US3794026A - Ventilating apparatus embodying selective volume or pressure operation and catheter means for use therewith - Google Patents

Abstract

A ventilating and resuscitator system for emergency and nonemergency uses which provides selective pressure or volume modes of operation. The control of flow of inflating pressurized gas, under pressures between 20 and 100 psi, is subject to either manual control or automatic control wherein the automatic control takes over ventilation or is responsive to the conditions of the patient. In the automatic mode, pressure responsive means such as pressure switches, which are responsive to the minimum or negative maximum as well as positive pressure variations in the thoracic intrapulmonary region, are utilized to program and control the inflation and deflation cycles. In addition, alarm means are provided to warn the attending personnel of patient failure, and to automatically secure a flow of breathing gas to the patient, overriding other control means. There is also provided means whereby, at desired intervals, the patient obtains ventilation effects equivalent to ''''sigh'''' type inhale and exhale cycles. The arrangement further provides a triple lumen catheter, preferably of total diameter of 0.5 to 2.0 millimeters, a flow line connected to each lumen, a pressure monitoring line and a valving system interconnecting the two minor flow lines and the pressure monitoring line whereby each minor flow line is alternately and cyclically connected to the pressure monitoring line. This arrangement maintains the pressure monitoring line free of mucous and other body secretions. While the invention is preferably practiced with a new triple lumen catheter means, other catheter means may be used. A novel inserter for the triple lumen catheter is also disclosed.

Description

United States Patent [191 Jacobs 1 Feb. 26, 1974 22 Filed: Aug. 3, 1972 211 Appl. No.: 277,628

Related US. Application Data [63] Continuation-impart of Ser. No. 162,944, July 15, 1971, which is a continuation-in-part of Scr. No. 59,206, July 29, l970, Pat. No. 3,682,l66.

[52] 11.1.8. Cl. 128/145.8, 128/351 [51] Int. Cl. A61! 16/00 [58] Field of Search 128/351, 349, 145.5, 145.6,

[56] References Cited UNITED STATES PATENTS 3,628,532 12/1971 Magrath 128/1458 3,529,596 9/1970 Garner..... 128/1456 3,322,126 5/1967 Rusch 128/351 Primary Examiner-Richard A. Gaudct Assistant Examiner--G. F. Dunne [57] ABSTRACT A ventilating and resuscitator system for emergency SUCTION SOURCE OXYGEN OR AIR SOURCE WATER SU 77 REDUCTION 36 and non-emergency uses which provides selective pressure or volume modes of operation, The control of flow of inflating pressurized gas, under pressures between 20 and 100 psi, is subject to either manual control or automatic control wherein the automatic control takes over ventilation or is responsive to the conditions of the patient. In the automatic mode, pressure responsive means such as pressure switches, which are responsive to the minimum or negative maximum as well as positive pressure variations in the thoracic intrapulmonary region, are utilized to program and control the inflation and deflation cycles. in addition, alarm means are provided to warn the attending personnel of patient failure, and to automatically secure a flow of breathing gas to the patient, overriding other control means. There is also provided means whereby, at desired intervals, the patient obtains ventilation effects equivalent to sigh type inhale and exhale cycles. The arrangement further provides a triple lumen catheter, preferably of total diameter of 0.5 to 2.0 millimeters, a flow line connected to each lumen, a pressure monitoring line and a valving system interconnecting the two minor flow lines and the pressure monitoring line whereby each minor flow line is alternately and cyclically connected to the pressure monitoring line. This arrangement maintains the pressure monitoring line free of mucous and other body secretions. While the invention is preferably practiced with a new triple lumen catheter means, other catheter means may be used. A novel inserter for the triple lumen catheter is also disclosed.

31 Claims, 21 Drawing Figures 45 manna VALVE m 725 GEARS CATHETER IN PATIENT AIR MOTOR THERMOSTAT VENTILATING APPARATUS EMBODYKNG SELECTIVE VOLUME OR PRESSURE OPERATION AND CATHETER MEANS FOR USE THEREWHTH This application is a continuation-in-part of my US. Patent application Ser. No. 162,944, filed July 15, 1971, which in turn is a continuation-in-part of my application Ser. No. 59,206, filed July 29, 1970, now Pat. No. 3,682,166.

Until the present invention, there have been three methods for controlling the breathing of a person who does not breathe on his own or who needs assistance.

The first method consists of placing a mask over the face, oncluding the mouth and nose, and forcing air or oxygen through it. The second method consists of placing a large tube, approximately 5 to millimeters in diameter, and a sealing balloon into the windpipe. The third method consists of performing a tracheostomy operation on the neck, and putting a large tube of 5-10 millimeter diameter with a balloon around it into the windpipe.

Using the conventional intubation procedure in an emergency, it is especially difficult to insert the tube through the mouth, and it is dangerous to perform the tracheostomy operation in a matter of less than a minute. The usual routine in the absence of tracheal obstruction is to place the mask unit over the face and to pump air into the lungs, rather than risk an emergency tracheostomy. However, the mask forcesair into the stomach and increases the chance of regurgitation up into the back of the mouth and down into the lungs. When the mask is removed prior to inserting the tube through the mouth into the windpipe, the person gets no ventilation whatsoever for the length of time that this procedure takes. Also, these procedures usually must wait until the patient is almost dead in order to proceed without difficulty. Many lives are lost because of the inadequate time for surgery and because of loss of control of the airway system in the first 3 minutes following the cessation of respiration.

The novel catheter of the present invention can be inserted prophylactically and automatically take over ventilation. Delay of over a few minutes with the other procedures causes irreversible brain damage.

In the use of chronic ventilation at the present time, two methods are employed, either with the large tube through the nose or mouth into the windpipe with the sealing balloon inflated, or the operation on the neck, placing the large tube into the windpipe and having the balloon inflated. With most of the present machines, the balloon must usually be inflated because the ventilation will not work properly with an air leak. Many modifications have been made of the large tube and balloon portion, but all exhibit a constant or almost constant pressure which causes erosions and destruction of tissue in that location, and this leads to scarring and narrowing in the subsequent weeks.

GENERAL STATEMENT OF THE INVENTHON The novel method and equipment are devised for immediate control of ventilation, eg in less than seconds. A catheter means can be inserted by any trained doctor, nurse, or technician in a safe, secure fashion. This consists of placing a very small plastic tube of 0.5 to 2.0 millimeters in diameter through the skin into the windpipe; and by use of high pressures through this new ventilating machine, which forces large volumes of oxygenated gas cyclically through the catheter, one can assist or control the ventilation of a person. The pressure used is from 40 to psi. This tube is formed around along needle. The needle is inserted into the windpipe and, when the position is known by withdrawing air through it, the catheter outer unit is advanced into the windpipe and the needle is removed. The relative position of the catheter to the windpipe is secured and checked by the return of air and the machine unit is attached. The specific arrangement of catheter and needle is partially disclosed in the parent co-pending application, Ser. No. 59,206, now Pat. No. 3,682,166.

Through the use of a triple lumen catheter (one larger proximal lumen and two smaller distal lumens), inserted through a break-away trochar, the machine can be controlled by the patient or it can control the patients respiration and continually monitors the distal intrapulmonic pressure, through the alternate cycled use of the distal smaller double lumen component. The larger proximal catheter forces in the oxygenated gas while one of the smaller catheters is cleansed of nearby mucus by gas flow through it, and the alternately cycled smaller distal catheter transmits the distal intrapulmonic tracheal pressure to the machine.

Through the use of this new ventilating machine and tiny catheter unit, the catheter being approximately one-half to 2 millimeters in diameter, a person can be ventilated immediately with oxygen, air, or anesthetic gases, and even in the presence of a leak coming out of the mouth, adequate and even over-adequate ventilation is always achieved. This is a safe and secure procedure. The equipment can control or assist a persons breathing, does not cause pressure destruction of the inside of the trachea by constantly inflated balloons, and does not leave any scars on the neck following its removal. The novel equipment can also be used in the presence of injury to the face or of congenital deformities. in newborns and children, the catheter means can be inserted through the mouth into the windpipe and secured against the lip without causing any pressure damage inside the windpipe.

The machine includes a ventilation and a pressure monitor which can take over and breathe for the patient when the respiration stops or becomes ineffective, and also sounds an alarm. By the use of one valve, the machine performs either as a volume-type respirator or a pressure-type respirator, depending upon the disease and patient requirement. in each of these modes it will function in the control or assist mode, has sigh control, and provides positive expiratory pressure, together with the alarm circuitry to alert attending personnel. At any point, the ventilating device can be operated manually. This machine delivers percent humidification, warms the breathing gases, and functions as a nebulizer.

A main object of this invention is to provide a ventilating arrangement to be used with the ventilating machine disclosed in my above-mentioned co-pending applications, Ser. No. 59,206, filed July 2.9, 1970, now Pat. No. 3,682,166, and Ser. No. 162,944, filed July 15, 1971, or with other similar ventilating machines, whereby various modes of ventilation, such as pressure mode, volume mode, etc., are provided.

A further object is to provide the above modes of operation with means to select the desired mode quickly, either by manual means or by automatic means, and to provide further pressure-responsive means whereby the operations are assisted and controlled by pressure variation in the patients thoracic intrapulmonic regions, these further means being controlled manually by personnel or automatically by mechanical program means.

A further object is to provide a machine capable of working with an internal pressure of up to 80 psi and capable of delivering oxygenated gas to specially designed, narro lumen catheters up to the above high pressure.

A further object is to provide a machine capable of alternating flow of gases and pressure sensing functions to tiny distal catheters while the main flow is through a small proximal catheter.

A further object is to provide a means whereby the narrow lumen catheters may be inserted percutaneously into the trachea either over an inner hollow trochar guide (single lumen) or through a hollow splitaway trochar guide for the triple lumen catheter.

A further object is to provide for the following modes of ventilation operations and means to select any of them:

operation in the volume mode operation in the volume mode control cycle operation in the colume mode assist cycle respiration monitor, alarm, and ventilation take-over in the volume assist or volume control mode volume mode low positive expiratory pressure volume mode assist or control sigh cycle manually controlled ventilation, humidification pressure mode operation pressure mode assist cycle with sigh control pressure mode control cycle with sigh control pressure mode low positive expiratory pressure A further object is to provide an efficient, disposable and easily connectable nebulizing means for the novel ventilating arrangement.

Further objects and advantages of this invention will be apparent from the following description and accompanying drawings in which:

FIG. 1 is a schematic view of the resuscitating or ventilating apparatus described in my co-penidng application, Ser. No. 162,944, filed July 15, 1971, with some additions thereto for illustrating how the novel arrangement cooperates therewith;

FIG. 2 illustrates the alternate positions of the inflate and deflate valves;

FIG. 3 is a schematic and diagrammatic illustration of the novel ventilating machine which is connected to the ventilating apparatus of FIG. 1, for obtaining selectively the various volume or pressure operations under manual or patient assist control with the valves set in position for volume-type ventilation;

FIG. 4 is a portion of FIG. 3, but illustrates the several valves and other ports shifted to positions opposite from their positions shown in FIG. 3 for carrying out pressure type ventilation;

FIG. 5 is a cross-section through the nebulizer;

FIG. 6 shows the single lumen patient adaptor means with inner needle-trochar member and attached syringe;

FIG. 7 shows a cross-sectional view through the skin anchoring flange level;

FIG. 8 shows the patient adaptor means assuming its pre-molded curve, within the trachea, after the needletrochar member has been removed;

FIG. 9 shows the distal half of the single lumen patient adaptor means with proximal partial tracheal obstructing balloon transiently inflated during its pressurized gas conducting cycle;

FIG. 10 is a cross-sectional view through the single lumen patient adaptor means and partial tracheal obstructing balloon at the catheter wedge gas inlet to the balloon chamber;

FIGS. 11A and 118 show the triple lumen patient adaptor means passing through the break-away trochar, following removal of inner needle guide and attached syringe;

FIG. 12 is a cross-sectional view through the triple lumen patient adaptor means at the proximal partial tracheal obstructing balloon level and gas inlet wedge passing through blunt split sided trochar;

FIGS. 13A and 133 show the triple lumen patient adaptor means assuming its proximal pre-molded curve after insertion through the skin into the trachea and removal of the break-away trochar member;

FIG. 14 shows one of the catheters of the longer double lumen pair serving as the minor pressurized gas conducting and self-cleansing lumen with its corresponding distal catheter serving as the pressure conducting catheter, and the proximal partial obstructing tracheal balloon transiently inflated;

FIG. 15 is a cross-sectional view of the triple lumen patient adaptor means of FIG. 14 at the level of the proximal partial obstructing tracheal balloon and wedge gas inlet site showing the transient inflation of the balloon;

FIG. 16 shows the alternate distal catheter of the double lumen distal pair serving as the minor pressurized gas conducting and self-cleansing lumen with its corresponding distal member serving as the pressure conducting catheter, and shows the proximal partial obstructing tracheal balloon transiently inflated;

FIG. 17 shows the proximal portion of the single lumen orally inserted patient adaptor means with its multi-level anchoring and compression withstanding ridges, and distal gas jet diffusing member plus cross section of the proximal portion at level of a compression withstanding and anchoring ridge;

FIG. 18 shows the proximal portion of the triple lumen orally inserted patient adaptor means with its multi-level anchoring and compression, and gas jet diffusing member attached to the main inflating lumen, plus cross section of the proximal portion at the level of a compression withstanding and anchoring ridge;

FIG. 19 shows a thin distal pressure sensing transducer in conjunction with the single lumen patient adaptor means, passing through said patient adaptor means and relaying distal intrapulmonic pressure values to its attached controlling ventilating means.

The basic cyclic ventilating apparatus and the humidifying means, illustrated in FIG. 1 and FIG. 2, will be sufficiently described herebelow so that their cooperation with the novel, additional volume and pressure ventilating means is clearly disclosed. For further disclosure of the details of construction and applications of the basic ventilating and humidifying systems, reference may be had to the above-mentioned parent applications, Ser. Nos. 59,206, new Pat. No. 3,682,166 and 162,944.

The system comprises a source of gas under high pressure (40-80 psi) 15. This source may be compressed air, pure oxygen, or air fortified with a higher percentage of oxygen than normal atmospheric air. The source is connected by conduit means 16 and 16' to a sputum trap 17. From sputum trap 17, a conduit means 18 extends to the catheter inserted into the trachea of the patient.

Conduit means 16-16 has a series of three- way valves 21, 22 and 23 inserted therein. Valve 21 has a handle means 24 to move it to a selected position. While valves 22 and 23 are shown diagrammatically as two separate plug means, their passages may be incorporated in a single plug valve device at axially spaced planes. To illustrate the unitary operation of valves 22 and 23, a handle 25 is provided for each valve, the handle being connected for joint movement by a connecting link means 26. Valves 22 and 23 rotate in opposite 90 directions.

Suction or vacuum source 27 has conduits 28 and 29 extending therefrom with conduit 29 connected to deflate valve means 30, and conduit 28 connected to valve 21.

A two-way valve means 31 is located between conduits l6 and 16' and functions as an inflate valve. For illustrative purposes, valves 30 and 31 are shown as separate valves. However, they work in unison by connecting means 32 which connects them to reduction gear drive 33.

It is preferable that the outlet ports 34A of the several passages 34 in valves 30 and 31 be of a tapered configuration. Outlet port 34A is elongated in the direction of valve movement and may be of elliptical or diamond configuration whereby the flow from the valve to the conduits connected thereto is gradually initiated and gradually cut off. The duration of time of fluid flow may be regulated by the length of the longer axis of the port configuration.

Reduction gear device is driven by fluid motor 35, connected by conduit 36 to conduit 16 and thus to source 15. The speed of motor 35 is regulated by an adjustable throttle valve means 37 inserted in line 36, which valve is diagrammatically illustrated as an adjustable choke valve.

A three-way valve 40 is connected by conduit 41 to valve 30 and by conduit 41 to valve 31. The function of valve 40 is to control the ratio of inflation pulses or phases to deflation phases during a revolution of valves 30-31. It may be termed an inflation and deflation phase control valve. A conduit 42 connects valve 30 to conduit 16'. Abranch conduit 43 connects conduit 42 to valve 40. A conduit 45 connects valves 22 and 23.

To control the rate of flow of the oxygenated gas in accordance with the age and size of the patient, throttle or choke valve 47 is inserted in line 16 upstream of valve 31, and a similar valve 47A is inserted in conduit 45. Valve 47 controls the rate of flow when the system operates automatically. Valve 47a controls the rate of flow during manual control of ventilation. The rate of flow of deflation gas from the patient may be controlled by throttle valve 48 inserted in suction line 29.

FIG. 1 illustrates the positions of the several valves in the system for automatic operation of the ventilating system. Air under suitable pressure flows from source 15 through conduits 16 and 16' and through the connecting passages in valves 21, 22, 31 and 23 to the sputum trap and, from there by conduit means 18, to the catheter. Thus, air with the proper selected percentage of oxygen flows to the patient at a rate controlled by throttle valve 47.

At this phase of the cycle; valve 30 cuts off the several connecting conduits and valve 40 from suction conduit 29.

Valve means 31 and 30 are continuously rotated in the direction of the arrows 49 at the proper desired speed by air motor 35. Assuming the setting of the valves in FIG. 1 to be 0, at 90 of rotation valve 31 blocks flow from conduit 16 to conduit 16, and valve 30 connects suction source 27 and conduit 29 to conduit 41 and, through valve 40, to conduits 43, 42 and 16', and thereby the catheter is connected to the suction source whereby deflation or exhalation of the patient is aided. At 180 of rotation, valve 31 still blocks the air flow to conduit 16, and valve 30 connects conduit 42 to conduit 29 and, therethrough, to suction source 27. At 270 of rotation, valve 31 still blocks flow to conduit 16 and valve 30 still connects conduit 42 to conduit 29. At 360 of rotation, valves 30 and 31 again assume the positions of FIG. 1 and air is again delivered to the patient to aid in the inhalation phase of breath- Thus, a single cycle or rotation of valve 30 and 31 results in one inflation and three deflation phases. Under certain conditions, it may be desirable to have the same extent of inflation and deflation. Inflation and deflation phase control valve 40 effects this last-named operation. If valve 40 is moved by its handle 50 to the position illustrated in FIG. 2, the following connections occur during a single cycle or rotation of valve means 30 and 31:

at 0, valve 31 connects conduits 16 and 16' and suction conduit 29 is cut off from all connection by valve 30;

at 90 of rotation in the direction of arrows 49, valve 31 disconnects conduits 16 and 16' and connects conduits 16 and 41, and, through the passages in valve 40, conduits 41', 43, 42 and 16 are interconnected for a second inflation phase, while deflation (suction) is blocked;

at 180 of rotation, conduit 16 is cut off from the other conduits by valve 31, and suction conduit 29 is connected by valve 30 to conduits 42, 16, and 18 to the catheter for the deflation phase;

at 270 of rotation, valve 31 still cuts off flow from conduit 16 and valve 30 connects conduits 29, 42 and 16' for a second deflation phase;

at 360 of rotation, the valves assume the positions illustrated in FIG. 2, e.g. the 0 position, in which an inflation phase is initiated.

Thus, with valve 40 in the position of FIG. 2, there are two inflation and two deflation phases during a cycle or a revolution of the valve means 30 and 31.

Under certain conditions, the patient cannot be subject to the automatic inflation and deflation, and the operator must manipulate the inflation and deflation phases in accordance with the abnormal conditions in the patient. Valves 22 and 23 are shifted by means of their handles from their positions of FIG. 1 to their opposite positions. Valves 30, 31 and 40 are by-passed, and at the same time, flow to motor 35 is shut off by valve 22. Thus, valves 22 and 23 interconnect conduit 16 to 16' at sputum trap 17 by means of conduit 45 which by-passes the valve means 30, 31 and 40 and their interconnected conduits.

Valve 21 is then manipulated by the operator from one position to another by handle 24. The position shown in solid lines is the inflate position wherein oxygenated pressure gas, regulated by throttle valve 47A, flows from source to conduits 16, 45, 16', 18 to the catheter. When deflation is desired, valve 21 is moved counter clockwise 90 to the dotted line positions of handle 24. In this deflate position, suction source 27 is connected by the valve means to conduits 16, 45, 16', 18 and the catheter. The duration of the inflation and deflation phases will be regulated by the operator in accordance with the requirements of the patient who is under his visual observation.

The humidifying means comprises a tank 60, preferably made of stainless steel or other material which may be subjected to sterilization and can withstand high internal pressure. The tank has a high pressure gas input pipe 61 which is secured by a conventional, quickacting, detachable coupling means 62 to high pressure pipe 63. Pipe 63 is connected to conduit 16 upstream of throttle valve 47. A throttle valve 64 is inserted in pipe 63 for controlling the rate of flow of humidifying gas and also for shutting off the flow through the pipe. A pipe connected to a suitable water supply is joined to pipe 63 upstream of coupling means 62. A check valve 67, opening toward tank 60, is inserted in pipe 65. For controlling the temperature and the degree of vapor saturation of the humidified breathing mixture, an electric heater means 68 is provided and is controlled by adjustable thermostat 69, whereby any desired temperature may be selected.

Tank 60 may be provided with a transparent sight tube 71, whereby the water level may be visually observed. A drainage valve 72 for emptying the tank whenever desired is inserted at the bottom of tank 60.

A tank outlet pipe 73 is secured to the top of tank 60. Pipe 73 may have a heat exchange means therein in the form of a heavy metal tube 74 to condense any excess water vapor which will drain back to the tank. Pipe 73 may have a finned portion in lieu of tube 74 to act as a heat exchanger to permit the outside air to cool and condense any excess water vapor generated in the tank.

Outlet pipe 73 is connected by a conventional, quickly detachable coupling means 75 to pipe 77, connected to pipe 16 between throttle valve 47 and valve 31, preferably close to valve 3l. A check valve 78, opening toward conduit 16, is inserted in pipe 77. Pipe 77 terminates in a shut-off valve 79, whereby pipe 77 may be closed to drain outlet 80 or be opened thereto. An optional throttle valve 82 may be inserted in pipe 77 to control the flow of humidified gas and may be used in conjunction with throttle valve 64 in line 63.

A gas disperser 83 may be connected to the open end of tube 61, whereby the gas is dispersed into numerous paths to increase the bubbling effect. Disperser 83 may be in the form of a hollow cylindrical body having numerous parts in its cylindrical wall, or it may assume any other well-known structure for breaking up a flow of fluid into numerous paths as, for example, a porous body, perforations in the walls of inlet tube 61, or any other similar structure.

In order to insure that the bubbling gas picks up only atomized or vaporized water particles, a baffle means comprising spaced perforated plates 85 is placed above the water level. Unduly large droplets or particles of water would impact against the plates and would not be carried along by the gas stream to outlet pipe 73.

The application of the humidifying system is initiated when application of the ventilating system is initiated, assuming throttle valve 64 is set to permit the desired flow of gas to tank 60, and the tank is partly filled with water, as illustrated in FIG. 1. Check valve 67 is closed under the pressure of the gas flowing in pipe 63. The gas flows through the open ends of inlet pipe 61 and through the gas dispersion unit 83 close to the bottom of tank 60 and bubbles through the preperly heated water. The fine bubbling causes atomization and vaporization of the water, and the outgoing gas at outlet pipe 73 is saturated with water moisture. Massive bubbling and very large water particles are blocked and returned to the water by baffle means 83. Excess moisture is condensed by passing through cooling means 74. The humidified gas then passes through pipe 77 and joins the gas flowing to the inflating valve 31.

The amount of moisture may be controlled by regulating the flow of gas in pipe 63 by throttle valve 31.

To replenish the water in tank 60, valve 64 is closed to sotp the flow of gas in pipe 63 and valve 79 is actuated to connect pipe 77 to the drain 80. Shut-off valve 86 in pipe 65 is opened and, under such pressure conditions, water flows through pipe 65 and check valve 67 into pipes 63 and 61 and the tank 60. The water level may be observed through sight tube 71, and when it reaches the desired height, valve 79 is turned to disconnect pipes 73 and 77 from the drain 80. This action stops the flow of water, and valve 83 in pipe 65 is closed to secure this inflow. By opening and regulating valve 64, the flow through pipe 63 is again resumed and humidified gas flows to valve 31.

If sterilization of tank 60 is desired, it may be quickly disconnected from pipes 63 and 77 by means of quickacting coupling means 62 and 75. Although the ventilation otherwise proceeds normally, in this instance humidification is absent. Thermostat 69 may be detachably plugged into the heater means.

Check valve 67 may be eliminated and check valve 77 may be replaced by a normally shut-off valve similar to valve 86. Thus, in replenishing tank 60, valves 86 and 79 would be opened to permit water to flow into the tank and the shut-off valve replacing valve 77 would be closed.

The above disclosed apparatus arrangement is sufficient in cases where a single lumen catheter is used in controlled volume mode ventilation. In many instances, it is necessary to utilize a triple lumen catheter 101 because it is desired to monitor the patients pressure condition and to assist as well as control ventilation. In such instances, the proximal lumen serves as the gas breathing mixture and suction conduit while the distal lumens are alternately connected to pressure sensors and similar devices and to the pressurized gas to cleanse the lumen and prevent blockage.

In order to cover various conditions which may occur in the patient, the invention provides for optional choices of volume control of the breathing gas or pressure control. In addition, manual control of inflation and deflation cycles and choice of degree and flow of inflating and deflating gas pressure are also provided. Further patient assist modes of breathing control are also provided.

Catheter 101 is a three-lumen catheter with a larger proximal and smaller double lumen distal portion, all

having the staggered side openings, being formed with end lumens 102 and 103 in catheter conduits 104 and 105 and larger proximal catheter 105A with lumen 1058. While any triple lumen catheter may be used, or even three separate closely spaced single catheters may be used, it is contemplated that the improved triple lumen catheter disclosed herebelow will be used for the reasons and advantages set forth in this application.

The flow of breathing gas to the catheters is controlled bya conventional three-way valve 107 inserted in conduit 16 upstream of valve 23. Valve 107 may be termed the pressure or volume mode selector valve. In the volume mode, conduit 110 connects valve 109 to valves 111 and 112. Valve 111 is connected to conduits 113 and 114, which are connected to conduit 115, and is also connected to conduit 116. Valve 112 is connected to conduits 118 and 119, which are connected to conduit 120, and is also connected to conduit 121. Conduits 115 and 120 are connected to sputum traps 123 and 124, respectively, and therethrough to conduits and openings 105-103 and 104-102.

The main ventilating gas flow to the larger proximal catheter 105A goes via conduit 110A (prior to the connection of conduit 110 to valves 111 and 112). This flows on and off with each ventilation cycle while the distal smaller catheters alternate pressure sensing functions and minor pressurized gas conducting-cleansing functions.

In the volume mode, valves 111 and 112 are cyclically driven in the directions of the arrows, preferably by motor 35, through a schematically shown connecting means 125. If desired, valves 111 and 112 may be cyclically actuated by other means. While valves 111 and 112 are schematically disclosed as rotary valves, in actual use they may be any type, such as single plug or disc valves, piston valves, etc. It is obvious that it is within the skill of a worker in the art to design a valve means which would perform the functions of valve means 1 11-112.

Conduits 116 and 121 are connected to a three-way valve 126 by conduit 127. A conduit 129 connects valve 126 to a pressure sensor means 130 which, for disclosure purposes, is a pressure-responsive switch. Any other type of pressure-responsive means may be utilized to sense the variation of pressure in conduit 129 and actuate desired devices. For example, a piezoelectric means or similar means having electrical characteristics may be used to generate signals in accordance with pressure variations in pipe 129 and thereby control the various control means. In the drawing, the several switches of the invention are shown as blocks identified by PS for pressure switches responsive to very low or negative thoracic intrapulmonary pressure, and by +PS for the higher pressure existing at the end of an inflation phase or at a sigh state.

For volume mode assist cycle operation, it is desired that a certain volume of breathing gas be fed to the patient upon a predetermined fall in the patients intrapulmonary pressure. To carry out this function, a normally closed valve 132 is inserted in air motor supply line 36. The valve is controlled by a spring biased solenoid means 133 which is connected by means of cable or conductor 134 to pressure switch 130. Thus, valve 132 is maintained closed until solenoid 133 is energized by the various switch means and controls.

Valves 109 and 126 are interconnected for joint operation by a schematically illustrated connecting means 135. A switch 136 is inserted in cable 134 and is connected to means 135. The arrangement is such that, when valve 109 is in its volume mode position (FIG. 3), valve 126 is also in its volume mode position and switch 136 is closed. When valve 109 is actuated to pressure mode position (FIG. 4), valve 129 is also shifted and switch 136 is open, thus maintaining sole noid 133 in its de-energized state, keeping valve 132 closed and motor unit 35 inoperative in the pressure mode.

In the pressure mode, a conduit connects pressure source 15 at conduit 77-16 tosupply humidified gas to the patient, to branches 139, each branch having an adjustable throttle valve 140 therein to regulate the rate of flow. If desired, an adjustable reducing or constant pressure maintaining valve 141 may be inserted in line 138, whereby the pressure of the breathing mixture may be varied to suit the conditions of the patient. A conventional selector valve 142 connects either branch 139 to conduit 143 which is connected to valve 109.

The pressure mode circuit comprises conduit 146, connecting valve 109 and two-way valve 147. Valve 147 is connected by conduit 149 to valves 150 and 151. Valve 150 is connected to conduit 115 and therethrough to lumen 105 and openings 103 in catheter 101. Valve 151 is connected by conduits 156 and 157 to conduit 158 which is connected to conduit 120 and therethrough to lumen 104 and opening 102 of catheter 101.

The above arrangement to the distal pair of catheters alternates them in their pressure sensing functions and minor pressurized gas conducting-cleansing functions. The main gas flow is to the proximal catheter 105A. This flow is through conduit 149A connecting conduit 149, between valves -173 and valves -151, to main catheter 105A.

Valves 150 and 151 are connected by conduits 160 and 161 to valve 126. Valves 150 and 151 are interconnected by connecting means, such as shaft 162, for joint operation. It is obvious that valves 150 and 151 may be replaced by a single valve device designed to make the several conduit interconnections now made by the valves. Means 162 is actuated by a four-lobed ratchet means 163 connected to shaft 162. Means 163 is actuated in steps of 90 by a device which may be an electric solenoid or a pressure fluid actuator. Preferably, the device comprises a spring biased pawl-like plunger 164 which rotates ratchet 163 90 each time the solenoid 165 is energized, and thus moves valves 150 and 151 from their positions of FIG. 3 to their opposite positions of FIG. 4.

Valve 147 is actuated to its open or closed position preferably by an electric means. The means may comprise a solenoid having a closing coil and an opening coil 171.. A conduit 172 bypasses valve 147 and has therein an on-off valve 173. Valve 173 is set at 90 to valve 147 and is connected to rotate with valve 147. An adjustable throttle valve 174 is inserted in bypass 172 upstream of valve 173.

In order to actuate the various valves in the several contemplated modes of operation, including the assist mode, that is, aiding the patient in his breathing, a network of switches, or similar means, is provided, which switches are responsive to the level of the pressures in the patients body at the locations wherein catheter 101 is inserted. A conductor 175 connects solenoid 165 to a pressure sensitive switch 176 connected to pressure line 129. Switch 176 closes to energize solenoid 165 upon a predetermined low pressure in line 129.

An adjustable pressure switch 178 is connected to line 129, this switch being responsive to a predetermined low pressure which may be negative. An adjustable pressure switch 179, responsive to a predetermined higher pressure than switch 178, and an adjustable pressure switch 180, responsive to an upper limit pressure, or sigh, which is higher than that to which 179 is responsive, are connected to line 129. A pressure responsive or alarm switch 182 is connected to line 129 and, upon a predetermined low pressure, which signities that in the patients spontaneous breathing function each respiration is adequate, plus predetermined high pressure which means that the ventilating machine is working, closes and energizes an adjustable delay relay 183. However, if the spontaneous low or machine assisted or controlled high positive pressures are not reached after a given time interval, the delay relay 183 de-energizes and its contacts energizes an alarm device 184. Alarm 184 may be of any design and it functions to give an audible or visual signal to the attending personnel that the patients breathing or ventilating machine is failing or has failed. Alarm 184 also functions to energize other devices and conductors, such as conductor 187 which is connected to a timer and selector device 186. A second conductor 188 connects device 186 to conductor 175. The operation of device 186 is described further on.

Switch 178 is connected by conductor 190 to coil 171. Switch 179 is connected by a conductor 19] to a timer and selector device 192. Switch 180 is also connected to device 192 by a conductor 194. Device 192 is connected by a conductor 195 to coil 170.

Device 192 is a timing device which can be set so that it interconnects either conductor 191 and switch 179 or conductor 194 and switch 180 to conductor 195 and thus move valve 147 to its closed position. The timing cycles may be adjusted to vary the selected number of interconnections per hour and further adjusted so that the time intervals wherein either switches 179 or 180 are connected to coil 170 may be varied.

Any resettable commercial timer may be used, but certain timers are preferred; namely, the timer available from Coulter Electronics, Hialeah, Florida under Crawford U.S.P. 3,187,319, the alarm-triggering apparatus of Soltau U.S.P. 3,383,674, the timer from Arvin Industries of Columbus, Ohio under Davisson U.S.P. 3,559,072, and the Bowes Engineering Fluidic Timer Model [-101 from the Bowes Engineering Company, Silver Spring, Maryland. The all-purpose timer of Dimco-Gray Company may also be used or an adjustable clock-timer which is motor operated may be used.

Device 186 is also a timed selector which may be adjusted to connect energized conductor 187 to a conductor 197, which is connected to conductor 190, a certain number of times per minute and for a definite time interval. Thus, device 186 connects energized alarm 184 a definite number of times per minute to coil 171 to open valve 147. At the same time, device 186 also connects energized conductor 187 to conductor 188 and therethrough to conductor 175 and solenoid 165. Device 186 may also be manually activated to thythmically control respiration by energization and de-energization of coils 171-170 to operate valve 147-173, and solenoid 165-163 to operate valves 150-151.

This invention is further provided with means for sigh respiration which is the periodic deeper respiration normally performed by a breathing individual, a moderate number of times per hour. This is controlled by timer selector 192 periodically (pre-set 0 to per hour) choosing the higher pressure valve 180 (rather than high pressure valve 179) to close valve 147 through 195-170, and therefore build up higher pressure and therefore a deeper inhalation cycle.

In the volume mode, an adjustable flow responsive device 200 is inserted in line 110. Device 200 may assume any well-known flowmeter form, but is is illustrated schematically as comprising a pivoted vane 201 in a casing and biased by an adjustable spring 202 to a neutral position. Flow of fluid in pipe impinges on the vane to move it to close a normally open switch 204 which is connected by conductor 205 to conductor 134. When no or adjustable low flow is present in pipe 110, spring 202 moves vane 201 to a neutral position wherein it engages a normally closed switch 206 to open it, that is, switch 206 is closed when flow takes place within pipe 110 and the vane is in contact with switch 204.

Thus, switch 204 is actuated to closed position by a predetermined amount of breathing gas flowing within conduit 1 10 and is opened upon no flow or upon an adjustable minimum flow in conduit 110.

A timer and switching selector device 210 is inserted in cable or conductor 134. A relatively high pressure switch 211 connected to line 129 is connected to conductor 134 by conductor 212. A manually operated override switch 214 to hold valve 132 open is connected to conductor 134 by conductor 215 in parallel with switches and 204.

Device 210, shown schematically, comprises a wiper arm 217 connected to one side of conductor 134 and driven by an adjustable timer motor 218 whereby arm 217 may rotate from, say, one to one hundred revolutions per hour. The other side of conductor 134'is connected to an adjustable segmental contact 219 which may comprise two relatively movable segments 220 and 221, whereby the interrupted portion or space 223 between the opposed ends of contact 219 may be varied. The opposed ends of contact 219 forming space 223 may be interconnected by a magnetic relay switch comprising solenoid 225 and contact 226 controlled by flowmeter switch 206 through conductor 207. When 206 is closed, that is, when fluid is flowing in line 110, the solenoid 225 is energized and contact 226 is pulled up to open space 223. Thus, as wiper 217 moves across contact 219, current in conductor 134 flows to solenoid 133 to keep valve 132 open. When wiper 217 moves across space 223, the circuit is opened and valve 132 closes only when there is fluid flowing in conduit 110. However, when no flow takes place in conduit 110, switch 206 is opened by vane 201, solenoid 225 is de-energized, and contact 226 is actuated by gravity or by a spring means to contact and bridge the opposed This sequence for the volume mode sigh operation can also be performed by electronic means such as bias control von the grid of a vacuum tube or solid state conductor, by one skilled in the art without changing its basic function.

An automatically resettable relay 227 reset by 183 is connected to delay relay 183 by conductor 229 whereby 227 is in parallel with alarm 184. Relay 227 may also be manually operated. Relay 227 is connected by conductor 230 to conductor 134. Thus if the patient fails to breathe or does not breathe deeply enough, pressure switch 182 does not re-energize delay relay 183 within the adjustable delay time and it (183) then energizes the alarm 184 plus relay 227. Relay 227 if placed in the automatic emergency assist mode only ventilates one time because pressure switch 182 will then be re-energized and reset relay 227 open again. If, however, relay 227 is placed in the emergency control mode, then only a manual reset will turn it ofi. Relay 227, when energized maintains solenoid 133 energized through conductors 230-134 and switch 136. When energized, solenoid 133 holds valve 132 open so that motor 35 continues its cyclical motion of valves 30-31.

At times it is desired to use a slight positive pressure during the exhalation phase, in lieu of suction, in the volume mode. To accomplish this operation, a threeway valve 236 (FIG. 1) is inserted in suction conduit 29, and a conduit 237 connects the valve to pressure conduit 16. A conventional, adjustable pressure-flow regulator 238 is inserted in conduit 237. By adjusting regulator 238, the pressure of the fluid in conduit 237 may be reduced and maintained constant at any desired pressure. A flowmeter or pressure gauge 239 may be inserted in line 237 to facilitate the adjustment of the desired degree of flow or pressure in line 237. By moving the handle of valve 236 from the solid line position to the dotted line position, valve 236 cuts off the suction source 27 from that portion of conduit 29 downstream of the valve and connects the portion to conduit 237 and pressure regulating valve 238.

Thus, the deflating fluid going to valve 30, under certain conditions, will be under selected degrees of low positive pressure.

At time it is desired to connect a lumen 10513 of catheter 101 directly to source 16. To accomplish this, a conduit 240 (FIGS. 1 and 3) is connected to source 16 and to a valve 231 in conduit 105C before the sputum trap 124A. A normally closed shut-off valve 241 connected to valve 231 by connecting means 232, and an adjustable throttle valve 242, is inserted in pipe 240. When circumstances so require, valve 241 is opened and valve 231, via connecting means 232 is moved to the position in FIG. 4 connecting conduit 240 to means 105C, 124A and to catheter 105A and lumen 105B. Breathing gas flows from source 16 directly to lumen 1058 at the rate determined by manual controlling valve 242. Pressure gauges 245 are inserted in the several pipes wherever pressure readings are desired. Volume Mode Operation For the volume mode operation, valve 107 is placed in the position of FIG. 3 wherein the single lumen catheter 100 is cut off from conduit 16. In this position, conduits 16' and 108 are interconnected. Interconnected valves 109 and 126 are placed in their positions of FIG. 3 by their interconnection 135 and switch 136 is closed to connect pressure switch 130 to solenoid 133. Valves 1 1 1 and 1 12 are rotated in the direction of the arrows by their operative connection 125 to the shaft driven by motor 35. In the valve positions of FIG. 3, the ventilating valves 30 and 31 are connected by conduit 16', valve 107, conduit 108, valve 109, conduit 1 10 with its associated flowmeter 200 and switch units, conduit 110A catheter A, valve 111, conduits 113 and 1 15, sputum trap 123 to catheter 105 and its opening 103. Thus, catheter lumen 105A forms the main ventilating path and catheter 105 acts as the minor ventilating and self cleansing path. Catheter lumen 104 acts as the pressure monitor line in view of its connection by means 124, 120, 118, valve 112, 121, 127, valve 126 and to the several pressure switches connected to line 129. When valves 111 and 112 are rotated to the position of FIG. 4, catheter lumen 104 becomes the minor ventilating and self-cleansing path in view of its connection to conduit by means 124, 120, 119, valve 112, conduit 110; conduit 110 catheter 105A again becomes the main ventilating path; and catheter lumen 105 becomes the pressure sensing line in view of its connection to conduit 129 by means 123, 115, 114, valve 111, 116, 127, valve 126, conduit 129. The alternate use of the lumens 104 and 105 as minor ventilating self-cleansing and pressure monitor conduit means is of great advantage because the alternate flow of ventilating fluid in the lumens keeps the lumens empty of mucous and other secretions which tend to enter the catheter openings and plug the lumens.

Thus, pressure sensing conduit 129 is always in free communication with the pressure conditions existing in the thoracic intra-pulmonic portion of the body as measured in the tracheo-bronchial tree.

Volume Mode Control Operation In the volume mode control cycle, ventilation of the patient is completely controlled and determined by the ventilator actions of valves 30 and 31. Pressure switch 130 is bypassed by the manual energization of switch 214. It should be noted that device 210 still supplies a sigh by periodically stopping motor 35 during the flow period in pipe 110 up to the pressure allowed by high pressure switch 211. Solenoid 133 is thus de-energized periodically when there is flow in pipe 110 and arm 217 traverses space 223 and valve 132 is periodically closed to stop flow to motor 35 to hold valves 30 and 31 open until the sigh pressure is reached in the patient. Volume Mode Assist Cycle In this operation, the patient assists in and controls the triggering of the ventilating cycles. Override switch 214 is in its open position. Low pressure switch 130 senses the predetermined low or negative pressure (whenever the patient initiates a breath) for which it is set and closes to energize conductor 134 and solenoid 133 to open valve 132. As before, flow from conduit 16' passes alternately through valves 111 and 112 and thereby alternately to lumens 104 and 105, whereby each lumen serves alternately as a pressure monitor and minor gas-conducting cleansing function. The main gas flow is through 110-110A-105C to catheter 105A. When flow occurs in pipe 110, switch 204 and switch 206 are closed. Switch 204 through conductor 205 to 134 then energizes solenoid 133 to keep valve 132 open and the motor turning. 204 supplies the only energy to 133 because pressure switch 130 is now open because of higher intra-pulmonary pressure present with maximum flow through 110 and lumen 105. Motor 35 keeps valves 30 and 31 turning until flow ceases. Whe inflate valve 31 closes, flow in pipe 110 ceases, vane 210 returns to neutral and switch 204 opens, switch 130 having opened when lung inflation has reached the pressure above the predetermined low pressure. When switches 204 and 130 open, solenoid 133 is de-energized, valve 132 closes and motor 35 stops, thus ending the inflation cycle. When the patient again initiates another breathing cycle, switch 130 responds to the low pressure to energize solenoid 133 and reopen valve 132 to start ventilator motor 35. It should be noted that when no flow occurs in pipe 110, switch 206 is held open by vane 210 and contact 226 bridges space 223 of device 210 so that the circuit through conductor 134 is complete at that time. Volume Mode Control Cycle In the volume mode control cycle, the machine ventilates the patient irrespective of his efforts or lack of efforts at respiration. The override control switch 214 is manually turned on and via conductor 215 and 134 continually (except for the optional and adjustable periodic sigh cycle) energizes solenoid 133 to keep valve 132 open thus continually having motor 35 rotate inflate-deflate valves 31-30 at the rate set by throttle valve 37 and at the flow rate by throttle valve 47 in conduit 16. Respiration Monitor, Alarm and Ventilation Take Over in Volume Assist or Volume Control Mode However, when there is very weak or no breathing, alarm pressure switch 182, which is adjustably set to close below the minimally acceptable pressure in line 129, remains open and therefore delay relay 183 deenergizes after a predetermined time interval, if the negative pressure in pipe 129 still has not been reached, and closes its contacts and causes the actuation of alarm device 184. Device 184 actuates a bell, light or similar device to call attention. At the same time, delay relay 183 also energizes self and manually resettable relay 227 to close and thereby energizes conductor 230 leading to conductor 134. The result is that solenoid 133 is energized, valve 132 is opened to drive motor 35 and initiate ventilation by valves 30 and 31. If the resettable relay 227 was placed in automatic mode then it must be manually reset to stop the automatic ventilating continuous cycling. However, if it was placed in the assist mode, then with that cycle, low-high pressure alarm switch 182 is actuated, energizes delay relay 183 and it resets 227. Volume Mode Low Positive Expiratory Pressure This provision is used both in the assist or control volume mode to help maintain the lungs at a partial inflation during the exhalation phase of respiration, under certain medical and physiological conditions, such as, pulmonary edema, hyaline membrane disease, shock lung, and lack of surfactant. This is achieved through valve 236 in suction conduit 29 when moved to dotted line position wherein the deflate valve 30 is connected to pressure conduit 16 through conduit 237 and adjustable pressure-flow regulator 238. Thus the deflate half of the respiratory cycle will act as a partial inflation by maintaining a lower adjustable flow through valve 30, conduit 16', valve 107, conduit 108, valve 109, conduit 110, the readjusted flowmeter and switch unit 200 for the new pressure conditions, through valve 111 and 112 and then to triple lumen catheter 101, and through conduit 110A, 105C to main catheter 105A of the triple lumen catheter 101. Volume Mode Assist or Control Sigh Cycle The volume mode sigh cycle operates mechanically and electrically the same in both the control or assist modes. Spring or gravity solenoid 225, when not energized, maintains contact 226 bridged across portion 223. However, with the onset of flow in 110 and through flowmeter 200, switch 206 is closed and through conductor 207 energizes 225 to retract 226 from space 223. When wiper 217 is within or crosses adjustable spaced open portion 223 (adjustable by movable segments 220 and 221 of segmental contact 219) energy through conductor 134 is interrupted. This de-energizes solenoid 133, closes valve 132, and stops the motor and inflate valve 31 in the maximal flow position (set by adjustable flowmeter unit 200). Maximal gas flow is maintained to the patient until either wiper 217 makes contact with 221 past the open portion 223 or until the higher sigh pressure is reached and adjustable sigh pressure switch 211 closes and remains closed until re-opened by low or negative adjustable pressure level sensed from 129. Switch 211, through conductor 212 bypassing 210 energizes line 134 and restarts the motor and moves valve 31 to stop flow to line 110. Only when wiper 217 is in open portion 223 with 225 energized can the sigh take place. Sigh motor 218 has an adjustable rate from 0-100 times per hour. However, switch 211 also acts as a safety during the assist cycle in that should flow responsive switch unit 204 fail to energize conductors 205 and 134 and thereby cause the closure of inflate valve 31 during the volume assist cycle, 211 will remain energized until re-set by a low or negative pressure from conduit 129 double lumen catheter 101.

Manually Controlled Ventilation (Bypass of Volume- Pressure Circuitry) When hand rate controlled ventilation is desired, interconnected valves 241(FlG. 1) and 231 are moved to connect pressurized gas source 16 through conduit 240 to conduit C and then to main gas flow lumen 105A of triple lumen catheter 101. In its shifted position, valve 231 disconnects conduit 149A A upstream therefrom from sputum trap 124A and connects conduit 105C downstream therefrom and sputum trap 124A to conduit 240. Then ventilation rate is set by the operator through valves 241-231 and the flow rate is adjusted by throttle valve 242. If desired, the humidifier circuit ( conduits 63, 77, and valve 47) may be inserted between the gas pressure source 15 and valve 21 to allow humidification to proceed even in the manual mode, without interfering with the suction provision. in that case, the motor 35 must be electric. However, a separate parallel conduit from the pressure source 15 to the air motor, controlled by the valve linked to 22 may be used, to allow humidification on all modes of operation.

Pressure Mode Operation in the pressure-mode operation, the mode selector valve 109 and valve 126 (through their connecting means are turned to their pressure positions illustrated in FIG. 4 wherein valve 126 connects conduits 160 and 129. Switch 136 is opened and valve 109 disconnects conduits 108 and 110. Flow from the source 15 through the humidifier line 77-16 reaches valve 109 through conduit means 138, 139 throttle valves 140, selector valve 142 and conduit 143. Valves 140 are adjusted to give two different rates of flow. Valve 142 connects either of branches 139 to conduit 143. If more different rates are desired, the numbers of branches and throttles therein, 139-140, may be increased. The flow from 143 passes through valve 109 into conduit 146, valve 147 (when open), conduit 149, ( conduit 149A, 105C to main gas catheter 105A), valve 150, conduits 153, 154, 115, sputum trap 123 and into lumen 105 and the patient.

Thus, the patient receives inflate pressure fluid. The other distal lumen 104 becomes the pressure monitor line in view of its connection to pressure sensing conduit 129 by means 124, 120, 158, 156, valve 151, 161, 160 and valve 126. i

As discussed previously and below, valves 150 and 151 alternate minor gas pressure conduction and intrapulmonary pressure sensing conduction to and from catheter lumens 105 and 104, respectively, while the main gas flow is through conduit 149, 149A, valve 231, conduit 105C to main proximal catheter 105A with its lumen 1053.

Pressure Mode Assist Cycle and Sigh Control At a predetermined low or negative pressure (patients inspiratory breathing effort) in line 129, switch 176 is closed whereby conductor 175 and solenoid 165 are energized to cause a forward movement of pawl 164 to advance interconnected valves 150 and 151 90 -to the positions of FIG. 4. At the same time, low pressure switch 178 is also actuated to closed position to energize conductor 190 and coil 171 to move valve 147 to open position of FIG. 4. In these valve positions (FIG. 4) flow takes place through conduit 146, valve 147, conduit 149, (conduit 149A, valve 231, conduit 105C, larger catheter 105A and to its proximal lumen 1058), open valve 151, conduit 157, 158 to conduit 120 and lumen 104. Lumen 105 becomes the pressure monitor via means 115, 154, 152, valve 150, 160, valve 126 and conduit 129. When the intra-pulmonic pressure attains a predetermined higher value than the .lower or negative pressure, pressure switch 179 is closed and conductor 191 is energized. Timer selector 192 usually connects conductor 191 to conductor 195 and coil 170 to move valve 147 to the closed position. Valves 150 and 151 remain in their position during the exhale cycle.

At the next inhale cycle, the action of switches 176, 178 and 179 are repeated. Switch 176 actuates pawl and ratchet means 163-164 to advance valves 150 and 151 another 90 (FIG. 3 positions; low pressure switch 178 energizes coil 171 to open valve 147; and at a higher pressure (end of the inspiration cycle), switch 179 energizes coil 170 (through timer selector 192) to move valve 147 to the closed position.

Pressure switch 180 connected to conduit 129 is the sigh responsive switch and is set to be activated to closed position at an adjustable, predetermined higher pressure than switch 179. It is connected by conductor 194 to timer selector 192 which periodically connects it to conductor 195 and off coil 170 to close inflate valve 147. Timer selector 192 is so adjusted that it connects conductor 191 and switch 179 to conductor 195 a major portion of the time cycles while conductor 194 and switch 180 are connected intermittently and evenly interspersed the remaining minor portion of the time cycles. After valve 147 is moved to closed position in response to switch 100, the exhale cycle starts and, at the proper low pressure, switch 178 is again activated to restart the inhale cycle. This periodically causes a sigh (sigh rate adjustable by 192) per hour and for only one isolated respiratory cycle.

- Pressure Mode Control Cycle with Sigh Control If the patient does not breath or generate a sufficient negative inspiratory effort, or one of deep enough value to energize switches 176, 178 and 182, the alarm 184 is energized by switch 182, after the adjustable delay due to delay relay 183. Alarm 184, in addition to giving a visual or audible signal, energizes conductor 187, which conductor timer device 186 connects at adjustable pre-set given intervals to conductors 197 and 190 to energize coil 171 and move valve 147 to the open position. This permits a flow of breathing gas to the valves and 151 as well as through conduit 149A, 105C and therefrom to the patient. The flow continues until the pre-set high intra-pulmonic pressure is reached and either pressure switches 179 or 180 are activated to return valve 147 to the closed position. At the end of the exhale cycle, either alarm 184 is again activated by the manual pre-set assist alarm mode, or low pressure switches 176 and 178 take over for a new cycle. However, alarm 184 may be pre-set in the alarm control mode and then timer 186 initiates controlled respiration with 179 and 180 closing valve 147 at the pre-set positive pressures as described above.

The timer device 186 may also be arranged to interconnect conductors 187 and 188 at the selected time intervals to energize conductor 175 and solenoid to advance the valves 150 and 151 90 to a new position to alternate the pressure monitor function of the lumens.

Pressure Mode, Low Positive Expiratory Pressure In certain disease states, it is desirable to maintain continual positive pressure in the lungs during the exhale phase to prevent the alveoli (air sac) from completely collapsing. This value is adjustable from 0 to 10 cm. of water pressure. This is accomplished in bypass 172 which is secured to valve 173 on the same shaft 162 as valve 147 but is disposed 90 thereto to the bypass closing rotating valve 147. Throttle valve 174 is adjusted to give the desired exhale positive pressure by the rate of gas flow it delivers to the patient during the exhale cycle. Switches 176 and are adjusted to respond to the new positive low pressures to initiate the inspiration phase. As before, each lumen serves alternately as a flow catheter and as a pressure monitor catheter.

Valve 173 is open in the deflate or exhale phase and valve 147 is closed at that time. At the initiation of the inspiratory phase by a low or negative pressure switch, valve 147 is actuated to the open position and valve 173 is in closed position (FIG. 4). This low positive expiratory pressure can function during the assist or controlled pressure modes.

The manually controlled ventilation works similarly as previously described following the volume mode description.

Nebulization Function in Volume and Pressure Modes As shown in FIGS. 3 and 4, a nebulizer is inserted in line 1 10 following the flowmeter unit 200 in the volume section, and in line 146 between valve 109 and conduit entrance 172 before the pressure valve 147 and 173. As shown in a more close-up view in FIG. 5, the nebulizer itself is connected to the conduit by connection to two conduits labeled 248A and 2488. These are plug-in or screw-on high pressure sealing connectors 250A and 2508 as is common in the present state of the art. The pressurized gas flows both down the long conduit shown in fragmentary view as well as up conduit 1488 through connecting and one way valve means 250A and down into the nebulizer tank circuit. The nebulizer tank consists of high pressurized outer steel cylinder 246 and a connecting top portion screw-on or snap-on but retained air tight and waterproof by the fastening means 245. Inside this is located the plastic or other disposable material container with the sterile nebulization fluid within and shown at the water level both in the main tank section and in the nebulization fluid level site tube 244. The pre-sterilized nebulization fluid in its disposable container has a plastic or rubber plugs at both ends which are perforated by members 243A and 2438 which then are connected to the circuitry. 243A and 2438 are very narrow gauge adjustable lumens of approximately 28 to 30 gauge size. By gravity and by differential pressure to be described, the nebulization fluid flows down 2408 through one way valve and connecting means 250B drips into the pressurized gas conducting conduit shown in fragmentary view. This conduit is either 110 in the volume mode or 146 in the pressure mode. The throttle valve 249 only minimally constricts this pressurized gas conducting conduit and in so doing creates a slight differential pressure between 248A and 2488 which then helps push the negulization fluid through 2438 besides being dependent upon gravity. The drop of fluid entering the conduit, shown in fragmentary view, is then nebulized by the massive flow through that line. Observing the water level in FIG. 5, the amount of fluid remaining can always be known. The disposable plastic unit 247 as described previously and the labeled 247A and 2478 rub ber or plastic perforatable sealed connectors always remain sterile and easily insertable. This is the description of the preferred embodiment although modification in its shape and form can obviously be made by anyone in the art without changing its basic function.

Connecting, Integral, Single and Triple Lumen Catheters The ventilating machine (FIGS. l-4) forces air or oxygen under high pressure (30-100 pounds per square inch) through the catheter into the trachea, and even in the presence of the air leak through the mouth (retrograde flow), pressures of to 35 cm. water are easily attainable (same pressure reached as present machines that use a closed system large tube and balloon cuff).

When the gas flow is discontinued, the patient exhales out of the normal oral route. In complete upper airway expiratory obstruction (above the catheter entrance site) suction is cyclically provided to aid exhalation. Using the single lumen catheter system the patient's ventilation is controlled by the ventilating machine, but with the triple lumen catheter and ventilating system, the patient can control the machine and therefore the assist ventilating mode plus measurement of intrapulmonic pressure as well as gas analysis is made possible. The larger proximal lumen conducts the ventilating gas while one of the other distal lumens alternately transmits the intra-tracheal (intra-pulmonic) pressure level to the sensing device, and conducts the minor high pressurized gas self cleansing flow.

The single lumen patient adaptor means (FIGS. 6-10, 17, 19) has a pressurized gas conduit 251 which conducts the pressurized gas from its connecting hub 256 to its terminal open lumen 264 plus side holes 261.

The thick walled inner hollow needle-trochar member 252 traverses the entire length of the pressurized gas conducting conduit 251 and extends beyond each end for a short distance (FIG. 6). The distal portion 293 has a sharp leveled cutting edge plus a small opening 299 which transmits air, when properly located within the trachea, to the proximal syringe 258. The syringe connecting member 259 fits snugly into the needle-trochar hub 257 and is an air tight connection. Air is transmitted through lumen 297 of the needle-trochar unit into the syringe 258, when in proper position by pulling on plunger unit 260. Following proper position, the catheter 251, is advanced into the trachea 265, holding the needle-trochar unit stable. When the catheter flange 253 and hub portion 255 reach the skin the needletrochar is removed. The catheter assumes a pre-molded 90 curve whose radius is one half the respective tracheal diameter, this curve being shown as curve 254 in FIG. 8 and which stabilizes it aimed down the trachea, without pressure .on the tracheal wall. Hub 256 has screw locking prong 291 which can screw lock onto the gas conduit from the ventilating machine, as well as receiving its receptable within said hub.

The side holes 261 provided along the catheter act as a safety valve when the end lumen 264 may be located at a poor angle in relation to the tracheal lumen. They also aid in lateral transmission of the pressurized gas (up to when the terminal porous gas diffusing member 287 is attached (FIG. 17). In this instance, insertion is within the breakaway needle trochar when placed through the skin, or passed without a trochar via the oral route. The porous gas diffusing member 287 decreases the constant aimed site of the single gas jet and diminished any local effect possible from it. The catheter has a skin anchoring flange 253 (FIGS. 6, 7, 8) which is firmly fixed and solid with the distal hub portion 255 and a solid part of catheter 251. This flange has holes 254 through which it may be sutured to the skin at the neck entrance site or tapes or strings attached to hold it in place on the neck.

Snugly placed around the catheter 251 and firmly integral to it is a balloon 263. As the pressurized gas flows down the catheter 251 it meets a small degree of resistance at the pre-molded, resiliant, inner projecting catheter gas inlet wedge 262 (FIGS. 6, 8, 9, 10). This wedge is held flat in position by the inner needletrochar unit but when the needle-trochar unit is removed, the gas inlet wedge partially springs into the lumen and by its presence channels some gas through its lumen and and distends the balloon 262. This proximal tracheal partial obstructing balloon effectively decreases the tracheal opening and therefore decreases the retrograde leak only while the pressurized gs is flowing in catheter 251. This allows the lungs to be distended to the same final pressure and volume by a lesser amount of the pressurized gas.

The single lumen catheter can be passed via the nasopharyngeal or oro-pharyngeal route between the vocal cords and positioned into the trachea. This method is especially desirous in infants and small children. The catheter 251 then does not have pre-molded curve 294 but is straight and has multi-level anchoring and compression withdranding ridges 285. These allow the catheter to be sutured or taped or tied in proper position through holes 286 at the correct level for each individual patient and prevents catheter 251 from bending to the degree where it will narrow its lumen and also prevents the teeth and gums from compressing the lumen. I

The triple lumen patient adaptor means .(FIGS. 11-16, 18) utilizes the larger proximal lumen as the main gas conducting catheter while it allows one distal lumen-to act as the pressurized gas conducting self cleansing conduit while at the same time the other distal lumen transmits the tracheal (intra-pulmonic) pressure to the ventilating machine. As in the single lumen variety there is a similar skin anchoring flange 253 but with three hubs 261, 262, 263. Each catheter 264, 265, 266 has its own respective lumen 267, 268, 269; respective side holes 270, 271, 272 but only the larger main proximal catheter has a gas wedge inlet 273 to its proximal partial obstructing tracheal balloon 274. As shown in FIGS. 14, 15, 16, 18 the main proximal lumen always acts as the main pressurized gas conducting conduit, while one distal lumen is cleansed by the minor gas flow and, at the same time, the other distal catheter transmits the intra-tracheal pressure back to the ventilating machine. With the next respiration cycle the other distal catheter conducts the gas cleansing flow while the former distal catherer now transmits the tracheal pressure.

The triple lumen patient adaptor means is inserted through a novel breakaway Ainch long trochar (FIGS. 11, 13). The trochar unit consists of a thick walled sharp straight inner needle 275, the same diameter as the triple lumen patient adaptor means used, with an attached syringe 276. Snugly fitting around this sharp hollow needle is a shorter blunt flat-ended trochar 277 which allows the triple lumen patient adaptor means to pass through it. This blunt trochar has a split shaft 278 and split hub 279 with attached separate wing handles 280, 281. When assembled, the sharp inner needle extends 2 mm. longer than the blunt flat-ended hollow trochar. This is thrust through the skin, then through the crico-thyroid membrane or crico-tracheal membrane) into the trachea. When air is aspirated back, the intra-luminal position is assured and the blunt trochar is advanced 4 mm. further, and held in place while the inner longer needle unit is removed. Next the triple lumen patient adaptoris passed through the blunt splitsided trochar down into the trachea. This is passed until the skin anchoring flange 253 reaches the separate wing handles 280, 281 of the trochar unit. At that moment the blunt split-sided trochar is pulled out of the trachea until its distal blunt end leaves the skin surface, leaving most of the triple lumen patient adaptor means within the trachea. The separate wing handles are grasped and bent toward each other, splitting open the whole blunt trochar member 277 (FIG. 13) by the separation of the split shaft edges, and causing it to fall away from the triple lumen patient adaptor means which remains within the trachea. This triple lumen unit has a blunt sliding stiffening rod 282 placed within the larger proximal lumen which now aids the triple lumen patient adaptor means placement further within the trachea by pushing it until the anchoring flange 253 is flush with the skin surface. Then this inner stiffening rod 282 is removed, the pre-molded self-retuming 90 curve 264 is assumed and the entire triple lumen patient adaptor means connected to its control ventilating and pressure regulating means. This advancement is also aided by the extra stiffness incorporated in the proximal one-half cm. of the catheter.

The triple lumen separating wall 283 (septum) divides the major gas inflating proximal lumen from the pressure sensing lumens. The wall 284 (septum) sepa rates each of the narrower alternate pressure sensing, self-cleansing lumens.

The triple lumen patient adaptor means may be passed via the oral route between the vocal cords and it also has the anchoring 286 and compression withstanding ridges 285 as well as the porous gas jet diffusing member 287 onthe main inflating lumen.

The triple lumen patient adaptor means could be constructed of three parallel tubular lumens (one larger proximal abd two narrower distal lumens) when passed via the oral route.

The single lumen patient adaptor means may have a thin, narrow pressure sensing transducer 288 placed distal to it and have the pressure sensing information conductor 289 passed through it (FIG. 19) or through a separate route to the controlling ventilating means with which it works to measure the trachea (intrapulmonic) pressures and utilize this pressure data to regulate, control and monitor the'ventilation of the patient.

The length between the wider, larger proximal lumen of the triple lumen patient adaptor means and the distal, narrower double lumen pressure sensing, selfcleansing means is from 1.5 to 15 cm. depending upon the size of the patient it is utilized in. The larger proximal lumen diameter is from 0.5 to 2 mm. depending upon the size of the patient. The ratio of the single lumen patient adaptor means (and main lumen of the triple lumen patient adaptor means) to the tracheal diameter is from 1:6 to 1:50 depending upon the size of the patient, patient disease, patient age and lung compliance as well as whether or not the proximal partial tracheal obstruction balloon is utilized. The patient adaptor means construction is such as to withstand pressures up to psi.

These patient adaptor means can remain in place and be utilized intermittently with the ventilator to give in termittent positive pressure breathing treatments, instillation and nebulization of mucolytic agents and antibiotics as well as measurements of expired air content of oxygen and carbon dioxide.

The catheter means for use with the present ventilating apparatus is the subject matter of my co-pending application entitled Distally Perforated Catheter for Use in Ventilating System filed on the same date that this application is filed. The nebulizer of the system is claimed herein whereas the new distal perforated catheters for single, double and triple lumen structures are claimed in said co-pending application just referred to.

What is claimed is:

I. A ventilating system comprising:

a first conduit for conducting breathing gas;

triple lumen catheter means having two pressuresensing lumens adapted to be inserted into a body cavity;

second and third conduits connecting said first conduit to one and the other lumens, respectively;

a pressure monitor line including sensing means for monitoring the pressure condtions in the body eavy;

and cyclically actuated valve means including operating means therefor for inter-connecting said first conduit with said second conduit and said third conduit with said pressure monitor line for one cycle, and thereafter interconnecting said first conduit with said third conduit and said second conduit with said pressure monitor line for the following cycle, whereby each of the second and third conduits serve cyclically and alternately as a breathing gas carrying conduit and as a pressure monitoring conduit to thereby maintain the conduits free of body secretions.

2. A ventilating system as claimed in claim 1, wherein the ventilating system comprises a source of pressurized breathing gas and a source of gas under low pressure, including sub-atmospheric pressure cyclically operated inflate and deflate valves connecting said sources of gas sequentially and alternately to an outlet conduit, said outlet conduit being connected to said first conduit.

3. A ventilating system as claimed in claim 2, wherein a catheter control valve is provided which in one position connects said outlet conduit to the first conduit, and in a second position connects said outlet to conduit to a conduit leading to a single lumen catheter.

4. A ventilating system as claimed in claim 2, wherein a single motor means is provided to cyclically drive the deflate and inflate valves and the valve means.

5. A ventilating system as claimed in claim 4, wherein control means are provided to energize said motor means, said control means being in a normal state wherein the motor means is not energized, and pressure responsive means responsive to a predetermined low pressure in the pressure monitor line to change the state of the control means to energize said motor means.

6. A ventilating system as claimed in claim 5, wherein said motor means comprises an air motor having a supply line, and said control means comprises a normally closed, supply valve in said supply line, means for opening said valve to permit the operation of the motor, and connecting means for interconnecting said pressure responsive means to said opening means to control the operation of said opening means.

7. A ventilating system as claimed in claim 5, wherein said pressure responsive means is a low pressure responsive switch.

8. A ventilating system as claimed in claim 6, wherein said pressure responsive means is a low pressure, normally open switch, and responds to said predetermined low pressure to close and thereby energize said opening means to open said supply valve.

9. A ventilating system as claimed in claim 8, wherein a manually controlled override switch is provided in parallel with said pressure responsive switch to open said valve.

10. A ventilating system as claimed in claim 8, wherein said connecting means comprises conductor means, periodically operated means for opening said conductor means for a predetermined interval, and flow responsive means responsive to a predetermined low or no flow in said first conduit for closing said conductor means during said interval.

11. A ventilating system as claimed in claim 10, wherein said periodically operated means comprises cooperating fixed and movable contact means intermediate said conductor means, said fixed contact means having adjustable spaced portions to form an opening in the conductor means, and said movable contact means being driven by a timing means, and wherein said flow responsive means controls the operation of a switch means to bridge said opening upon a predetermined drop in flow.

12. A ventilating system as claimed in claim 11 wherein said flow responsive means comprises a first normally'open switch which is closed upon full flow to cause movement of said bridging switch means to nonbridging position, and a second normally open switch which is closed in response to full flow, and wherein said system further includes second conductor means connecting said second switch to the first conductor means between the low pressure responsive switch and the periodically operated means.

13. A ventilating system as claimed in claim 12, wherein a first high pressure switch is connected to the pressure monitor line and is responsive to a predetermined high pressure in said line, and a third conductor means connecting said high pressure switch to said first conductor means between said periodically operated device and said valve opening means.

14. A ventilating system as claimed in claim 1, wherein the ventilating system comprises a source of pressurized gas, a fourth conduit connecting said source and said first conduit, and pressure regulating means in said fourth conduit.

15. A ventilating system as claimed in claim 14, wherein said conduit includes a plurality of parallel branches, a pressure regulating valve in each branch and a selector valve for selectively connecting any of said branches to the first conduit.

16. A ventilating system as claimed in claim 14, including first motor means for cyclically operating said valve means, and first control means responsive to pressure variations in said pressure monitor lines for controlling the energization of said first motor means.

17. A ventilating system as claimed in claim 16, wherein a cut-off valve is provided in the third conduit upstream of said valve means, second motor means to actuate said cut-off valve to an open or closed position and second control means responsive to pressure variations in said pressure monitor line for controlling the energization of said motor means.

18. A ventilating system as claimed in claim 17, wherein said first and second motor means are electrical motor means, and the first and second control means are pressure operated switches responsive to pressure existing in the pressure monitor line.

19. A ventilating system as claimed in claim 18, wherein the first control mean comprises a first low pressure responsive switch and first conductor means connecting said switch to said first motor means to energize the same and actuate said valve means to a sequential cyclic position.

20. A ventilating system as claimed in claim 19, wherein the second control means comprise a second low pressure switch and a high pressure switch, second conductor means connecting said second low pressure switch to said second motor means, third conductor means connecting said high pressure switch to said second motor means, said second motor means opening said cut-off valve when said second low pressure switch closes in response to a predetermined low pressure, and clsoing the cut-off valve when the high pressure switch responds to a predetermined high pressure.

21. A ventilating system as claimed in claim 20, wherein a sigh pressure switch is provided which is responsivc to a higher pressure in the pressure monitor line than that preset pressure to which the high pressure switch responds, and a timer selector device is inserted in said third conductor to connect either the high pressure switch or sigh pressure switch to the third conductor to energize said second motor means to close the cutoff valve.

22. A ventilating system as claimed in claim 20, wherein a third low pressure-responsive switch is provided, together with alarm means and fourth conductor means, said fourth conductor means connecting said third low pressure switch and said alarm to activate the alarm upon reaching a predetermined low pressure.

23. A ventilating system as claimed in claim 22, wherein a delay relay is provided in said fourth conductor means to delay the energization of the alarm for an adjustable time interval.

24. A ventilating system as claimed in claim 22, wherein a timer selector device and a fifth conductor means are provided to be energized by said alarm, said timer selector device alternately and sequentially connecting said fifth conductor means to said first conductor means and said second conductor means, whereby said first motor means cyclically operates said valve means and said second motor means opens said cutoff valve.

25. A ventilating system as claimed in claim 17, wherein a bypass line is provided around said cutoff valve, shut-off valve means in said bypass being arranged to close the bypass when said cutoff valve is in open position, said cutoff valve and shutoff valve means being arranged for joint actuation by said second motor means.

26. A ventilating system as claimed in claim 17, wherein an adjustable throttle valve is provided in said bypass.

27. A ventilating system as claimed in claim 8, further including a second low pressure switch which is closed in response to a predetermined low pressure in the pressure monitor line, a delay relay connected to said switch to be energized thereby upon closure, and a switch means connected to said delay relay and to said opening means to be energized by said relay after a delay, thereby energizing the opening means to open the supply valve.

28. A ventilating system as claimed in claim 1, further including a three-way valve in a conduit which is connected to a lumen of the triple lumen catheter means downstream of said cyclically actuated valve means, a source of pressurized breathing gas, a pipe connecting said source to said three-way valve, and an adjustable throttle valve in said pipe upstream of said three-way valve, the three-way valve thereby connecting said lumen to either said cyclically actuated valve means or to said pressurized gas source.

29. A ventilating system as claimed in claim 28, further including a cut-off valve which is provided in said pipe upstream of said adjustable throttle valve, and means connecting said cut-off valve and said three-way valve for joint cooperative movements.

30. A ventilating system as claimed in claim 29, including a pipe means which interconnects said pressurized gas source, a shut-off valve and a pressure regulator valve, said valves being serially arranged in said pipe line for selectively increasing the pressure in the low pressure source in accordance with the setting of the pressure regulating valve.

31. A ventilating system as claimed in claim 1, including a nebulizer fitted with quick-attaching valves, fluid level control means and a reservoir for administering medication with nebulized water vapor for passage to and through a catheter inserted into the respiratory system of the patient.

Claims (31)

1. A ventilating system comprising: a first conduit for conducting breathing gas; triple lumen catheter means having two pressure-sensing lumens adapted to be inserted into a body cavity; second and third conduits connecting said first conduit to one and the other lumens, respectively; a pressure monitor line including sensing means for monitoring the pressure condtions in the body cavity; and cyclically actuated valve means including operating means therefor for inter-connecting said first conduit with said second conduit and said third conduit with said pressure monitor line for one cycle, and thereafter interconnecting said first conduit with said third conduit and said second conduit with said pressure monitor line for the following cycle, whereby each of the second and third conduits serve cyclically and alternately as a breathing gas carrying conduit and as a pressure monitoring conduit to thereby maintain the conduits free of body secretions.

2. A ventilating system as claimed in claim 1, wherein the ventilating system comprises a source of pressurized breathing gas and a source of gas under low pressure, including sub-atmospheric pressure cyclically operated inflate and deflate valves connecting said sources of gas sequentially and alternately to an outlet conduit, said outlet conduit being connected to said first conduit.

3. A ventilating system as claimed in claim 2, wherein a catheter control valve is provided which in one position connects said outlet conduit to the first conduit, and in a second position connects said outlet to conduit to a conduit leading to a single lumen catheter.

4. A ventilating system as claimed in claim 2, wherein a single motor means is provided to cyclically drive the deflate and inflate valves and the valve means.

5. A ventilating system as claimed in claim 4, wherein control means are provided to energize said motor means, said control means being in a normal state wherein the motor means is not energized, and pressure responsive means responsive to a predetermined low pressure in the pressure monitor line to change the state of the control means to energize said motor means.

6. A ventilating system as claimed in claim 5, wherein said motor means comprises an air motor having a supply line, and said control means comprises a normally closed, supply valve in said supply line, means for opening said valve to permit the operation of the motor, and connecting means for iNterconnecting said pressure responsive means to said opening means to control the operation of said opening means.

7. A ventilating system as claimed in claim 5, wherein said pressure responsive means is a low pressure responsive switch.

8. A ventilating system as claimed in claim 6, wherein said pressure responsive means is a low pressure, normally open switch, and responds to said predetermined low pressure to close and thereby energize said opening means to open said supply valve.

9. A ventilating system as claimed in claim 8, wherein a manually controlled override switch is provided in parallel with said pressure responsive switch to open said valve.

10. A ventilating system as claimed in claim 8, wherein said connecting means comprises conductor means, periodically operated means for opening said conductor means for a predetermined interval, and flow responsive means responsive to a predetermined low or no flow in said first conduit for closing said conductor means during said interval.

11. A ventilating system as claimed in claim 10, wherein said periodically operated means comprises cooperating fixed and movable contact means intermediate said conductor means, said fixed contact means having adjustable spaced portions to form an opening in the conductor means, and said movable contact means being driven by a timing means, and wherein said flow responsive means controls the operation of a switch means to bridge said opening upon a predetermined drop in flow.

12. A ventilating system as claimed in claim 11 wherein said flow responsive means comprises a first normally open switch which is closed upon full flow to cause movement of said bridging switch means to non-bridging position, and a second normally open switch which is closed in response to full flow, and wherein said system further includes second conductor means connecting said second switch to the first conductor means between the low pressure responsive switch and the periodically operated means.

13. A ventilating system as claimed in claim 12, wherein a first high pressure switch is connected to the pressure monitor line and is responsive to a predetermined high pressure in said line, and a third conductor means connecting said high pressure switch to said first conductor means between said periodically operated device and said valve opening means.

14. A ventilating system as claimed in claim 1, wherein the ventilating system comprises a source of pressurized gas, a fourth conduit connecting said source and said first conduit, and pressure regulating means in said fourth conduit.

15. A ventilating system as claimed in claim 14, wherein said conduit includes a plurality of parallel branches, a pressure regulating valve in each branch and a selector valve for selectively connecting any of said branches to the first conduit.

16. A ventilating system as claimed in claim 14, including first motor means for cyclically operating said valve means, and first control means responsive to pressure variations in said pressure monitor lines for controlling the energization of said first motor means.

17. A ventilating system as claimed in claim 16, wherein a cut-off valve is provided in the third conduit upstream of said valve means, second motor means to actuate said cut-off valve to an open or closed position and second control means responsive to pressure variations in said pressure monitor line for controlling the energization of said motor means.

18. A ventilating system as claimed in claim 17, wherein said first and second motor means are electrical motor means, and the first and second control means are pressure operated switches responsive to pressure existing in the pressure monitor line.

19. A ventilating system as claimed in claim 18, wherein the first control mean comprises a first low pressure responsive switch and first conductor means connecting said switch to said first motor means to energize the same and actuate said valve means to a sequential cyclic position.

20. A ventilating system as claimed in claim 19, wherein the second control means comprise a second low pressure switch and a high pressure switch, second conductor means connecting said second low pressure switch to said second motor means, third conductor means connecting said high pressure switch to said second motor means, said second motor means opening said cut-off valve when said second low pressure switch closes in response to a predetermined low pressure, and clsoing the cut-off valve when the high pressure switch responds to a predetermined high pressure.

21. A ventilating system as claimed in claim 20, wherein a sigh pressure switch is provided which is responsive to a higher pressure in the pressure monitor line than that preset pressure to which the high pressure switch responds, and a timer selector device is inserted in said third conductor to connect either the high pressure switch or sigh pressure switch to the third conductor to energize said second motor means to close the cutoff valve.

22. A ventilating system as claimed in claim 20, wherein a third low pressure-responsive switch is provided, together with alarm means and fourth conductor means, said fourth conductor means connecting said third low pressure switch and said alarm to activate the alarm upon reaching a predetermined low pressure.

23. A ventilating system as claimed in claim 22, wherein a delay relay is provided in said fourth conductor means to delay the energization of the alarm for an adjustable time interval.

24. A ventilating system as claimed in claim 22, wherein a timer selector device and a fifth conductor means are provided to be energized by said alarm, said timer selector device alternately and sequentially connecting said fifth conductor means to said first conductor means and said second conductor means, whereby said first motor means cyclically operates said valve means and said second motor means opens said cutoff valve.

25. A ventilating system as claimed in claim 17, wherein a bypass line is provided around said cutoff valve, shut-off valve means in said bypass being arranged to close the bypass when said cutoff valve is in open position, said cutoff valve and shutoff valve means being arranged for joint actuation by said second motor means.

26. A ventilating system as claimed in claim 17, wherein an adjustable throttle valve is provided in said bypass.

27. A ventilating system as claimed in claim 8, further including a second low pressure switch which is closed in response to a predetermined low pressure in the pressure monitor line, a delay relay connected to said switch to be energized thereby upon closure, and a switch means connected to said delay relay and to said opening means to be energized by said relay after a delay, thereby energizing the opening means to open the supply valve.

28. A ventilating system as claimed in claim 1, further including a three-way valve in a conduit which is connected to a lumen of the triple lumen catheter means downstream of said cyclically actuated valve means, a source of pressurized breathing gas, a pipe connecting said source to said three-way valve, and an adjustable throttle valve in said pipe upstream of said three-way valve, the three-way valve thereby connecting said lumen to either said cyclically actuated valve means or to said pressurized gas source.

29. A ventilating system as claimed in claim 28, further including a cut-off valve which is provided in said pipe upstream of said adjustable throttle valve, and means connecting said cut-off valve and said three-way valve for joint cooperative movements.

30. A ventilating system as claimed in claim 29, including a pipe means which interconnects said pressurized gas source, a shut-off valve and a pressure regulator valve, said valves being serially arranged in said pipe line for selectively increasing the pressure in the low pressure source in accordance with the setting of the pressure regulating valve.

31. A ventilating system as claimed in claim 1, including a nebulizer fitted with quick-attaching valves, fluid level control means and a reservoir for administering medication with nebulized water vapor for passage to and through a catheter inserted into the respiratory system of the patient.

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