US3319623A

US3319623A - Blood pressure monitors

Info

Publication number: US3319623A
Application number: US382255A
Authority: US
Inventors: Seymour B London
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-07-13
Filing date: 1964-07-13
Publication date: 1967-05-16
Anticipated expiration: 1984-05-16

Description

May 16, 1967 Filed July 13, 1964 BLOOD PRESSURE MONITORS S. B. LONDON F/G. I

AMPLIFIER BLEEDER IGURM CUFF) 3 sheets-sheet 1 N O K10 QOUDOCOQUoOa 24(MAN0METER) M (SIGNAL LAMP) ATTORNEYS May 16, 1967 s. a L @NDON 3,39,623

BLOOD PRESSURE MONITORS Filed July 13, 1964 3 Sheets-Sheet 2 QGVDSSS AMPLIFIER 3s K49KBM6VDCM GV- OCS i6( AHM 36 (MICROPHONE) novAc5 PUMP INVENTOR SEYMOUR B. LONDON F/G. 2 www (v3/Sgam' ATTORNEYS May 16, 1967 s. B. LONDON 3,319,623

BLOOD PRESSURE MoNToRs 3 Sheets-Sheet 5 Filed July 1s, 1964 AMPLIFIER 38 swzosvocss SWZOGVDCSG swzaevocs? INVENTOR SEYMOUR B. LONDON United States Patent O 3,319,623 BLOOD PRESSURE MONITORS Seymour B. London, 35 E. Dilido Drive, Dilido Ave.,

Miami, Fla. 33139 1 Filed July 13, 1964, Ser. No. 382,255 13 Claims. (Cl. 12S-2.05)

The present application relates to blood pressure monitors and in particular to mercury column manometer and aneroid manometer monitors for determining and Visually presenting systolic and diastolic blood pressure readings, and in a continuation-in-part of my copending -application which issued August 24, 1965 as U.S. Patent No. 3,202,148.

To gain a proper appreciation of the scope of invention of the blood pressure monitors disclosed herein and to properly understand the problems inherent in distinguishing different types of blood pressure determination, the following background of historical medical events relating to blood pressure determination is presented herewith:

SYSTOLIC AND DIASTOLIC Systole is the forceful contraction of the heart. Acting as a pump each contraction of the heart ejects into the aorta about 60 cc. of blood which produces a wave of blood through the arterial system. The crest of this pressure wave is called systolic pressure. Diastole is the period of relaxation of the heart when the heart iills with blood. The diastolic period of the pressure Wave is the trough of the wave; that is Ia point of minimal pressure coinciding with the resting phase or diastolic phase of the heart. The mean pressure of the arterial systern is usually given as one-half of the sum of value of the systolic and diastolic pressures but may be slightly lower.

Pulse pressure is the Ldifference between systolic and diastolic pressures. For instance, if the blood pressure were 120 systolic and SO diastolic, the pulse pressure would then be the difference between 120 and 80 or 40 millimeters of mercury.

The pressure in the arterial system depends upon several factors:

(1) The pumping -action of the heart forces blood into the arterial system.

(2) The peripheral resistance of the arterial system. This is determined by the caliber of the small blood vessels which respond to stimulation of the controlling nerves with constriction or relaxation, thus regulating the rate of the outow of blood from the arterial system into the capillaries and Veins.

(3) The -amount of blood in the arterial system also contributes to the pressure inasmuch as the blood vessels are elastic, the vessels must be lled to capacity before there is any blood pressure and then overilled to slightly distend the walls to elevate the pressure to the normal physiologic limits. It is this distention of the elastic Walls of the blood vessels which produces blood pressure. The diastolic pressure provides for a uniform flow through the small blood vessels and arterioles.

DIRECT MEASUREMENT The earliest and perhaps the most complicated method of measuring blood pressure was the direct method. In this method a needle is introduced directly into the artery and by appropriate connection, a transducer is used to relate the pressure in the artery to a graph or other form 3,319,623 Patented May 16, 1967 ice of recording device. Of the various direct systems the optical method, the rst method used, simply consisted of a mirror attached to a membrane or tambour that uctuated with each pulse as it was transmitted up the needle through a -rigid tubing. This fluctuation was inscribed by photographic means on a recording surface. Conclusions could be drawn as to the relative pressure in the arterial system by properly standardizing the equipment. The electrical transducer, a little more sophisticated, consists of three basic varieties:

(a) Condenser, (b) Strain gauge, and (c) Inductance type of transducers.

Here the fluctuations of pressure create variations in electrical voltage and by quantitating the electrical current and Voltage, a measure of the pressure variations can then be obtained. It is generally conceded that the accuracy of the direct blood pressure determination is quite good with errors of plus or minus 5 millimeters of mercury being considered acceptable.

INDIRECT MEASUREMENT The indirect method of blood pressure determination measures the lateral pressure of the arterial wall as opposed to the end pressure as measured by the intraarterial needle in the direct method.

1) Palpaton of pulses-About 65 to 70 years ago one of the physiologists in Italy by the name of Riva- Rocci devised the blood pressure arm cuif and manometer as we presently know it. By this means the pressure in the cuff acting as a tourniquet on the arm is increased until the blood flow in the artery beneath the cufr" is obstructed. At this point no pulse is palpable below the constricting cuff. By rst constricting the artery then feeling for the pulse below, while observing the manometer, the first pulse felt after the constricted artery was released was indicative of the height of the blood pressure wave or systolic pressure. Generally, this pulse was felt about 8 to 12 millimeters below true arterial pressure and while it served as a crude guide it had much to -be desired from a point of view of accuracy and direct relationship to the arterial pressure.

(2) Auscultaton or sounds.-In 1905 the Russian physiologist, Korotkow, made observations which are of eX- treme importance in clinical medicine today. He found that under ordinary circumstances while listening with a stethoscope placed on an artery, no sounds were heard. Therefore, he concluded that the flow of blood along arterial channels was inaudible to the human ear despite the fact that you could feel .a pulse. If the artery was compressed by the cuff attached to a manometer so as to completely arrest the flow of blood, no sounds were heard below the compression, but when the compression of the artery was slowly released, a sharp tapping sound could be heard in rhythm with the heart beat by allowing the pressure in the cui to fall just enough so that a small amount of blood could pass beyond the compression point. These sounds bear the name of the original observer and are called Korotkow sounds. They are found over a range of .approximately 40 to 50 millimeters of mercury and then disappear. They cannot be heard below the diastolic trough of pressure. Therefore, the rst sound that is heard Vindicates systolic pressure and the last sound heard indicates diastolic pressure. The difference between the systolic and diastolic pressure is again given as pulse pressure. Thus, one must distinguish the Korotkow sounds heard as opposed to pulses because while the sounds could noz be heard below the diastolic pressure, the pulses could easily be palpable without any compression of the artery.

(3) Small vessels ndces.-The auscultatory method is used in present-day medicine to determine the indirect blood pressure. The third method of indirect blood pressure determinations which has proved to be of some interest in laboratory investigation but has little clinical value, is the electrical recording -of pulse variations either `distal to an arm cuff or by transducer directly connected to a linger cui. Changes in such .a plethysmograph type of tracing have been recently devised and modified so that pulse changes can be picked up by a photoelectric cell transducer attached to the ear or linger. Generally these methods have not been reliable because they attempt to detect blood pressure changes only in the small blood vessels and reiiect mainly volume and ow type changes in the part (linger, etc.) rather than a true intra-arterial pressure change.

Numerous patents, such as that granted to Williams et al. (US. Patent No. 2,352,875), disclose the use of the `above-mentioned auscultatory method to determine indirect blood pressure. There is, however, no evidence that the Williams instrument has ever measured anything7 except a pulse detected via a Wrist culi". The Williams machine determines pulses by pressure variations in the culi touriquet depending on a succession of diastolic pulses to indicate that the diastolic pressure has been reached. Physiologists, who have studied this problem, feel that this type of determination could not give an accurate end point and is merely representative of pulsatile expansion to the artery rather than diastolic pressure. Comparative studies with intra-arterial pressure determinations by means of strain gauge manometers and other measuring devices reveal a -great discrepancy between the pulsatile phenomena as detected 4by a blood pressure culi and the diastolic blood pressure. The present invention constitutes a substantial improvement in this iield since determinations of the diastolic pressure are made by the established principle of indirect blood pressure determination using the disappearance of the Korotkow sounds as the simultaneous end point of diastolic blood pressure. Fur- ,therthe detection lof Korotkow sounds within a range of 2% mm. Hg is contemplated by the invention disclosed herein. That is, since this invention is designed to detect and register differences of pressure in units of 5 mm. of Hg, the units sensitivity is i2.5 mm. of Hg.

Since the unit measures and registers the blood pressure objectively in units and `by techniques employed universally, i.e. the recognition of the level of the first and last blood pressure sound, its use in epidemiological studies suitably oiiers comparative information available for analysis. Indices of the prior art are unsuitable for collecting and comparing epidemiological data as they do not measure the pressure of the brachial artery.

It is further submitted that the present invention constitutes a substantial improvement over the Pigeon (U.S. No. 2,821,188) and Gilford (U.S. No. 2,827,040) patents, which disclose sphygmomanometers having separate circuits used to convert pressures to electrical signals as the pressure drops from systolic to diastolic, since neither -of these patents discloses limiting means for actuating indiciaat times when Korotkow sounds are detected.

The present invention, then, distinguishes from the prior art devices in its unique capability of performing the following separate functions:

(l) Measurng.-Continuous intermittent registration of the indirect blood pressure on a read-out panel at intervals which can -be varied at will.

(2) Monitoring-Alarm signal or other electrical devices as might be used to resuscitation can be activated if the blood pressure falls below'or rises above a prescribed level which can be varied by a selector switch.

(3) Programming of treatment.-Intravenous infusion of medication to raise and lower pressure can be com-V pletely automated by closed loop system and pressures of mercury in the column, means for selectively and in-AY dependently activating the visual indicators as the Korotkow sounds are detected.

Still another object of invention is to provide in a blood pressure monitor device, of the type having an aneroid manometer and visible indicators correlative to air pressure within the manometer, means for selectively and independently activating the Visible indicators as the Korotkow sounds are detected.

Still a further object of invention is to provide in a blood pressure monitor device means for separately registering indirect blood pressure on a read-out panel at variable intervals, activating an alarm system when blood pressure falls below or rises above a prescribed level, and programming of treatment.

Yet additional objects of invention will become appar-V ent from the ensuing specification and attached drawings wherein:

FIG. l is a schematic View of blood pressure monitor with cuff 16 and microphone 36 aixed adjacent the brachial artery;

FIG. 2 is schematic view of mercury column blood pressure monitor and appropriate circuits;

FIG. 3 is schematic view of aneroid manometer blood pressure monitor and related circuits; and

FIG. 4 is schematic view of the programming and alarm system used in conjunction with either mercury column or aneroid manometer blood pressure monitors.

As seen in FIGS. 1 and 2, the basic component parts of the mercury column manometer blood pressure monitor consist of a circuit actuating push-button 10, pump 12,

arm cuff 16, manometer 24, bleeder valve 28, solenoid valve 31, microphone 36, amplifier 38, contact points C2 through C53, relays K1 through K47, signal lamps'30, 35 40 255, systolic limiting switch 2i) and diastolic terminating switch 32.

The operation of the mercury column blood pressure monitor is as follows:

As seen in FIG. 2, the closing of the volt A.C. circuit Iby push-button 10, initiates the pump 12 action through 110 volt A.C. line 6 in contact through Vthe normally closed contacts of relay K1 with 110 volt A.C. 7. The pump acts as a compressor inllating the arm cuff 16 and at the same time through tube 15 connected by a T- tube connection 17 with tube 14 compresses the chamber" 44 of the manometer 24. The increase in pressure in the chamber 44 will force the mercury column 26 up establishing a mercury contact to the various contact po-ints on the contact column 52. Because contact 25 is connected to the minus side of the 6 volt D.C. by lines DC69 and 6 volt DC70 the circuit is closed between the various contact points C2 through C53 and the -6 volt D C. supply, as long as the mercury is in contact with these points.

The pressure of pump 12 continues to force the mercury column 26 up to contact C53,` which is connected by line KIC, DC7 and KlC, DC6 to the coil of the three pole 6 volt D.C. relay K1. The mercury 26 contact acts to close the circuit to the coil, which is supplieddirectly on the positive side by the lines 6 volt D.C. 1, 6 volt D.C. 3, 6 volt D.C. S connections. Pole I of K1 relay connected by line 6 volt D.C. 4 to ground, in the active position supplies through its normally open contacts 6 volt D.C. through line 6 volt D.C. 10 to the positive side of the coils of relays K2 through K47 and including solenoid valve 30 (KS2). As soon as pole I circuit of relay K1 is closed the isolating relays K2 through K47 are pulled into the active position by closure of their respective circuits by virtue of the contact of the mercury column to contacts C2 through C53 and their connections to lines DC11 through DC56. Pole Il of K1, normally open contacts, are connected to the negative side of the 6 volt D.C. supply, through connection with line DC68 through the normally open contacts of sensitive relay K55. By establishing contact with line DC11 through lines DC6, 8 and 9, pole Il provides a hold for the coil of K1, so that the relay K1 is maintained in an active position. The second pole of relay K1 through line 6 volt D.C. 9 is also connected to switch 20. Switch 20 is a systolic limiting switch and performs a function of shorting from contact S3 to contact 41 and contact 37 and contact 33, as will be further described. Pole IH of K1 through the ll() volt connection of AC6 and AC7 in the normally closed position, supplies 110 volt circuit to the pump 12, until relay K1 coil is closed (interrupting the 110 volt circuit and discontinuing the pump action). Following interruption of the pump 12 circuit, slow decompression of the cuff 16 and the chamber 44 of the manometer 24 occurs simultaneously as a result of the bleeder valve 28. With the drop in pressure in the chamber 44, the mercury column 26 will drop at a controlled rate of 21/2 to 5 mm. per second.

In the upper right hand corner of the schematic is the amplifier 38 whose input is connected to microphone 36 held in the arm cuff 16. The power supply to the amplifier is through line 9 volt D.C. 1 and an additional 9 volt D.C. battery by 9 volt D.C. B1. With the detection of a Korotkow sound by microphone 36, held in place over the artery on the arm, amplication through the amplifier 38 circuits by

transistors

1, 2, 3 and 4, would cause sensitive relay K49 to pull in to an active position. This creates a signal by virtue of the connections of lines DCS9 and DCSS with the normally open contacts of relay K49. DCSS leads to the normally open contacts of relay K2 which corresponds to a position of 255 mm. of Hg (CS2) and since the mercury column 26 is still in contact with CS2, K2 will switch the 6 volt signal through its normally open but now closed contacts to signal lamp 255, causing signal lamp 255 to ash simultaneously with each pulse and Korotkow sound heard in the artery above 25 5 mm. of Hg.

As the mercury column 26 descends due to the action of bleeder valve 2S contact of the mercury with contact CS2 is lost, K2 coi is interrupted, and the normally closed contact of K2 will switch the signal of line 6 volt D.C. S8 to the normally open, but now closed contacts of K3. Pressure sounds detected by the microphone with the mercury column 26 at this contact point, will close the circuit of the memory relay coil K3M. Providing a connection between this side of the coil of memory relay with line 6 volt D.C. 60 by the normally open contact will result in a hold7 action to the coil and the K3M relay will remain in an active position. Since signal light 259 is parallel to K3M coil, the signal light will remain illuminated as long as the coil is in an active position. Similarly, as the mercury column descends, K3 coil will become interrupted when contact of the mercury column 26 to CS1 is interrupted. The normally closed contacts of K3 will switch the signal to the normally open, but now closed contacts of K4, which in turn will close the circuits to the K4M memory relay and signal light 24S will become illuminated upon detection of a signal by microphone 36.

As the mercury column 26 drops, each subsequent isolation relay (K3 through K47) switches the signal circuit and contact to its companion memory relay, K4M through K47M, only while its own coil is closed by the connection to the mercury column. As each isolation relay coil is interrupted, its normally closed contacts switch the signal from the microphone (through K49 to DC58) to the next relay with the closed coil at the top of the mercury column. Thus each relay isolates the signal so that the signal is transmitted only to its companion memory relay illuminating the signal lamp that corresponds to the millimeters of Hg at which the sound was detected. A signal produced at any other time except for this sensitive or receptive period has no eiect on any lof the memory relays. Since the level of the blood pressure corresponds to the level at which sounds in the artery are present, the signal lamps will become illuminated and give a read out of the blood pressure.

Switch 32 is a diastolic termination switch, so that after diastolic pressure has been established, the cuff can rapidly be decompressed to atmospheric pressure. Since in individual patients diastolic termination may be desirable at different levels, the choice between 90, 70 and 50, 30 mm. of Hg is oiered by

contact points

7, 11, 15 and 19. Switch 32 through line DC78, 77, 76 and 75 with contact t-o DC64 provides the negative side of the coil of relay KS3 with a closed circuit. The positive side of the coil of KS3 is to ground so that KS3 will remain in an active position until the dropping mercury column opens the circuit of coil of relay KS3 through switch 32 and through line DC64.

During its active state, pole II of relay KS3 acts to charge capacit-or C8 of the time delay. When capacitor C8 is charged, transistor Q of the time delay circuit will conduct and maintain the normally open contacts of relay KSS closed. When transistor Q ceases to conduct by virtue of decay of the charge of capacitor C8, the contacts of relay KSS open and the minus side of the 6 volt circuit is interrupted, the coil of K1 is opened and the entire cycle is re-started. Pole I of relay KS3 through the normally closed contacts, closes the circuit to solenoid valve 39 (KS2) and rapid decompression of the arm cui 16 and mercury chamber 44 occur. The positive side of solenoid valve 39 (KS2) is through line DCS7, thus the solenoid valve will be held in an active position, i.e., valve is open, until the 6 volt D.C. circuit is interrupted by K55 through the time delay mechanism. The length of time that the time delay maintains the normally open contacts of KSS in a closed position depends upon the capacitor 8 charge. When capacitor 8 is charged, because Q, the transistor in the time delay is an NPN configuration, conduction through the transistor will occur. Relay K55 is a sensitive relay and will be activated by conduction through the transistor. The duration of conduction through the transistor controlled by switch 34 which, by virtue of R12, a variable resistor can regulate the rate of decay by increasing or decreasing the resistance.

Switch 32, the diastolic limiter switch, in eect, then controls theA solenoid valve 39 through pole I of relay KS3 and also starts the time or interval delay mechanism in operation through pole I Switch 20 similarly performs a function of limiting the level of rcompression of the arm cuff 16 and the mercury manometer 24, so that by the connections with lines DC71, 72, 73 and 74 to contacts 27, 33, 37 and 4.1 respectively, inflation of the cuil to 130, 160, 180, 20() or 250 mm. of Hg can be selected. Systolic limiting switch 20 establishes a contact between C53 `which corresponds to a level of 260 mrn. of Hg and either contact 41 corresponding to 20() mm. of Hg or contact 37, 180 mm. of Hg or contact 33, 16() mm. of Hg or contact 27, 130 mm. of Hg.

As seen in FIG. 2, the basic component parts of the aneroid manometer blood pressure monitor consist of pump \12, arm cuff 16, the aneroid manometer 24A (comprising chamber 44A, Contact arm 26A, piston arrangement and eccentric gears 91 and 92), bleeder valve 7 28, microphone 36, amplifierA 38, contact points C1 through C53, relays K1 through KS4, signal

lamps

30, 35, 40 25S, systolic limiting switch 20 and diastolic terminating switch 32.

The operation of the aneroid rnanometer sure manometer is as follows:

By virtue of the connection of the 100 A C. 7 and 110 A.C. 8, the pump action is initiated and pump 12 through

tubings

14 and 15 simultaneously inflates the arm cuif 16 and at the same time compresses air into the chamber 44A of the aneroid manometer 24A. As Ithe pressure is increased in the chamber 44A, a piston arrangement 90 rotates an eccentric gear 91 which because of its ratio to the gear 92 rotates the contact arm 26A from its zero position in a clockwise direction. The 6 volt D.C. current reduced and rectified through transformer number two by a lead from the minus side of the 6 volt D.C. power supply labeled 6 volt D.C. 60 is led to relay KS4 and the normally closed contacts of KS4 allow the circuit to continue rvia 6 volt D.C. 59 connection to 6 volt D.C. 50 leading to point 25A which is a contact point supplying the arm 26A closing circuit from 26A to the various contact points. The arm 26A would continue to rotate until contact 53, which corresponds to a pressure of 260 millimeters of mercury, is reached. At this point through 6 volt D.C. lines 53, and 6 volt D.C. 52, the coil of relay K1 is closed since 6 volt D.C. 51 is connected directly to positive pole or ground.

Relay K1 is a three pole relay. Pole \1 connected by 6 volt D.C. 2 and 6 volt D.C. 1 to ground supplies 6 volt D.C. by line labeled 6 volt D.C. 3 to the isolating relays as soon as K1 is in the active position. Pole 2 by virtue of its connection -to 6 volt D.C. 53 through 6 volt D.C. 5S line supplies the negative leads 'which maintains K1 in a closed position by D.C. 59 connection with 6 volt D.C. 60. Through the contacts of relay KS4 the circuit is opened by activation of relay KS4 at the termination of the cycle. Pole 3 of K1 throughthe 110V volt A.C. 6 in the normally closed position supplies 110 volt circuit to Athe pump by AC7 until K1 is pulled into the active position and the circuit to the pump interrupted.

Following interruption -of the pump circuit, decompression of the cuff, and the chamber 44A occur simultaneously as a result of bleeder valve 28 which allows a slow escape of air rotating the arm 26A on the face of Ydial 52A countercloclwvise from contact 53 to 52 to 51 etc. down to contact 1, establishing a contact at each of these contact points. t

In the upper right hand corner of the schematic is amplier 38 which is connected to microphone 36. It is supplied by a 9 Volt lead DCI plus Ithe small 9-volt transistor battery labeled B. As illustrated when a Korotkow sound is detected, amplification 'by transistors l1, 2, 3, and 4 occur after filtering etc. pulls into an active position. With the detection lof the Korotkow sounds by microphone 36, a signal is created by K49 as the minus 6 volt lead D.C. 63 leads through the closed contacts Iof K49 via DC62 to the contacts of relay K2. Relay K2 corresponds by virtue of connection DC4 to contact C52 Ito a position of 255 millimeters of mercury. If this signal is present because the normally open circuits of K2 are closed when lever arm 26A is at contact point C52, a signal lamp 255 will be illuminated as a ash. As the decompression of the cuff and chamber occurs simultaneously, signal arm 26A will slowly rotate down or counterclockwise lby virtue of

gears

91 and 92 from contact 52 to contact 51 and relay K3 will, because of its contact to 6 volt D.C. 5, pull linto the active position. A Korotkow sound received at microphone 36 is switched through the normally closed contacts of K2 through the normally open but now closed contacts of K3 (closing the circuit of the isolation relay to the memory relay K3M). The KorotkowV sound received at .the microphone which closes the signal circuit by relay K49 will thus activate the relay of K3M, cause K3M conblood presand K49 the sensitive relay Y further sounds are heard, and

tacts to close, which in the closed position will form a lock or hold by virtue of the common supply to N.O.

contacts and to the coil of K3M by WC61. Signal light 250 will therefore also become illuminated simultaneously since in essence it is parallel to the coil of K3M. Thus,

as the arm rotates to ythe next contact point represented p by C50 at 245 millimeters of mercury, relay K4 'will,

in turn, become active as the coil K4 is closed yby virtuel at any other time relays.

As the arm rotates each'subsequent signal Vlamp is illuminated until the diastolic level is reached. Since no despite the fact that each subsequent isolation relay is activated, no further signals are produced. When the contact arm rotates to zero position by contact and connection DC82, relay KS4 is activated. When relay KS4 is activated, the circuit to the minus side of the power supply is opened through leads DC59 and DC60. This in turn releases the hold mechanism for K1, all the signal lights are turned otf because of the interruption of the hold relays K3M to K47M and the cycle restarts when the normally closed contacts of pole 3 close the 110 volt circuit for the pump 12.

Switch 32 provides a diastolic termination regulator so that after the diastolic pressure has been established the cuff can rapidly avoiding discomfort and irritation of the sensitive tissues of the arm. This is accomplished by switching system is decompressed to zero atmos- Because the contacts of switch 32 alis supplied by pole 2. Pole 2 through the N.C. contacts by 6 volt D.C. 73 supplies a positive lead through 6 volt D.C. 74 to the positive side of the capacitor in the time delay circuit thus charging the cap-acitator.

Because of the NPN configuration of Q, a positive charge will produce ow in the NPN transistor Q and relay K55 will pull in, interrupting the circuit supplied by DC67 to the contact points of K55. Because of a hold contact arm 26A returns to C`1 position, the coil of KS3 remains closed interrupting the pole of KS4 opening the circuits fromrthe 6 volt power supply lead 60 and 59. As indicated earlier, this immediately restarts the entire cycle. As in our previous descriptions 52A is a plastic face with the contacts superimposed and isolated from each other. The side view of the plastic face and the contacts and the contact arm 26A is provided to the right of the schematic. Contact 25A lis also demonstrated.

In addition to the diastolic terminating switch 32 there is a systolic terminating switch -or a systolic limiting switch 20. The purpose of switch 20 as illustrated is to establish a contact between C53 which corresponds to a level of 260 millimeters of mercury, Oil-corresponding to 200 millimeters of mercury, C37--180 millimeters of mercury, CSS-160 millimeters of mercury, C29-130 millimeters of mercury. By this switch 20 the pump compression of the arm cuff and chamber can be terminated at any of these points once it is determined that useful range of monitoring is accomplished by .a lower level than 260 millimeters of mercury.

The electrical circuitry for the programming Yand alarm system. as shown in FIG. 3, is initiated by relay KS3 (in both FIGURES 1 vand 2). Upon completion of measuring cycle, rapid decompression of the cuff is accomplished by closing the coil of relay KS3, a double pole relay. Pole II through its N O. contacts supplies a 6 v. D.C. positive supply in the active poosition to coils of the relays and solenoids of the alarm and programming systern, K75, K76, K77, K78, K79, K8() and the positive terminal of alarm buzzer B115. The negative leads to close the various circuits originate with the terminal contacts of the circuits oi' the memory relays K3M through K47M as illustrated in FIGURES 1 and 2.

For this type of therapy programming a range of 20-30 points millimeters of mercury is desirable and contact points to the left of the read-out panel, a to c, d, e, f, corresponding to 60 thru 150 mm. Hg were selected for shock treatment programming with g, h, z', j, k, l points corresponding to 130 to 220 mm. Hg for high blood pressure treatment programming. Each of points a thru f will close circuits only if their respective memory relay coil is open, points g thru l will close circuits only if their respective memory relay circuits are closed. Between 120 and 150 mm. Hg, the two types of programming overlap without interferences.

Automated closed loop feed back high blood pressure control and treatment is directed to the regulation of the amount of certain medications introduced by the intravenous tubing into the blood stream, dependent upon the level of blood pressure (FIGURE 3),

flask

101 and 102 contain stronger and relatively weaker concentrations of the medications respectively. In essence the treatment program depends on the ability to cycle olir and on either

ilask

101 or 102 depending on the blood pressure control point selected. Selector switch PAI and P2 regulate levels at which the medications in asks 101 and 102 are available for intravenous therapy. PA1 diers from PA2 only inasmuch as PAI sounds alarm in addition to programming therapy when its circuit is closed. Switch 120 closes the circuit to the alarm buzzer B115. It is parallel electrically to the coils of relay K75, a disconnect relay. The two systems are coordinated so that PAI will `automatically supersede the circuitry of P2 through the disconnect relay of K'75 since the lead from switch P2 to flask 102, solenoid valve 106 (K78) is through the normally closed contacts of relay K75 by means of leads DC124 and DC134.

Two contact points, one 20 mm. below the other are programmed .as a sequence, l and k, k and j, j .and l, l and h, h and g, each will function to cycle ask 102 on, if the blood pressure reading on the manometer coordinates with the contact point from the switch P2. If the blood pressure continues to move up another 2O` mm. Hg, ask 102 is cycled off, flask 101 will be automatically cycled on and treatment will proceed through the tubing T1, T5, T9, T11 allowing uid into the vein 112.

A sample response to therapy can be illustrated as follows: With PAI set at 220 and P2 set Vat 210 and switch 120 closed, if after the iirst measuring cycle the pressure is registered on the panel at 210 mm. Hg, by means of leads DC124, 134, the circuit to solenoid valve 106 (K73) is closed. The closing of the circuit to K78 pulls open solenoid valve 106 allowing the iluid in the ask 102 to flow into the vein and treatment is started. If upon completion of the next measuring cycle of the blood pressure manometer, the blood pressure continues elevated and 220 mm. Hg is registered, the circuit of PA1 is closed by contact 1, 6 v. D.C. 121, 6 v. D.C. 122 to the solenoid valve (K77) of flask 101. Not only will flow start in flask 101 through tubing T1, T5, T9, T11 but simultaneously through 6 v. D.C. 123, 6 v. D.C. 128, 6 v. D.C. 130, the alarm B will sound and through 6 V- D.C. 129, the coil of K75 will be closed interrupting the circuits of solenoid valve 106. The iluid in flask 101 will continue to run into the vein until the next automatic blood pressure measuring cycle. If the blood pressure responds to the medication and drops below 220, ask 101 will be cycled to the Off position and the circuit to flask 102 will automatically be closed .and solenoid valve 106 opened. Thus the elevation of blood pressure above the preselected point, in this case 210, instituted therapy with flask 102, continuation of blood pressure elevation to 220 mm. Hg started flask 101, discontinued flask 102, and sounded alarm B115. Return of blood pressure to levels below 220 discontinued treatment by flask 101, restarted iiask 102, and discontinued the buzzer alarm B115. Upon response of blood pressure to below 210, both ask 101 and ilask 102 will be discontinued. By moving the switch clockwise blood pressure control contact points labeled I to g on FIGURE 3 can be selected to automatically maintain relatively stable and constant blood pressure at a medically desirable level using appropriate concentration of medications in asks 101 and 102.

The lower portions of FIGURE 3 diagrammatically illustrates the programming of the monitor to automatically control treatment of dangerously low blood pressure such as may be seen in heart conditions, injuries, burns, etc. For low pressure, switch is opened and switch 130 closed the control switches P3 and PA4 are positioned t0 the desired control points. Control programming switch P3 and programming alarm switch PA4 `are interlocked and coordinated providing two control contact points, one 20 mm. Hg below the other, programmed ,as a sequence. When switch P3 circuit is closed, flask 103 will institute intravenous corrective treatment. But if the pressure drop to the next control point, P3 is superseded by PA4 and ask 104 replaces 103 as treatment.

In a patient, whose blood pressure should be maintained `at 110 mm. Hg P3-PA4 is rotated clockwise to position c corresponding to 110 mm. Hg in the P3 circuit and 90 mm. Hg in the PA4 circuit. Following the blood pressure measuring cycle of the automatic monitor, no action will ensue if the read-out panel lamp corresponding to 110 mm. Hg remains illuminated. If on the next determination there is a drop in blood pressure to levels less than 110 mm. Hg, i.e. 105 mm. Hg the circuitry of P3 is closed, 6 v. D.C. 112, 6 v. D.C. 117, 6 v. D.C. 125 through the normally closed contacts of pole II of relay K76 and 6 v. D.C. 133, close the coil of K79 of solenoid valve 107, opening solenoid valve 107 and allowing the medicated contents of ask 103 to tlow through tubing T3, T7, T10, T11 and into the Vein 112. If this therapy is adequate the blood pressure again on the next cycle will be back to its original level of 110, P3 circuits will be open and treatment by flask 103 discontinued through the closing of the solenoid valve 107 to its normally closed position. If, however, on the next measurement cycle the pressure drops below 90 mm. Hg the circuit of the programming -alarm switch PA4 will be closed. Leads 6 v. D C. 126, 131, 132 close the coil of K76 a two-pole relay, whose pole I normally closed contacts are opened, opening the circuit to flask 103 returning solenoid valve 107 to its normally closed position. Pole II of Arelay K76 normally open contacts close the 110 volt A.C. circuit to the ECG monitor (commercially available). Simultaneously institution of therapy with contents of flask 104 replaces flask 103 closing the circuit to KSU, controlling solenoid valve 108, allowing the iluids to flow through the tubing T4, T8, T10, and T11 into the vein 112. With the onset of therapy with flask 104 the buzzer alarm B115 continues to ring until manually discontinued by switch 130 or until the next automatic measuring cycle. If the blood pressure on the next cycle is registered at 90 mm. Hg, switch PA4 circuit remains open and switch P3 circuit will be closed. Flask 103 will be restarted for treatment into the vein, ask 104, electrocardiogram monitor and alarm B115 discontinued. .Thus ask' 103 and 104 in essencercycle olf and on depending on the level of the blood pressure and the setting7 selected on switch P3 and PA4, controlling abnormally low dangerous level by an automated closed feed back system.

Manifestly, various substitutions of parts and changes in circuitry can be adopted without departing from the spirit and scope of invention defined in the subjoined claims.

I claim:

1. A blood pressure monitor apparatus comprising:

(a) an inflatable cuff;

(b) pump inflating means including a conduit' in communication with said cuff; Y

(c) a bleeder valve positioned in said conduit to allow said cuff to so decompress;

(d) an electrically conductive pressure responsive aneroid manometer in communication with said conduit;

(e) a display panel electrically connected via a series of independent circuits to respective pressure gradient contact points adjacent said aneroid manometer, said display `panel including Visual indicia means corresponding to mid-pressure gradient contact points adjacent said manometer;

(f) a source of electrical energy supplying said pump infiating means, said aneroid manometer, and said display panels;

(g) a pressure select switch in circuit with said aneroid manometer and said pump intl-ating means, said pressure select' switch being actuable within said aneroid manomet'er to cut off said source of electrical energy from said pump inliating means 'at a predetermined pressure;

(h) a decompression valve in said conduit and la pressure responsive switch interconnecting said aneroid manometer and said valve, gauging decompression according as a pre-set pressure is detected in said manometer;

(i) Van interval control switch in circuit with said source of electrical energy and closing said source of energy with said pump inating means .at predetermined intervals; and

(j) sound detecting means in communication with said cuff and independently relayed to said visual indicia, so as to limit electrical energization of said indicia, except as Korotkow sounds are detected.

2. A blood pressure monitor as in claim 1, wherein said sound detecting means includes ya microphone positionable adjacent said cuff for detection of Korot-kow sounds, together with an independent amplifier.

3. A blood pressure monitor apparatus comprising:

(a) an inflatable cult; v

(b) pump inating means in cul;

(c) bleeder valve means positioned intermediate said pump inlating means and said culi to allow said cuff to slowly decompress;

(d) electrically conductive pressure detecting means in communication with said communication with said cuff and responsive to changes in pressure therein;

(e) a display panel electrically connected to said pressure detecting means, said display panel including visual indicia means corresponding to pressure level ygradients of 5 mm. of Hg registered by said pressure detecting means;

(f) a source of electrical energy supplying said cuit inating means, pressure detecting means, and display panel;

(g) sound detecting means in electrical communication with said cutf and energized independently of said source of electrical energy supplying said pump inating means, said pressure detecting means and said display panel so as to limit electrical energization of said indicia, except as Korotkow sounds are detected; and

(h) therapy programming means including (l) a plurality of flasks containing variations of medications therein together with intravenous systems for introducing said medications into the blood stream;

(2) valve means associated with said asks for regulating the ow of medications therethrough; and

(3) electrical means for translating said changes in pressure determined by said pressure detecting means into actuation of certain of said valve means'of said flasks, as predetermined.

4. Method of blood pressure monitoring and treatment programming, comprising:

(a) pressurizing a sound detecting cuff adjacently positioned to a blood containing artery and a pressure detecting device;

(b) electrically energizing said pressure detecting device anda visual display indicia so as to be responsive to changes in pressure within said cult;

(c) detecting Korotkow sounds through said cu` and limiting energization of said visual display indicia, except as Korotkow sounds are detected; and

(d) translating electrically said detected changes in pressure to regulation of introduced into the bloodstream.

5. Method as in claim 4, wherein said regulation includes automatic cycling of medications of varying strength.

6. Method as in claim 5, wherein said pressure detecting and introduction of medications are cycled such that response to said medications can be gauged by said. pressure detecting device before introduction of further medications.

7. Method as in claim 6, wherein said regulation includes both shock treatment programming and pressure treatment programming.

8. Method as in claim 6, including translating electrically detected changes actuation of an electrocardiogram monitor.

9. Method as in claim 8,'including translating electriin pressure of preselected levels to actuation of alarm signal to coincide wtih cycling of preselected medications. Y

10. A blood pressure monitor as in claim 3, including means for automatically cycling medications from preeslected asks in response to changes in pressure determined by said pressure detecting means.

11. A blood pressure monitor as in claim 9, including an electrocardiogram monitor and means for actuating same as preselected pressure level is gauged by said pressure detecting means.

12. A blood pressure monitor as in claim 11, including an alarm system and means for actuating same as preselected pressure levels are `gauged by said pressure detecting means.

13. A blood pressure monitor as in claim 12, including means for cycling the operation of said pressure detecting intravenous medications in pressure of preselected level t0 14 Pigeon 12S-2.05 Goolkasian 12S-2.05 Vibber et al 128-214 De Beer et al 128-214 Kompelian 1282.05 Dymski 12S-2.05 Smith 128--2.05

RICHARD A. GAUDET, Primary Examiner.

13 means and actuation of said valve means of said asks 2,848,992 such that response to intravenous treatment by said medi- 2,918,054 cations can be gauged before continuing said therapy. 2,925,814 2,979,055 References Cited by the Examiner 3,051,165 UNITED STATES PATENTS o 2,352,875 7/ 1944 Williams 1282.05 77 2,690,178 9/1954 Bickford 128-213 2,821,188 1/1958 Pigeon 12S-2.05 2,827,040 3/195s Gilford 12s-2.05 10 SIMON B RODER, Examiner.

Claims

1. A BLOOD PRESSURE MONITOR APPARATUS COMPRISING: (A) AN INFLATABLE CUFF; (B) PUMP INFLATING MEANS INCLUDING A CONDUIT IN COMMUNICATION WITH SAID CUFF; (C) A BLEEDER VALVE POSITIONED IN SAID CONDUIT TO ALLOW SAID CUFF TO SO DECOMPRESS; (D) AN ELECTRICALLY CONDUCTIVE PRESSURE RESPONSIVE ANEROID MANOMETER IN COMMUNICATION WITH SAID CONDUIT; (E) A DISPLAY PANEL ELECTRICALLY CONNECTED VIA A SERIES OF INDEPENDENT CIRCUITS TO RESPECTIVE PRESSURE GRADIENT CONTACT POINTS ADJACENT SAID ANEROID MANOMETER, SAID DISPLAY PANEL INCLUDING VISUAL INDICIA MEANS CORRESPONDING TO MID-PRESSURE GRADIENT CONTACT POINTS ADJACENT SAID MANOMETER; (F) A SOURCE OF ELECTRICAL ENERGY SUPPLYING SAID PUMP INFLATING MEANS, SAID ANEROID MANOMETER, AND SAID DISPLAY PANELS; (G) A PRESSURE SELECT SWITCH IN CIRCUIT WITH SAID ANEROID MANOMETER AND SAID PUMP INFLATING MEANS, SAID PRESSURE SELECT SWITCH BEING ACTUABLE WITHIN SAID ANEROID MANOMETER TO CUT OFF SAID SOURCE OF ELECTRICAL ENERGY FROM SAID PUMP INFLATING MEANS AT A PREDETERMINED PRESSURE;