction with volatile explosive anaesthetics has been, eliminated by the use, instead of a system of mechanically operated electrical relays, which would'spark, of a vacuum tube amplifier relay system, whereby the current passing across the electrical contacts is so small that no sparking can occur, and the machine can therefore be safely operated even in an atmosphere of cyclopropane and oxygen in their most explosive proportions. Besides, the con trolling contacts are not in the stream of gas, but are in a chamber separate from the gas channels. This may, if desired, be hermetically sealed, although this precaution is unnecessary.

The present invention aims to provide a device of the general character indicated which is relatively simple in construction, easy and economical to fabricate and assemble, and admirably adapted for the performance of the critical functions which his intended to carry out.

In the accompanying specification I shall describe and in the annexed drawings show an illustrative embodiment of theresuscitating device of the present invention. It is, however, to be clearly understood that I do not wish to be limited to the details shown inasmuch as changes therein may be made without the exercise of invention and within the scope of the claims hereto appended.

, In the accompanying drawings Figure 1 is a partiallyschematic. P rtially sectional view of a resuscitating device made in' accordance with the principles of the present invention; and i p Figure 2 is a schematic showingof the electrical hookup employed in the vacuum tube utilized as part of the combination of elements making up the present invention.

Before describing my invention in detail, I deem it advisable briefly to referto some of the disadvantages existing in, devices hitherto employed for corresponding purposes so that the manner in which the present invention overcomes and eliminates the same may be more readily appreciated.

In positive pressure, and positive and negative pressure resuscitating devices now in use there is a tendency for the critical pressure that the lungs can withstand to be exceeded, so that I'have observed at autopsies done on infants that have died after "unsuccessful attempts at'resuscitat'ion extensive emphysema of the lungs, both on cross section, in the parenchyma of the lungs, and

subpleurally. Some of the subpleuralemphysl ematous blebs are occasionally seen to be ruptured. In several adults that have died after periods of respiratory failure, during which time they had been maintained by positive and negative pressure resuscitation methods, I have observed that not only is there marked pulmonary emphysema that does not occur otherwise in such patients, but in one case air had actually been forced into the mediastinal connective tissue, and had extended down along the paravertebral tissues. In the pulmonary veins of thissame case was found considerable amounts of foam, shown by aerobic and anaerobic cultures not to be-due to gas. forming micro-organisms. The resuscitation devices used on these patients have been both manually and mechanically operated; each showing similar pathological results. By means of the present invention, the instrument may be,

set' at the critical pressure, which will them not be exceeded during the resuscitating procedure. Other objects and advantages of the present in- 'ention will readily occur to those skilled in the art to which the present invention relates as the detailed description thereof progresses.

Referring now more in detailto the aforesaid illustrative embodiment of the present invention and with particular reference to the drawings illustrating the same, it might be stated that the device comprises, enerally. three main operating units; a pressure-operated circuit-controlling device 5, a valve mechanism S, and a vacuum tube relay device 1.

The pressure-operated circuit-controllingdevice 5 consists of a cylindrical housing 8 which is open at its upper end and provided with a cover plate 8 and-which is further provided in relay 6 the bottom wall thereof, with a vent ll. En,

closed within the housing 8 is a pressure operated bellows Ii, the lower end of which is sealed to the bottom of the cylinder, but is opento the vent l and the upper end of which is secured to a plate I! from which there extends a rod it, the upper end of which is' covered by an insulating cap l3. Secured to the cover plate 8 and depending tram-the underside thereof into the housing 8 is an insulating block i4, which supports an intermediate spring contact l5, which T is bent seas to rest against the insulating cap I II at the end of-rod' II atall times during the operation of the device, a lower spring contact i8 and an upper spring contact II. In order to ad- .iust the spacing between the three contacts i5,

i6, and I! I provide adjusting screws i8 and i9 respectively provided with insulating caps i8 and I8, the former operating upon the lower contact It to determine that point to which the pressure in the system must fall before the circuit between contacts I! and I6 is made, and the latter operating upon the contact i! to determine that point towhich the pressure must rise in order to close the circuit between contacts I 5 and [1. Thus the upper and lower limits of pressure desired for resuscitation may .be selected by operating the machine against avproperlyadapted water manometer, and the machine may thus be standardized screws i8 and IS being provided with arrows, pointing to pressures engravedon a dial placed at the periphery of the screws (not shown). The screws l8, and I! are stabilized by passage 23 which, in eilect, constitutes a continuation of the inlet passage 2i. Intermediate the passages 2i and 23 I provide a plurality of.

vents 24 normally closed by a safety valve 25. For directly controlling the flow of gas from passage 2i to passage 23 I provides sliding valve N.

The vacuum tube relay device 1, in and of itself,,is no part of the present invention. It is a unit that utilizes a well known electrical engineering circuit. For the purpose of describing its function in the present invention it is suihcient to say that the relay device 1 includes a plurality of vacuum tubes, the operation of one or more of whichlis designed to excite another tube and deliver to its grid a positive charge which sets up a current through the solenoid 21,-the current operating the solenoid continuing in flow until such time as the vacuum tube which controls the same, has delivered thereto a negative charge, at which time the current through the solenoid is discontinued and the solenoid permitted to return to its normal position.-

The three mechanisms are structurally connected with each other as follows: 0

vSecured to the housing 8 of the circuit control device I is a tube 28, the upper end of which is sealed and the lower segment or which communicates with the vent i0 and also with a flexible hose 2!, the latter in turn being connected with an exhaust tube 20. Included in tube 28 and adapted tocontrol the open cross-section thereof for a purpose which will hereinafter be more iully set forth, is-a manually operated gate valve I2. Adjacent the "closed upper end o thetube 28 I provide a passage It whereby the tube 28 connects with an inlet tube It provided at the upperend thereof with a delivery tube extension 35.

The lower end of the tube 34 is connected. with a flexible hose 36 in turn communicating-by means of a fitting 31 with the outlet passage 23- of the valve block 20.

The exhaust valve 3| is carried at one end ofa rocker arm 38 pivoted at 39 to an'extension 40 formed on the valve block 20. The other end of the arm 38 is pivotally connected at. 4i to a link 42 attached to the sliding valve 26 and another link 43, an extension and part of the rocker arm 38, pivotally connected at 44 to the core of the solenoid 21. Intermediate the valve block 20 and the rocker arm 38' on the exhaust valve side thereof I provide a spring 45 which maintains the exhaust valve 3! in the open position, and the intake valve 28, in the closed position when the solenoid coil is not actuated by a.

erator, and in a more simplified fashion, if the I unit 5 be incorporated'on the same base as the valve mechanism 6 and the'vacuum tube relay circuit 1, modifying it, however, so that vent in,

connecting the interior of the bellows II with the gas supply, is connected as a direct perpendicular extension from the intake 23. The tubes 29 and 36 then are connected to a Y tube, (not shown), the third tube of this Y tube then delivering the gaseous mixture to the patient, and returning it to the machine. It should be noted that with this arrangement the intake tube '36 should be of larger diameter so as to decrease the pressure gradient to an inconsequential level at the maxi-- mum rate of flow of the gas. 1

The various mechanisms are electrically con- I nected with each other as follows:

The numerals 4? and 48 designate the main supply line for a source of electrical current.

These leads enter the vacuum tube relay 1. The

relay is connected by conductors 49 and It to the solenoid 2! and the various circuits which control the supply of current to the solenoid 21 are completed by means of conductors SI, 52 and 53, the first of these conductors ng connected with the intermediate contact it, e second of the transformer as is tapped to suppl current to the filament ofa rectifier tube 51, the two plates of which are likewise supplied with current from the secondary of the transformer 55. Associated with the rectifier i! is a filter, comprising the resistors 88, 58 and M and the condensers Cl, 82 and '68, which, in turn, is elec-=' trically connected through resistors 64 to It inelusive, with two high-mu tubes I4 and II. It will be ,noted that the electrical connections are such that the tubes 14 and" cannot bothbe conducting at the same time; only one or the,

other can be so functioning at any given time.

The

tubes

14 and 15 are respectively connected with the upper and lower contacts II and I6 of the pressure operated circuit-control by means of the

conductors

53 and 52 and are also connected with the intermediate contact I5 01 said control by means of the conductors.

The secondary of the transformer 56 supplies unrectified alternating current to another vacuum tube 16 and, through the

conductors

49 and 50 to the solenoid 21.

Thus, when the contacts l5 and I6 are engaged, the tube becomes conducting and the tube 14 does notconduct so that the tube 16 permits the passage of current to the solenoid 21. When there is engagement between the contacts I 5 and H, the tube 15 ceases to conduct and the tube 14 becomes conducting. The potential drop due to the anode current f this tube.

flowing through the resistors 61 and 68 provides a negative voltage between the grid and cathode of the tube 16 thus stopping the passage of current to the solenoid.

This completes the description of the aforesaid illustrative embodiment of the device of the present invention and the mode of operation and use thereof may be briefly summarized as follows:

Assuming that the device is to be used for resuscitation, the hose 46 is connected with a source of oxygen, as described above. First the oxygen supply is turned on to deliver the desired flow per minute, which is gauged by the requirements of the patient-adult or infant. The current supplying the vacuum tube circuit is turned on. Since the pressure in the tube supplying the gas to the patient is atmospheric, contacts l5 and iii are together, and when the vacuum tubes become heated and begin to function, the solenoid coil is activated, the core is drawn into the axis of the coil, thus opening valve 253, allowing the gas to flow along tube 36 toward the patient, and simultaneously closing valve 3 5, thus shutting off the exhalation valve. The tube 323 may then be connected with a tracheal airway already in place in the patient, or with a rigid face mask, fastened over the patients nose'and mouth in the standard manner used with closed system anaesthesia. The gas enters the patients lungs and expands them up to the predetermined level at which time a back pressure is built up in the extensiontfi, which back pressure is communicated by way of the vent 33 to the outlet tube 28 which in turn conveys the built up pressure by way of vent Hi to the bellows H. When this pressure rises above the predetermined min" imai pressure (in actual trials this has been of the order of 1 and 2 millimeters of water pressure), the bellows H expands so as to move the plate I2, and with it the rod 13, upwardly in the cylinder 8, so as to break the contact between I6 and 15. However, notwithstanding the breaking of the circuit through the contacts 15 and Hi, the relay I, originally operated by reason of the engagement between the contacts l5 and I6, maintains the supply of current through the solenoid 21 to keep the valve 25 open and the valve 3| closed. However, as the pressure operating upon the bellows l I increases, another criticalpoint is reached and at the instant that this point is reached a new circuit is established by reason of the engagement between the intermediate contact l5 and the upper contact II. This circuit through the relay 1, delivers a negative charge to the vacuum tube controlling the flow of current through the solenoid 21 and this negative charge brings about cessation of current operating the solenoid 21 so that the spring 45 can then function to pivot the rocker arm 38 thereby closing the inlet valve 26 and'opening the exhaust valve 3|. This operation results in a reduction of pressure throughout the system with the result that the bellows ll moves toward its collapsed position. The movement of the bellows must be gradual rather than sudden inasmuch as a sudden drop of the bellows results in vibrations which will move the contact I 5 rapidly into and out of engagement with the contacts l6 and i1, thus interfering with the proper operation of the device. In order to prevent this sudden drop in pressure, the valve 32 must be adjusted so, that rate of expiration of the patient, caused by the collapse of his naturally elastic lungs, just filled by the resuscitator will maintain intratracheal pressures within the exhalation tube, and thus within the control bellows ,l I. This will vary from adult to infant, and therefore the valve must be marked for three positions corresponding to the tidal respiratory exchange from adult to infant. Thus, the valve 32 is capable of adjustment so that the cross section of its airway can be made to correspond with the cross section of the trachea of the patient being treated. Inasmuch as there is little variation in the cross sectional area of newborn infants (for practical purposes)? chiidren, and adults, a suitable scale may be constructed for the operation of this valve. Inthis way, the lungs of the patient will be allowed to collapse at their natural free rate. As soon as the pressure in the system as a whole begins to reduce from the upper critical limit, the contact is becomes disengaged from the contact i l, but this has no eifect upon the circuits set up in the relay l to control the solenoid 2i inasmuch as again another holding tube in the circuit of the relay 1 continues to function under its negative charge untii such time as the pressure in the systemas a whole is reduced to the lower critical point, at which time contact is re-established between the contacts l5 and I6 and the "holding tube of the relay '5 is again supplied with a positive charge. This results in a repetition of all of the operations just described and these operations are continued until such time as the patient being operated upon is able to breathe of his own volition. The device is then withdrawn from the patient.

This completes the description of the mode of operation and use of the device of the present invention. As stated above, instead of oxygen being supplied through the hose 46, the latter can be connected with a source of general anesthetic and the device used just as efficiently for this function in properly selected cases.

It will be noted from all of the foregoing that the resuscitating device of the present invention is simple in construction, easy and economical to fabricate and assemble and admirably adapted to perform the intended function reliably.

What I claim as my invention is: 1. In a device of the character described, an intake conduit for conveying a gas'to a persons trachealpassage, an exhaust conduit communicating with said intake conduit and also with a the atmosphere, inlet and outlet valves for said intake and exhaust conduits, electro-magnetic means for operating said inletand outlet valves,

a vacuum tube operated'triggermechanism for controlling the operation of said electro-magnetic means and means, communicating with said exv let and outlet valve-operating means, said means take and exhaust conduits, a solenoid for operating said inlet and outlet valves, and means, communicating with said exhaust conduit and responsive to predetermined upper and lower pressure limits within the entire system, for establishing a plurality of electrical circuits to control the functioning of said solenoid whereby a flow of current thereto is initiated when the pressure reaches the lower limit and is maintained therein until the pressure reaches the upper limit, when said flow of .current is discontinued and remains so until the pressure returns to the lower limit.

including a plurality of electrical contacts and a bellows connected with one of said contacts and adapted to move the same into and out of electrical engagement with the remaining contacts.

.6. In a device of the character described, an intake conduit for conveying a gas to a persons tracheal passage, an exhaust conduit communicatingwith said intake conduit and also with the atmosphere, inlet and outlet valves for said. intake and exhaust conduits, electro-magnetic means for operating said inlet and outlet valves, a vacuum tube operated trigger mechanism for controlling the operation of said electrd-magnetic means and means, communicating with said exhaust conduit and responsive to predetermined upper and'lower pressure limits within the eni tire system. for establishing a plurality of elec- 3. In a device of the characterdescribe'd, an

. limits within the entire system, for establishing a plurality of electrical circuits through said trigger mechanism to. control the functioning of said electro-magnetic inlet and outlet valve-operating means. I

4. In a device of the character described, an intake conduit for conveying a gas to a persons tracheal passage. an exhaust conduit communieating with said intake conduit and also with the atmosphere. inlet and outlet valves for said intake and exhaust conduits, a solenoid for operating said inlet and outlet valves, and bellowsoperated means, communicating with said exhaust conduit and responsive to predetermined upper and lower pressure limits within the entire system, for establishing a plurality of electrical circuits to control the functioning of said solenoid whereby a flow of current thereto is initiated when the pressure reaches the lower limit and is maintained therein until the prestrical circuits through said trigger mechanism to control the functioning of said electro-magnetic inlet and outlet valve-operating means, said means including a plurality of electrical con tacts, a bellows connected with one of said contacts and adapted to move the same into and out of electrical engagement with the remaining contacts, and means to adjust the amounts of pressure necessary to consummate said electrical engagements. I

'7. In a device of the character described, an intake conduit for conveying a gas to a persons tracheal passage, an exhaust conduit communicating with said intake conduit and also with sure reaches the upper limit, when said flow of current is discontinued and remains so until the pressure returns to the lower limit.

5. In a device of the character described, an intake conduit for conveying a gas to a persons tracheal passage, an exhaust conduit communicating with said .intake conduit and also with the atmosphere, inlet and outlet valves iorsaid intake and exhaust conduits, electro -magnetic means for operating said inlet and outlet valves, a vacuum tube operated trigger mechanism for controlling the operation of said electro-magnetic means and means, communicating with said exhaust conduit'and responsive to predetermined upper and lower pressure limits within the entire system, for establishing a plurality of electrical circuits through said trigger mechanism to control the functioning of said electro-magnetic inthe atmosphere, inlet and outlet valves for said intake and exhaust conduits, a solenoid for operating said inlet and outlet valves, and means, communicating with said exhaust conduit and responsive to predetermined upper and lower pressure limits within the entire system,'for establishing a plurality of electrical circuits to. control the functioning of said solenoid whereby a flow of current thereto is initiated when the pressure reaches the lower limit and is maintained therein until the pressure reaches the upper limit, when said flow of current is discontinued and remains so untilthe pressure returns to the lower limit, said means including a plurality of electrical contacts, and a bellowsconnected with one 'of said contacts and adapted to move the same intoand out of electrical en- 7 gagement with the remaining contacts.

8, In a device of the character described, an intake conduit for conveying a gas to a persons tracheal passage, an exhaust conduit communicating with said intake conduit and also with the atmosphere, inlet and outlet valves for said intake and exhaust conduits, a solenoid for operating said inlet and outlet valves, and means, communicating with said exhaust conduit and responsive to predetermined upper and lower pressure limits within the entire system, for establishing a plurality of electrical circuits to 1 control the functioning of said solenoid whereby a flow of current thereto isinitiated when the pressure reaches the lower limit and is maintained therein until the pressure reaches the upper limit, when said flow of current is discontinued and remains so until the pressure returns to the lower limit,'said means including a plurality of electrical contacts, a bellows connected with one of said contacts and adapted to move the same into and out of electrical engagement with the remaining contacts, and means to adjust the amounts of pressure necessary to consummate said electrical engagements.

9. In a device of the character described an intake conduit for conveying a gas to a person's tracheal passage, an exhaust conduit'communieating with said intake conduit and also with the atmosphere, inlet and outlet valves for said intake and exhaust conduits, electro-magnetic means for operating said inlet and outlet valves, a vacuum tube operated trigger mechanism for controlling the operation of said ,electro-magnetic means and means, communicating with said exhaust conduit and responsive to predetermined upper and lower pressure limits within the entire system, for establishing a plurality of electrical circuits through said trigger mechanism to control the functioning oi! said electro-magnetic means whereby a flow of current thereto is initiated when the pressure reaches the lower limit and is maintained therein until the pressure reaches the upper limit, when said flow of current is discontinued and remains so until thepressure returns to the lower limit.

10. In a device oi. the character described, an intake conduit for conveying a gas to a person's tracheal passage, an exhaust conduit communicating with said intake conduit and also with the atmosphere, inlet and outlet valves for said intake and exhaust conduits, electro-magnetic means for operating said inlet and outlet valves,

a vacuum tube operated trigger mechanism i'or controlling the operation of said electro-magnetic means and bellows-operated means, communicating with said exhaust conduit and responsive tracheal passage, an exhaust conduit communicating with said intake conduit and also with the atmosphere, inlet and outlet valves for said intake and exhaust conduits, electro-magnetic means for operating said inlet and outlet valves, a vacuum tube operated trigger mechanism for controlling the operation of said electro-magnetic means and means, communicating with said exhaust conduit and responsive to predetermined upper and lower pressure limits within the entire system, for establishing a plurality of electrical circuits through said trigger mechanism to control the functioning of said electro-magnetic means whereby a flow of current thereto is inieating with said intake conduit and also with I the atmosphere, inlet and outlet valves for said intake and exhaust conduits, electro-magnetic means, for operating 'said inlet and outlet valves, a vacuum tube operated trigger mechanism for controlling the operation oi said electro-magnetic means and means communicating with said exhaust conduit and responsive to predetermined upper and lower pressure limits within the ,en-

I ments.

tire system, for establishing a plurality of electrical circuits through said trigger mechanism to control the functioning of said electro-magnetic means whereby a flow of current thereto is initiated when the pressure reaches the lower limit and is maintained therein until the pressure,

ALVIN M. CAHAN.