Anaesthetizing apparatus

Nov. 12, 1935. w. r, henion 2,020,643

ANESTHETIZING APPARATUS

Filed Aug. 28, 1933 3 Sheets-Sheet 1

3

<img file="US2020643A_D0001.tif" />

Attorneys

Nov. 12, 1935.

2,020,643

W. R. HENION

ANESTHETIZING APPARATUS

Filed Aug. 28, 1933 3 Sheets-Sheet 2

<img file="US2020643A_D0002.tif" />

Nov. 12, 1935,

W. R. HENION

2,020,643

ANESTHETIZING APPARATUS

Filed Aug. 28, 1933 3 Sheets-Sheet 3

<img file="US2020643A_D0003.tif" />

Attorneys

Patented Nov. 12, 1935

2,020,643

UNITED STATES PATENT OFFICE

2,020,643

ANESTHETIZING APPARATUS Walter R. Henion, Minneapolis, Minn, Application August 28, 1933, Serial No. 687,109

Claims.

This invention relates to improvements in apparatus for administering inhalation fluids and has, as an important object, the control of delivery of such fluids as a result of respiratory effort.

The invention finds valuable application in controlling analgesia particularly dental analgesia, a condition in which the patient cannot feel pain but retains voluntary motor ability. Exact control of analgesia is difficult of accomplishment 10 since the control must, so to speak, be “geared” to the patient. The present invention provides for a control exactly suited to the needs of the individual. A feature of the invention relates to an arrangement whereby a valve controlling the 15 delivery of inhalation fluid is operable by the patient as a result of reflex or voluntary gripping when in pain.

The invention also relates to an apparatus wherein the respiratory effort of the patient is ²⁰ utilized to control the flow of inhalation gas, either anaesthetizing or nonansesthetizing substances or analgesic substances, to the organs of respiration. A feature includes an arrangement whereby the valves can be manually set to admit analgesic fluid 25 and stop the flow of air to the patient and wherein these valves are automatically reset after a predetermined number of inhalations or exhalations by the patient to stop flow of analgesic fluid and admit air.

Another feature relates to· the means whereby the patient controls these valves at all times independently of any control by respiratory effort, so that the valves can be moved to one control position, whatever the state or position of the oa valve control means, which is operated as the result of respiratory effort.

In the present embodiment, the keeping of the patient in a state of analgesia is accomplished . psrmitting the patient to take a predetermined number of breaths of anesthetizing or analgesic gas after which the flow of anaesthetizing fluid is stopped and air is allowed to flow to· the organs of respiration. The method of patient control is of great importance because both the gas flow ° and the air port valves are manually controlled by the patient by means of the gripping action of one hand.

Features of the invention include all details of construction, as well as combinations and subcombinations of the parts, along with the broader ideas of means inherent in the disclosure.

Objects, features and advantages of the invention will be set forth in the description of the 55 drawings forming a part of this application, and in said drawings

Figure 1 is a side elevation illustrating my apparatus for administering inhalation fluids;

Figure 2 is a vertical longitudinal section of 60 °ne form of apparatus taken approximately on (Cl. 128—203) line 2—2 of Figure 3 with the parts set for delivering anaesthetic or analgesic fluid;

Figure 3 is a vertical transverse section approximately on lines 3—3 of Figures 1 and 2;

Figure 4 is a vertical longitudinal section ap- 5 proximately on line 4—4 of Figure 3; and

Figure 5 is a vertical longitudinal section of a modified form of apparatus taken approximately on line 2—2 of Figure 3 with the parts in their initial position, as before operation by the patient. 10

The present device may be applied to any suitable type of machine but has been illustrated as applied to that type of machine shown in my copending application for Anesthetizing anparatus, Serial Number 644,219 filed Nov. 25, 1932. 15

First referring to Figures 1 and 2: Numeral 1 indicates the top portion of a floor standard acting as a support for the apparatus. Mounted on the standard is a frame structure including various tubular members forming passages for the ²⁰inhalation fluids. The lower part of the structure includes yokes 2 which may be of any preferred form for supporting the gas containers and connecting them to deliver into the system. Pairs of yokes are generally provided, two for 25 containers of nitrous oxide and two for containers of oxygen. The gas containers have not been shown. The usual pressure-regulating device is generally indicated, at 5. There are generally two of these devices. A suitable pressure gauge is ³⁰indicated at 6.

Whatever the construction of this part of the apparatus, the gases (whether mixed or not mixed) Anally are delivered to a passage 10 herein referred to as the delivery passage. This ³⁵passage, see Figure 2, is formed in the wall of a casing generally indicated at i I and in a tubular member 12, by which the casing is attached to the supply machine. This casing is provided with an air intake passage 13, and a bag passage 14, ⁴θ formed in enlargements and extensions of its lower wall 15. The bag 16 suitably attached to an extension communicates with passage 14.

The breathing line generally indicated at IT is provided with any preferred form of mask in- ⁴⁵dicated at 18, preferably without any valve, since all inhaling and exhaling openings or valves are at the chamber 11. This tube is suitably attached to a tubular member 20, see Figure 2. This tube passes through the vertical wall of the casing 5« II, and has a down-turned terminal portion 21 capped by a removable casing 22 having an orifice 23 in its lower wall, normally closed by a gravity acting plate valve 24. The valve 24 is raised during inhalation and falls to closed po- 55 sition during exhalation.

The passages 10, 13 and 14 are controlled by a valve means, in this instance including a bar 29 translatably guided by rollers 31. The end 30 of the bar functions as a valve, cooperating with 60

2,020,643 valve seat 32 to close the delivery passage 18. Attached to the bar by cross pin 34 is a block 35 which is part of the valve structure for closing-either the air passage 13 or the bag passage 5 14. Referring to Figure 3, this block has extending from Its broadened bottom, guide pins 3S which loosely traverse openings 3: of valve element 38. A spring 33 housed in a socket of the block 35 sealingly presses the valve element 38 10 against the upper surface 40 of the lower wall of casing if.

The sequence of operation of the valves is the same as in my copending application previously mentioned. Referring to Figure 5, when the valve 15 30 of the bar 28 is closing the passage iO, the valve 33 closes the bag passage (4. V/hcn the valve 30 is open, see Figure 2, the valve 38 is closing the air passage and the bag passage is open. The valve means may be said, therefore, to con20 trol the delivery and air passages SO—!3 to open one when the other closes and vice versa, and this valve means so operates that the delivery and bag passages are opened after which the air passage is closed, on movement of the valve means 25 in one direction, and on movement in the opposite direction the air passage is first opened and then the delivery and bag passages are closed.

A spring 42 moves the valves 30 and 33 normally to the position shown in Figure 5. To move 30 the valves against the action of this spring to open valve 3S and obtain a supply of fluid from passage 10, there is provided a patient-controlled means. This means includes a plunger 43 slidable in the wall of the casing !! and this plunger 35 has a head 44 inside the casing. Rotation of the plunger 43 is prevented by means of pin 45 passing loosely through an opening in the head 44. The head cooperates with the vertical wall to limit outward movement of the plunger. Spring ₄₀ 48 is attached to the head 44 and acts to advance the head in a direction to obtain latching. In Figure 5, it acts to advance valve 30 to closed position.

In order to provide a device by which the pa43 tient can control the valve means by hand, either to close or open the same, coupling means is used to draw the valve means to the position shown in Figure 2 against the action of the springs 42 and 46. This coupling means has herein the form of 50 a latch 47 pivoted as at 48 to the head 44. This latch has a notch 49 cooperative with pin 34, and a spring 50 moves the latch to latching position. Upward movement of the latch is limited by pin 52. ,.

Referring to Figure 1: The patient-operable valve control means includes, in addition, a wire SO suitably attached as at 61 to the plunger, said wire passing through a tubular member 62 rotatable and translatable upon a tubular extension 00 §3 in which the plunger 43 slides. This tubular member may be translated outwardly by the doctor to bring its inner face 64 into abutting engagement with the outer surface 6S of the tubular member 63, to hold the valve mechanism in the ₆₅ ’ position shown in Figure 2, independently of operation of the valve mechanism through means of the wire SO.

For administering anaesthesia, as distinguished from analgesia, it is not necessary that the 70* breath-actuated mechanism operate, nor under these conditions is it possible for the patient to control any part of the mechanism. This being the case, the patient control grip is allowed to hang from its support on the casing, arid the 75 swivel sleeve 61 is pulled out to its locking posi tion, in the manner previously described in which position the air port is closed and the main valve 30 is open for delivery of anesthetic. Thus, the manually operable patient control device is made inoperative, so as not to interfere with the ad- 5 ministration of anaesthetic fluid. At the same time, the breath-operated means is rendered inoperative in a manner below set forth.

To the outer end of the tubular member 62 is attached one end of a flexible tube 66 in this 10 instance formed by a wire coil. To the outer end of this coil is attached a stiff tube 67. To the opposite end of the tube 67 is attached another coiled wire tube 69 and to this is attached, by means of tubular element 70, a gripping element 15 7 i which has substantially the same form as the grip of an automatic pistol. Pivoted to this grip element is a trigger 72 which is related to the element 71 as the corresponding member of the grip of an automatic pistol. To the other end 20 of this grip, the wire 60 is attached, and when the grip is moved inwardly sufficiently from its position shown in Figure 1, the valve means is moved to the position shown in Figure 2. This is an important feature of the invention, since 25 the flexible connection 66 allows the grip to be swung to any angular position, and the valve means can be operated by a gripping action of the whole hand, without necessity for motion of any other part of the arm. Thus the patient’s 30 arm can rest on a chair arm or bed, and the valves can be controlled simply by gripping with the entire hand.

A broad feature of this invention is means operative as the result of respiratory effort to 35 control the valve means in a predetermined manner. There is no intention to be limited to the particular kind of control means, although a specific control means is also claimed herein. In this instance, respiratory effort effects the 40 tripping of the latch 47, after a predetermined number of respiratory motions, to stop flow of analgesic or anesthetic substance to the patient. In this way, the pressure set up by the patient’s breathing controls closure of the valve. On the 45 other hand, the patient can at any time release the grip on the element 12, and obtain closure of the valve 30, and opening of the air valve 38. These valves are thus controlled independently of any breathing effort by the patient. A device 50 is thus provided which is under full patient control for opening or closing the delivery valve by hand, and for closing as a result of a predetermined amount of respiratory effort.

The latch 47 has an extension 75 which is 55 adapted at the end of a certain number of respiratory movements to be engaged and depressed by pin 76 to release the latch. This pin is carried by a ratchet wheel 77 (see Figures 2 and 3) suitably rotatably mounted, see Figure 3, on a 60 stub shaft 78 secured to wall 79 of the casing by screw 80. ' Rotatable about a tubular extension 83 of the wheel and attached for movement therewith is a drum 81 having a flange frictionally engaged by. a wire 82 acting as a brake to 65 prevent over-run, and to hold the wheel in any of the successive positions to. which it is rotated. The drum is secured to the wheel extension by means of a set screw 84, so that relative angular adjustment can be obtained. 70

The ratchet wheel is rotated by pawl 85 pivoted to arm 86, in turn pivoted on the tubular bearing extension 83 of the ratchet wheel. The outer end of this lever is attached as at 87 to a vertical stem 90 passing upwardly loosely through 75

2,020,643 tubular extensions 91 which communicate with the tube 20. The stem 90 is attached as at 92 to a diaphragm 93, having its periphery suitably sealingly clamped between members 94—95 by 5 means of screws 96. The upper member 95 has an air vent 97. The stem is slidably guided in the member 95, and a screw 98 is provided for securing the stem in fully raised position when its operation is no longer desired. The teeth 10 only extend part way around the ratchet, to keep the breath-actuated mechanism from moving the wheel after tripping has taken place and before relatching and re-setting by the patient. Moreover, such continued movement would so tighten 15 the flexible element 101 as to render the bellowsoperative stem inoperative.

The stem has a disk 99 loosely operating in the lower extension 91 to substantially prevent exhalation flow in the direction of the full line 20 arrows, so that such exhaled fluid will move the diaphragm upwardly, also in direction of the full line arrows, thus raising lever 86 and causing pawl 85 to rotate ratchet wheel 77 the distance of one tooth in the direction of the arrow, 25 or clockwise. There may be any number of ratchet teeth. Adjustment of the pin to cause tripping of the latch by a greater or lesser number of respiratory efforts can be made by loosening set screw 84 and rotatably adjusting the 30 wheel relative to the drum. By this means, adjustment to the needs of the particular patient can be made, when required; but it will be noted that the patient can stop the flow at any time, independently of the breath control. The 35 ratcheting mechanism is only operable when the valves are in the position shown in Figure 2.

During exhalation, valve 24 prevents exit of out-breathed fluid, the valves 24 and 99 acting together for this purpose. During exhalation, 40 valve 99 rises to the position shown in dotted lines. As the patient inhales, valve 24 moves in direction of the dotted line arrow. Pressure is reduced in the tube 20, the diaphragm falls to the position shown in Figure 2, and the pawl is 45 lowered to engage another tooth of the ratchet wheel. The disk 99 also acts as a guide for stem 90. It is conically and downwardly convergently formed on its lower side to assure registration with and free entry into the tubular ex50 tension 91 on its way down from the dotted line position shown.

Means is also provided for setting the ratcheting mechanism in a predetermined initial position, so that pin 76 will always start its motion 55 from a given position and therefore always move a given distance, to tripping position. In this instance, it is set as a result of movement of the latch 47 to latching position. In the modified form of Figure 5 this setting takes place on move60 ment of valve 39 to cut off the supply of analgesic or other fluid.

Referring to Figure 4, which shows the position of the parts when the valve 30 is closed: Secured to· the drum 81 by one end as at 100 is a 65 flexible element 101 secured at its opposite end as at ΙΘ2 to a lever 103 pivoted as at 104 to the rear wall of the casing. The lower arm of the lever is pivoted to link 105 in turn pivoted as at 106 to the head 44, see also Figures 2 and 5. A 70 guide roller 107 is provided. The flexible element 101 operates to rotate the drum and ratchet wheel in counter-clockwise direction to bring the pin to the initial position shown in Figures 2 and 5.

As the latch moves to latching position, link

105 acts on the lever moving its upper end in clockwise direction as shown by the arrow, to slacken the element 101, so that the drum can move in clockwise direction, as a result of ratcheting movements. During drum motion in clock- 5 wise direction, the element 101 is wound on the drum to take up sufficient slack to assure that on movement of the lever 103 to· the position shown in Figures 4 and 5, the pin 76 will again be brought to its initial position. Thus the patient 10 re-sets the ratchet. In Figure 5, the lever 103 acts as valve 30 closes.

As the lever 103 moves to the position shown in Figure 2, its periphery engages a pin 110 of pawl 85 to move the pawl to operative position. To 15 assure that this operation will take place, even when the lever 86 is in its uppermost position, the lever 103 is provided with an upward extension 111. At the same time, a pin 112 carried by the lever 103 engages a spring arm 113 to move 20 it to the position shown in Figure 2, to permit movement of the pawl to· operative position. This spring arm 113 acts to move the pawl to inoperative position and thus acts when released by movement of the lever 103 to the position shown 25 in Figure 4, that is on movement of the latch to latching position. This pawl release, of course, takes place before action by the flexible element 101 on the drum begins, to bring the pin 76 to initial position. Thus mechanism is provided for 30 setting the ratcheting mechanism in a predetermined initial position as the result of movement of the latch to latching position. In Figure 5, this setting takes place on movement of the valve 30 to closed position. 35

It is noted that at any time before the pin 76 trips the latch, the patient can, by releasing the grip on the element 72, allow the valve 30 to automatically move to closed position.

Referring to Figure 3, the pin 34 is used here- 40 in to operate a mechanism for signaling the operator or patient that the valve 30 is closed, and that air is available through passage 13. The pin engages the slot of lever 115, the lever being suitably pivoted as at 117 on removable cover 45 plate 116 of the casing II. The pivot 117 has attached thereto, at the outer side of the plate 116, a resilient arm 118 having a ball 119 adapted to ring bell 120.

A feature is the placement of an exhaling valve 50 on the casing, to take care of all exhalation, in lieu of its placement on the mask. To this end, plate 116, see Figure 3, has an opening in which a tubular member 121 is fitted. Threaded to this member 121 is a sleeve 122 having openings 123 55 and seated against the outer end of the tube 121 is a valve 124. The outer side of this valve is engaged by a light tension spring 125, the tension of which can be adjusted by cap 126 having threaded engagement with the sleeve 122. This ⁶⁰valve prevents over-distension of the bag and building up of counter-pressures against the diaphragm of the breath-actuated mechanism and is a valuable feature. An air valve 124^a is also installed on the casing. It has a rotatable cap 65 124” by which it can be adjusted. The valve is used for control of analgesia, and also tends to prevent over-expansion of the bag and relieves counter-pressures. It permits dilution of analgesic fluid while the air intake passage 13 is closed ⁷⁰and without re-setting the regulator. Such valves have generally been used on masks.

In Figure 5 a modification has been shown in which the element 29^a instead of being movable with the element 35^a is movable independently 75

2,030,643 of this element and is rigidly attached to the plunger ¢3. The element 3 5^a in this instance slides upon the bar 29^a and the pin 34^a does not pass through the bar 29^a as in the first case.

The other structures of this form are otherwise substantially identical with those previously described.

In Figure 5, the main gas valve 30 is not controlled by the patient’s breathing, but is only con10 trolled by gripping action of the hand of the patient, and not as a result of respiratory effort. In this modification, the breath-actuated mechanism is used solely for opening the air port, and closing the bag passage, but the patient may still 15 move this valve to close the air port by gripping action of the hand, and must so move it to condition it for breath-control. It will be seen that the patient can open and close the delivery opening 10 independently of the position of the valve 20 38. With this construction, the gas flowing after the air port has been open, is diluted with atmospheric air, and the patient breathing this diluted substance is made to remain in a deeper stage of analgesia than would be if the gas were com25 pletely shut off. In this case the alarm gives warning that the air port only has been automatically opened by the breath-actuated mechanism.

As in my previously mentioned case, means is 30 provided by which gas from either supply carboy can be directly introduced into the breathing line without passing through the main delivery passage 80. In this way NaO or oxygen, or both, may be bypassed. For this purpose, pipe con35 nections are made with the chamber of each regulator, the connection being herein shown only for one of the regulators 130. The pipe 13( extends upwardly and traverses the wall· of the chamber !! and the pipe 29, and delivers directly into the 40 tube 28 at that portion of the tube which lies, in the drawing, at the left of the diaphragm-operated stem SO. The pipe has a valve (32, and any amount of gas can be bypassed independently of any control by the patient and at the will of 45 the anesthetist or operator. Suitable means for gauging the amount of bypassed fluid is used and includes graduated dial 133 and finger (34 attached to the valve moving there-over. The bypassage is generally adjusted to supply greater 50 or lesser quantities of gas than is normally delivered through the main passage (0. It is noted that the bag is also bypassed so that gas is shot directly and quickly to the patient without mixture in the bag. With bypass, the patient can⁵⁵ not entirely cut off the inhalation fluid. Although he can close the main supply valve 30, the bypass continues to deliver into the inhaling tube. When he does close the main valve, he gets a mixture of air as before, the only result being that ⁶⁰ he cannot get as much air as he wishes.

This scheme somewhat parallels the effect of. using the device with means for administering gas to a patient through more than one passage, when the gas is flowing through more than one ⁶⁵ passage simultaneously. With the second passage for gas, means have been provided for gas to flow after the main passage has been closed, and this gas flowing from the second passage mixes with the air from the air port to assist in the maintenance of analgesia. This mixing of gas with air only takes place, of course, while the air port is open.

Operation

In the operation of the device, when analgesia is desired, the patient grips the element 72 pulling the valves to the position shown in Figure 2. Thus analgesic fluid is delivered into chamber II. The patient inhales and fluid is drawn through opening 23, past valve 24, into tube 29, breathing 5 line 17 to mask 18. The rebreathing bag passage 14 is now open and the air port is closed. The patient inhales and exhales; each exhalation resulting in advancement of the pin 76 a distance equal to the length of a ratchet tooth, io After a certain number of exhalations have been made, the latch 47 is tripped and valve 30 is closed, valve 33 uncovers the air port and closes the bag passage.

When the patient releases the grip, lever 103 is 15’ moved to the position shown in Figure 4, releasing the spring 113 to let it engage the pin ! 10 and pull the pawl from operative position. Flexible element ί 01 then acts to move the ratchet wheel in counter-clockwise direction to the position 20 shown in Figures 2 and 5.

In the operation of Figure 5, the patient operates the grip to move plunger 43 to open valve 30, and by means of the latch to move valve 38 to close the air passage. Thereafter as the 25 patient breathes, the pin 76 is moved to Anally trip the latch and release the valve 38 only, which then moves to the position shown in Figure 5 to open the air port. At this time if the patient has continued gripping action, the valve 39 is in 30 open position. While this remains open, and while the valve 38 remains in the position shown in the figure, a mixture of air and anesthetizing or analgesic substance is available for the patient.

The success of any device for obtaining and 35 maintaining a state of analgesia depends upon a fine adjustment to the needs of the particular patient. Because of the different requirements of the different patients, it is a difficult problem to provide a device which, so to speak, is geared up 40 to the patient, that is a device which can be controlled by the patient or by the patient and the doctor in just the proper way to unfailingly maintain analgesia. This invention provides such a fine and sensitive control because part of the con- 45 trol is by the respiratory effort of the patient, and part is by the hand of the patient. In this way, a very exact and unvarying control can be had.

Although the device shown herein is designed to power-operate during exhalation, it is obvious 50 that the device can be made to operate on inhalations without departing from the spirit of the invention.

It is contemplated herein that the air alone, or any combination of fluid substances, be con- 55 trolled by respiratory action in the manner set forth, and there is no intention, to limit the invention only , to alternate control of air and inhalation gases, one of the broad features herein being the idea of control of . a valve both θθ manually and/or by means of respiratory action during administration of any inhalation fluid or fluids.