JPS63212326A - Acceleration pulse wave detector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an acceleroplethysmometer used for health checks in health care rooms, training centers, and the like.

BACKGROUND OF THE INVENTION Conventionally, this type of accelerometer pulse wave meter has been designed to maximize the accelerated pulse wave by further differentiating the accelerated pulse wave obtained by second-order differentiation of the pulse wave to obtain the third-order differentiation.

A device is known that calculates the minimum value, digitizes the characteristics of the waveform based on this value, and displays and records it (Japanese Unexamined Patent Application Publication No. 1987-1999).
93036).

Problems to be Solved by the Invention In such a conventional configuration, it is necessary to repeat the differential operation three times, and if this was attempted to be done on an electronic circuit, the circuit configuration would be extremely complicated. Even if we tried to do it digitally by applying microcontrollers, etc., the programming software would inevitably become cumbersome. Furthermore, when differentiation is performed, even the slightest variation in the waveform will appear in an extreme form, and even a slight waveform distortion due to noise etc. can be detected as an extreme value, as shown by Q in Figure 2, which shows the waveform of an accelerated pulse wave. There was a problem with this.

The present invention solves these problems by using extremely simple comparison operations to find the extreme values of a waveform, without performing differentiation operations that may cause troublesome circuit or program problems. It attempts to find the value and its position.

Means for Solving the Problem In order to solve this problem, the present invention uses an acceleroplethysmometer with a blood flow pickup that detects the flow of blood in the fingertip or earlobe, and a pulse waveform that is the output waveform of this blood flow pickup. an acceleration pulse wave converter that second-order differentiates the wave, converts it into an accelerated pulse wave, and outputs it as digital data; a memory device that stores this digital output as temporally continuous data; The continuous data is compared with a reference value having a predetermined numerical range in order from the oldest in time, and a plurality of pieces of data that match this are selected. An arithmetic unit that can select the maximum and minimum data from a plurality of continuous data between the data, and an acceleration pulse wave curve that is calculated from the extreme values obtained by this arithmetic unit and the data in the memory unit. This configuration includes an extreme value detector that selects the position of an extreme value.

Function: With this configuration, in order to find the extreme value of the accelerated pulse wave, an extremely simple operation is required: just compare the accelerated pulse wave data stored in the memory device with a reference value having a predetermined numerical range using the arithmetic unit. Things will get better just by doing the following. Furthermore, by selecting the signal with the extreme value of the accelerated pulse wave, the characteristics of the accelerated pulse wave can be easily known.

EXAMPLE Hereinafter, an example of the present invention will be explained based on FIGS. 1 and 2. In Figure 1, 1 is a blood flow pickup;
Blood flow in the fingertip or earlobe is detected by photoelectric conversion or impedance conversion. 2 is an acceleration pulse wave converter which second-order differentiates the pulse wave which is the output waveform of the blood flow pickup 1, converts it into an accelerated pulse wave, and outputs it as digital data; 3 is a digital signal obtained from the acceleration pulse wave converter 2; A memory device (such as a RAM) that stores data as temporally continuous data. 4 is an arithmetic unit, which compares the continuous data stored in the storage unit 3 with a reference value having a predetermined numerical range in order from the oldest in time, and selects a plurality of pieces of data that match the reference value; Further, among the selected data, the maximum or minimum data can be selected from a plurality of continuous data between two temporally adjacent data. Reference numeral 6 denotes an extreme value detector, which is configured to detect the temporal position of the extreme value of the accelerated pulse wave curve from the extreme value obtained by the arithmetic unit 4 and the data stored in the storage device 3. 6 calculates the positional relationship of each maximum and minimum value based on the results obtained by the extreme value detector 6, obtains an index representing the characteristics of the acceleration pulse wave waveform, and calculates the calculation result and the acceleration pulse waveform. This is a controller that displays waveforms on the display 7.

To explain the operation of the above configuration, the pulse wave detected by the blood flow pickup 1 is converted into an accelerated pulse wave by the accelerated pulse wave converter 2, and is stored in the storage device 3 as digital data. At this time, the arithmetic unit 4 compares the digital data stored in the memory 3 with a reference value a having a predetermined numerical width Δa as shown in FIG. , a2. a3. a4
An operation is performed to select °a5. Then, among the data obtained in this way, the maximum or minimum data P1, P2 are selected from among the temporally adjacent data, that is, continuous data between al and a2, or a2 and a3, etc.
．． P3. A task is performed to select P4. The extreme value of the accelerated pulse wave obtained in this way is sent as data to the extreme value detector 6, and the extreme value detector 5 determines the extreme value of the accelerated pulse wave curve from this extreme value and the data in the memory 3. Temporal position ti.

t2. t3. Determination of t4 is performed. Next, the controller 6 calculates the positional relationship between the maximum and minimum values based on these data, obtains an index representing the characteristics of the accelerated pulse waveform, and displays the index on the display 7 together with the waveform.

Effects of the Invention As described above, according to the present invention, the extremum value of the accelerated pulse wave waveform is determined by extremely simple and clear means without using complicated electronic circuits such as differentiation or troublesome program software, and the accelerated pulse wave curve is obtained. It is possible to select the position of the extreme value of , and the characteristics of the accelerated pulse wave waveform can be easily known. This method also eliminates the problem of misidentifying minute waveform fluctuations as extreme values, which is a weak point of differentiation, so it is easy to understand the index, which is said to have great significance in the use of accelerometers. It can be determined accurately and is extremely useful in practice.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG.
The figure is an explanatory diagram to facilitate understanding of the present invention. 1... Blood flow pickup, 2... Acceleration pulse wave converter, 3... Memory device, 4...
Arithmetic unit, 5... Extreme value detector.

Claims (1)

[Claims] A blood flow pickup that detects the flow of blood in the fingertip or earlobe, and an acceleration pulse wave converter that takes second derivatives of the pulse wave that is the output waveform of this blood flow pickup, converts it into an acceleration pulse wave, and outputs it as digital data. , a memory device that stores this digital output as temporally continuous data, and a memory device that compares the continuous data stored in this memory device with a reference value having a predetermined numerical range in order from the oldest one in terms of time. An arithmetic unit that can select a plurality of pieces of data that match this, and further select the maximum or minimum data from among a plurality of continuous data between two temporally adjacent pieces of selected data. and an extreme value detector that selects the position of the extreme value of the acceleration pulse wave curve from the extreme value obtained by the arithmetic unit and the data in the storage device.