JP2003310580A - Biological signal detector and correction processing program for biological signal detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To alway obtain the stable measured result without being affected by variance in performance for each probe or a little performance lowering in a biological signal detector for irradiating an examinee body with light, detecting and measuring a status of the examinee body based upon the transmitted light or the reflected light of the irradiation light. <P>SOLUTION: A ratio a/b of a measured value (a) of a light receiving level signal Va to be read into a CPU 25 in accordance with a light receiving current IF to be outputted from a light receiving device 12 when a light emitting device 11 of a prove part 1 mounted at present is driven to emit light with a prescribed light emission driving current in the case of turning on a power source, for example, and a specific value (b) of the light receiving level value Va stored beforehand to be read into the CPU 25 when the reference (designed) probe part 1 is defined as a target is stored into a probe light receiving quantity correction coefficient memory 29a as a probe light receiving correction coefficient X10 and afterwards, the light receiving level signal Va to be read into the CPU 25 is corrected by the correction coefficient X10 of the probe light receiving quantity to maintain the high-accuracy organism measurement. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a living body signal detecting device and a living body for irradiating a subject or an irradiated body with light and detecting and measuring the state of the subject or the irradiated body based on transmitted light or reflected light thereof. The present invention relates to a calibration processing program for a signal detection device.

[0002]

2. Description of the Related Art A pulse oximeter is known as a typical conventional biological signal detecting device.

This pulse oximeter is one of hemoglobins in blood and oxygenated hemoglobin combined with oxygen.
The ratio of reduced hemoglobin that is not bound to oxygen is detected and calculated and displayed as the oxygen saturation%. The infrared emission LED having high absorbance for oxygenated hemoglobin and the red light emitting LED having high absorbance for reduced hemoglobin are used.
This light receiving element includes one light emitting element and a light receiving element that alternately transmits two light emitting elements having different emission wavelengths and irradiates the living body (finger or earlobe) with the transmitted light transmitted through the living body. The ratio of the received light amount of each transmitted light through the living body at the time of infrared light emission and that at the time of red light emission, that is, the ratio of the absorbance is calculated and calculated as oxygen saturation%.

Further, in this pulse oximeter, since the received light signal corresponding to the pulsation of blood is obtained from the transmitted light of the living body, it is possible to calculate and measure the pulse.

Incidentally, as a general biological signal detecting apparatus utilizing such irradiation and reception of light to the living body, a portion for directly detecting the state of the living body, that is, a light emitting section for irradiating the living body with light and irradiation of this light. The light receiving portion that receives the light from the living body and the portion that extracts the received light signal are referred to as a probe.

[0006] Since this probe is in direct contact with the living body and repeats the light emitting and light receiving operations every time the living body is measured, the performance is remarkably lowered depending on the environment in which it is used.
Periodic replacement is required to maintain the measurement accuracy above a certain level.

[0007]

However, in such a biological signal detecting device, the replacement cost of the probe is high, which makes it difficult to spread to general users.

Therefore, it is conceivable to reduce the price of the probe. However, if inexpensive light emitting elements and light receiving elements, which are the main components of the probe, are used, individual differences will occur between the probes, and a predetermined amount will be required when the probe is replaced. There is a problem that it is not clear whether the measurement accuracy of is obtained.

That is, the drive control of the light emitting portion of the probe and the signal detection from the light receiving portion are both performed on the side of the apparatus main body, and based on the light receiving detection signal when the predetermined light emission drive control is performed, the pulse rate and the oxygen saturation level are determined. For example, if the light emitting efficiency and the light receiving efficiency of each probe vary, or if the light emitting efficiency and light receiving efficiency of the same probe decrease, the measurement accuracy also varies. .

The present invention has been made in view of the above problems, and it is possible to always obtain a stable measurement result without being affected by variations in the performance of each probe and a slight decrease in performance. An object of the present invention is to provide a biological signal detection device and a calibration processing program for the biological signal detection device.

[0011]

That is, a first biological signal detecting apparatus according to the present invention is a light emitting means and light from the subject obtained by irradiating the subject with light emitted by the light emitting means. A probe having a light receiving means for receiving the light, a light emitting drive means for driving the light emitting means of the probe, and a light receiving output of the light receiving means of the probe when the light emitting means of the probe is driven by the light emitting drive means. A signal level measuring means for measuring a signal level of a signal; and a signal level of a light receiving signal measured by the signal level measuring means when the light emitting means of the probe is driven by the light emitting drive means at a predetermined light emitting drive level. A correction coefficient calculating means for calculating a correction coefficient of the measured signal level based on a prescribed signal level according to the predetermined light emission drive level, State correction means for correcting the signal level of the received light signal measured by the signal level measurement means based on the correction coefficient of the signal level calculated by the correction coefficient calculation means to measure the state of the subject. It is characterized by

In such a first biological signal detecting apparatus according to the present invention, when the light emitting drive means drives the light emitting means of the probe at a predetermined light emission drive level, the light receiving signal measured by the signal level measuring means. A correction coefficient for the measured signal level is calculated based on the signal level of the signal level and a prescribed signal level corresponding to the predetermined light emission drive level, and the signal level measuring means is based on the calculated correction coefficient for the signal level. Since the signal level of the received light signal measured by is corrected and the state of the subject is measured, the variation of the probe performance is calibrated and the state of the subject is measured.

The second biological signal detecting apparatus according to the present invention includes a light emitting means and a light receiving means for receiving light from the subject obtained by irradiating the subject with light emitted by the light emitting means. And a light emission drive means for driving the light emission means of the probe, and when the light emission means of the probe is driven by the light emission drive means, the signal level of the light reception signal output from the light reception means of the probe is measured. Signal level measuring means, state measuring means for measuring the state of the subject based on the signal level of the received light signal measured by the signal level measuring means, and the light emitting driving means for controlling the light emitting means of the probe to a predetermined object level. When driven at a light emission drive level corresponding to the pseudo pulse waveform according to the state of the sample, the state measurement value measured by the state measuring means and the predetermined value Based on the state of the sample, a correction coefficient calculation means for calculating a correction coefficient for the measured state measurement value, and a correction coefficient for the state measurement value calculated by the correction coefficient calculation means are measured by the state measurement means. And a state measurement value correction means for correcting the state measurement value.

In such a second biological signal detecting apparatus according to the present invention, when the light emitting means of the probe is driven, the signal level of the light receiving signal output from the light receiving means of the probe is measured by the signal level measuring means. The state of the subject is measured by the state measuring means based on the measured signal level of the received light signal, and the light emission drive means causes the light emitting means of the probe to emit a pseudo pulse waveform according to the predetermined state of the subject. When driven at a light emission drive level corresponding to, the correction coefficient of the measured state measurement value is calculated based on the state measurement value measured by the state measurement means and the state of the predetermined subject, and this calculation is performed. The state measurement value measured by the state measuring means is corrected based on the correction coefficient of the state measurement value. It will be but is maintained.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an electronic circuit of a biological signal detecting apparatus according to an embodiment of the present invention.

This biological signal detecting apparatus includes a probe unit 1 for alternately irradiating a subject (for example, a fingertip) 10 with light of two wavelengths and receiving the transmitted light, and a probe unit 1 in the probe unit 1. A system unit 2 is provided for controlling the light emitting operation and for calculating and outputting the oxygen saturation% of the pulse and arterial blood by taking in the received light signal obtained by the probe unit 1.

The probe unit 1 is provided with a light emitting device 11 and a light receiving device 12.

The light emitting device 11 is provided with a red LED 11a which emits light having an emission wavelength of 660 nm and an infrared LED 11b which emits light having an emission wavelength of 890 nm.
The red light emission and the infrared light emission alternately emitted by 1 are applied to the subject 10 sandwiched between the light receiving device 12.

The light receiving device 12 is provided with a photodiode 12a for receiving the transmitted light which passes through the subject 10 when the light emitting device 11 irradiates the subject 10 with light. The received light current IF output according to the light receiving operation is the system unit 2
It is amplified through an amplifier circuit (current amplifier) 21 inside and is supplied to a current / voltage conversion circuit 22 for voltage conversion.

The received light signal of the transmitted light of the living body (subject 10) whose voltage is converted by the current / voltage conversion circuit 22 is multiplied by N (N = 2, 4, 8, ...) Through the amplification circuit 23. The amplified signal is supplied to the first terminal CH1 of the A / D conversion circuit 24 and digitally converted into the received light level signal Va1 which is C.
It is read into PU25. On the other hand, it is directly supplied to the second terminal CH2 of the A / D conversion circuit 24 and read by the CPU 25 as a digitally converted light reception level signal Va2.

The light reception level signals Va1 and Va2 read by the CPU 25 are based on the light reception level signals Va1 and Va2 when a predetermined light emission drive is performed on the reference (as designed) probe unit 1. It is read after being corrected by a correction coefficient obtained by the matching process (see FIGS. 6 to 8) according to the difference from the actual light reception level.

On the other hand, in the current / voltage conversion circuit 22, an operation reference voltage when the light emitting device 11 of the probe section 1 is in a non-light emitting state, that is, the photodiode 12a of the light receiving device 12 through the subject 10. The operating point voltage, which is the reference for the light receiving operation when the transmitted light is not received, is
It is controlled and set by the reference voltage given from the voltage control circuit 26, and the signal for adjusting the reference voltage to be given from the voltage control circuit 26 to the current / voltage conversion circuit 22 is a light emitting device in the probe unit 1. 11 when the light is not emitted, the D / A conversion circuit 2 in the voltage control circuit 26 is generated by the CPU 25 on the basis of the received light level signals Va1 and Va2 read from the A / D conversion circuit 24.
6a is output.

That is, in the current / voltage conversion circuit 22, where it is desired to set the operating point reference voltage corresponding to the received light current IF from the light receiving device 12 in which the light emitting device 11 in the probe unit 1 is in the non-light emitting state as VREF, Part 1
When the external light in the installation environment is received by the photodiode 12a of the light receiving device 12, even if the light emitting device 11 is in a non-light emitting state, the received light current IF corresponding to the reception of the external light is received.
Is output and the operating point reference voltage VREF in the current / voltage conversion circuit 22 shifts. Therefore, in the biological signal detecting device according to the embodiment of the present invention, the operating point reference voltage due to the influence of the external light reception. A correction process for eliminating the fluctuation (shift) of VREF is performed.

That is, when the light emitting device 11 of the probe unit 1 is in a non-light emitting state, the CPU 25 reads the light reception level signal Va1 through the amplifier circuit 23 which should be the operating point reference voltage VREF of the current / voltage conversion circuit 22, and the amplification is performed. Circuit 23
When the value (N · VREF) obtained by multiplying the reference voltage VREF by the amplification factor N of 1 and the received light level signal Va1 do not match, the difference (shift amount) Vb (= N · VREF−Va1) is calculated. Output to the voltage control circuit 26.
Then, the voltage obtained by adding the actual shift value Vb / N in the current / voltage conversion circuit 22 obtained by dividing Vb by the amplification factor N to VREF is applied to the current / voltage conversion circuit 22 as the reference voltage (VREF + Vb / N).

Further similarly, the light emitting device 1 of the probe unit 1
1 is the light-emission level signal Va2 as it is which should be the operating point reference voltage VREF of the current / voltage conversion circuit 22 in the non-light emitting state.
Is read by the CPU 25, and the received light level signal V
When a2 and the reference voltage VREF do not match, the difference (shift amount) Vb (= VREF−Va2) is calculated and output to the voltage control circuit 26, and the current / voltage from the voltage control circuit 26 is calculated. The voltage obtained by adding the actual shift value Vb in the conversion circuit 22 to VREF is given to the current / voltage conversion circuit 22 as the reference voltage (VREF + Vb).

In this way, by performing the correction control of the operating point reference voltage VREF for the two-stage current / voltage conversion circuit 22 based on the received light level signal Va1 via the amplifier circuit 23 and the received light level signal Va2 as it is, Even when external light is received by the light receiving device 12, the operating point reference voltage VREF in the current / voltage conversion circuit 22 can be set to be constant.

On the other hand, the CPU 25 is further provided with a light emission current control circuit 25a and a timing generation circuit 25b. The light emission current control signal from the light emission current control circuit 25a and the light emission timing control signal from the timing generation circuit 25b are It is output to the LED drive device 27.

The LED drive device 17 is provided with a red light emission drive circuit 27a and an infrared light emission drive circuit 27b for respectively lighting the red LED 11a and the infrared LED 11b in the light emission device 11 of the probe unit 1. A constant current circuit 27c for setting the respective light emission drive currents by the drive circuits 27a and 27b is provided.

The set value of the light emission drive current in the constant current circuit 27c is adjusted by the light emission current control signal from the light emission current control circuit 25a in the CPU 25, and each of the LEDs 11a, 11b by the light emission drive current is adjusted. The drive timing (see FIG. 4) depends on the CPU.
It is controlled by the light emission timing control signal from the timing generation circuit 25b in 25.

Here, the LED according to the actual biometric measurement
Red LED 11 by constant current circuit 27c of drive device 27
The set value of the light emission drive current for a and the set value of the light emission drive current for the infrared LED 11b are as described above in the state where the transmitted light from the subject 10 is received by the light receiving device 12 due to their respective light emission. The light reception level signal Va1 read from the A / D conversion circuit 24 to the CPU 25 is adjusted by the light emission current control circuit 25a so as to be set to a predetermined level. In this case, the timing at which the inflow of arterial blood into the subject 10 is minimum. That is, the fixed absorption due to the tissue and venous blood of the subject 10 is mainly, the absorption due to the arterial blood is minimized, the amount of light received by the photodiode 12a is maximized, and the light reception level signal Va1 read by the CPU 25 is maximized. At the timing (see FIGS. 2 and 5),
The light emission amounts of the LEDs 11a and 11b are adjusted so that the received light level signal Va1 is set to a predetermined level.

As described above, the light emitting device 1 is used for the biological measurement.
When the light receiving device 12 receives the transmitted light from the subject 10 at the time of the light emission of 1, the LED light emission amount is corrected so that the light reception level signals Va1 at the time of the red light emission and the infrared light emission can be obtained as the predetermined levels. As a result, even if there is individual difference such that the light transmittance of the subject 10 is extremely low or high, it is possible to read the stable received light level signal Va1 and perform proper measurement of the oxygen saturation% of the arterial blood. Become.

Further, the CPU 25 has an input device 2
8, storage device 29A, external storage device 29B, display unit 3
0, a backlight control device 32 for controlling lighting of the backlight 31 of the display unit 30, and an output device 33 are connected.

The input device 28 is provided with a power-on switch of this device, a measurement start switch for instructing the start of the biological signal detection process, and the like.

In the memory device 29A, the LEDs 11a of the light emitting device 11 are driven by the LED drive device 27 at a predetermined light emission drive current for the reference (as designed) probe portion 1.
When the 11b is driven to emit light, the light-reception level signals Va1 and Va2 corresponding to the light-reception current IF that should be output from the photodiode 12a of the light-receiving device 12 are stored as reference data of light-emission current vs. light-reception level (see FIG. 6). To be done. The probe matching process (see FIG. 8) is performed according to the reference data of the light emission current vs. the light reception level, and the correction coefficient x10 corresponding to the difference from the actual light reception level signal Va by the current probe unit 1 is stored in the probe light reception amount correction coefficient memory It is stored in 29a. The light reception level signals Va1 and Va2 read from the A / D conversion circuit 24 into the CPU 25 are corrected by the correction coefficient x10 of the probe light reception amount, so that the probe performance varies with the replacement of the probe unit 1 and the change over time. Even if there is, stable light reception level signals Va1 and Va2 can be obtained. The probe matching process may or may not be performed with the pseudo analyte having an absorbance of 1 / N sandwiched between the probe units 1.

Further, the storage device 29A includes a probe unit 1
On the other hand, the pseudo pulse emission drive table for driving the LEDs 11a and 11b of the light emitting device 11 to emit light by the LED drive device 27 at the emission drive current and the emission timing corresponding to the pulsating waveform of the predetermined pulse (see FIG. 10) (see FIG. (See 9)
Is memorized. A pulse measurement confirmation process (see FIG. 11) is performed according to this pseudo pulse emission drive table, and a correction coefficient x20 corresponding to the difference from the current pulse rate measured by the probe unit 1 is stored in the pulse measurement correction coefficient memory 29b. Then, when the pulse measurement is actually performed on the subject 10, the correction is performed by the pulse measurement correction coefficient x20, so that the probe unit 1
It is possible to perform pulse measurement with stable accuracy even if there is a variation in probe performance due to replacement or change over time. The LED light emission drive signal corresponding to the pulsating waveform of the predetermined pulse (see FIG. 10) may be generated by calculation to perform the pulse measurement confirmation process (see FIG. 12).

Further, in the storage device 29A, when the reference (as designed) probe portion 1 is targeted, the red / infrared light reception level ratio R corresponding to the absorbance ratio of arterial blood which gives a predetermined oxygen saturation%. / IR received light level signal VaR / VaIR should be obtained.
Pseudo pulse predetermined ratio light emission drive table (see FIG. 1)
4) is stored. Oxygen saturation measurement confirmation processing (see FIG. 17) is performed according to this pseudo pulse predetermined ratio light emission drive table, and a correction coefficient (or correction shift value) x30 according to the difference with the current measured oxygen saturation% by the probe unit 1 Are stored in the oxygen saturation correction coefficient memory 29c. Then, when the oxygen saturation is actually measured for the subject 10, the oxygen saturation correction coefficient x30 is used to correct the oxygen saturation, so that even if there is a variation in the probe performance due to replacement of the probe unit 1 or aging, stable accuracy can be obtained. Oxygen saturation measurements can be made. The LED light emission drive signal corresponding to the pseudo pulse waveform (see FIG. 13) that should obtain the red / infrared received light level signal VaR / VaIR having the predetermined absorbance ratio is generated by calculation to perform pulse measurement confirmation processing. It may be configured.

Further, the storage device 29A is provided with a probe drive accumulated time memory 29d for storing the accumulated time t when the LED driving device 27 emits light for the probe unit 1 currently mounted. When the accumulated time t exceeds a preset probe driving life time T, a message for probe replacement is displayed and notified.

The external storage device 29B stores various data measured according to the biological signal detection process centered on the CPU 25.

The CPU 25 of this biological signal detecting device
A program for controlling an electronic circuit (computer) centered on is a ROM built in the CPU 25,
Alternatively, it is stored in the storage device 29A, or is externally written and stored in the external storage device 28B such as a memory card.

The backlight control device 32 includes a display unit 30.
The backlight 31 is controlled to be turned on and off, and a lighting level is controlled when the backlight 31 is turned on. The light emitting device 11 is accompanied by the reference voltage (VREF) correction process of the light receiving operation in the current / voltage conversion circuit 22. When the light-reception level signal Va1 corresponding to the amount of external light received by the light-receiving device 12 in the non-light-emitting state is read by the CPU 25,
The light reception level signal Va1 determines the brightness of the external environment, and the lighting level for the backlight 31 is controlled to an optimum level accordingly.

Here, the pulse of the subject 10 detected by the biological signal detecting apparatus is the peak value of the received light level signals Va1 and Va2 (in accordance with the pulsation of the biological body obtained by driving the light emitting device 11 of the probe unit 1 to emit light). (See FIGS. 2 and 5)
Is calculated and measured depending on how many times it is counted per predetermined time.

Next, the principle for measuring the oxygen saturation of arterial blood of the subject 10 by the biological signal detecting apparatus will be described.

This device is a device for measuring the oxygen saturation of arterial blood by utilizing the fluctuation of blood volume of the artery due to the pulse, and it is not necessary to collect blood and the subject 10 (for example, finger)
Since it can be measured simply by shining light on it, it is used as an area monitor for anesthesia and intensive care, as well as various tests and clinical research equipment.

Among hemoglobins in blood, hemoglobin bound to oxygen is called oxyhemoglobin (HbO ₂ ), hemoglobin not bound to oxygen is called reduced hemoglobin (Hb), and this percentage is represented by oxygen saturation. Degree (SpO ₂ ).

The blood becomes red when oxygen is included, and black when oxygen is lost. Therefore, the oxygen amount can be evaluated by looking at the color of blood. When measuring from the outside of the body, the arterial flow and the venous flow are obtained in a mixed state, but since the saturation of the arterial flow alone is actually measured, the pulsation of the arterial flow is used.

FIG. 2 is a diagram showing the ratio of each light absorption component to the total light absorption when light is transmitted to the human body and the change state of the light absorption due to its pulsation.

The degree of light absorption when light is transmitted through the subject 10 naturally has a pulsating component. This pulsating component is caused by the pulsation of the artery.

It is the arterial component that changes in accordance with the pulsation of the heart. Therefore, by extracting the color of the blood in this pulsating portion, it is possible to measure only the color of the arterial blood separately.

That is, as shown in FIG. 2, the absorption of light by tissues other than blood vessels and venous blood is constant because it is not affected by the heartbeat, whereas arterial blood pulsates, so the absorption of light by its components is synchronized with the heartbeat. And fluctuate.

As described above, since the absorption due to arterial blood fluctuates with the heartbeat, if the invariant component of the fluctuation is numerically subtracted from the overall absorption, the absorption component due to human tissue or venous blood is removed, Only the light absorption component due to arterial blood remains, which indicates the oxygen saturation of arterial blood.

The principle of measuring oxygen by light is Lamb
It is based on the ert-Beer law and the principle of measurement by absorption.

(Lambert-Beer) law Basic: "Absorbance is proportional to the product of incident light and solute concentration" A solution in which a substance is dissolved in a liquid, the incident light Iin and the transmitted light I
The out ratio is attenuated by an amount proportional to the concentration of the substance and the optical path length.

A = log (Iin / Iout) = E · C · D A: Absorbance C: Concentration E: Extinction coefficient D: Thickness extinction coefficient E is a constant representing the intensity of light absorption specific to the sample, It depends on the wavelength of the incident light.

Here, it is assumed that the thickness increases by ΔD and the transmitted light decreases (Iin−ΔI). This is equivalent to the case where the incident light Iout enters the thickness ΔD and the transmitted light of (Iout−ΔI) is obtained. Therefore, the following equation is established.

ΔA = log {Iout / (Iout-ΔI)}
= E · C · ΔD In this apparatus, it is considered that the pulsation of arterial blood causes a change in thickness ΔD, and as a result, the absorbance changes by ΔA.

When ΔA is measured at two wavelengths, ΔA1 = E1 · C · ΔD ΔA2 = E2 · C · ΔD E1: extinction coefficient of arterial blood of wavelength 1 E2: ratio of extinction coefficient of extinction coefficient of arterial blood of wavelength 2 When ΔA1 / ΔA2 is obtained as φ, the concentration C and the change ΔD of the thickness are constant regardless of the wavelength, and therefore φ = ΔA1 / ΔA2 = E1 / E2.

Since the oxygen saturation S and φ have a one-to-one relationship, if φ is determined, S is also determined.

Therefore, it becomes possible to obtain the oxygen saturation of arterial blood from the ratio of oxyhemoglobin and deoxyhemoglobin using light sources of two different wavelengths.

FIG. 3 is a diagram showing changes in absorbance with respect to oxyhemoglobin and reduced hemoglobin at red emission wavelengths and infrared emission wavelengths, and changes in oxygen saturation depending on the absorbance ratio. FIG. 3A shows oxyhemoglobin. And (B) are diagrams showing the relationship between the emission wavelength and the absorbance with respect to reduced hemoglobin, and FIG. 7B is a diagram showing the relationship between the absorbance ratio R / IR of the red light R and the infrared light IR and the oxygen saturation SpO ₂ .

FIG. 4 shows a red LED of the biological signal detecting device.
It is a timing chart which shows the light emission drive interval in 11a and infrared LED11b.

FIG. 5 shows a red LED of the biological signal detecting device.
It is a figure which shows each received light signal waveform according to the pulsation accompanying the light emission of 11a and infrared LED11b.

That is, the red LED 11a and the infrared LED 11b in the light emitting device 11 of the probe unit 1 are as shown in FIG.
As shown in FIG.
The time-divisional driving is performed according to the light emission timing control signal output from the LED drive device 27 to the LED driving device 27, as shown in FIG.
The arterial oxygen saturation (SpO ₂ ) is determined by the ratio (A / B) of the received light level signal Va for each light emission wavelength separated from the received light combined signal corresponding to the pulsation read from the A / D conversion circuit 24 to the CPU 25. Calculated and calculated.

In this case, the timing at which the arterial blood flows into the subject 10 is the maximum, that is, the fixed absorption by the tissue and venous blood of the subject 10 and the absorption by the arterial blood are maximized, and the amount of light received by the photodiode 12a is minimum. When the light reception level signal Va read by the CPU 25 becomes minimum (dark level maximum in FIG. 5), the light reception level signal VaR accompanying red light emission and the light reception level signal VaIR accompanying infrared light emission are Separated,
Arterial oxygen saturation (Sp) corresponding to the ratio (A / B)
O ₂ ) is measured.

The specified value of the oxygen saturation (SpO ₂ ) corresponding to the ratio R / IR of the received light levels of the red light R and the infrared light IR is stored in advance as a ROM table (see FIG. 16) and corresponds at the time of measurement. Data may be read out, and the absorbance ratio (ΔA1 / Δ) accompanying the pulsation may be read each time.
The calculation may be performed based on A2).

Next, a series of operations of the biological signal detecting device having the above-mentioned configuration will be described.

(Probe Matching (Calibration)) FIG. 6 is a diagram showing reference data of light emission current vs. light receiving level which becomes a reference for driving the probe in accordance with the probe matching process of the biological signal detecting apparatus. In the reference data of the light emission current vs. the light reception level, the specified value of the light reception level signal (V) with respect to the change of the predetermined light emission drive current (mA), the actual measurement value, and the correction coefficient of the actual measurement value are associated with each address.

FIG. 7 shows a prescribed value curve of the light receiving level when light emission is driven for the reference (as designed) probe portion 1 according to the reference data of the light emitting current versus the light receiving level associated with the probe matching process of the biological signal detecting device. It is a figure which shows in comparison with the measured value curve of the light reception level at the time of light emission drive targeting the present probe part 1. In FIG. 7, the horizontal axis represents the light emission drive current value (mA), and the vertical axis represents the voltage value (V) of the light reception level.

FIG. 8 is a flow chart showing a probe matching process of the biological signal detecting apparatus.

This probe matching process is performed every time the power is turned on, for example, and is performed twice for the red LED 11a and the infrared LED 11b.

When the power of the biological signal detecting device is turned on,
The probe matching process in FIG. 8 is started according to the system program stored in the internal ROM of the CPU 25, the storage device 29A, or the external storage device 29B.

When this probe matching process is started, first, the drive current I for the light emitting device 11 of the probe unit 1 is set to the initial value "0 (mA)" (step A1), and the light emission shown in FIG. Reference data AD of current vs. received light level
DRESS “00” is designated (step A2).

Then, the LED (11a or 11b) is driven to light by the set drive current I (initial value "0") (step A3), and the light receiving level according to the light receiving current IF output from the light receiving device 12 at this time. The measured value (“0” in this case) of the signal (Va1 or Va2) is written in correspondence with the designated ADD “00” of the reference data (step A4).

Then, the LED is turned off (step A5), and the designated ADD of the reference data is incremented by 1 to ADD.
RESS "01" is designated (step A6), and the LED drive current I is set to +5 (mA) and set to "5 (mA)" (step A7).

Here, it is judged whether or not the set drive current I exceeds the maximum matching value of 40 (mA) (step A).
8) If it is determined that the matching maximum value of 40 (mA) is not exceeded, L is set by the set drive current I (in this case, "5 (mA)") updated and set in step A7.
The ED is driven to light (step A8 → A3), and the measured value of the received light level signal Va at this time (in this case, "0.2"
5 ") is written in correspondence with the designated ADD" 01 "of the reference data (step A4).

Thereafter, the steps A3 to A8 are repeated in the same manner as described above, so that each ADDRESS (0
(0 to 08), the measured values of the light reception level signal Va at the time of LED lighting, which correspond to the light emission drive current I respectively, are sequentially written to the corresponding designated ADDs.

Then, in step A8, when it is determined that the set drive current I exceeds the matching maximum value of 40 (mA), the light emission drive current I (0, 5, 5) based on the current probe unit 1 is used. 10, ..., 40 mA), each received light measurement value in the case of lighting drive is obtained, and the designated ADD of the reference data is reset to "00" (steps A8 → A9).

Here, the allowable error range y1 associated with the light emitting and light receiving operations of the probe unit 1 is set (y1 = 20% in this case) (step A10), and the correction coefficient x1 is reset to "0". (Step A11).

Then, the measured value corresponding to the current designated ADD "00" in the reference data (see FIG. 6) is set in the register a (step A1).
2) The specified value that should have been obtained when the probe unit 1 is the reference (as designed) is set in the register b (step A13), and the ratio a / b between the measured value a and the specified value b corresponds. It is set as the correction coefficient x1 (step A1)
4).

Then, the ratio a between the measured value a and the specified value b
It is determined whether the correction coefficient x1 composed of / b is within or outside the allowable error range y1 set in step A10 (steps A15 and A16), and when it is determined that the correction coefficient x1 is within the allowable error range y1. , The correction coefficient x1 is written corresponding to the current designated ADD "00" (step A1).
7).

Then, the designated ADD of the reference data is +1.
As a result of being updated (step A18), the specified ADD exceeds the final "08", the above step A1.
The processes of 2 to A19 are repeated (step A19), and the correction coefficient x1 ... Which is the ratio a / b with the specified value b for each measured value a corresponding to each address ADD of the reference data is acquired.

When it is determined in step A19 that the designated ADD of the reference data exceeds the final "08", that is, the correction coefficient x1 for each measured value a ... Corresponding to each address ADD of the reference data. When it is determined that all are within the allowable error range y1, a probe matching end message is displayed on the display unit 30, and the average value of the correction coefficients x1 written in each ADD of the reference data or The correction coefficient x1 of the intermediate value is extracted and the correction coefficient x10 of the received light level signal Va for the current probe unit 1 is extracted.
Is stored in the probe light receiving amount correction coefficient memory 29a of the storage device 29A (step A20).

On the other hand, if it is determined in steps A15 and A16 that the correction coefficient x1 corresponding to the measured value a corresponding to the designated ADD of the reference data is outside the allowable error range y1, the probe A guide message such as "Please wipe the light emitting surface and the light receiving surface of the probe" is displayed on the display unit 30 together with the NG message (step A21).

Here, when the user re-calibrates (matches) the user's operation of the input device 28 after the current light-emitting surface and light-receiving surface of the probe unit 1 are wiped by the user (step A22), The probe matching process from step A1 is restarted from the beginning, and in the same manner as above, the actual measurement process of the received light level signal Va by the current probe unit 1 according to the reference data (steps A1 to A8), the measured value a and the specified value. an allowable error (y1) determination process of the correction coefficient x1 according to the ratio a / b with b (steps A9 to A19), and a writing process of the correction coefficient x1 (step A17),
Is repeated.

When the probe matching completion message is displayed on the display unit 30 in step A20, all the light received by the CPU 25 is read from the A / D conversion circuit 24 as the probe unit 1 emits light. The level signal Va is corrected by the correction coefficient x10 stored in the probe light receiving amount correction coefficient memory 29a, so that the accuracy is stable even if there is some variation in the probe performance due to replacement of the probe unit 1 or aging. It is possible to obtain the received light level signal Va of.

On the other hand, when the probe NG message is displayed again by the recalibration (matching) process after wiping the dirt of the light emitting surface and the light receiving surface of the probe unit 1, the probe performance itself is within the allowable error range. A probe exchange message is displayed together with the message indicating that the value has dropped beyond y1 (step A21).

As a result, the user not only can use the probe unit 1 while being worn up to the maximum performance limit within the allowable error range y, but also use the probe unit 1 in which the performance of the probe unit 1 cannot be maintained constant. When the level drops to an impossible level, it is possible to easily know that probe replacement is necessary immediately.

(Confirmation of Accuracy of Pulse Measurement) FIG. 9 shows a pseudo pulse emission drive table for pseudo emission drive of the probe unit 1 according to a predetermined pulse in accordance with the pulse measurement confirmation process of the biological signal detecting apparatus. It is a figure. In FIG. 9, the current value for pseudo light emission driving and the address of the memory for storing the data of the current value are displayed in association with the current value.

FIG. 10 is a diagram showing a light emission drive curve corresponding to a pulsating waveform of a predetermined pulse when the probe unit 1 is driven to emit light according to the pseudo pulse light emission drive table accompanying the pulse measurement confirmation processing of the biological signal detecting apparatus. The horizontal axis represents a value corresponding to the address (ADD) of the pseudo pulse light emission drive table as the elapsed time, and the vertical axis represents the current value for the pseudo light emission drive as the light emission amount.

FIG. 11 is a flow chart showing the pulse measurement confirmation processing (table system) of the biological signal detecting apparatus.

This pulse measurement confirmation processing is executed according to the system program stored in the internal ROM of the CPU 25 or the storage device 29A or the external storage device 29B, for example, following the probe matching process executed every time the power is turned on. Then, either the red LED 11a or the infrared LED 11b is driven to emit light in a pseudo manner according to a predetermined pulse.

In the pulse measurement confirmation process, when the predetermined pulse is set to 60 beats in one minute, for example, the pseudo pulse emission drive table (see FIG. 9) has a light emission drive cycle that produces one pseudo pulse. (ADD1-6, 7-12, ...) is repeated in 1 second.

When the pulse measurement confirmation process in FIG. 11 is started, first, the address of the pseudo pulse emission drive table is displayed.
ADD is designated as "1" (step B1), and this designated ADD
L by the LED drive current I (= 10) corresponding to “1”
The ED is driven to light up (steps B2 and B3).

Then, the designated ADD of the pseudo pulse emission drive table is incremented by 1 to designate ADD "2" (step B4), and the LED drive current I (= 12) corresponding to the designated ADD "2" is used. The LED is driven to light (step B5 → B2, B3).

Thereafter, as the designated ADD of the pseudo pulse light emission drive table is sequentially incremented by +1 as described above, the LED drive current I is made to correspond to the pseudo pulse waveform corresponding to a predetermined pulse (see FIG. 10). The light emitting device 11 is repeatedly turned on and driven (steps B2 to B5).
The pulse calculation is repeated depending on how many times the peak value of the received light level signal Va within the fixed time is counted in the PU 25 (step B5).

When the CPU 25 calculates the pulse according to the light emission drive corresponding to the pulsating waveform of the predetermined pulse, the allowable error range y2 of the pulse measurement due to the variation in the performance of the probe unit 1 is set (in this case, Is y2 = 1
0%) (step B6), and the correction coefficient x2 is reset to "0" (step B7).

Then, in step B5, the CPU
The pulse measurement value measured in response to the pseudo pulse emission drive for the probe unit 1 calculated in step 25 is set in the register a (step B8), and the reference (as designed) is set.
The predetermined pulse prescribed value (for example, 60 beats) which should have been obtained in the case of the probe unit 1 of (1) is set in the register b (step B9), and the ratio a / of the measured value a and the prescribed value b is set.
b is set as the pulse correction coefficient x2 (step B
10).

Then, the pulse correction coefficient x2 consisting of the ratio a / b between the pulse measurement value a using the current probe unit 1 and the predetermined pulse regulation value b is the allowable error range y2 set in the step B6. Is determined to be within or outside the range (steps B11 and B12), and if it is determined to be within the allowable error range y2, a pulse measurement OK message is displayed on the display unit 30, and the pulse correction coefficient x2 is displayed. The correction coefficient x20 for pulse measurement using the current probe unit 1 is stored in the pulse measurement correction coefficient memory 29b of the storage device 29A (step B13).

On the other hand, in steps B11 and B12, a pulse correction coefficient x2 consisting of the ratio a / b of the current pulse measurement value a using the probe unit 1 and the predetermined pulse regulation value b is used.
When it is determined that is outside the allowable error range y2, a guide message such as "Please wipe the light emitting surface and the light receiving surface of the probe" is displayed on the display unit 30 together with the probe (pulse measurement) NG message. (Step B14).

[0100] Here, after the user wipes the current dirt on the light-emitting surface and the light-receiving surface of the probe unit 1 and then a re-measurement is instructed by the user operation of the input device 28 (step B15), from the step B1. The pulse measurement confirmation process is restarted from the beginning, and in the same manner as above, the pulse measurement process (steps B1 to B5) associated with the current emission drive of the probe unit 1 corresponding to the pseudo pulse waveform of the predetermined pulse (measured value a).
The allowable error (y2) of the correction coefficient x2 according to the ratio a / b between the reference value b and the specified value b (steps B6 to B12), and the writing processing of the pulse correction coefficient x2 (step B10),
Is repeated.

Then, in step B13, when the pulse measurement OK message is displayed on the display unit 30,
Along with the actual pulse measurement for the subject 10 after this, the CP
The pulse value calculated in U25 is corrected by the pulse correction coefficient x20 stored in the pulse measurement correction coefficient memory 29b, so that there is some variation in the probe performance due to replacement of the probe unit 1 and aging. Even with this, pulse measurement can be performed with stable accuracy.

On the other hand, by the re-measurement process after wiping off the dirt on the light emitting surface and the light receiving surface of the probe unit 1,
When the probe (pulse measurement) NG message is displayed again, the probe replacement message is displayed together with the fact that the current pulse measurement accuracy using the probe unit 1 has fallen beyond the allowable error range y2 (step). B1
4).

As a result, the user not only can use the probe unit 1 while being worn up to the maximum performance limit within the allowable error range y, but also cannot use the probe unit 1 with a constant performance of pulse measurement. When the level drops to an impossible level, it is possible to easily know that probe replacement is necessary immediately.

Note that the LED light emission drive signal corresponding to the pulsating waveform of the predetermined pulse (see FIG. 10) is generated by calculation regardless of the pseudo pulse light emission drive table (see FIG. 9) and the pulse measurement confirmation process (see FIG. 12)).

FIG. 12 is a flow chart showing the pulse measurement confirmation processing (calculation method) of the biological signal detecting apparatus.

In the pulse measurement confirmation processing of this calculation method, the light emission drive current I for the probe unit 1 is changed from I = 10 to I =
By repeating the process of driving the LEDs to be turned on by increasing the calculation by “2” by 20 at regular intervals (for example, 1 second in the case of 60 beats per minute) according to a predetermined pulse rate (steps C1 to C6). ) Similarly to the above, the pulse measurement process associated with the current light emission drive of the probe unit 1 corresponding to the pseudo pulse waveform of the predetermined pulse is executed.

Even in the pulse measurement confirmation processing of this calculation method, the tolerance (y) of the correction coefficient x2 according to the ratio a / b between the measured value a and the specified value b accompanying steps B6 to B15
2) The determination process and the writing process of the pulse correction coefficient x2 are the same as those in the case of the table system, and the pulse measurement correction coefficient of the storage device 29A is used as the correction coefficient x20 of the pulse measurement using the current probe unit 1. It can be stored in the memory 29b.

Therefore, also in this case, the pulse value calculated by the CPU 25 along with the actual pulse measurement for the subject 10 is corrected by the pulse correction coefficient x20 stored in the pulse measurement correction coefficient memory 29b. Even if there is some variation in the probe performance due to replacement of the probe unit 1 or change over time, pulse measurement can be performed with stable accuracy. Further, when the performance of the probe unit 1 is lowered to an unusable level at which a constant pulse measurement accuracy cannot be maintained, it can be easily known that the probe needs to be replaced promptly.

(Accuracy Confirmation of Oxygen Saturation Measurement) FIG. 13 shows a predetermined light emission level ratio R / IR corresponding to an arterial blood absorbance ratio which becomes a predetermined oxygen saturation% accompanying the oxygen saturation measurement confirmation processing of the biological signal detecting device. It is a figure which shows the light emission drive curve corresponding to the pseudo pulse waveform of. The horizontal axis represents a value corresponding to the address (ADD) of the pseudo pulse predetermined ratio light emission drive table as an elapsed time, and the vertical axis represents a current value for pseudo light emission drive as a light emission amount.

FIG. 14 shows a predetermined pseudo pulse for driving the probe unit 1 to emit light in a pseudo manner at a light emission level ratio R / IR that provides a predetermined oxygen saturation% in accordance with the oxygen saturation measurement confirmation process of the biological signal detecting apparatus. It is a figure which shows a specific light emission drive table.
In this pseudo pulse predetermined ratio light emission drive table, the red LED 11a corresponding to the pseudo pulse waveform of the predetermined light emission level ratio R / IR
And the light emission drive current (mA) of each of the infrared LEDs 11b is set in association with each address.

FIG. 15 shows a prescribed value curve of the oxygen saturation measurement according to the change of the emission level ratio R / IR due to the emission drive in the pseudo pulse waveform accompanying the oxygen saturation measurement confirmation process of the biological signal detecting device and the current curve. It is a figure which shows in comparison with the measured value curve of the oxygen saturation measurement at the time of light emission drive targeting the probe part 1. The abscissa indicates the emission level ratio R / IR, and the ordinate indicates the oxygen saturation%.

FIG. 16 is a table showing the specified values of oxygen saturation corresponding to the absorbance ratio R / IR of arterial blood accompanying the oxygen saturation measurement confirmation processing of the biological signal detecting device, the respective measured values and the correction coefficient x3 thereof. Is. In this table, the specified value of the oxygen saturation% with respect to the change in the absorbance ratio R / IR of the arterial blood, the actual measurement value, and the correction coefficient of the actual measurement value are associated with each address.

FIG. 17 is a flow chart showing the oxygen saturation measurement confirmation processing of the biological signal detecting apparatus.

This oxygen saturation measurement confirmation processing is, for example, following the probe matching processing and pulse measurement confirmation processing executed every time the power is turned on, and then the internal RO of the CPU 25.
M or storage device 29A or external storage device 29B
Is carried out according to the system program stored in.

In this oxygen saturation measurement confirmation processing,
Absorbance ratio R / IR of arterial blood by red light R and infrared light IR
With the emission ratio corresponding to the pseudo pulse waveform according to
Is driven to emit light, and the measurement correction coefficient x3 of the oxygen saturation is obtained from the ratio (difference) between the measured oxygen saturation and the specified value.

When the oxygen saturation measurement confirmation processing in FIG. 17 is started, first, the update interval of the emission ratio R / IR is set to z.
(= 0.2), and the address of the table in FIG.
(ADR) is designated as "00" (step D1).

In order to obtain the pseudo pulse waveform corresponding to this set emission ratio R / IR (= 3.6), the emission ratio R / IR in the initial measurement confirmation is set to "3.6" (step D2). The pseudo pulse predetermined ratio light emission drive table (see FIG. 14) is generated and its head address (ADD = 1) is designated (step D3).

Then, the set emission ratio R / IR (=
According to the pseudo pulse predetermined ratio light emission drive table generated corresponding to 3.6), the red LED 11a is changed by the change of the light emission drive current I corresponding to the pseudo pulse waveform of the predetermined light emission ratio R / IR.
And the infrared LEDs 11b are driven to emit light (step D4
During this period, the CPU 25 repeats the calculation of the oxygen saturation level according to the light reception level signal VaR for red light emission and the light reception level signal VaIR for infrared light emission (step D7).
7).

Then, the predetermined light emission ratio R / IR (=
CPU according to the light emission drive corresponding to the pseudo pulse waveform of 3.6)
When the oxygen saturation is calculated at 25, the probe unit 1
The allowable error range y3 of the oxygen saturation measurement due to the variation of the performance of (3) is set (y3 = 10% in this case) (step D8), and the correction coefficient x3 is reset to "0" (step D9).

Then, in step D7, the CPU
The oxygen saturation measured in response to the pseudo pulse emission drive at the predetermined emission ratio R / IR (= 3.6) for the probe unit 1 calculated in step 25 is set in the register a (step D10). , Arterial blood absorbance ratio R / IR (=
The prescribed value of oxygen saturation in the case of 3.6) is the register b.
Is set (step D11), and the ratio a / b between the measured value a and the specified value b is set as the oxygen saturation correction coefficient x3 (step D12).

Then, the oxygen saturation correction consisting of the ratio a / b between the measured oxygen saturation value a and the specified value b at the predetermined light emission ratio R / IR (= 3.6) using the present probe unit 1 is used. It is determined whether the coefficient x3 is within or outside the allowable error range y3 set in step D8 (step D1).
3, D14), and if it is determined that it is within the allowable error range y3, the correction coefficient x3 is written in correspondence with the current table designation ADR "00" (see FIG. 16) (step D15).

Then, the predetermined light emission ratio R / IR (=
Probe O corresponding to the confirmation of oxygen saturation measurement in 3.6)
While the K determination message is displayed on the display unit 30 (step D16), the next predetermined light emission ratio R / IR is -z.
(= 0.2) and updated to "3.4" (step D
17), the table designation ADR "00" is incremented by 1 and updated to "01" (step D18).

Then, the next predetermined light emission ratio R / IR (= 3.4) updated and set in step D17 is the minimum predetermined light emission ratio R in this oxygen saturation measurement confirmation processing.
/ IR (= 0.4), it is determined whether or not it has been set (step D19), and the minimum predetermined light emission ratio R /
When it is determined that the value is not lower than IR (= 0.4), the processes of steps D3 to D7 are repeated.

In other words, the updated light emission ratio R / IR
According to the pseudo pulse predetermined ratio light emission drive table (see FIG. 14) generated corresponding to (= 3.4), the predetermined light emission ratio R /
The red LED 11a and the infrared LED 11b are driven to emit light by the change of the light emission drive current I corresponding to the pseudo pulse waveform of IR (steps D4 to D7). The calculation of the oxygen saturation level according to the received light level signal VaIR is repeated (step D7).

Then, the updated predetermined light emission ratio R /
When the oxygen saturation level is calculated in the CPU 25 according to the light emission drive corresponding to the pseudo pulse waveform of IR (= 3.4), the allowable error range y3 of the oxygen saturation level measurement due to the variation in the performance of the probe unit 1 becomes similar to the previous time. Is set (step D8),
The correction coefficient x3 is reset to "0" (step D
9).

Then, in step D7, the CPU
The oxygen saturation measured in response to the pseudo pulse emission drive at the predetermined emission ratio R / IR (= 3.4) for the probe unit 1 calculated in step 25 is set in the register a (step D10). , Arterial blood absorbance ratio R / IR (=
In the case of 3.4), the specified value of the oxygen saturation is the register b.
Is set (step D11), and the ratio a / b between the measured value a and the specified value b is set as the oxygen saturation correction coefficient x3 (step D12).

Then, the oxygen composed of the ratio a / b between the measured oxygen saturation value a and the specified value b at the predetermined emission ratio R / IR (= 3.4) after the update using the current probe unit 1 is performed. It is again determined whether the saturation correction coefficient x3 is within the allowable error range y3 or not (steps D13 and D14). If it is determined that the saturation correction coefficient x3 is within the allowable error range y3, the current table designation ADR " The correction coefficient x3 is written corresponding to 01 "(see FIG. 16) (step D15).

That is, by repeating the processes of steps D3 to D19, the predetermined light emission ratio R / IR is obtained.
From (= 3.6) to R / IR (= 0.4), while being updated and set at each update interval z (= 0.2), the oxygen saturation measurement result at each predetermined light emission ratio R / IR ... a and specified value b
The oxygen saturation correction coefficient x3 consisting of the ratio a / b is calculated, and it is confirmed that it is within the preset allowable error range y3, and the correction coefficient is added to each corresponding designated ADR in the table in FIG. x3 is set sequentially.

Thereafter, in step D19, the updated next predetermined light emission ratio R / IR is the minimum predetermined light emission ratio R / IR (= 0.
4) If it is determined that the setting is lower than that, that is, from the predetermined light emission ratio R / IR (= 3.6) to R / IR
(= 0.4) Allowable error range for all oxygen saturation correction coefficients x3 ... Comprising the ratio of each oxygen saturation measurement value corresponding to probe driving at each emission ratio R / IR ... and its preset value If it is determined to be within the range of y3, an oxygen saturation measurement OK message is displayed on the display unit 30,
Of the correction coefficients x3 written in each ADR in the table, the correction coefficient x3 at the average value or the intermediate value or a typical oxygen saturation predetermined value (= 50, 80%, etc.) is extracted to obtain the current value. The correction coefficient x30 for oxygen saturation measurement using the probe unit 1 is stored in the oxygen saturation correction coefficient memory 29c of the storage device 29A (step D20).

On the other hand, in steps D13 and D14, it is determined that the correction coefficient x3 corresponding to the oxygen saturation measurement value a corresponding to the probe driving at a predetermined light emission ratio R / IR is outside the allowable error range y3. When the determination is made, a guide message such as "Please wipe the light emitting surface and the light receiving surface of the probe" is displayed on the display unit 30 together with the probe (oxygen saturation measurement) NG message (step D21).

When the user now operates the input device 28 to instruct re-measurement after the current light-emitting surface and light-receiving surface of the probe unit 1 are wiped by the user (step D22), the steps from the step D1 are started. The oxygen saturation measurement confirmation process is restarted from the beginning, and the oxygen saturation measurement process associated with the current emission drive of the probe unit 1 corresponding to the pseudo pulse waveform of the predetermined emission ratio R / IR is performed in the same manner as described above (steps D1 to D1). D7), a permissible error (y3) determination process of the correction coefficient x3 according to the ratio a / b between the measured value a and the specified value b (steps D8 to D14), and a writing process of the oxygen saturation correction coefficient x3 (step D15). ), Is repeated.

Then, in step D20, when the oxygen saturation measurement OK message is displayed on the display unit 30, the oxygen calculated by the CPU 25 in accordance with the subsequent actual measurement of the oxygen saturation of the subject 10. The saturation is corrected by the oxygen saturation correction coefficient x30 stored in the oxygen saturation correction coefficient memory 29c, so that the probe performance is stable even if there is some variation in the probe performance due to replacement of the probe unit 1 or aging. Oxygen saturation can be measured with the specified accuracy.

On the other hand, further, by re-measurement processing after wiping off the dirt on the light emitting surface and the light receiving surface of the probe unit 1,
When the probe (oxygen saturation measurement) NG message is displayed again, it is considered that the current measurement accuracy of oxygen saturation using the probe unit 1 has fallen beyond the allowable error range y3, and the probe exchange message is issued. It is displayed (step D21).

As a result, the user not only can continue to use the probe unit 1 being mounted up to the performance limit within the allowable error range y, but also maintain the performance of the probe unit 1 at a constant oxygen saturation measurement accuracy. If it drops to an unusable level, which is impossible, it is possible to easily know that probe replacement is necessary immediately.

Incidentally, in this oxygen saturation measurement confirmation processing,
Obtain the ratio a / b between the measured oxygen saturation value a and the specified value b when the probe is driven at a predetermined light emission ratio R / IR as the oxygen saturation correction coefficient x3 (FIG. 17 (step D15)).
However, the difference ab between the measured oxygen saturation value a and the specified value b may be acquired as an oxygen saturation correction (shift) coefficient and stored in the oxygen saturation correction coefficient memory 29c.

Further, the LED light emission drive signal corresponding to the pulsating waveform (see FIG. 13) which should obtain the red / infrared light receiving level signal VaR / VaIR of the predetermined light absorption ratio is converted into the pseudo pulse predetermined ratio light emission drive table (see FIG. 13). 14)), the oxygen saturation measurement confirmation processing may be performed by generating by calculation.

(Monitoring of probe replacement time) In this biological signal detecting device, when the power is turned on, for example, the probe which is currently mounted and is stored in the probe drive accumulated time memory 29d of the storage device 29A at a constant interval. The drive accumulated time t for the unit 1 is read out, and it is monitored whether or not the preset probe drive life time T has been exceeded.

When the probe drive accumulated time t exceeds the probe drive life time T, a guide message such as "probe replacement time" is displayed.

As a result, the user can easily know the probe replacement time as a guide.

Next, the operation when the pulse measurement and the oxygen saturation measurement are performed on the actual subject (living body) 10 will be described.

FIG. 18 is a flow chart showing a biological signal detecting process for the subject (living body) 10 by the biological signal detecting apparatus.

The subject 10 is sandwiched between the light emitting device 11 and the light receiving device 12 in the probe unit 1, and the input device 28
When the measurement start key provided in is operated, the biological signal detection process in FIG. 18 is started according to the system program stored in the internal ROM of the CPU 25, the storage device 29A, or the external storage device 29B.

(Elimination of influence of extraneous light) When this biological signal detection process is activated, first, the light reception level signal Va1 on the side through the amplifier circuit 23 when the light emitting device 11 is not emitting light, that is, the subject 10 is passed through. Even before the reception of the transmitted light, the light reception level signal output from the A / D conversion circuit 24 after being multiplied by N by the amplification circuit 23 in accordance with the external light reception operation in the light reception device 12 according to the installation environment of the probe unit 1. Va1 is CPU2
5 is read (step S1).

Then, the amplification side light receiving level signal V read by the CPU 25 when the light emitting device 11 is not emitting light is received.
Whether a1 is equal to the reference voltage (N · VREF) for the light receiving operation multiplied by N, that is, the output voltage output from the voltage / current conversion circuit 22 according to the light receiving operation in the light receiving device 12 is
It is determined whether or not the reference voltage VREF is set in advance (step S2).

Here, since the external light according to the installation environment of the probe unit 1 is received by the photodiode 12a of the light receiving device 12, the current / voltage conversion circuit 22 responds to the increase in the received light current IF. The output voltage shifts from the reference voltage VREF, whereby the light-receiving level signal Va1 on the amplification side read by the CPU 25 becomes the reference voltage (N
If it is determined that the difference is not equal to VREF), Vb (= N · VREF−Va1) which is the difference (shift amount) is calculated and output to the voltage control circuit 26 (steps S2 → S3).

Then, from the voltage control circuit 26, the V
The voltage obtained by adding the actual shift value Vb / N in the current / voltage conversion circuit 22 obtained by dividing b by the amplification factor N to VREF is supplied to the current / voltage conversion circuit 22 as the reference voltage (VREF + Vb / N) (step S4). ).

In this way, the first stage current / voltage conversion circuit 22 based on the received light level signal Va1 via the amplifier circuit 23.
By the correction control of the operating point reference voltage VREF with respect to, even if the external light is received by the light receiving device 12 with the subject 10 sandwiched therebetween, the amplification side light receiving level signal Va1 when the light emitting device 11 is not emitting light is N If it is determined that the reference voltage (N · VREF) for the doubled light receiving operation is set to be the same, the operating point reference of the current / voltage conversion circuit 22 in the light emitting device 11 of the probe unit 1 in the non-light emitting state is similarly obtained. Voltage V
The received light level signal Va2 that should be REF is CP
Read in U25 (steps S1, S2 → S
5).

When it is determined that the received light level signal Va2 read by the CPU 25 does not match the reference voltage VREF, the difference (shift amount) Vb (=
VREF−Va2) is calculated and output to the voltage control circuit 26 (steps S6 → S7).

Then, the actual shift value Vb in the current / voltage conversion circuit 22 is set to VREF from the voltage control circuit 26.
Is added to the current / voltage conversion circuit 22 as a reference voltage (VREF + Vb) (step S8).

In this way, the subject 10 is sandwiched by the correction control of the operating point reference voltage VREF for the second stage current / voltage conversion circuit 22 based on the received light level signal Va2 from the current / voltage conversion circuit 22 as it is. Even if external light is received by the light receiving device 12, the light emitting device 1
When it is determined that the light receiving level signal Va2 in the non-light emitting state of 1 is set equal to the reference voltage (VREF) of the light receiving operation, the process shifts to the light emitting level control process in steps S9 to S16 (steps S5, S6 → S9). ).

As described above, the operating point reference voltage for the two-stage current / voltage conversion circuit 22 based on the received light level signal Va1 via the amplifier circuit 23 and the received light level signal Va2 as it is with the object 10 sandwiched therebetween. By performing VREF correction control, the operating point reference voltage VREF in the current / voltage conversion circuit 22 can be set to a constant value with high accuracy even when external light is received by the light receiving device 12.

(Removal of Influence of Individual Difference of Subject) Step S
When the correction control of the operating point reference voltage VREF in 1 to S8 is performed and the influence of external light is removed, steps S9 to S are performed to remove the influence of the individual difference in the light transmittance of the subject 10.
The process shifts to the control process of the light emission level in 16, and first,
A light emitting current control circuit 25a of the CPU 25 outputs a light emitting current control signal for driving red light emission of a predetermined initial level to the constant current circuit 27c of the LED driving device 27, and the red light emitting drive circuit 27a outputs a red light in the light emitting device 11 of the probe unit 1. The LED 11a is turned on with a predetermined initial level of light emission (step S9).

Then, the transmitted light of red emission that has passed through the subject 10 is received by the photodiode 12a of the light receiving device 12, and from the current / voltage conversion circuit 22 in accordance with the received light current IF output from the photodiode 12a. Is a light reception voltage signal shifted from the reference voltage VREF by the amount of light received, and the light reception level signal Va1 output from the A / D conversion circuit 24 is read by the CPU 25 in response to this, and the red light emission Receiving level signal V according to transmitted light
It is determined whether or not a1 is equal to a predetermined light receiving level within the range necessary for performing an appropriate measurement process (steps S10 and S11).

Here, for example, since the finger which is the subject 10 sandwiched between the probe portions 1 is very thick, the light transmittance thereof is extremely low, and the finger from the reference voltage VREF obtained by the operation of receiving the red transmitted light. When it is determined that the light receiving level signal Va1 corresponding to the shift amount is significantly smaller than the predetermined light receiving level because the shift amount is very small, the light emitting current control circuit 25a of the CPU 25 transfers it to the constant current circuit 27c of the LED driving device 27. The emitted light emission current control signal for driving red light emission drives the emission drive current for the red LED 11a from the red light emission drive circuit 27a to be increased (steps S11 → S12).

Thus, as the amount of light emitted by the red LED 11a increases, the amount of red transmitted light that has passed through the subject 10 in the light receiving device 12 also increases, and
When it is determined that the received light level signal Va1 read from the D conversion circuit 24 into the CPU 25 has become equal to the predetermined received light level within the range necessary for performing proper measurement processing, the light emitting current control of the CPU 25 is similarly performed. Circuit 25
A light emission current control signal for driving the infrared light emission of a predetermined initial level is output to the constant current circuit 27c of the LED driving device 27, and the infrared light emitting drive circuit 27b causes the infrared LED 11b in the light emitting device 11 of the probe unit 1 to be predetermined. The light is turned on at the initial level of light emission (steps S10, S11 → S1).
3).

Then, the transmitted light of the infrared light emitted through the subject 10 is received by the photodiode 12a of the light receiving device 12, and the current / voltage conversion circuit 22 is generated according to the received light current IF output from the photodiode 12a. Outputs a light receiving voltage signal shifted from the reference voltage VREF by the amount of light received. Corresponding to this, the light receiving level signal Va1 output from the A / D conversion circuit 24 is read by the CPU 25, and the infrared light is emitted. Receiving level signal V according to the transmitted light of the emitted light
It is determined whether or not a1 is equal to a predetermined light receiving level in the range necessary for performing an appropriate measurement process (steps S14 and S15).

Here, for example, as in the case described above, since the finger which is the subject 10 sandwiched in the probe unit 1 is very thick, the light transmittance thereof is extremely low, and the reference voltage obtained by the operation of receiving infrared transmitted light is extremely low. Since the shift amount from VREF is also very small, if it is determined that the corresponding light reception level signal Va1 is significantly smaller than the predetermined light reception level, the CPU
25 to the LED drive device 27
The emission current control signal for driving the infrared emission for outputting to the constant current circuit 27c controls the increase of the emission drive current from the infrared emission drive circuit 27b to the infrared LED 11b (steps S15 → S16).

Thus, as the amount of light emitted by the infrared LED 11a is increased, the amount of infrared transmitted light that has passed through the subject 10 at the light receiving device 12 is also increased.
When it is determined that the received light level signal Va1 read from the D conversion circuit 24 into the CPU 25 becomes equal to the predetermined received light level within the range required for proper measurement processing, the above-described pulse measurement and arterial oxygen saturation ( Sp
The measurement process follows the measurement principle of O ₂ ) (steps S14, S15 → S17).

That is, the red light from the red LED 11a and the infrared LED 11 which are continuously driven to alternately emit light after that.
The received light level signals Va1 (R) and Va1 (IR) of each transmitted light corresponding to the infrared light from b are sequentially read, and first, the subject 1
The timing when the flow of arterial blood to 0 becomes maximum,
That is, the absorption of light by the arterial blood is maximized, the amount of light received by the photodiode 12a is minimized, and the CPU 25
The timing at which the received light level signal Va read in is minimum (maximum dark level in FIG. 5) is repeatedly counted at regular intervals to calculate and calculate the pulse.

At this time, the pulse measurement value is stored in the external storage device 29B as a value corrected by the pulse measurement correction coefficient x20 stored in the pulse measurement correction coefficient memory 29b of the storage device 29A, and is displayed on the display unit 30. Since it is displayed, even if there is some variation in the probe performance due to replacement of the probe unit 1 or change over time, it is possible to obtain pulse measurement results with stable accuracy.

Similarly to the above, the timing at which the inflow of arterial blood into the subject 10 is maximized, that is, the absorption of light by the arterial blood is maximized, and the photodiode 12a
The received light level signal Va read by the CPU 25 is minimum (the maximum dark level in FIG. 5).
At this timing, the arterial blood oxygen saturation (SpO) is determined based on the absorbance ratio (A / B) of the subject 10 obtained as the ratio of the received light level signals Va1 (R) and Va1 (IR) of the red light and the infrared light. ₂ ) is calculated.

At this time, the measured value of the arterial blood oxygen saturation is stored in the external storage device 29B as a value corrected by the oxygen saturation correction coefficient x30 stored in the oxygen saturation correction coefficient memory 29c of the storage device 29A. Then, the measurement result of the oxygen saturation can be obtained with stable accuracy even if there is some variation in the probe performance due to the replacement of the probe unit 1 or the change over time, because the measurement result is displayed on the display unit 30.

Therefore, according to the biological signal detecting device having the above-mentioned configuration, for example, when the light emitting device 11 of the probe part 1 currently mounted is driven to emit light by a predetermined light emitting drive current when the power is turned on, the light receiving device 12 outputs the light. Received light current I
Light reception level signal Va read by the CPU 25 according to F
The ratio a / b between the measured value a of ## EQU1 ## and the specified value b of the pre-stored received light level signal Va that should be read by the CPU 25 when the reference (as designed) probe unit 1 is targeted,
The probe light receiving amount correction coefficient x10 is stored in the probe light receiving amount correction coefficient memory 29a, and the light receiving level signal Va read by the CPU 25 thereafter is corrected by the probe light receiving amount correction coefficient x10. Even if there is a variation in the probe performance due to the change, it is possible to obtain a stable light reception level signal Va and maintain highly accurate biometric measurement.

The measured value a of the received light level signal Va
When the probe received light amount correction coefficient x1, which is the ratio a / b between the measured value and the specified value b, exceeds the preset allowable error range y1, the probe NG message is displayed together with the message for wiping the probe light emitting surface / light receiving surface. Since it is displayed on 30, the probe unit 1 can be used for the longest time and the replacement time can be easily known.

Further, according to the biological signal detecting device having the above-mentioned configuration, for example, when the light emitting device 11 of the probe part 1 currently mounted is driven to emit light by the light emission drive current corresponding to the pulsating waveform of the predetermined pulse when the power is turned on. Further, the ratio a / b between the measured pulse value a calculated based on the received light level signal Va read into the CPU 25 according to the received light current IF output from the light receiving device 12 and the prescribed value b of the predetermined pulse is Pulse measurement correction coefficient x20 as pulse measurement correction coefficient memory 29b
When the pulse measurement is performed by storing the actual subject (living body) 10 in the probe unit 1, the measured pulse value is corrected by the pulse measurement correction coefficient x20 and the result is displayed. Even if the probe performance varies due to replacement of the probe unit 1 or change over time, highly accurate pulse measurement can be maintained.

Further, the pulse measurement correction coefficient x2 consisting of the ratio a / b of the pulse measurement value a by the probe driving corresponding to the pulsation waveform of the predetermined pulse and the specified value b which is the predetermined pulse is set to a preset allowable error. When the value exceeds the range y2, the probe NG message is displayed on the display unit 30 together with the message for wiping the probe light-emitting surface / light-receiving surface, so that the probe unit 1 can be used for the maximum length while maintaining the pulse measurement accuracy. You can easily know when to replace.

Further, according to the biological signal detecting device having the above-mentioned configuration, for example, when the power is turned on, the red LED 11a and the infrared light L in the light emitting device 11 of the probe part 1 which is currently mounted are
When the ED 11b and the ED 11b are driven to emit light by the drive current of the red / infrared emission ratio R / IR corresponding to the pseudo pulse waveform of the predetermined oxygen saturation, the CPU 25 is controlled according to the received light current IF output from the light receiving device 12. Ratio (or difference) a / b between the measured value a of oxygen saturation calculated based on the read received light level signal Va and the specified value b of the predetermined oxygen saturation.
(A-b) is stored in the oxygen saturation correction coefficient memory 29c as the oxygen saturation correction coefficient x30, and after that, when the actual subject (living body) 10 is sandwiched in the probe unit 1 and the oxygen saturation measurement is performed. In addition, since the measured oxygen saturation is corrected by the oxygen saturation correction coefficient x30 and displayed as a result, even if there is a variation in the probe performance due to replacement of the probe unit 1 or aging, it is highly accurate. Oxygen saturation measurements can be maintained.

Further, a pulse measurement correction coefficient x3 consisting of a ratio a / b of the oxygen saturation measurement value a by probe driving corresponding to the pseudo pulse waveform of the predetermined oxygen saturation and the specified value b which is the predetermined oxygen saturation. If the value exceeds the preset allowable error range y3, the probe NG message is displayed on the display unit 30 together with the message for wiping the probe light emitting surface / light receiving surface, so that the probe unit 1 maintains the oxygen saturation measurement accuracy. However, it can be used for the longest time, and it is easy to know when to replace it.

In the biological signal detecting apparatus according to the above-mentioned embodiment, the probe unit 1 is constructed so that the light emitted from the light emitting device 11 is transmitted to the subject 10 and the transmitted light is received by the light receiving device 12. However, the same light emitting device 11
The light emitted by the light may be reflected by the subject 10 and the reflected light may be received by the light receiving device 12. Even in the case of a biological signal detecting device using such an object reflected light receiving type probe unit, by performing the probe matching process and the pulse measurement confirmation process and the oxygen saturation measurement confirmation process exactly the same as in the above embodiment, Probe part 1
Even if there is a variation in probe performance due to replacement or change over time, the probe can be used for the longest time while maintaining measurement accuracy, and the replacement time can be easily known.

The method of probe calibration and biometric measurement by the biological signal detecting device described in the above embodiment, that is, the probe matching (calibration) process shown in the flowchart of FIG. 8 and the pulse measurement confirmation process shown in the flowchart of FIG. 11 ( Table method), pulse measurement confirmation processing (calculation method) shown in the flowchart of FIG. 12, oxygen saturation measurement confirmation processing shown in the flowchart of FIG. 17, biological signal detection processing for the subject (living body) 10 shown in the flowchart of FIG. Each of the above methods is a program that can be executed by a computer as a memory card (ROM card, RAM card, etc.), magnetic disk (floppy disk, hard disk, etc.), optical disk (CD-ROM,
DVD, etc.), external recording medium (29B) such as semiconductor memory
It can be stored and distributed in. Then, various computer devices having a light emission drive function and a light reception signal input function for the probe unit 1 are provided with the external recording medium (29
By reading the program stored in B) and controlling the operation by the read program, the probe calibration function and the biometric function described in the above-described embodiment are realized, and the same processing is performed by the method described above. be able to.

The invention of the present application is not limited to the above-described embodiments, but can be variously modified at the stage of implementation without departing from the spirit of the invention. Furthermore, each of the embodiments includes inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, some constituents may be deleted from all constituents shown in each embodiment, or even if some constituents are combined, the problems described in the section of the problem to be solved by the invention can be solved, When the effects described in the section of the effects of the invention can be obtained, a structure in which these constituent elements are deleted or combined can be extracted as the invention.

[0172]

As described above, according to the first biological signal detecting apparatus of the present invention, when the light emitting means of the probe is driven at the predetermined light emitting drive level by the light emitting drive means, the signal level measuring means is used. A correction coefficient of the measured signal level is calculated based on the signal level of the measured light receiving signal and a prescribed signal level according to the predetermined light emission drive level, and based on the calculated correction coefficient of the signal level,
Since the signal level of the received light signal measured by the signal level measuring means is corrected and the state of the subject is measured,
Variations in probe performance are calibrated to measure the condition of the subject.

According to the second biological signal detecting apparatus of the present invention, when the light emitting means of the probe is driven, the signal level of the light receiving signal output from the light receiving means of the probe is measured by the signal level measuring means. The state of the subject is measured by the state measuring means based on the measured signal level of the received light signal, and the light emission drive means causes the light emitting means of the probe to emit a pseudo pulse waveform according to the predetermined state of the subject. When driven at a light emission drive level corresponding to, the correction coefficient of the measured state measurement value is calculated based on the state measurement value measured by the state measurement means and the state of the predetermined subject, and this calculation is performed. The state measurement value measured by the state measuring means is corrected based on the correction coefficient of the state measurement value. Become to be maintained.

Therefore, it is possible to always obtain stable measurement results without being affected by variations in the performance of each probe and a slight decrease in performance.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an electronic circuit of a biological signal detection device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a ratio of each light absorption component to the total light absorption when light is transmitted through a human body and a change state of the light absorption with pulsation thereof.

FIG. 3 is a diagram showing changes in absorbance with respect to oxyhemoglobin and reduced hemoglobin at red emission wavelengths and infrared emission wavelengths, and changes in oxygen saturation depending on the absorbance ratio, and FIG. 3 (A) shows oxyhemoglobin and reduction. Diagram showing the relationship between emission wavelength and absorbance for hemoglobin, same figure (B)
FIG. 3 is a diagram showing a relationship between an absorbance ratio R / IR of red light R and infrared light IR and oxygen saturation SpO ₂ .

FIG. 4 is a timing chart showing a light emission drive interval in the red LED 11a and the infrared LED 11b of the biological signal detecting device.

FIG. 5 is a diagram showing respective received light signal waveforms according to pulsations associated with light emission of the red LED 11a and the infrared LED 11b of the biological signal detecting device.

FIG. 6 is a diagram showing reference data of a light emission current versus a light reception level, which is a reference for driving the probe in accordance with the probe matching process of the biological signal detecting apparatus.

FIG. 7 shows a prescribed value curve of the light receiving level when the light emission drive is performed on the reference (as designed) probe unit 1 according to the reference data of the light emitting current vs. the light receiving level associated with the probe matching process of the biological signal detecting device and the current curve. The figure which shows in comparison with the measured value curve of the light reception level at the time of light emission drive targeting the probe part 1.

FIG. 8 is a flowchart showing a probe matching process of the biological signal detecting apparatus.

FIG. 9 is a view showing a pseudo pulse emission drive table for pseudo emission drive of the probe unit 1 according to a predetermined pulse in accordance with the pulse measurement confirmation process of the biological signal detecting apparatus.

FIG. 10 is a diagram showing a light emission drive curve corresponding to a pulsation waveform of a predetermined pulse when the probe unit 1 is driven to emit light according to a pseudo pulse light emission drive table accompanying the pulse measurement confirmation processing of the biological signal detection apparatus.

FIG. 11 is a flowchart showing a pulse measurement confirmation process (table system) of the biological signal detection apparatus.

FIG. 12 is a flowchart showing a pulse measurement confirmation process (calculation method) of the biological signal detection apparatus.

FIG. 13 is a graph showing a light emission drive curve corresponding to a pseudo pulse waveform of a predetermined light emission level ratio R / IR corresponding to an arterial blood absorbance ratio that results in a predetermined oxygen saturation% associated with the oxygen saturation measurement confirmation process of the biological signal detecting device. FIG.

FIG. 14 is a pseudo pulse predetermined ratio light emission for pseudo light emission driving of the probe unit 1 at a light emission level ratio R / IR that provides a predetermined oxygen saturation% in accordance with the oxygen saturation measurement confirmation processing of the biological signal detection device. The figure which shows a drive table.

FIG. 15 is a prescribed value curve of oxygen saturation measurement according to a change in emission level ratio R / IR due to emission drive in a pseudo pulse waveform accompanying the oxygen saturation measurement confirmation processing of the biological signal detection device and the current probe unit. The figure which shows in comparison with the measured value curve of the oxygen saturation measurement at the time of light emission drive targeting 1.

FIG. 16 is a diagram showing a specified value of oxygen saturation corresponding to the absorbance ratio R / IR of arterial blood accompanying the oxygen saturation measurement confirmation processing of the biological signal detecting device, each corresponding measured value and its correction coefficient x.
A table showing 3.

FIG. 17 is a flowchart showing an oxygen saturation measurement confirmation process of the biological signal detecting device.

FIG. 18 is a subject (living body) using the biological signal detecting apparatus.
10 is a flowchart showing a biological signal detection process for 10.

[Explanation of symbols]

1… Probe section 10 ... Subject (living body) 11 ... Light emitting device 11a ... Red LED 11b ... infrared LED 12 ... Light receiving device 12a ... Photodiode 2 ... System Department 21 ... Amplifying circuit (current amplifier) 22 ... Current / voltage conversion circuit 23 ... Amplifying circuit (voltage amplifier) 24 ... A / D conversion circuit 25 ... CPU 25a ... Emission current control circuit 25b ... Timing generation circuit 26 ... Voltage control circuit 26a ... D / A conversion circuit 27 ... LED driving device 27a ... Red LED driving circuit 27b ... Infrared LED drive circuit 28 ... Input device 29A ... Storage device 29a ... Memory for correcting the amount of light received by the probe 29b ... Pulse measurement correction coefficient memory (x20) 29c ... Oxygen saturation correction coefficient memory (x30) 29d ... Probe drive accumulated time memory (t) 29B ... External storage device 30 ... Display 31… Backlight 32 ... Backlight control device 33 ... Output device (connector) Va (R) ... Red transmitted light reception signal Va (IR)… Infrared transmitted light reception signal

Claims (8)

[Claims] 1. A probe having a light emitting means and a light receiving means for receiving light from the subject obtained by irradiating the subject with light emitted by the light emitting means, and driving the light emitting means of the probe. Light emission drive means, signal level measurement means for measuring the signal level of a light reception signal output from the light reception means of the probe when the light emission means of the probe is driven by the light emission drive means, and the light emission drive means When the light emitting means of the probe is driven at a predetermined light emission drive level, the measurement is performed based on the signal level of the light receiving signal measured by the signal level measuring means and a prescribed signal level according to the predetermined light emission drive level. And a correction coefficient calculating means for calculating a correction coefficient for the signal level, and a correction coefficient for the signal level calculated by the correction coefficient calculating means. Come, the signal level measurement unit corrects the signal level of the measured received signal by the above and a state measuring means for measuring the state of the subject, the biological signal detecting apparatus characterized by comprising a. 2. A probe information output means for outputting information on the probe when the correction coefficient of the signal level calculated by the correction coefficient calculation means exceeds a preset allowable error range. The biological signal detecting device according to claim 1, which is characterized in that. 3. A probe having a light emitting means and a light receiving means for receiving light from the subject obtained by irradiating the subject with light emitted by the light emitting means, and a light emitting means of the probe is driven. The light emission drive means, the signal level measurement means for measuring the signal level of the light reception signal output from the light reception means of the probe when the light emission means of the probe is driven by the light emission drive means, and the signal level measurement means State measuring means for measuring the state of the subject based on the measured signal level of the received light signal, and light emission means of the probe for causing the light emitting means of the probe to emit light corresponding to a pseudo pulse waveform corresponding to the predetermined state of the subject. When driven at a drive level, the measured state based on the state measurement value measured by the state measuring means and the state of the predetermined subject. A correction coefficient calculation means for calculating a correction coefficient of a constant value, and a state measurement value correction means for correcting the state measurement value measured by the state measurement means based on the correction coefficient of the state measurement value calculated by the correction coefficient calculation means. And a biological signal detecting apparatus comprising: 4. A probe information output means for outputting information about the probe when the correction coefficient of the state measurement value calculated by the correction coefficient calculation means exceeds a preset allowable error range. The biological signal detecting device according to claim 3, wherein 5. The biological signal detecting apparatus according to claim 2, wherein the information regarding the probe is at least one of information regarding contamination and replacement of the probe. 6. The biological signal detecting apparatus according to claim 1, wherein the state of the subject is at least one of a pulse rate and an oxygen saturation level. 7. A probe having a light emitting means and a light receiving means for receiving light from the subject obtained by irradiating the subject with light emitted by the light emitting means, and a light emitting means of the probe. A calibration processing program for a biological signal detection device for controlling a computer of a biological signal detection device comprising a light emission drive means, wherein the computer, when the light emission means of the probe is driven by the light emission drive means, A signal level measuring means for measuring a signal level of a light receiving signal output from the light receiving means of the probe; and when the light emitting means of the probe is driven at a predetermined light emitting drive level by the signal level measuring means. The measurement is performed based on the measured signal level of the received light signal and the prescribed signal level according to the predetermined light emission drive level. Correction coefficient calculating means for calculating a correction coefficient of the signal level, and correcting the signal level of the received light signal measured by the signal level measuring means based on the correction coefficient of the signal level calculated by the correction coefficient calculating means. A computer readable calibration program for a biological signal detecting device, which is made to function as state measuring means for measuring the state of a subject. 8. A probe having a light emitting means and a light receiving means for receiving light from the subject obtained by irradiating the subject with light emitted by the light emitting means, and a light emitting means of the probe. A calibration processing program for a biological signal detection device for controlling a computer of a biological signal detection device comprising a light emission drive means, wherein the computer, when the light emission means of the probe is driven by the light emission drive means, Signal level measuring means for measuring the signal level of the light receiving signal output from the light receiving means of the probe, state measuring means for measuring the state of the subject based on the signal level of the light receiving signal measured by the signal level measuring means, The light emission drive means causes the light emission means of the probe to emit a light emission drive signal corresponding to a pseudo pulse waveform according to a predetermined state of the subject. Correction coefficient calculation means for calculating a correction coefficient of the measured state measurement value based on the state measurement value measured by the state measurement means and the state of the predetermined subject when driven by a driving device. A computer-readable bio-signal detection device that functions as state measurement value correction means for correcting the state measurement value measured by the state measurement means based on the correction coefficient of the state measurement value calculated by the calculation means. Calibration processing program.