EP0148819A1 - Method and apparatus for diagnosis of coronary artery disease - Google Patents
Method and apparatus for diagnosis of coronary artery diseaseInfo
- Publication number
- EP0148819A1 EP0148819A1 EP19830902404 EP83902404A EP0148819A1 EP 0148819 A1 EP0148819 A1 EP 0148819A1 EP 19830902404 EP19830902404 EP 19830902404 EP 83902404 A EP83902404 A EP 83902404A EP 0148819 A1 EP0148819 A1 EP 0148819A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- slope
- exercise
- subject
- systolic
- during
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
- A61B5/02007—Evaluating blood vessel condition, e.g. elasticity, compliance
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
- A61B5/021—Measuring pressure in heart or blood vessels
- A61B5/022—Measuring pressure in heart or blood vessels by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers
- A61B5/02208—Measuring pressure in heart or blood vessels by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers using the Korotkoff method
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/22—Ergometry; Measuring muscular strength or the force of a muscular blow
- A61B5/221—Ergometry, e.g. by using bicycle type apparatus
- A61B5/222—Ergometry, e.g. by using bicycle type apparatus combined with detection or measurement of physiological parameters, e.g. heart rate
Definitions
- Electrocardiograph (ECG) measurements also are of well known diagnostic significance in heart disease.
- ECG Electrocardiograph
- An object of the preset invention is the provision of improved diagnostic method and apparatus for the improved diagnosis of coronary artery disease.
- An object of the present invention is the provision of improved diagnostic method and apparatus of the above-mentioned type which provides a measure of heart contractility of a subject during a range of exercise.
- the above and other objects and advantages of this invention are obtained by recurrently obtaining a measure of the time rate of change in the intra-arterial pressure of a subject during systole (i.e. systolic slope of blood pressure waves in an artery of a subject) before, during and after exercise performed by the subject.
- One means for obtaining recurrent measures of the systolic slope of the arterial blood pressure waves includes the use of an inflatable cuff which is inflatable to a pressure above systolic pressure and deflatable to a pressure below diastolic pressure.
- a pressure transducer is connected to the inflatable cuff for generating a signal which is a function of cuff pressure.
- a microphone detects Korotkov sounds during deflation of the cuff, and electrodes attached, to the subject pick-up electrocardiograph signals.
- a K-sound detector detects Korotkov sounds from, the microphone and an R-wave peak detector detects the peak of the ECG R-wave.
- the K-sound and R-wave signals from the detectors are converted to signals for use by a computer, and the pressure transducer output is converted to digital form for transfer to the computer and storage in the computer memory.
- the R-wave and K- sound signals may be supplied as interrupt signals to the computer with the time of arrival of such signals being stored in the computer memory.
- ECG and/or Korotkov sound waveforms may be digitized and input to software R-wave and/or K-sound detectors in the computer with the time of arrival of the software detected R-waves and/or K-sounds being stored in the computer memory.
- the time intervals between the time of arrival of the R-wave signals and the associated K-sound signals during a cuff deflation are determined by the computer and the resultant RK intervals and associated cuff pressures are stored in the computer memory.
- the RK intervals are processed to discriminate between true Korotkov sounds and artifacts.
- minimum mean-squared fitting techniques a straight line is fitted by the computer to the collection of true RK interval versus cuff pressure points, which line has a slope inversely proportional to the systolic slope of the arterial blood pressure wave.
- CAD coronary artery disease
- Fig. 1 is a plot of an electrodardiographic signal and an associated arterial blood pressure wave showing RK intervals; measurements of which are made using the system shown in Fig. 3;
- Figs. 2A and 2B each show graphical representations of arterial blood pressure waves at different times during a range of exercise for subjects without and with, respectively, coronary artery disease;
- Fig. 3 is a simplified block diagram of a system for recurrently obtaining a measure of the systolic slope of a blood pressure wave and for displaying said measurements, which system embodies the present invention
- Fig. 4 is a plot of RK interval as a function of cuff pressure for use in explaining the operation of the system shown in Fig. 3;
- Figs. 5A -5D are graphs of measurements of slope versus heartbeat rate for subjects with no known coronary artery disease
- Figs. 6A-6D are graphs which are similar to those shown in Figs. 5A-5D for subjects known to have coronary artery disease;
- Fig. 7 is a flow chart for use in explaining operation of the system shown in Fig. 3;
- Fig. 8 shows graphs of measurements of "RK-slope" versus time for a subject with and a subject without coronary artery disease
- Fig. 9 shows details of a step of the flow chart of Fig. 7 wherein various parameters of the systolic slope measurements are employed by the computer for use in identifying subjects with CAD.
- Reference first is made to Fig. 1 wherein portions of an electrocardiograph signal 10 and associated brachial artery pressure wave 12 are shown.
- recurrent measurements of the systolic slope of the pressure wave are made during an exercise routine. Measurements of the slope together with measurements of certain changes therein which occur during the course of an exercise protocol are evaluated based on corresponding measurements obtained from other subjects with and without known coronary artery disease (CAD) for diagnosis of the disease.
- CAD coronary artery disease
- FIGS. 2A and 2B are representative of many, but not all, types of CAD, and are shown for purposes of illustration only, Systolic slope portions of pressure waves obtained before, during and after exercise stress are depicted in Figs. 2A and 2B.
- the same reference characters are used in Figs. 2A and 2B for pressure pulses obtained at the same relative time during an exercise protocol, except for the use of the suffixes A and B in Figs. 2A and 2B, respectively.
- the at rest, before exercise, waves are identified by reference characters 20A and 20B. Both of these waves show systolic and diastolic pressures which are considered to be within normal ranges thereof.
- the systolic slope of the waves differ, with the systolic slope of pressure wave 20A being greater than that of pressure wave 20B.
- the pre-exercise, resting, systolic slope for subjects with CAD is less than that of subjects without CAD.
- Pressure waves 22A-1, 22A-2 and 22A-3 shown in Fig. 2A are typical of those observed after 2, 4 and 6 minutes, respectively, of exercise.
- the systolic slope slowly increases with increasing exercise.
- the systolic slope generally increases to a maximum value, and remains substantially at said value during continued exercise.
- representative pressure waves 24B-1, 24B-2 and 24B-3 during exercise for a subject with CAD show an increase in the systolic slope with exercise, followed by a decrease therein with further exercise.
- the ejection percentage divided by 100, is the ejection fraction (EF).
- EF can be measured by injecting a radioactive solution into the blood and then "photographing" the left ventricle with a radionuclide camera at a rate of approximately 30 to 40 photographs per second.
- Figs. 2A and 2B Pressure waves 24A-1, 24A-2 and 24A-3 are typical of a healthy subject observed 2, 4 and 6 minutes, respectively, after exercise.
- the systolic slope remains substantially the same as the slope immediately before the end of exercise, and then slowly decreases with time to the pre-exercise, resting slope. This pattern is in contrast to that observed in many subjects with CAD wherein, after exercise, the systolic slope often decreases beneath the pre-exercise, resting, slope before returning to such pre-exercise slope.
- the digitized cuff pressure signal is connected through a digital multiplexer 42 to a computer 44 which includes memory 44A where cuff pressure signals obtained during a cuff deflation temporarily are stored for use in computing a measure of the systolic slope of blood pressure waves during said deflation.
- the cuff 30 With the cuff 30 attached to the upper arm of the subject, the cuff is inflated to a pressure above systolic pressure. Then, as the cuff pressure is decreased, the first Korotkov sound appears at the systolic pressure, and the last at the diastolic pressure.
- a microphone 46 picks up the Korotkov sound (K-sound) at a plurality of cuff pressures between systolic and diastolic.
- the microphone output signal is amplified by amplifier 48, and the amplifier output is supplied both to a signal converter 50 and to a K-sound detector 52.
- the converter 50 simply may include a one shot for generation of a pulse output in response to an amplified K-sound output from amplifier 48, which pulse output is connected to the multiplexer 42.
- the K-sound detector 52 distinguishes between true K-sounds and artifacts, and produces an output in response to said true K-sounds, which output is connected to an address input of the multiplexer.
- the output from the converter 50 is connected through the multiplexer 42 to an interrupt input of the computer 44 to produce a K-sound timing signal which, together with an associated R-wave timing signal, provides a measure of the RK interval.
- ECG electrodes 60 attached to the subject's body pick up ECG signals which are amplified by amplifier 62 and then supplied to a converter 64 and to an R-peak detector 66.
- the converter 64 also may include a one-shot for generation of a pulse output in response to the R-wave component of the amplified ECG signal.
- the pulse output from the converter 64 is connected to the multiplexer 42 for connection as an interrupt input to the computer 44.
- the R-peak detector detects the R-wave of the ECG signal while discriminating against noise and other components, such as the P and T wave components.
- the R-peak detector output is supplied as an address input to the multiplexer 42 for connection of the output from the converter 64 to an interrupt input of the computer 44 when an R wave is detected.
- the difference in time between the arrival of an R wave input and associated K-sound signal at the interrupt inputs to the computer provides a measure of the RK interval, which interval is temporarily stored in the computer memory 44A for use with other such RK interval values obtained at different cuff pressures for use in calculating a value related to the systolic slope of the subject's arterial blood pressure wave.
- Another address input for the multiplexer 42 is obtained from the computer 44 through a control unit 70. Under control of unit 70, the multiplexer 42 is switched for connection of cuff pressure signals from, the A/D converter 40 to the computer 44. Also, multiplexer address input information is supplied to the computer 44 through the control unit 70 for use by the computer in controlling operation of the multiplexer.
- a keyboard 72 may be included for manual supply of information to the computer, such as the name of the subject to be tested, facts concerning the subject, and various points in the exercise protocol including the start and end of the exercise portion thereof.
- Data display and recording unit 74 may be used to display and/or record systolic slope information at different exercise levels of the subject.
- the computer may be programmed to compute systolic and diastolic blood pressure, which values also may be displayed and/or recorded by unit 74.
- a system of the type shown in Fig. 3 for measuring systolic and diastolic blood pressure is shown in the above-mentioned Weaver et al article entitled A Study of Non-invasive Blood Pressure Measurement Techniques, the entire disclosure of which article specifically is incorporated by reference herein.
- the relationship between systolic slope as a function of exercise stress and CAD is not disclosed in the article, nor are means for the diagnosis of CAD using measurements of the systolic slope, and changes in the slope, disclosed therein.
- Fig. 1 wherein the relationship between systolic slope of the blood pressure wave 12 and RK interval is shown.
- the RK interval i.e. the time interval between the occurrence of the R wave peak and the associated K-sound, is maximum at systolic pressure and minimum, at diastolic pressure. As the cuff pressure is decreased from systolic, the RK interval also decreases.
- the K-sounds are of maximum amplitude intermediate the upper and lower ends of the systolic slope and gradually decrease to zero at systole and diastole.
- a plurality of RK interval measurements are obtained, and a plot of such measurements as a function of cuff pressure is shown in Fig. 4 to which reference now is made.
- a straight line 80 is shown fitted through the series of points using minimum mean-squared error fitting techniques readily implemented by use of the computer.
- the slope, ⁇ RKinterval / ⁇ pressure, of the line is inversely proportional to the systolic slope of the blood pressure wave, as depicted in Fig. 1 and, therefor, provides a measure of the systolic slope of the blood pressure wave.
- the slope of line 80 decreases, and vice versa.
- the slope of the straight line 80 is determined and utilized in a program for distinguishing between true Korotkov sounds and artifacts.
- the maximum and minimum cuff pressures at which true Korotkov sounds are obtained provide a measure of the systolic and diastolic blood pressures, respectively, as seen in Fig. 4.
- the same process disclosed in the Weaver et al article may be used in the present invention to distinguish between true Korotkov sounds and artifacts in order that a true measure of the systolic slope may be obtained. It here will be noted that knowledge of the systolic and diastolic blood pressures is not required in the practice of the present invention.
- the slope of the line 80 may be established using only points adjacent the center of the line 80, and not those adjacent the opposite ends thereof where the Korotkov sounds are much weaker.
- the apparatus may be used for measuring systolic and diastolic blood pressures, and such pressures may be displayed and/or recorded or stored along with the diastolic slope measurements, if desired. Since the present invention is not specifically directed to the method of distinguishing between true Korotkov sounds and artifacts, it will be understood that such artifacts are removed by suitable processing of the signals from the detector 52, and that points in the plot of Fig. 4 to which the straight line 80 is fitted are obtained using true Korotkov sounds, not artifacts.
- a series of points are obtained, as shown in Fig. 4, through which the straight line 80 is fitted.
- the slope of such line is readily calculated by the computer.
- the time interval between adjacent R-peak waves is determined, and the reciprocal thereof is calculated to provide a measure of heart rate during the cuff deflation.
- the above-described operation is repeated whereby a plurality of values of slope as a function of heart beat measurement, or of time, are obtained, which values may be displayed and/or recorded at display and/or recording unit 74 of Fig. 3.
- the RK interval versus cuff pressure slope i.e. slope of line 80 of Fig.
- FIG. 4 is referred to as RK slope, for convenience.
- FIGs. 5A-5D and Figs. 6A-6D wherein records of the type which may be provided by the present system, are shown.
- the slope of the straight line fitted to the measured points for each cuff deflation i.e. RK slope
- FIG. 5A-5B was obtained from four healthy subjects having no known CAD while those of Figs. 6A-6D have CAD.
- the symbol X marks the point obtained with the subject at rest, before exercise. Points obtained during exercise are identified by the symbol , and those obtained after exercise are identified by the symbol o.
- Points for the plots were obtained at two-minute intervals, which intervals may be programmed in the computer 44, or entered through the keyboard 72. It will be understood that substantially continuous measurements may be made, and plotted, there being no requirement for the two-minute spacing between measurements.
- a clock 44B shown in Fig. 3, is included to provide time measurements.
- the RK interval/ cuff pressure slope (RKslope) for the four healthy subjects at rest, before exercise is within the range of approximately .6 to 1.5.
- the resting slope generally equals or exceeds 2, as seen in Figs. 6A-6C. Since systolic slope is inversely related to the illustrated slope, it will be seen that the resting systolic slope for a subject with known CAD is generally equal to or less than .5.
- the subject with CAD is shown to have a normal starting slope of approximately 1.
- the RK slope for healthy subjects decreases substantially exponentially to a value slightly above zero, as shown in Figs.
- the RK slope also generally decreases during exercise, as seen in Figs. 6A, 6B and 6C but never reaches levels as low as those reached by healthy subjects.
- Figs. 6D there was essentially no change in slope during the entire cycle which too is unlike the change in slope observed in healthy subjects.
- the RK slope for healthy subjects shown in Figs. 5A-5D, slowly returns to the pre-exercise level, while remaining generally within the upper and lower limits reached during exercise.
- the slope rapidly rises during the post-exercise period.
- the post- exercise slope exceeds the pre-exercise slope, as seen in Figs. 6A-6B, which means that the systolicslope of the brachial artery pulse is low, as is the ejection fraction EF.
- the post-exercise slope did not significantly change.
- cuff inflation step 108 is entered wherein the cuff 30 is inflated under control of the computer to a pressure above systolic blood pressure through operation of the cuff pressure controller 34 to occlude blood flow in the brachial artery.
- the cuff pressure is reduced to a pressure at which true Korotkov, or artifact, sounds are first detected, which, for true Korotkov sounds, is the systolic blood pressure.
- the cuff pressure is entered into the computer memory 44A through use of transducer 36, amplifier 38, A/D converter 40 and digital multiplexer 42, as indicated by step 112.
- an R-peak wave is detected and its time of arrival is entered in the computer memory.
- the time of arrival of an associated Korotkov sound also is entered into the computer memory.
- the K-spund detector 52 may also respond to artifacts, in which case the time of arrival of such artifacts also is entered into the computer memory. For any given R-peak wave the time of arrival of the true, K-sound and that of one or more artifacts may be stored.
- the RK-interval is calculated, and the RK- Lnterval value, or values, are stored (step 118) with the associated cuff pressure.
- the cuff pressure at step 120, is then reduced an incremental amount of, say 4mmHg.
- the decision step 122 next is performed to determine whether or not outputs are produced from the K-sound detector 52. If not, it is known that cuff pressure has been reduced beneath diastolic pressure. If the decision is affirmative, i.e. that K-sounds are still being detected, step 112 is again entered, whereupon the new reduced cuff pressure value is stored, together with new associated RK-interval values.
- step 132 using the slope calculated at step 130 and heart rate calculated at step 124, a point is recorded on a slope versus heart rate plot (of a type shown in Figs. 5A-5D and 6A-6D).
- the decision step 134 then is entered at which point a decision is made as to whether or not the test is to be continued. Keyboard switches, not shown, may be included for manual entry of the decision into the computer 44. If the decision is made to continue the test, step 106 is reentered, at which point the operator, or physician, may enter the next stage in the exercise cycle, such as "exercise". The subject then begins, or continues, that portion of the exercise cycle, and another measure of systolic slope is made and added to the plot.
- step 136 is entered at which point an analysis is made of the plot by the physician to determine whether or not the plot differs from those of healthy subjects for diagnosis of CAD.
- the test and diagnosis ends at step 138. It here will be noted that certain steps of the flow chart may be performed in different order.
- Fig. 8 wherein a graph, or plot, of measurements of RK slope versus time for a subject without CAD and a subject with CAD are shown, which graph is readily available as an output from the computer.
- Parameters 1 and 3-7 are identified on the graph of the subject with CAD. It will be noted that the slope of the graph during the first several minutes of exercise changes substantially exponentially for the subject without CAD. On the other hand, the slope of the graph for the subject with CAD during the same initial time period is substantially constant for approximately two minutes, then abruptly decreases. This rate of decrease of the slope is employed in the evaluation of parameter 2.
- threshold values may be set, or established from an examination of data from a large number of subjects.
- the threshold for parameter 1 the resting RK-slope prior to exercise, is set between the average for persons with CAD and the average for persons without CAD. From an examination of Figs. 5A through 5D for healthy subjects the average resting RK-slope before exercise is on the order of 1.2, and from Figs. 6A through 6D for subjects with known CAD, the average resting slope is on the order of 2.5. A threshold value between, these averages of, say 1.8 may be employed. This, and thresholds for the other parameters are stored in the computer memory. For parameter 1, the computed resting RK-slope is compared to the 1.8 threshold value and, if it is less than the threshold it is considered normal.
- a value of 1 (one) may be assigned thereto, and if it is below the threshold, a value of -1 may be assigned thereto.
- These outputs are weighted according to the importance of the parameter in the diagnosis; with negative weights being assigned to parameters where necessary.
- the weighted values for the various parameters simply may be added to provide an overall figure indicative of the condition of the subject's coronary arteries. This figure, together with the individual weighted values may be read out from the computer.
- Such a system is well adapted for screening large numbers of subjects for CAD.
- the parameter values may be obtained directly from the plot or graph of the RK-slope versus time and that manual calculation may be employed in the evaluation.
- the computer is well adapted for performing such calculations.
- Fig. 9 to which reference now is made, details for the block 136 of the Fig. 7 flow chart are shown for computer evaluation of the RK-slope vs time information obtained during an exercise routine of a subject. Parameters 1-7 are determined and/ or evaluated and weighted at steps 136-1 through 136-7, respectively, and at step 136-8 the weighted values are summed, and the results are displayed.
- a nonlinear discriminant function which is not suitable for manual analysis also may be included in an algorithm for computer evaluation of measured data.
- the invention is not limited to the above-described algorithmic process.
- the above-described parameters can be weighted to indicate the relative abnormality of the heart condition. These weighted values may be summed and the total compared to a cut-point for an indication of a normal or an abnormal condition. Again, such an evaluation may be performed manually or by the computer based on the data obtained during the exercise routine.
- Heart rate can be substituted for time in the above analyses. All of the parameters except parameter 2 are defined as above.
- systolic and diastolic blood pressure measurements may be obtained from cuff pressure measurements made when true Korotkov sounds are first heard during a cuff deflation, and are last heard, and these pressures also, may be displayed and/or recorded.
- the operation of the present apparatus does not depend upon determination of systolic and diastolic blood pressures.
- inputs may be supplied to the computer from the exercise device, or the like, used by the subject whereby the work performed by the subject throughout the exercise cycle may be recorded.
- means other than interrupt inputs may be used to input the time of occurance of the R-peak wave and Korotkov sound to the computer. Either a general purpose or dedicated computer may be employed. Also, a recording of the necessary inputs may be made, and the recording played back to provide the computer inputs.
- other blood pressure transducers and systems may be used from which a measure of the systolic slope may be obtained, including, for example, invasive devices. It is intended that the above and other such changes and modifications shall fall within the spirit and scope of the invention defined in the appended claims.
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- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Cardiology (AREA)
- Heart & Thoracic Surgery (AREA)
- Molecular Biology (AREA)
- Physiology (AREA)
- Biophysics (AREA)
- Pathology (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Vascular Medicine (AREA)
- Medical Informatics (AREA)
- Physics & Mathematics (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Ophthalmology & Optometry (AREA)
- Physical Education & Sports Medicine (AREA)
- Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
Abstract
Procédé et appareil pour obtenir de manière récurrente une mesure de la pente systolique de l'onde de pression sanguine dans l'artère d'un sujet pendant une série d'activités physiques, ou d'exercices. Un plan ou enregistrement des mesures de la pente par rapport au taux de pulsation cardiaque, un point dans un protocole d'exercice ou autre est prévu permettant de distinguer entre les sujets souffrant d'une affection de l'artère coronaire (CAD) et les sujets exempts de CAD.Method and apparatus for recurrently obtaining a measurement of the systolic slope of the blood pressure wave in a subject's artery during a series of physical activities, or exercises. A plan or recording of the measurements of the slope relative to the rate of cardiac pulsation, a point in an exercise protocol or other is provided making it possible to distinguish between subjects suffering from a coronary artery disease (CAD) and those CAD free subjects.
Description
Claims
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/US1983/001010 WO1985000279A1 (en) | 1983-06-30 | 1983-06-30 | Method and apparatus for diagnosis of coronary artery disease |
Publications (1)
Publication Number | Publication Date |
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EP0148819A1 true EP0148819A1 (en) | 1985-07-24 |
Family
ID=22175324
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19830902404 Withdrawn EP0148819A1 (en) | 1983-06-30 | 1983-06-30 | Method and apparatus for diagnosis of coronary artery disease |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0148819A1 (en) |
JP (1) | JPS60501740A (en) |
DE (1) | DE148819T1 (en) |
WO (1) | WO1985000279A1 (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0532082Y2 (en) * | 1988-07-26 | 1993-08-18 | ||
US5752521A (en) | 1993-11-12 | 1998-05-19 | Dardik; Irving I. | Therapeutic exercise program |
US5980464A (en) * | 1996-12-19 | 1999-11-09 | Colin Corporation | Apparatus for evaluating exercise function of person |
US5906581A (en) * | 1996-12-19 | 1999-05-25 | Colin Corporation | Apparatus for evaluating exercise function of person |
FR2757367B1 (en) * | 1996-12-24 | 1999-03-05 | Colin Corp | APPARATUS FOR EVALUATING THE EXERCISE FUNCTION OF A PERSON |
WO2002003076A2 (en) | 2000-06-30 | 2002-01-10 | Lifewaves International, Inc. | Systems and methods for assessing and modifying an individual's physiological condition |
US6702720B2 (en) | 2001-04-24 | 2004-03-09 | Lifewaves International, Inc. | Systems and methods for breathing exercise regimens to promote ischemic preconditioning |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3675640A (en) * | 1970-04-09 | 1972-07-11 | Gatts J D | Method and apparatus for dynamic health testing evaluation and treatment |
US3908639A (en) * | 1971-04-02 | 1975-09-30 | Kevin M Mcintyre | Detecting impaired heart mechanical performance |
US3903872A (en) * | 1974-02-25 | 1975-09-09 | American Optical Corp | Apparatus and process for producing sphygmometric information |
US4418700A (en) * | 1981-03-11 | 1983-12-06 | Sylvia Warner | Method and apparatus for measurement of heart-related parameters |
-
1983
- 1983-06-30 JP JP83502463A patent/JPS60501740A/en active Pending
- 1983-06-30 EP EP19830902404 patent/EP0148819A1/en not_active Withdrawn
- 1983-06-30 WO PCT/US1983/001010 patent/WO1985000279A1/en not_active Application Discontinuation
- 1983-06-30 DE DE1983902404 patent/DE148819T1/en active Pending
Non-Patent Citations (1)
Title |
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See references of WO8500279A1 * |
Also Published As
Publication number | Publication date |
---|---|
WO1985000279A1 (en) | 1985-01-31 |
DE148819T1 (en) | 1985-11-21 |
JPS60501740A (en) | 1985-10-17 |
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