US3356088A

US3356088A - Breath-controlled anesthetic applicator and method of operation

Info

Publication number: US3356088A
Application number: US311461A
Authority: US
Inventors: Sidney W Nelson
Original assignee: Ohio State University
Current assignee: Ohio State University
Priority date: 1963-09-25
Filing date: 1963-09-25
Publication date: 1967-12-05
Anticipated expiration: 1984-12-05

Description

Dec. 5, 1967 s. w. NELSON 3,356,088

BREATH-CONTROLLED ANESTHETIC APPLICATOR AND METHOD OF OPERATION Filed Sept. 25. 1963 2 Sheets-Sheet 1 so I 25 59 2O 6. g I N 46 47 43 45 9o-. 1

44b EBA.

&

05 Ill a F1733 z INVENTOR. 5' 0.1 5001 BY O 0.305 I 2 345 I0 zoaoso IOO EQUIVALENT PARTICLE DIAMETER. MICRONS Dec. 5, 1967 s. w. NELSON 3,356,088 BREATHCONTROLLED ANESTHETIC APPLICATOR AND METHOD OF OPERATION Filed Sept. 25, 1963 2 Sheets-Sheet 2 IO 52 lOo.

I N VEN TOR.

United States Patent 3,356,088 BREATH-CONTROLLED ANESTHETIC APPLICA- TOR AND METHOD OF OPERATION Sidney W. Nelson, Columbus, Ohio, assignor to The Board of Trustees of the Ohio State University, Columbus, Ohio, an institution of Ohio Filed Sept. 25, 1963, Ser. No. 311,461 14 Claims. (Cl. 128-488) This invention relates generally to a method and means of administering medication, and particularly to apparatus for applying medication or anesthesia directly to the internal area of interest in a controlled and accurate manner and without danger or discomfort to the recipient.

In recent years medical advances have been made in the examination and treatment in illnesses affecting the pharynx, bronchial tree and other parts of the body reached through the mouth opening. Unfortunately, however, these advances have often not been utilized, and in many instances the examination and treatment of these internal illnesses have been purposely avoided or neglected. Adequate topical anesthesia is vital to the success of bronchography or endoscopy of the larynx and tracheobronchial tree, and, unfortunately, the conventional methods of topical anesthesia of the respiratory tract that are being used cause apprehension, gagging and coughing which create an ordeal for both the physician and the patient.

There have become commercially available, in recent years, manual aerosol methods and sprays, and even more recently, a spray-type of anesthetic. Some alleviation of the problems in application of topical anesthesia of the respiratory tract has attended the use of manual aerosol methods. Again, however, manual aerosol methods have not been very satisfactory in the general application of topical anesthesia from either the patient or anesthetist standpoint. This type of anesthesia requires considerable cooperation from the patient, and in many instances, such as in elderly patients, and especially so in those experiencing hardening of the arteries of the brain, cooperation is lacking. Also, from the standpoint of the anesthetist, there is no way to determine the amount of anesthesia administered to the patientand whether the anesthesia that has been administered to the patient has reached the critical area to be examined. Consequently, even an exceptionally well trained anesthetist would not be able to administer the commercially available spraytype anesthesia in a controlled and accurate manner. A positive pressure method also has been devised to administer an aerosolized anesthetic agent employing the Bennett-type of valve. But, again, this method delivers much of the anesthetic agent to the alveoli where it is not needed (no nerve endings) and where unwanted absorption into the blood stream can occur.

The present invention is an improved method and means of applying anesthesia to the patient utilizing an aerosolized anesthetic agent which is highly effective, accurately controlled, and without discomfort to the patient. Essentially, the basis for the present invention is an automatic method of administering an aerosolized anesthetic agent to the patient during normal inspiration by means of breath-actuated valves. In general, the apparatus consists of an inhale-exhale closed-loop mechanical valve system that is actuated in its initial cycle by the inhalation of the patient and then reset by the exhalation of the patient. In this way there is administered to the patient during inhalation a controlled amount of aerosolized anesthesia. More specifically, the system comprises in a preferred embodiment an aerosolized anesthetic agent opening into a breathing tube to be fitted into the mouth of the patient and associated mechanical and electrical apparatus for activating the anesthetic spray upon each inhalation and resetting the system upon exhalation.

It is accordingly a principal object of the present invention to provide a new and improved method and means of applying medications to a patient.

It is ,a further object of the present invention to provide a new and improved method and means of applying medications to a patient that may be accurately controlled in an effective manner and without discomfort to the patient.

Another object of the present invention is to provide an improved method and means of applying topical anesthesia to the respiratory tract of the patient utilizing a physiological method of delivering an aerosolized anesthetic agent.

Another object of the present invention is to provide an improved method and means of applying medications 1 to a patient utilizing a system and apparatus activated by the breathing of the patient.

Another object of the present invention is to provide an improved method and means of applying medications to a patient that may be adapted to and become a part of accepted medical practice thereby permitting the medical profession to fully utilize the medical advances in the treatment and examination of illnesses and diseases to bronchography or endoscopy of the larynx and tracheobronchial tree and to other parts of the respiratory tract reached through the mouth opening.

Still another object of the present invention is to provide an improved medical system and apparatus that is rugged, reliable and continuously operable without fault, but yet is relatively simple in construction to permit manufacturing reproduction with consistency.

Other objects and features of the present invention will become apparent from the following detailed description when taken in conjunction with the drawings in which:

FIGURE 1 is a pictorial schematic of a complete preferred embodiment of the invention;

FIGURES 2, 2a, and Zb-illustrate the operation of the breathing tube in a complete cycle of operation;

FIGURES 3 and 3a illustrate in detail the two-state operation of the metering valve in the anesthesia spray; and,

FIGURE 4 is a graph illustrating the particle size vs. weight of the anesthetic Xylocaine.

Although an aerosol anesthesia system has been known,

the implementation of the system to a practical uncomplicated method of creating a small aerosol cloud during the inhalation phase of respiration has been difiicult.

Various methods of actuating aerosols with cylinders of compressed gas as the aerosolizing force, etc., were studied, but their bulk and complexity eliminated their use in a practical system.

It was the next expedient, therefore, that a metering valve be used with a liquid carrying agent as both the propellant and solvent for the anesthetic since various types of metering valves were already being used for the manual administration of aerosolized medications from operation of the invention, is the proper choice of anesthesia and the aerosolized agent.

In accordance with its general concepts, the system of the present invention, as shown in FIGURE 1, comprises a mouth piece 10, a flutter valve 15, a diaphragm actuated switch 20, a power source 30, a counter 35, an electrical solenoid 49, an anesthesia vial 50, and a metering valve 60.

The system is a closed loop system, i.e., the electrical/mechanical arrangement of components are each operative in sequence and one in response to another from the initiation to the completion of the operation.

The mouthpiece or breathing tube is of an appropriate size to conveniently permit its end 10a to enter to the mouth opening of the patient. The breathing tube should, of course, be made of material such as stainless steel that may be readily sterilized. Inserted through a first cross-sectional aperture in the breathing tube 10 is the aerosol shaft 51.

Next positioned on the breathing tube 10 is the air pressure line 25 opening at one end into the tube 10 and at its other end into the diaphragm switch valve 20. Adjacent the air pressure line 25 is the air vent or sleeve valve structure 22 fitted in an air ti-ght manner through a second cross-sectional aperture in the breathing tube 10. The sleeve of the air vent 22 is open at its upper end 27 into the atmosphere and also has ports therein to permit outside air to enter the tube 10.

At the extreme other end of the breathing tube 10 is the two-position flutter valve 15. In the preferred embodiment, the flutter valve generally comprises a plug-like insert 14 having means to allow the complete exhaust of air on exhalation and to permit the passage of a small amount of outside air into the end 1% of tube 10. A rubber disc-like member is movably positioned on the end of the valve 15.

As mentioned above, the other end of the air pressure line is connected to the diaphragm switch 20. This element is commercially available and again, per se, does not form a part of the invention. In a typical illustration, it would include a pressure cylinder having, internally, a butterfly-type of diaphragm structure. The diaphragm is so positioned in the pressure cylinder that it is permitted normally to be in a free position but movable with a change of pressure in the outer cylinder. Also within this element is an open electrical circuit including contacts adapted to become closed by the butterfly-type diaphragm when it is moved.

The electrical circuit 30, in this particular embodiment, comprises an alternating current source and a selenium rectifier for converting the power to direct current. It is, of course, apparent a DC. power pack may be substituted for the electrical source shown. A counter is connected to the electrical circuit 30 to count the number of times the circuit is actuated. This counter further includes a shut-off switch for concluding the operation of the system when a predetermined amount of actuations have occurred.

Connected to the electrical source is a DC. solenoid secured to the housing 90 by bracket 48 and adjustable in position by adjustable screw 49. In a conventional manner, the completion of the electrical circuitry causes magnetization of the arm 42 and hence draws (attracts) the arm 42 within the core. At the outer end of the arm 42 is a first pivotal joint 41 connected to one end 44a of the L shaped linkage 44. To maintain positioning of the linkage 44 within the housing 90 and relative to the other elements therein, the elbow 46' of linkage 4.4 is pivotally mounted by mounting 47 to the outer housing 90. Centrally positioned on the other half 44b of the L shaped linkage is a second pivotal joint 43. Also connected to this joint is a spring loaded shaft 61. A third pivotal joint at the second end of the linkage 44 is connected to a rod' 24 that forms a part of the air vent 22. Through the connection of the pivotal joint 46 of the linkage 44 to the inner wall of the outer housing 90, the upper arm 44b of the L shaped member is caused to move upwardly as its lower arm 44a is moved inwardly by the withdrawal of the solenoid arm 42.

The spring loaded shaft 61 is so positioned between support 59 connected to the housing and the pivotal joint 43 to the linkage arm 44b, the spring action will cause the L shaped arm 44b to return to its normal position when the electrical circuitry is broken, i.e., when the solenoid is demagnetized. This, in turn, also causes the end joint 45, connected to the air vent shaft, to force the rod 24 downwardly and hence to return to its normal position; and, as set forth hereinafter, close the air vent to the breathing tube 10. Resting on the spring within the shaft 61 is the rod 58 having the seat 57 at its other end for seating the vial 50. Through continuous linkage of the solenoid 40, linkage 44, shaft 61, and the seat 57, the vial 50 is raised upwardly when the electrical circuit is closed. The vial 50, in turn, by upward movement, activates the metering valve 60, thereby introducing a passage therein to permit the aerosolized anesthetic agent to pass from its high pressure position into a low pressure area in the breathing tube 10.

Also through continuous linkage of rod 24 with respect to the linkage arm 44a, the air vent 22 is permitted to form an air opening when it is moved up into the breathing tube 10 and to close the same when it is returned to its normal position.

Referring now specifically to FIGURES 2, 2a, and 2b, there is illustrated in detail the three cycles of operation of the breathing tube 10. The condition shown in FIGURE 2 is the initial or quiescent condition. The anesthesia vial 50 is retracted and pressure sealed, the air intake tube 22 is also retracted, preventing air to be taken in, and the flutter disc 18 is in its outwardly position permitting a free flow of air to pass through the openings 19.

When the patient breathes in, the flutter disc 18 of valve 15 immediately closes the ports 19 by occupying its closed position as shown in FIGURE 2a. By preventing air to be taken in, the air is pulled from the tube 25 and consequently there is a decrease in the pressure on the pressure switch 20, as set forth above. This causes air vent tube 21 to be raised in its sleeve 22, thereby permitting its aperture 26 in the sleeve 22 to become registered with the aperture 28 in the inner air vent. This, in turn, permits air to be sucked in by the patient through the outside opening 27. The sleeve 22 may be supported at its lower end beneath the major housing 90 by the flange 22a integrally formed therewith. Simultaneously, with the air intake, the vial 50 is pushed upward permitting the spray nozzle 55 in the shaft 51 to become a low pressure area for the aerosolized anesthetic fluid and thereby expelled through port 53. An anesthesia spray is thereby expelled into the mouthpiece 10, and together with the air from the air intake 27, is taken by the patient.

To secure the shaft 51 in the tube 10, it is fixedly positioned by the threaded nut 52 at its uppermost end and by the washer type positioner 54 at its other end. The washer 54 further serves to maintain the breathing tube 10 in its proper position relative to the housing 90. The shaft 51 has drilled therein an aperture 55 registering at one end with the port 53 and at its other end with the opening 76a of the anesthesia vial 50.

When the patient exhales, the air pressure in diaphragm valve 20 becomes greater and consequently opens the switch, as also set forth above. This causes the anesthesia bottle to become retracted as shown in FIG- URE 2b and the air vent tube 22 to be dropped. The

ports

26 and 28 are disaligned cutting off the opening to the outside air. The anesthesia and the air intake are thusly cut off. The flutter valve 18 is shown in FIGURE 2b in its closed position merely to illustrate that its movement is last to be affected by the patient exhaling. However, since all other openings in the tube 10 are closed,

the air exhaust from the patient exhaling passes around the sleeve 22 and causes the flutter valve 18 to move outwardly and thereby releases to the atmosphere the patients breath through the openings 19.

The construction of the flutter valve 15 comprises in a preferred embodiment a disc-like plug insert 14 that is fitted in the end 10b of the mouthpiece 10 and thereby sealing the opening 1%. A series of ports 19 are conveniently placed in the insert 14. Centrally fixed to the insert 14 is a T-type structure comprising a neck 12 and an end plate 17. Of substantially the same size as the end plate is a rubber-like disc 18 that is slideably fitted on the neck 12 and operative to seal off the ports 19. The screw 16 is an adjustment to control the length of travel of the diaphragm 18 and thereby control the air entering or exhausted from the ports 19.

In operation of the metering valve 60, reference is made to FIGURES 3 and 3a. When the anesthetic bottle is in its normal position, the metering valve 60 is positioned as that shown in FIGURE 3. The plunger valve 70 is retracted, permitting an opening around the guide stem 74 in the seal 72, thereby allowing the aerosolized anesthetic agent to enter the metering area 66. At the other end of the valve 60 the seal 62 has abutted thereto the upper cap 78 of the stem 80 to prevent the escape of the pressurized fluid entering the metering area. When the metering valve is activated, as set forth hereinabove, the plunger valve 70 joins the opening in the seal 72 preventing further entry of anesthesia into the metering area 66. At the other end, however, the cap 78 and the upper tube 64 are retracted within the metering area. The opening 76a provides a low pressure area for the pressurized fluid in the metering area 66 carrying the aerosolized anesthetic agent into the aperture 55 of shaft 51 and hence out of port 53 (FIGURE 2) into the breathing tube 10.

Upon deactivation of the metering valve, the spring 68 yieldingly unges the stem 80' and hence cap 78 to return to its normal upward position, wherein again the expulsion opening 76 is sealed and the metering area is again opened to the anesthesia.

The apparatus defined above cooperatively forms a closed-loop control system for anesthetizin-g a specific body area of a patient. The sequence of operation of the preferred embodiment in a typical application may now be described.

In the normal inactivated condition of the system adjoining the mouthpiece or breathing tube 10, the patient will simply inhale and exhale air through in the two-psition flutter valve 15. The valve 15, at this time, will permit air to be taken into the tube as well as'to exhaust the tube 10. In the active condition of the system-for administering the anesthesia to the patient as the patient inhales, air is pulled into the mouthpiece or tube 10 through the opposite end 1012 and the flutter valve 15. A fraction of a second later, during inhalation, the flutter valve closes, resulting in a sudden drop in pressure that is applied to the diaphragm 20 via pressure tube 25. The decrease in pressure, in turn, causes the diaphragm in the switch 20 to change position and make electrical circuit 30. The electrical circuit once completed, applies an electromotive force to the solenoid magnetizing the arm 42 and drawing it inwardly towards the core. As the arm 42. of the solenoid is moved inwardly, the lower segment of the linkage arm 44 is moved inwardly and through the elbow connection 46, the upper segment 44b of the linkage arm 44 is moved upward. The upper segment 44a of the linkage arm 44 as it moves upward pushes the spring loaded shaft 61 upwardly and consequently the anesthesia vial is moved upwardly. In this way the metering valve for the anesthesia having its casing integrally formed with the vial 50 also is moved upwardly. This, in effect, lowersits needle val-ve into the vial 50. The metering valve being actuated causes a given amount of anesthesia to enter a small spray tube 6 in the mouthpiece and to be aerosolized through the orifice 53 into the breathing tube 10.

Simultaneously, with the activation of the metering valve 60, the air vent shaft 24 being connected to linkage arm 44b is also moved upwardly, permitting the

ports

26 and 28 to register, therefore opening a direct passage 27 to permit air to enter the breathing tube 10. Thusly, there is permitted an uninterrupted free flow of room air to carry the simultaneously aerosolized anesthetic agent into the tracheobronchial tree during the remainder of the inhalation.

In the return cycle, i.e., during the expiratory phase of respiration, the breath actuated flutter valve 15 on the end 10b of the breathing chamber 10 opens permitting the exhaled air to escape through ports 19. Again, this builds up a pressure in the chamber 20 which causes the diaphragm to return to its original position and consequently break electrical contact. With the current cut off, the solenoid 40 will become demagnetized and consequently permit arm 42 to be returned to its outward position and linkage arm 44 to its original position with the help of the force supply by the spring in the shaft 61. This action causes the vial 50 to be lowered to its resting position, and in this way resets the metering valve. The linkage arm 44 also lowers the rod 24 which shuts off the air intake and the system is again ready for the next cycle. In actual practice, little force is required by the system and through continuous breathing the system is substantially a continuous cycle of operation.

The vial 50 carrying the aerosolized anesthetic agent in the preferred embodiment comprised a 50 cc. glass vial containing a 10% solution of Xylocaine. This anesthetic is prepared by suspending crystalline Xylocaine in a mixture of Freon 12 (20%) and Freon 114 which remains a liquid at three atmospheres of pressure. During the unactuated state (i.e., during exhalation), the three atmospheres of pressure within the vial 50 forces the Xylocaine-Freon solution through a small plastic tube 63 leading from the bottom of the vial into the metering chamber. After the actuation, the liquid Freon at three atmospheres of pressure quickly flows from the metering chamber into the spray tube, from which it is aerosolized through a tiny orifice 53 into the mouthpiece 10 where normal atmospheric pressure rapidly causes the liquid Freon to become a gas. Thus, the Xylocaine crystals remain in the form of a solid particle heterogeneous aerosol which is inhaled physiologically into the pharynx and respiratory tract.

At the present time the volume of the metering chamber (60 cu. ml.) and concentration (10%) of the Xylocaine results in the aerolization of six milligrams of crystalline Xylocaine during each activation; i.e., during each inhalation. This knowledge allows precise control of the amount of anesthetic agent administered so as to avoid exceeding known safe maximal amounts.

The retention of airborne particulates within the respiratory tract has been theoretically calculated. The amount of an airborne particulate which is deposited in the respiratory tract and the location in which it is deposited are functions of particle size. The deposition of aerosol particles in various portions of the respiratory tract has also been explained.

A heterogeneous aerosol such as the anesthetic Xylocaine contains a wide spectrum of particle sizes (see FIG- URE 4). The theoretical and experimental data indicates that the vast majority of particles larger than 30 micra in diameter are deposited in the bronchial tree, whereas the majority of particles in the 310 micra diameter range are deposited in the bronchioles and alveolar ducts. Many particles l-3 micra in diameter reach the alveoli and are probably deposited there. Particles less than 0.5 micra in diameter easily reach the alveoli, but probably many of these particles are exhaled again without being deposited. Thus, the theoretical particle size distribution curve of the anesthetic used by us shows that approximately 30% of the Xylocaine is 30 micra or greater in diameter, these being previously deposited in the mouth, pharynx, larynx, and trachea. Approximately 50% of the Xylocaine is in the form of particles 10-30 micra in diameter, thus affording the deposition of an adequate amount of anesthetic in the bronchial tree. Approximately 25% of the Xylocaine is in the form of particles 3-10 micra in diameter, thus providing anesthesia to the level of the alveolar ducts. Only about 6% of the Xylocaine is in the form of particles 3 micra or less in diameter, thus fortunately precluding the passage of a significant amount of anesthetic agent into the alveoli where anesthesia is unnecessary because of the absence of sensory nerve elements, and where rapid absorption of the Xylocaine might theoretically create a hazard.

The first two or three inhalations of the agent taste somewhat bitter, but the patient is told to expect this. As a result of the brief preliminary instructions from the radiological technician, the patient actually anesthetizes himself in three or four minutes. Shortly after the procedure begins, the patient feels numb in the mouth, pharynx, larynx, and substernal region.

The technician can easily administer the aerosol anesthesia, although the physician should be available at all times to treat the occasional reaction to the anesthetic agent. The patient is instructed to inhale and exhale with a little more than usual vigor, and is encouraged to breathe deeply and slowly to permit the maximal amount of crystalline Xylocaine to be deposited upon the mucosa.

Quantitative studies now under way indicate that of the anesthetic agent is deposited in crystalline form on the inner wall of the breathing tube during inhalation. An additional small amount may be lost through the flutter valve during exhalation, but this amount is not known. Theoretically, then, the maximum amount of anesthesia that can reach the patients mouth, pharynx, larynx, and tracheobronchial tree is 75-80% of the anesthesia released by the metering valve. It is believed by many that it is safe to give 200-300 mgs. of Xylocaine intratracheally. The LD 50 (lethal dose in dogs, i.e., toxicity wherein 50% of dogs will not survive) in animals and the therapeutic ratio are much greater for Xylocaine than for Pontocaine and Cocaine. With the method here described, 40 inhalations result in the release of 240 mgs. of Xylocaine, of which about 170-180 mgs. actually enter the patients oral and respiratory structures. The supplemental use of 10 ccs. of aqueous 1% Xylocaine through the endotr-acheal catheter adds 80-90 mgs., the total amount being about 250-270 mgs. of Xylocaine for most patients. As much as 55 activations (330 mgs. of Xylocaine) have been used for large patients or those having excessive secretions. In small women and children 20-30 activations are sufiicient.

Although the clinical results have been exceptionally good with the use of Xylocaine as an anesthesia as described above, it is to be understood, of course, that the invention is not to be so limited and other known anesthesias may be substituted therefore. Similarly, the agent Freon is merely illustrated as being particularly adaptable to the anesthesia used. Again, however, other agents for carrying the anesthesia or medication may just as readily be utilized.

An automatic counter can be preset to determine the number of activations for a given patient, the counter automatically concluding the operation of the system by electrical interruption when the predetermined number of actuations (inhalations) have been completed. A small red signal light may be connected to the counter and placed on the top cover of the unit to signal the completion of the procedure.

By using the aforementioned method and equipment, more than ninety percent of almost three hundred patients have obtained satisfactory anesthesia with very little time and effort expended by the physician and with reasonably little discomfort to the patient. Good anesthesia is an absolute prerequisite for precision spot-film bronchography, which, in turn, is essential for the most detailed study of the wide variety of bronchopulrnonary diseases which can be clarified by this diagnostic approach. It is hoped that this method of applying topical anesthesia to the tracheobronchial tree will result in the increasing utilization of bronchography by radiologists.

Naturally, this method of anesthesia is applicable to endoscopic procedures of the larynx and tracheobronchial tree. Furthermore, it is proving useful in performing positive contrast examinations of the hypopharynx and larynx. It should also be very useful for direct digital and bimanual examinations of lesions of the mouth, pharynx, and larynx when precise evaluation of extent of a cancerous lesion is being attempted prior to therapy.

This automatic method of aerosolizing anesthesia, as described above, is not to be so limited and may be applicable to other problems in clinical therapy. The word medication, as used herein, is intended to include anesthesia since the system will readily adapt itself and be operable in the same method and manner in applying other forms of medications to the patient in the treatment of internal illnesses.

What is claimed is:

1. A closed loop system for incrementally administering a predetermined amount of medications to a patient comprising; a patients breathing means having a first opening adapted to be received by the patient, an oppositely positioned second opening including a two-position element cyclically closing said opening upon inhalation and providing an air outlet upon exhalation, means containing an aerosolized medicated agent having a dispensing means also opening into said breathing means, and means connected to said breathing means and operative with said two-position element for cyclically activating said dispensing means upon inhalation and for deactivating said dispensing means upon exhalation of the patient.

2. A closed loop system for incrementally administering a predetermined amount of medications to a patient comprising; a patients breathing means having a first opening adapted to be received by the patient, an oppositely positioned second opening including a two-position element cyclically closing said opening upon inhalation and providing an air outlet upon exhalation, means containing an aerosolized medicated agent having a dispensing means also opening into said breathing means, and means connected to said breathing means and operative with said two-position element for cyclically activating said dispensing means upon inhalation and for deactivating said dispensing means upon exhalation of the patient, and mete-ring means in said dispensing means for controlling the amount of medication released into said breathing means.

3. A closed loop system for incrementally administering a predetermined amount of medications to a patient comprising; a patients breathing means having a first opening adapted to be received by the patient, an oppositely positioned second opening including a two-position element cyclically closing said opening upon inhalation and providing an air outlet upon exhalation, an air vent means in said breathing means in a normally closed position, aerosolized medication dispensing means also opening into said breathing means, and means connected to said breathing means and operative with said two-position element for cyclically activating said dispensing means and opening said air vent upon inhalation and for deactivating said anethetic dispensing means and closing said air vent upon exhalation of said patient.

4. A closed loop system for incrementally administering a predetermined amount of medications to a patient comprising; a patients breathing means having a first opening adapted to be received by the patient, an oppositely positioned second opening including a two-position element cyclically closing said opening upon inhalation and providing an air outlet upon exhalation of said patient,

an air vent means in said breathing means in a normally closed position, means containing an aerosolized medicated agent having dispensing means also opening into said breathing means, means connected to said breathing means and operative with said two-position element for cyclically activating said dispensing means and opening said air vent upon inhalation and for deactivating said dispensing means and closing said air vent upon exhalation of said patient, and metering means in said dispensing means for controlling the amount of medication released into said breathing means.

5. A closed loop system for incrementally administering a predetermined amount of medications to a patient comprising; a patients breathing means having a first opening adapted to be received by the patient, an oppositely positioned second opening including a two-position element closing said opening upon inhalation and providing an air outlet upon exhalation, aerosolized medication dispensing means also opening into said breathing means; linkage means connected at one end to said dispensing means, an electrical solenoid connected at the other end of said linkage means, and a pressure activated electrical switch responsive to pressure in said breathing means and operative with said two-position element for energizing said solenoid and thereby moving said linkage means to activate said dispensing means upon inhalation and for deactivating said dispensing mean-s upon exhalation of the patient.

6. A closed loop system for incrementally administering a predetermined amount of medications to a patient comprising; a patients breathing means having a first opening adapted to be received by the patient, an oppositely positioned second opening including a two-position element closing said opening upon inhalation and providing an air outlet upon exhalation, aerosolized medication dispensing means also opening into said breathing means; linkage means connected at one end to said dispensing means, an electrical solenoid connected at the other end of said linkage means, and a pressure actuated electrical switch having an air tube entering said breathing means and operative with said two-position element for energizing said solenoid and thereby moving said linkage means to activate said dispensing means upon inhalation and for deactivating said dispensing means upon exhalation of the patient.

7. A closed loop system for incrementally administer ing a predetermined amount of medications to a patient comprising; a patients breathing means having a first opening adapted to be received by the patient, an oppositely positioned second opening including a two-position element closing said opening upon inhalation and providing an air outlet upon exhalation of said patient, an air vent means in said breathing means in a normally closed position, means containing an aerosolized medicated agent having dispensing means also opening into said breathing means; linkage means connected at one end to said dispensing means, an electrical solenoid connected at the other end of said linkage means, said linkage being further connected to said air vent means, a pressure actuated electrical switch having an air tube entering said breathing means, and operative with said two-position element for energizing said solenoid and thereby moving said linkage means for activating said dispensing means and opening said air vent upon inhalation and for deactivating said dispensing means and closing said air vent upon exhalation of said patient.

8. A closed loop system for incrementally administering a predetermined amount of medications to a patient comprising; a patient's breathing means having a first opening adapted to be received by the patient, an oppositely positioned second opening including a two-position element closing said opening upon inhalation and providing an air outlet upon exhalation of said patient, an air vent means in said breathing means in a normally closed position, means containing an aerosolized medicated agent having dispensing means also opening into said breathing means; linkage means connected at one end of said dispensing means, an electrical solenoid connected at the other end of said linkage means, a pressure actuated electrical switch having an air tube entering said breathing means, and operative with said two-position element for energizing said solenoid and thereby moving said linkage means for activating said dispensing means and opening said air vent upon inhalation and for deactivating said dispensing means and closing said air vent upon exhalation of said patient; a counter operative to advance one position upon each closure of said switch, and stop means for terminating the operation of said system when said counter has advanced to a predetermined number.

9. A system as set forth in claim 8 wherein said medication is the anesthetic Xylocaine.

10. A system as set forth in claim 8 wherein said medication is the Xylocaine dispersed in liquid Freon.

11. A system as set forth in claim 8 wherein said medication is the anesthetic Xylocaine dispersed in Freon and wherein said container means is maintained under pressure to retain said Freon in a liquid state until released into said breathing means.

12. incrementally administering a predetermined amount of medication to a patient comprising aerosolizing said medication, metering predetermined amounts of said medication, dispensing one of said metered amounts, guiding internally of said patients said dispensed medication, sensing said patients inhalation and exhalation cyclically controlling the dispensing of said medication in response to the inhalation and exhalation of said patient, providing an outlet for said patient exhalation, cyclically repeating dispensing said metered amounts internally of said patient, and terminating said administration of medication upon reaching a predetermined total amount.

13. Inc-rementally administering a predetermined amount of anesthetic to a patient comprising pressurizing Xylocaine in a carrying agent, metering predetermined amounts of said anesthetic, dispensing one of said metered amounts, guiding internally of said patient said dispensed anesthetic, sens-ing said patients inhalation and exhalation cyclically controlling the dispensing of said anesthetic in response to the inhalation and exhalation of said patient, providing an outlet for said patient exhalation, cyclically repeating dispensing said metered amounts internally of said patient, and terminating said administration of anesthetic upon reaching a predetermined total amount.

14. Incrementally administering a predetermined amount of anesthetic to a patient comprising aerosolizing an anesthetic, metering predetermined amounts of said anesthetic, dispensing one of said metered amounts, guiding internally of said patient said dispensed anesthetic, sensing said patients inhalation and exhalation cyclically controlling the dispensing of said anesthetic in response to the inhalation and exhalation of said patient, providing an outlet for said patient exhalation, cyclically repeating dispensing said metered amounts internally of said patient, and terminating said administration of anesthetic upon reaching a predetermined total amount.

References Cited UNITED STATES PATENTS 2,754,819 7/1956 Kirschbaum 128-188 3,083,707 4/1963 Seeler 128194 XR 3,126,001 3/1964 Engstrom 128188 XR 3,138,289 6/1964 Jones et a1. 222-20 XR 3,151,618 10/1964 Wakernan 128203 3,187,748 6/1965 Mitchell et al. 128-208 XR RICHARD A. GAUDET, Primary Examiner.

W. E. KAMM, Examiner.

Claims

1. A CLOSED LOOP SYSTEM FOR INCREMENTALLY ADMINISTERING A PREDETERMINED AMOUNT OF MEDICATIONS TO A PATIENT COMPRISING; A PATIENT''S BREATHING MEANS HAVING A FIRST OPENING ADAPTED TO BE RECEIVED BY THE PATIENT, AN OPPOSITELY POSITIONED SECOND OPENING INCLUDING A TWO-POSITION ELEMENT CYCLICALLY CLOSING SAID OPENING UPON INHALATION AND PROVIDING AN AIR OUTLET UPON EXHALATION, MEANS CONTAINING AN AEROSOLIZED MEDICATED AGENT HAVING A DISPENSING MEANS ALSO OPENING INTO SAID BREATHING MEANS, AND MEANS CONNECTED TO SAID BREATHING MEANS AND OPERATIVE WITH SAID TWO-POSITION ELEMENT FOR CYCLICALLY ACTIVATING SAID DISPENSING MEANS UPON INHALATIO AND FOR DEACIVATING SAID DISPENSING MEANS UPON EXHALATION OF THE PATIENT.