US3882847A

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Publication number: US3882847A
Application number: US423762A
Authority: US
Inventors: Harvey Barry Jacobs
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-12-11
Filing date: 1973-12-11
Publication date: 1975-05-13
Anticipated expiration: 1992-05-13

Abstract

Low-cost pneumatic apnea or respiration monitor adapted to sound an alarm for a patient whose breathing is controlled by a ventilator or whose respiration has ceased. In the disclosed arrangement, pressure from an air pressure source is modulated by chest movement to admit air to either of two air storage tanks, each of these storage tanks having an adjustable throttle or bleed valve in a vent. Each tank feeds air to a low pressure actuated switch or valve which actuates an alarm when the pressure falls below a critical low value in the storage tanks indicating a slowing or cessation of breathing.

Description

United States Patent Jacobs LOW-COST PNEUMATIC APNEA OR RESPIRATION MONITOR Harvey Barry Jacobs, 11607 Foxclove Rd., Hunters Woods, Reston, Va. 20091 Filed: Dec. 11, 1973 Appl. No.: 423,762

[76] Inventor:

U.S. Cl. 128/2 S; 128/142; 340/279 Int. Cl. A6lb 5/10; A6lm 16/00 Field of Search 128/25. DIG. 29, 203, 2 R,

References Cited UNITED STATES PATENTS 9/1968 Finan 128/203 3/1974 Franic r. 340/279 OTHER PUBLICATIONS IBM Technical Disclosure, Vol. 6, No. 6, 11/63.

[4 1 May 13,1975

Primary ExaminerRichard A. Gaudet Assistant ExaminerG. F. Dunne Attorney, Agent, or Firm-Abraham A. Saffitz [57] ABSTRACT Low-cost pneumatic apnea or respiration monitor adapted to sound an alarm for a patient whose breathing is controlled by a ventilator or whose respiration has ceased.

9 Claims, 7 Drawing Figures 1 LOW-COST PNEUMATIC APNEA OR RESPIRATION MONITOR BACKGROUND OF THE INVENTION FIELD OF THE INVENTION This invention relates to a low-cost apnea or respiration monitor which is adapted to sound an alarm for a patient whose breathing is controlled by a ventilator or which signals the stopping of breathing in a patient not on a respirator whose illness requires monitoring.

More particularly, the invention relates to a low-cost, reliable, respiration monitor which operates on simple mechanical and pneumatic principles and is not subject to electrical failure as may be caused by deterioration of electronic components such as capacitors, vacuum tubes, or transistors.

In the pneumatic system described herein, pressure from an air pressure source is modulated by chest movement to admit air to either or two air storage tanks, each of these storage tanks having an adjustable bleed valve. Each tank feeds air to a low pressure switch or valve which actuates an alarm when the pressure falls below a critical low value in the storage tanks indicating a slowing or cessation of breathing.

OBJECTS OF THE INVENTION An object of the invention is to provide a low-cost apnea or respiration monitor which is free from capacitors, vacuum tubes and other electronic components and which operates on pressure fluid principles. The pressure system is provided with time delay means to indicate by audible, visual, and other alarm means failure of breathing of the patient in either the inspriatory or expiratory phase of each respiration cycle to indicate cessation of breathing by the patient.

BRIEF DESCRIPTION OF THE DRAWING Other objects of the invention will become apparent from the following detailed description and drawings, in which:

FIG. 1 is a partially diagrammatic illustration showing the chest air valve unit connected to the appropriate pneumatic pressure sources and delay air storage tanks for inhalation and exhalation, respectively.

FIG. 2 is detail partly in section and partly in elevation of one end of the chest air valve unit showing the spring meter mechanism for the air valve piston.

FIG. 3 is a sectional view showing one of the stops at each end of the chest air valve unit which limits the reciprocating movement of air valve piston in response to inspiration and exhalation.

FIG. 4 is an elevational view of the rigid chest mounting plate which can be detached from the air valve unit when the latter is repaired or replaced.

FIG. 5 is a sectional diagrammatic view of the chest air valve unit in mid respiration.

FIG. 6 is a sectional diagrammatic view of the chest air valve unit in exhalation phase.

FIG. 7 is a sectional diagrammatic view of the chest air valve unit in inhalation phase.

The several figures herein illustrate a pressure system for an apnea monitor in which thoracic movement actuates alarms or signals. The basic principle of the pressure chest monitor system is that increments of air supplied to an air tight tank will gradually build up the pressure in that tank to the level of the source of air pressure. If the tank has a continuous slow vent or leak the maximum pressure that can be built up by a regular series of inputs will be lower because of leakage. A calibrated pressure switch or valve connected to the air tank will be actuated if the incoming increments of air continue for a time period set by the adjustable throttle valve for respiration rate. The actuation of the switch due to this change in input to the tank can be utilized to energize an alarm indicating that the input has decreased or stopped entirely. A pressure gauge connected to the tank measures the respiration rate on the lowest swing of the guages needle. The slower the respiration rate the higher the pressure is in the tank per impulse and the faster the respiration, the lower pressure per impulse. Thus, the tank acts as an adjustable timing means for varying or delaying the timing of pressure built up in the system and activating the alarm means.

FIG. I is a schematic view of anair valve 61 receiving air under pressure fromsource 91 throughinput 74 to atubular member 66. Preferably this tube should be transparent and the impact-resistant synthetic resin known as ABS, available from the Carlon Company, has been found satisfactory.Tubular member 66 has two other ports and 76 extending respectively to

air tanks

96 and 92. Each of the air tanks has an

adjustable throttle valve

97 and 93 respectively, and alow pressure switch 98 and 94 respectively.

Tube 66 is supported on abreastplate 63 by means of footing members and 86, each of which holds a circular supporting

unit

83 and 84. Thetube 66 is snugly retained near each end by these ring-

shaped members

83 and 84. Within thetube member 66 is a reciprocating unit comprising arod 70 having aneyeshaped member 72 at one end. Thismember 70 is threaded to receive threaded

members

68 and 69. Secured to threaded

members

68 and 69 are

tubular members

67 and 100. The opposite ends of thetubular members 67 and carrry-piston unitis 64 and 65. These

piston units

64 and 65 are slidable within thetube 66. As shown in FIGS. 5, 6 and 7 they shift from the mid position of FIG. 6 to the left and right in accordance with the motion ofrod 70.

Rod 70 may be connected ateye 72 to asnap fastener 73 that is secured to abody belt member 79 that surrounds the body of the patient. The opposite end ofbelt 79 as shown at the right side of FIG. 1 has adetachable hook 80 that may be secured in acorresponding opening 81 that is part of thechestplate 63.

As portrayed in FIG. 7, when the patient takes a breath, thebelt 79 pulls oneye 72 drawing therod 70 to the left. The two

plungers

64 and 65 will then be positioned so the air in the pressure tank can entertube 66 atport 74 and escape atport 76. This adds an increment of air to tank 92.

Conversely, as shown in FIG. 6, when the patient breathes outbelt 70 becomes slack, allowingrod 70 to move to the left under the influence of two springs to be described presently. At this moment of exhalation, as shown in FIG. 6, the

pistons

64 and 65 permit air from the pressure tank to enter atport 74 and to leaveport 75 to go totank 96.

Thus,tank 92 can be designated the inhalation tank and thetank 96 can be designated. the exhalation tank. Since both tanks are equipped with

adjustable throttle valves

93 and 97, any slowness of operation ofrod 70, or cessation of motion thereof, will soon result in a rise of pressure in one or the other of the two tanks. Such rise in pressure will actuate the

appropriate signal alarm

95 or 99 to notify an attendant of the critical situation respecting this particular patient.

Pressure gauges H66 and 107 may be attached to

timing tanks

92 and 96. To an observer, the pressure gauges will indicate the breathing conditions of the patient by registering the low and high pressure cycles in the attached tank. Too high pressure would indicate that the patients chest is not moving sufficiently for proper breathing.

The spring suspension that causesrod 76 to return to the extreme right position when not under any pull from thebelt 79 is shown in detail in FIG. 2. This figure shows the left half of the rod portrayed in FlG. 1. Thepiston member 65 is a snug fit within theplastic tube 66 and carries atubular member 67 which is secured to the threadedmember 69 at its other end. Consequently, the weight of one end ofrod 76 is carried through the agency of member 6%,tube 67 andpiston 65 by thetube 66.

Exactly similar support means is found at the right end oftube 66 androd 76 wherepiston 64 carries the tubular member Wt) threadedmember 68 and the right end of threadedrod 70.

It will be seen that the threaded

members

68 and 69 can position the

pistons

64 and 65 in different lengthwise locations alongrod 70 and thereby determine the interval between the passage of these pistons over the

ports

75 and 76.

Referring again to FIG. 2, thetube member 67 is surrounded bycoil spring 89. This coil spring is secured, as by soldering, to thetube 67 atpoint 101. The other end of the spring is secured, as by crimping, over the edge oftube 66. Thespring 89 is under partial compression when therod 76 is in mid position shown in FIG. 5. At this moment theother spring 88 at the right end is under partial tension. Consequently, rod '70 is released from any pull by thebelt 79 will spring to the right end under the impetus of two springs. This is the situation in FIG. 6.

It is desirable that

pistons

64 and 65 be limited in their extreme movements to avoid pulling them fromtube 66. FIG. 3 shows such a stop member comprising a rubber grommett which fits snugly over the end oftube 66 and projects inwardly into the tube to the point where the motion of the piston is to be stopped. This grommett is indicated as 77 and 78 in FIG. 1.

FIG. 4 is a partial detail of the supporting means and thetube 66 carried by the supporting means. This figure might be regarded as the stationary portion of the air valve, the other elements moving more or less in accordance with the pull on belt '79 produced by the action of the patients chest in breathing.

Footing members

85 and 86 are shown attached to thebreastplate 63. The latter is shown as slightly curved at each end to conform to the human anatomy. At the top of

parts

85 and 86, ring-shaped

members

83 and 84 are secured and in turn carry thetransparent tube 66 approximately at each end thereof. At the right end ofbreastplate 63 anapertured projection 81 provides means for detachably connecting the body belt "79 to the breastplate.

From the above description of a preferred embodiment of my pneumatic respiration monitor, it will be seen that no electricity is employed in the vicinity of the patient and need not be employed in the same room as the patient. lf the alarms and 99 are electrical,

they can be energized by pneumatic tubing from an adjoining room. In some situations (operating rooms, for example), electrical sparks are to be avoided at all costs. The alarms may be pneumatic, such as an air whistle.

What is claimed is:

l. A pressure fluid breathing monitor for a patient comprising:

a support,

a valve means having two relatively movable valve parts;

a body belt adapted to partly surround the patients chest;

means connecting one end of the belt to one valve part and means for connecting the other end of the belt to said support;

said valve parts moving relatively to each other in response to the inhalation and exhalation motions of the chest;

a source of pressure fluid connected to the valve means;

pressure fluid operated alarm means including two alarm devices, each connected to said valve means by a separate conduit means, one alarm responding to abnormal inhalation motion and the other to abnormal exhalation motion;

conduit means connecting said alarm means to said valve means to receive pressure fluid therefrom for operation of said alarm device;

delay means connected to said conduit means to control the time interval wherein the pressure fluid effects the activation of the alarm means; and,

said relatively movable valve parts controlling the flow from said pressure fluid source to said conduit means in response to the inhalation and exhalation motions of the chest.

2. The breathing monitor as claimed in claim 1 wherein one valve part is mounted on a support resting on the chest with one belt end connected to the support and the other belt end connected to the other valve part.

3. The breathing monitor as claimed inclaim 2 wherein the movable valve parts comprise two nested outer and inner parts, with the source of pressure fluid and the conduit means connected to the other valve part.

4. The breathing monitor as claimed in claim 3 wherein the outer part comprises a tubular member secured to said support and having three spaced ports, one connected to the source of pressure fluid and the others to the conduit means, and wherein the inner part carries means to interconnect the pressure fluid source to either of said ports.

5. The breathing monitor as claimed in claim 4 wherein spring means are provided to act on the inner part to bias it to a desired position to interconnect the pressure fluid source to a port.

6. The breathing monitor as claimed in claim 4 wherein the delay means comprises a vent to permit a portion of the pressure fluid flowing to the alarm device to escape.

7. The breathing monitor as claimed in claim 6 wherein an adjustable throttle valve controls the flow through the vent.

8. The breathing monitor as claimed in claim 4 wherein the delay means comprised a fixed volume 6 tank with a throttle valve controlling the flow and the tank, an adjustable throttlevalve to control the flow quanmy of mud wlthm the tank through the vent and a conduit connecting said tank to 9. The breathing monitor as claimed in claim 5 wherein the delay means comprises a fixed volume tank connected to the conduit means, a vent connected to 5 said alarm device.

Claims

1. A pressure fluid breathing monitor for a patient comprising: a support, a valve means having two relatively movable valve parts; a body belt adapted to partly surround the patient''s chest; means connecting one end of the belt to one valve part and means for connecting the other end of the belt to said support; said valve parts moving relatively to each other in response to the inhalation and exhalation motions of the chest; a source of pressure fluid connected to the valve means; pressure fluid operated alaRm means including two alarm devices, each connected to said valve means by a separate conduit means, one alarm responding to abnormal inhalation motion and the other to abnormal exhalation motion; conduit means connecting said alarm means to said valve means to receive pressure fluid therefrom for operation of said alarm device; delay means connected to said conduit means to control the time interval wherein the pressure fluid effects the activation of the alarm means; and, said relatively movable valve parts controlling the flow from said pressure fluid source to said conduit means in response to the inhalation and exhalation motions of the chest.

3. The breathing monitor as claimed in claim 2 wherein the movable valve parts comprise two nested outer and inner parts, with the source of pressure fluid and the conduit means connected to the other valve part.

8. The breathing monitor as claimed in claim 4 wherein the delay means comprised a fixed volume tank with a throttle valve controlling the flow and quantity of fluid within the tank.

9. The breathing monitor as claimed in claim 5 wherein the delay means comprises a fixed volume tank connected to the conduit means, a vent connected to the tank, an adjustable throttlevalve to control the flow through the vent and a conduit connecting said tank to said alarm device.