JPH0584222A - Heart beat fluctuation analyzing device - Google Patents

Abstract

PURPOSE:To easily diagnose the normalness of an autonomic nerve exactly, and also, without giving troublesomeness to a testee. CONSTITUTION:The device is provided with a cuff 2 to be attached to a testee and pressurized, a pressure sensor 7 for detecting internal pressure of its cuff 2, and a high-pass filter 8 for detecting its fluctuation component from a detected output by its pressure sensor 7, and by a CPU 15, the number of pulses within a prescribed timer or the time for the prescribed number of pulses is measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heart rate variability analyzer.

[0002]

2. Description of the Related Art It is known that the interval between human and animal heartbeats varies greatly according to breathing when the autonomic nerve is normal, but when the abnormality is abnormal, the degree of fluctuation is small (Clinical EEG Vol. .32 No. 1 1990: 1, pp. 101-106, "Paper entitled" Diabetic neuropathy-autonomic neuropathy "". As a method of diagnosing the normality of the autonomic nerve, a method of measuring a heartbeat interval by an electrocardiograph and a method of attaching a pulse wave sensor to a fingertip and measuring a heartbeat interval are known.

[0003]

Among the conventional methods for diagnosing the normality of autonomic nerves, the method using an electrocardiograph is capable of automating the measurement, but the electrocardiograph is attached to the body of the subject. Since it is necessary to attach the electrodes, the subject has to take off his clothes, which is a drawback that the subject is annoyed.

In the method using the pulse wave sensor, since the pulse wave sensor only needs to be attached to the fingertip, there is no fear that the subject will be annoyed, but according to the respiration of the heartbeat interval detected from the fingertip. Since the fluctuating state is affected not only by the state of the autonomic nerve but also by the state of the peripheral nerve, there is a drawback that the state of the autonomic nerve cannot be accurately diagnosed.

In view of the above point, the present invention is intended to propose an apparatus capable of diagnosing the normality of autonomic nerves accurately and easily without causing any trouble to the subject.

[0006]

According to the present invention, a cuff 2 attached to a subject and pressurized, a pressure sensor 7 for detecting the internal pressure of the cuff 2, and a detection output of the pressure sensor 7 are used. It is a heartbeat variability analysis device having a fluctuation component detecting means 8 for detecting a fluctuation component and a measuring means 15 for measuring the number of beats within a predetermined time or the time of the predetermined beat from the detection output of the fluctuation component detecting means 8.

[0007]

According to the present invention, the number of beats within the predetermined time or the time of the predetermined beat is measured from the detection output of the fluctuation component detecting means 8 to diagnose the normality of the autonomic nerve.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[Structure of Device of Embodiment] First, the structure of the device of the embodiment will be described with reference to FIG. Reference numeral 2 is a cuff, which is wrapped around the hand of the subject, for example, the upper arm (or foot) of the subject, and is pressurized by air. Reference numeral 3 is a pressurizing air pump, and the air from this is sent to the cuff 2 through a pipe 6. A valve 4 for rapid exhaust and a valve 5 for constant speed exhaust are provided in the middle of the pipe 6.

A pressure sensor 7 detects the internal pressure of the cuff 2, and communicates with the cuff 2 through the pipe 6 described above. The detection output of the pressure sensor 7 is supplied to the multiplexer 9 and the high pass filter 8. The high-pass filter 8 detects the fluctuation component from the detection output of the pressure sensor 7, and the detection output is supplied to the multiplexer 9. A bandpass filter may be used instead of the highpass filter 8.

The multiplexer 9 alternately outputs the detection output of the pressure sensor 7 and the fluctuation component from the high-pass filter 8, and the output is supplied to the A / D converter 10 and converted into a digital signal, and the CPU It is supplied to the (microcomputer) 15. The CPU 15 includes a memory (built-in memory) 11 and a display device (including a CRT, LCD, etc.) 1.
2. A recorder (tape recorder or the like) 13 and a printer 14 are connected.

The CPU 15 measures the number of beats within a predetermined time (for example, 1 minute) and the time for a predetermined number of beats (for example, 100 beats) from the detection output of the fluctuation component detecting means 8 and statistically processes the measurement result. (Calculation of average, standard deviation, median, Hin value dispersion, etc.) is performed, and the normality of the autonomic nerve is diagnosed from the processing result. Further, the CPU 15 controls rotation and stop of the pump 3 and opening / closing of the valves 4 and 5.

[One Example of Heart Rate Variability Analysis of Example]
Referring to the flowchart (1) in FIG. 2, the operation of the heart rate variability analysis device and the CPU 15 as an example of the heart rate variability analysis.
The function of is explained.

First, the flowchart (1) of FIG. 2 will be described. In step ST-1, both valves 4 and 5 are closed, and then the process proceeds to step ST-2. In step ST-2, after the pressurizing air pump 3 is started, step ST-
Move to 3. In step ST-3, the waveform (pulse wave) of the fluctuation component of the cuff internal pressure from the high-pass filter 8 (see FIG. 4).
It is determined whether or not the amplitude of (see) is maximum. If NO, the process returns to step ST-3, and if YES, the process proceeds to step ST-4. In this case, the cuff internal pressure is actually slightly higher than the pressure when the amplitude of the fluctuation component is maximum. Therefore, in step ST-4, the pump 3
After stopping the operation, the process proceeds to step ST-5, the constant speed exhaust valve (small valve) 5 is opened to gradually exhaust the air to gradually reduce the cuff internal pressure, and then the process proceeds to step ST-6. In this case, the pressure applied to the subject's upper arm is too high,
In order to avoid giving pain, a cuff pressure slightly lower (about several mmHg to several tens of mmHg) than the cuff pressure at which the amplitude of the fluctuation component becomes maximum is determined as the optimum pressure (reference pressure). In addition, the cuff internal pressure at which the amplitude of the fluctuation component is maximum or a pressure slightly higher (several mmHg) than the cuff internal pressure may be set as the optimum pressure (reference pressure). In step ST-6, it is determined whether or not the measured cuff internal pressure is the optimum pressure. If NO, the process returns to step ST-6, and if YES, the process proceeds to step ST-7. The above steps ST-1 to ST-6 are preliminary measurements.

In step ST-7, the constant speed exhaust valve 5 is closed, and then the process proceeds to step ST-8. In step ST-8, a pulse is detected from the fluctuation component of the cuff internal pressure from the high pass filter 8, and then the process proceeds to step ST-9. In step ST-9, after calculating the pulse interval, the process proceeds to step ST-10. The calculated pulse interval is stored in the memory 11. In step ST-10, it is determined whether or not the pulse rate has reached the specified pulse rate (and specified time). If NO, the process returns to step ST-8 and Y
If it is ES, the process proceeds to step ST-11. Thus, the number of beats within the specified time (for example, 1 minute) and the time of the specified number of beats (for example, 100 beats) are measured. In step ST-11, after closing both valves 4 and 5, the process proceeds to step ST-12. In step ST-12, the measurement result is statistically processed (calculation process of average, standard deviation, median value, Hin value dispersion degree, etc.), and then the process proceeds to step ST-13. In step ST-13, the measurement and processing results are displayed on the display 12, and then the process proceeds to step ST-14. In step ST-14, the measurement and processing results are printed on paper by the printing machine 14, and then step ST-
Move to 15. In step ST-15, the measurement and processing results are recorded on a recording medium such as a magnetic tape of the recording machine 13 and the process ends. Therefore, the normality of the autonomic nerve is diagnosed from the measurement result and / or the processing result.

[Another Example of Heart Rate Variability Analysis of the Embodiment] By the way, the operation of the pump 3 is often discontinuous in terms of fluid dynamics, and the resulting pressure variation is superimposed on the pulse wave. It is difficult to accurately detect whether or not the pulse wave has the maximum amplitude. Therefore, in consideration of this point, the operation of the heart rate variability analysis apparatus and the function of the CPU 15 as another example of the heart rate variability analysis that can surely perform the amplitude variation analysis even if an inexpensive pump is used are described. 3 will be described with reference to the flowchart (2) of FIG. In addition, in the flowchart (2) of FIG. 3, the flowchart (1) of FIG.
Steps corresponding to are given the same step numbers, and some overlapping description will be omitted. Steps different from the flowchart (1) of FIG. 2 will be indicated by adding A after the number as a step number.

Steps ST-1 and ST2 are the same as those in the flowchart (1). After step ST-2, the process proceeds to step ST-3A. In step ST-3A, it is judged whether or not the cuff internal pressure has reached the reference pressure, and thereafter, the same step ST-4 as in the flowchart (1),
5 and after step ST-5, step ST-
Move to 6A. In step ST-6A, the detected cuff pressure and pulse wave (both digital values) are read into the memory 11, and then the process proceeds to step ST-7A. In step ST-7A, it is determined whether the cuff internal pressure does not exceed the reference pressure. If NO, the process returns to step ST-6A, and if YES, the process proceeds to step ST-8A.
In step ST-8A, the rapid exhaust bubble 4 is opened to rest the subject, and then the process proceeds to step ST-9A.
In step ST-9A, the cuff internal pressure and the pulse wave stored in the memory 11 are read out, the cuff internal pressure when the amplitude of the pulse wave is maximum is calculated, and then the process proceeds to step ST-10A. Steps ST-1 to 9A are referred to as predictive measurement.

Thereafter, the main measurement is started. Step ST-
In 10A, after closing both valves 4 and 5, step ST
Move to -11A. In step ST-11A, after starting the pump 3, the process proceeds to step ST-12A.
In step ST-12A, it is determined whether or not the cuff internal pressure has reached the reference pressure. If NO, step ST-12
Returning to A, if YES, the process proceeds to step ST-13A. In Step ST-13A, after stopping the pump 3,
The process proceeds to step ST-8 similar to the flowchart (1), and then the same step ST as the flowchart (1).
Follow -9 to 15. Therefore, the normality of the autonomic nerve is diagnosed from the measurement result and / or the processing result.

In the examples of the flow charts (1) and (2) of FIGS. 2 and 3, the pressure detected by the pressure sensor 7 may not be read into the memory 11 during the measurement of the last pulse interval. Also, the pulse wave itself, not the pulse interval,
Further, both the pulse interval and the pulse wave may be stored in the memory 11.

Further, in the example of the flowchart (2) of FIG. 3, the output of the high pass filter 8 may not be read during the pressurization of the cuff 2 in step ST-3A.
Further, the preliminary measurement may be started only by stopping the pump 3 after reaching the specified pressure by pressurizing the constant speed exhaust valve 5 without closing it (omission of step ST-5).

[Example of Variation of Pulse Rate within a Specified Time and Respiration of Specified Pulse Rate over Time] FIGS. 5A and 5C show an example of variation of a pulse rate for one minute according to breath, where A is autonomous. The subject has normal nerves, and C is the subject (severe diabetic patient) with abnormal autonomic nerves. In A and C, m
Indicates the average value of the pulse rate for 1 minute.

Further, FIGS. 5B and 5D show an example of fluctuations according to respiration at a pulse rate of 100, where B is the subject with normal autonomic nerves and D is the subject with abnormal autonomic nerves. This is also for examiners (severe diabetic patients). In B and D, m represents an average value during a pulse rate of 100.

[0023]

According to the heart rate variability analysis apparatus of the present invention described above, the normality of the autonomic nerve can be accurately diagnosed easily without causing any trouble to the subject.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a heart rate variability analyzer according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an example of heart rate variability analysis according to the embodiment.

FIG. 3 is a flowchart showing another example of the heartbeat variability analysis of the embodiment.

FIG. 4 is a curve diagram showing a pressure fluctuation waveform in an arm band.

FIG. 5 is a graph showing a pulse rate within a specified time and a variation example of the specified pulse rate according to breathing during time.

[Explanation of symbols]

 2 Cuff 3 Air pump for pressurization 4 Valve for rapid exhaust 5 Valve for constant speed exhaust 6 Pipe 7 Pressure sensor 8 High pass filter 9 Multiplexer 10 A / D converter 11 Memory 12 Display 13 Recorder 14 Printer 15 CPU (microcomputer) )

Claims (1)

[Claims] 1. A cuff that is attached to a subject and is pressurized, a pressure sensor that detects the internal pressure of the cuff, and a fluctuation component detection unit that detects the fluctuation component from the detection output of the pressure sensor, A heartbeat variability analysis device, comprising: a measuring unit that measures the number of beats within a predetermined time or the time of the predetermined number of beats from the detection output of the fluctuation component detecting unit.