JPH06233827A - Electric stimulating device - Google Patents

Abstract

PURPOSE:To stably detect the pulse wave invariably by dissolving the instability of the pulse wave detection caused by external factors such as the color of the skin. CONSTITUTION:This electric stimulating device for detecting a specific segment from the pulse wave electric signal obtained by a pulse wave sensor 1 and outputting electric stimulation on the specific segment is constituted of a detecting means 3 detecting the signal level of the pulse wave electric signal, and an adjusting means 22 adjusting the amplification quantity of the pulse wave electric signal based on the level quantity or the level change quantity of the signal level of the level detecting means 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric stimulator which detects a specific section from a pulse wave and outputs electrical stimulation on the specific section.

[0002]

2. Description of the Related Art A pulse wave is constantly detected, a diastolic period is detected mainly from this pulse wave signal, an expansion period is detected, and electrical stimulation is output on this specific segment, and this output is applied to the abdomen for a long time. A device has been proposed which significantly enhances blood circulation and has a slimming effect. Various methods have been adopted as means for detecting a pulse wave. Among them, if a light transmission or reflection type means by a combination of an LED and a phototransistor is selected as the detection site of the living body, it is relatively accurate and easy. It is preferable in that waves can be detected.

[0003]

However, the LED
In the light transmission type or light reflection type with the phototransistor and the light transmitted or reflected due to the color of the skin or the like is attenuated, it becomes difficult to accurately detect the pulse waveform. The functions for section analysis and output of electrical stimulation became inaccurate. Further, when the amount of light transmitted or reflected is too large, the output of the phototransistor or the amplifier is saturated, which makes it difficult to detect the pulse waveform. However, such a problem can be said not only in the photoelectric conversion method but also in the piezoelectric conversion method.

[0004]

In view of the above, the present invention detects the level amount of the pulse wave electric signal or the amplified pulse wave electric signal when generating the pulse wave electric signal, and based on this level amount, the pulse wave electric signal is detected. If the amount of signal amplification is too large, adjust it in the decreasing direction, and if it is too small, adjust it in the increasing direction so that a stable pulse wave electrical signal can always be obtained without being affected by external factors such as skin color. It was realized. The level amount shown here means a DC component voltage value or an impedance value caused by a bias current or the like required when converting a pulse wave into an electric signal, or after further amplifying the pulse wave, It shows a value obtained by rectifying the amplitude value, and further shows the internal impedance of the pulse wave sensor.

[0005]

FIG. 1 is a diagram showing an embodiment of the present invention.
Reference numeral (1) is a pulse wave sensor unit, which is composed of a combination of an LED (11) and a phototransistor (12). Both a reflective type and a transmissive type are possible, and as an example of use, the sensor unit is attached to a fingertip portion or an earlobe. Reference numeral (2) is amplification means, which is a combination of transistors, FETs, operational amplifiers, etc., and is composed of an amplifier (21) and a gain adjustment means (22) for variably adjusting the gain. (3) is a level signal detecting means, which generates a level signal such as a DC voltage from the input signal and outputs it to the amplifying means (2). The pulse wave signal photoelectrically converted by the pulse wave sensor unit (1) is input to the amplifying unit (2), amplified and input to the control unit and the level signal detecting unit (3) via the output end (b). . Level signal detection means
(3) generates a level signal from the signal amplified by the amplification means (2). The level signal is a signal mainly composed of a DC component. A specific example of the level signal detecting means (3) is a combination of a peak hold circuit for detecting a peak voltage and a smoothing circuit, or a combination of this and a voltage divider.
When the amplifying means (2) receives the level signal, the gain adjusting circuit (22) operates so as to adjust the gain in accordance with the level signal. For example, the transconductance and resistance of the bias circuit are adjusted so that the bias current of the amplifying means (2) increases when the level signal decreases. It is also possible to exemplify not only controlling the bias current, but also preparing a plurality of amplifiers each having a different amplification factor as shown in FIG. 2 and switching the amplifiers depending on the strength of the level signal. Next, the embodiment of FIG. 2 will be described.

In FIG. 2, (a) corresponds to (a) of FIG. 1 and (b) corresponds to (b) of FIG. 1, and can be replaced. (4) is a changeover switch, which receives the output signal of the level signal detecting means (3) and performs a switch operation. The level signal detecting means (3) sends a changeover operation signal to the changeover switch (4) when the level change exceeds the threshold value by setting the threshold value.
(211) and (212) are amplifiers having different amplification factors. The amplifier is selectively connected by the switching operation of the changeover switch (4). The amplification means is 2
It is not limited to one and may be more than this. At this time, there are a plurality of changeover switches, and the level signal detecting means also sends a plurality of threshold values as identification signals corresponding thereto.

A more specific embodiment will be described with reference to FIG. In FIG. 3, reference numeral (31) is an amplifier, which is an IC such as an operational amplifier. (32) is a variable resistor,
The resistance value changes depending on the input c. The variable resistor (32)
An example is a combination of a resistor and a FET. The FET utilizes the property that the resistance between the source and the drain changes according to the change in the voltage between the gate and the source. (33) is a resistor.
(3) is an amplitude voltage detection circuit, which detects and outputs an amplitude voltage indicating an average value, an effective value or a maximum value of the amplitude from the output signal of the amplifier. Examples of the amplitude voltage detection circuit include a smoothing circuit and a thermistor. Reference numeral (34) is an adjusting means, which outputs an adjusting signal for adjusting the resistance value of the variable resistor (32) according to the change of the output voltage value of the amplitude voltage detection circuit (3).

Next, the operation will be described. Amplifier (31) is a resistor
(33) and the variable resistor (32) form a non-inverting amplifier. The pulse wave signal input to the terminal (a) is amplified by the amplifier (31) at an amplification rate according to the ratio of the resistance (33) and the variable resistance (32), and the output terminal (b) and amplitude voltage detection Output to circuit (3). The amplitude voltage detection circuit (3) detects the average value, effective value, maximum value, etc. from this amplified signal,
Output to the adjusting means (34). The adjusting means (34) outputs an adjusting signal for adjusting the resistance value of the variable resistor (32) from this voltage value. The variable resistor (32) receives the signal from the adjusting means (34) and sets the resistance value corresponding to the adjusted signal. For example, if the pulse wave signal from terminal (a) becomes weak,
The amplified signal at (31) also becomes small, and the amplitude voltage detection means (3)
Output voltage becomes smaller. The adjusting means (34) outputs a signal for decreasing the resistance value of the variable resistor (32) due to the decrease in the output voltage. For example, if the FET constituting the variable resistor is an N channel, a negative voltage is applied, and if it is a P channel, a positive voltage is applied. At this time, the resistance between the drain and the source decreases linearly for the FET, so that the amplification factor increases. Although the embodiment shown in FIG. 3 is a non-inverting amplifier, it may be converted to an inverting amplifier.

Another embodiment will be described with reference to FIG. In FIG. 4, (1) is a pulse wave sensor, and (2) is an amplifying means. The amplification means (2) is provided with gain conversion means. Reference numeral (41) is a pulse converting means, which converts a pulse indicating a systole or a pulse indicating a diastole from a pulse wave signal and outputs the pulse. (42) is a signal processor, which is configured by a one-chip microcomputer or the like. (43) is an adjusting means, which inputs a pulse signal and outputs an adjusting signal corresponding to the pulse to the gain converting means of the amplifying means (2). (44) is an output forming means, which converts the pulse signal output from the signal processor (42) into a stimulus output signal and outputs it. Examples of the conversion mechanism include a combination of an inductor and a driver or a combination of an inductor and a capacitor. Reference numeral (45) is a conductor, which is attached to or attached to the human body and is an interface for outputting the electrical stimulation output of the output forming means (44) to the human body.

Next, the operation will be described. The pulse wave signal input to the pulse wave sensor (1) is input to the amplification means (2) via (a). The amplification means (2) amplifies the pulse wave signal with an amplification factor based on the value of the gain conversion means. The amplified pulse wave signal is (b)
Is input to the pulse conversion means (41) via. The pulse conversion means (41) converts the amplified pulse wave signal into a pulse indicating a systole or a diastole and outputs it. This pulse wave pulse is (d)
Is input to the signal processor (42) via. Signal Processor (42)
Receives this pulse wave pulse, calculates the stimulation pulse output period, and outputs the pulse to the output forming means (44) via (e) mainly in this period. The output forming means (44) converts the power source energy of the battery or the like into stimulating energy capable of stimulating the human body based on this pulse, and outputs it to the conductor (45).

When the pulse wave signal from the pulse wave sensor becomes weak, the amplified pulse wave signal of the amplifying means (2) also becomes small and the output of the pulse wave pulse converting means (41) becomes unstable. Signal processor (4
2) outputs a pulse signal to the adjusting means (43) when the output becomes unstable. The adjusting means (43) converts this pulse signal into an adjusting signal and outputs it to the gain converting means of the amplifier (31). The gain converting means receives this signal and converts the gain so as to increase the gain of the amplifying means (2). Adjustment means (43)
When the signal output from the signal processor (42) is a pulse train, interprets this and outputs a pulse signal if it is a signal of a level corresponding to it or a gain conversion means as shown in FIG. Output. Further, the adjusting means (43) is a signal processor (4
If the signal from 2) is a step pulse or the like, this pulse may be directly converted into a signal for gain conversion. The adjusting means (43) may be incorporated in the signal processor (42). The configuration of the output forming means (44) is, for example, a combination of a transistor such as a transistor or EFT that switches based on a pulse output from the signal processor (42) and an inductor element including a coil or a transformer. . In the operation by this configuration, the current flowing in the inductor element is interrupted by turning the driver on and off, and at this interruption, ~ 200 (V), ~ 1 (ms)
The ec) stimulus pulse is output. Alternatively,
By combining the driver, inductor element, and capacitor element, the current flowing to the inductor can be interrupted ~ 20
After generating a boosting pulse of 0 (V) to several (μsec), the capacitor element stores the boosting pulse, and the other driver interrupts this to cause the electrical energy accumulated in the capacitor element to rise to 200 ( V) to several hundreds (μse
It is also possible to exemplify the one that is converted into the stimulation pulse of c) and output.

The embodiment shown in FIG. 5 will be further described. (1
1) is an LED, which outputs infrared rays. (12) is a phototransistor. (13) and (14) are variable resistors whose resistance values are changed linearly or digitally by an external input signal. Both (13) and (14) need not be variable resistors, and one may be a fixed resistor. (3) is a level signal detecting means. The level signal detecting means (3) is the same as that in the previous embodiment, and the explanation is omitted.

Next, the operation will be described. The LED (11) and the phototransistor (12) are attached to the pulse wave measurement site.
The variable resistors (13) and (14) are in a state of exhibiting a constant resistance value by the output of the level signal detecting means (3). The phototransistor (12) receives a light beam transmitted or reflected by a living body and converts it into an electric signal. The electric signal amplitude at this time is determined by the values of the variable resistors (13) to (14). The amplifier (2) outputs the electric signal converted by the phototransistor (12) to (b) and the level signal detecting means (3). The level signal detecting means (3) detects the level value of the pulse wave signal and outputs an analog or digital signal corresponding to the level of the amplitude signal to the variable resistor. This signal has the content of reducing the resistance value of the variable resistor when the amplitude signal becomes small.

Next, another more specific embodiment of the present invention will be described with reference to FIG. (61) is an LED, which is the same as that described above. Reference numeral (62) is a phototransistor, which is the same as the one described above similarly to the LED (61).
(61) and (62) form a pulse wave sensor. (63) (65) (67) are resistors and (66) (68) are capacitors. (64) is a P-channel type FET. (69) is a battery, and (70) is an operational amplifier. The operational amplifier (70) constitutes an active filter, an amplifier and the like. The anode of the LED (61) is
The cathode is connected to the (+) side of the battery (69) and the cathode is connected to the (-) side of the battery (69). The (−) side of the battery (69) is expressed as ground.
The collector of the phototransistor (62) is connected to one end of the resistor (63), and the other end of the resistor (63) is connected to the drain of the FET (64), one end of the resistors (65) (67), and one end of the capacitor (68). , And one input terminal of the operational amplifier (70). The other end of the resistor (65) and one end of the capacitor (66) are connected to the gate of the FET (64),
The (+) pole of the battery (69) is connected to the source of the FET (64). Connect the battery to the other end of the capacitor (66) and the other end of the resistor (67).
The (+) pole of (69) connects.

Next, the operation will be described. A pulse wave sensor consisting of an LED (61) and a phototransistor (62) is attached to the measured part of the human body. The amount of light such as infrared rays output from the LED (61) changes as it passes through or is reflected by the human body. This changed light beam is collected by the phototransistor (62). The phototransistor (62) changes the impedance between the collector and the emitter according to the amount of input light. At this time, if the amount of light input to the phototransistor (62) becomes excessive, the impedance between the collector and the emitter decreases. When the impedance between the collector and the emitter decreases, the gate voltage of the FET (64) decreases and the impedance between the drain and source of the FET increases. When the impedance between the drain and the source increases, the phototransistor
The current supplied to (62) is regulated and the amplification amount decreases. Conversely, when the amount of light input to the phototransistor (62) decreases, the impedance between the collector and emitter increases,
Since the gate voltage of T (64) increases, the impedance between the drain and source of the FET (64) decreases, the current supplied to the phototransistor (62) increases, and the amplification amount increases. In this way, the embodiment in which the current flowing to the phototransistor (62) is changed according to the amount of light input to the phototransistor (62) can have a very compact structure,
In addition, it is an extremely preferable example for practical use because the amplification factor can be accurately controlled.

[0016]

As described above in detail, the present invention eliminates the instability of the pulse wave detection due to the color of the skin, etc., and can always stably and accurately detect the pulse wave signal. It has effects such as detection of diastole from inside and accurate timing of electrical stimulation.

[Brief description of drawings]

[Figure 1]

FIG. 2 is a diagram showing an embodiment of the present invention.

[Figure 3]

[Figure 4]

[Figure 5]

FIG. 6 is a diagram showing more specific and different embodiments of the present invention.

[Explanation of symbols]

 1 pulse wave sensor 2 amplifier 3 level signal detecting means

Claims (1)

[Claims] 1. An electrical stimulator that detects a specific section from a pulse wave electrical signal obtained by a pulse wave sensor and outputs electrical stimulation on the specific section, and detects the signal level of the electrical pulse wave signal. An electrical stimulator comprising: a detection unit and an adjustment unit that adjusts the amplification amount of the pulse wave electric signal based on the level amount or level change amount of the signal level of the detection unit.