JPS60176625A - Light measuring apparatus - Google Patents

Abstract

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

Description

Detailed Description of the Invention [Technical Field 1] The present invention non-invasively measures arterial blood oxygen saturation (hereinafter referred to as 5a02+
This relates to a photometric device used in oximeters and the like that measure and display information.

[Prior art 1: Conventionally, optical oximeters use the measurement subject's finger, etc. as a measuring table."
It is known that the oxygen saturation level (Sad) in arterial blood is measured from the transmitted light by irradiating light onto the two. In such an optical oximeter, if the measuring part, such as a finger, moves during the measurement, the light passing through the measuring part changes, which causes noise and causes errors in the measured values. . Here, it is impossible to eliminate the movement of the living body itself, so conventional methods have been used such as detecting the presence or absence of movement of the living tree and not displaying the measurement results when the movement of the living body is detected. is being taken.

As a method for detecting the presence or absence of sway in a living tree, the first method is to detect that the amplitude of the pulse wave signal suddenly changes dramatically and to determine that there is sway. , the rising time of the pulse wave signal when there is no oscillation, and the rising 1 or 5' time of the pulse wave signal when there is oscillation.
The second method uses the difference between the descending time and the
The second method is known, and the second method is known. However, in the first method, it is impossible to detect the movement of live trees when it occurs continuously, and in the second method, it is impossible to detect the movement of living trees when it occurs continuously. Accurate detection is difficult due to individual differences and environmental factors, and the third method also has the disadvantage of not being able to detect periodic movement of living trees. There is. .

Therefore, the applicant of the present application first proposed Japanese Patent Application Laid-Open No.
85 F3 Publication 11L, the amount of light transmitted through the measuring section F, au Ea, + Eaz at three wavelengths was measured respectively, and the change in absorbance E11. , F:l+2. l″
,1), for each wavelength, and then Ec, =
El)l-t]I),, Lc2= lEl], -Eb
We have proposed an optical oximeter that calculates the blood oxygen saturation by calculating Ec++Ee, respectively, and removes the influence of the movement of the living body to calculate the oxygen saturation. Even with this optical oximeter, errors will occur in the measurement results if the amount of light emitted from the light source to the measuring section changes due to fluctuations in the power supply voltage.

A method of stabilizing a power source for driving a light source in order to prevent this kind of fluctuation in the light source requires a stabilized power source, which is expensive.

-In addition to the above, ■ Light that has passed through the measuring section and light that has not passed are alternately incident on the light receiving element via a spectroscopic element, and the signals that have passed through the measuring section and the signals that have not passed are separated from the output of the light receiving element. Take the ratio of

(Also, the light that passes through the measurement section passes through a spectroscopic element, and the light that does not pass through the measurement section enters the light receiving element through the same or separate spectroscopic elements.The ratio of the outputs of these light receiving elements is I take the.

(2) Calculate the ratio of the output of the light-receiving element that receives the light that has passed through the measuring section and is not separated into spectra, and the output of the light-receiving element that receives the light that has not passed through the measuring section and is not separated.

Kasa's method or method? The method (2) requires an optical path switching means and a trust/separation circuit, resulting in a complicated configuration.

(If the same spectroscopic element is used in the method described in 9), an optical path switching means is required, which makes the process complicated. Also, if separate spectroscopic elements are used, as many spectroscopic elements as the number of wavelengths to be used are required, which increases the cost.

(In method 3., the noise caused by the change in the light intensity of the light source is different when spectroscopy is performed and when it is not performed, so it is not possible to completely remove the pulp.

Furthermore, the light that has passed through the measuring section and the light that has not passed through the measuring section are alternately passed through the spectroscopic means and entered into the light receiving element -1'- for each wavelength range.
One possible method is to calculate the ratio by dividing the output signal of each light-receiving element into the signal when the light passing through the measuring section is received and the signal when the light not passing through the measuring section is received. Alternatively, this method requires means for switching the optical path and means for separating the output signals of each light receiving element r, (
I'4 becomes the stopper 21j.

i! +11Receive the light that has passed through the constant part through the spectroscopic means)■-
・Receives light that does not pass through the measurement section separately from each light receiving element.
Another possible method is to provide a reference light-receiving element for each wavelength range and calculate the output ratio between the light-receiving element and the reference light-receiving element for each wavelength range. In this case, if the reference light-receiving element is configured to receive light that does not pass through the measuring section through the same spectroscopic means, an optical path switching means is required, which complicates the structure. Therefore, if another spectroscopic means is used, the number of spectroscopic means such as spectral filters corresponding to the number of wavelength ranges will be required in addition to those passing through the measuring section, making the configuration complicated and expensive. Furthermore, variations in the characteristics of the spectroscopic means affect the measurement degree.

In addition, a single reference light-receiving element is arranged so as to receive light that does not trace to the measuring section without passing through the spectroscopic means, and the output ratio between the light-receiving element for each wavelength range and the reference light-receiving element is calculated. Although other methods can be considered, it is not possible to completely remove fizz because it depends on changes in the light intensity of the light source, or because it differs between when spectroscopy is performed and when it is not.

[Objective of the Invention 1] The present invention aims to provide a photometric device with a simple configuration that can provide accurate measurement results even when the light source changes, while eliminating the various drawbacks mentioned above. .

[Summary of the Invention 1 A reference light receiving element is provided that receives light from a light source that does not pass through the measuring section.

The side effects of the alternating iQ component due to changes in the light intensity of the light source with respect to the DC component of the light receiving output of the reference light-receiving element, and the side effects of the AC component with respect to the DC component of the output of the light-receiving element There is a certain relationship between the ratio.

Therefore, the reference light that receives the light that is not spectrally separated and does not pass through the photometering section is produced monthly based on the ratio of the DC component and the AC component of the output of the photodetector that receives the light that has passed through the measurement section. By controlling the ratio of the Il, E'/IC component and the AC component of the output of the element, it is possible to correct the fluctuation of the light source and perform accurate measurements.

1 Embodiment 1 In the following, the structure of an embodiment of the present invention will be explained. fj
As shown in Figure S1, the W
l! For example, the light that has passed through the optical system 1 and the measuring section h1 for irradiating the I constant R1 quantitative 1 light is '650 μl +,
'710 μJ 8 ('15 μm11 first to third light receiving elements that split light into first, second, and third different wavelength ranges and convert each light into first to third electrical signals.''J'-3
6, 3'7, and 38; A reference light section 3 including a reference light receiving element 31 for monitoring the emission intensity of the light source. It has a reference charging current/voltage converter 4 that converts the output current of the reference converter (j) into a voltage. The first to third ones take the logarithm of the outputs of the first to third light receiving elements.
number of lights conversion unit S+6+7+first to third number of months conversion unit 5,
fiS1 to third low-pass filters 8.9,1() for removing pulsating components in the output of 6.7.

Outputs 5, 6, '7 of the first to third Me/J number converters
and the first to third low-pass filters 8 produced monthly for them.
The first to third differential amplifiers 11. which output the respective differences with the output of ゜9.1o. ]2,13. First to third differential amplifiers] 1, 12. The first to third outputs are rectified by double-wave rectification, respectively.
Both wave pair flow sections 14, 15, 16. Third month number conversion section 7
A light quantity measuring section 17 is provided which performs predetermined calculations on the output of the light source.

The analog multiplexer 18 is: I
1: Select one of the measurement units 17 and transmit it to the next stage 1
-ru. Its analog output is double integrator 1! Ja, and comparator 1 (]Il ノ\1-) conversion unit 2
0 and converted to a digital value. The dental output is supplied to a control method t98 section 26, which will be described later. First differential amplifier] The output of 1 is a pulse wave shaping f which is converted into a pulse waveform.
It is supplied to the jll control function f;I: section 26 via i1i2+.

Further, a pulse wave signal converter 2 converts the output of the first differential amplifier 11 into a signal suitable for human power of the pulse wave display ammeter 213.
2. A pulse wave output section 23 that converts the output of the first differential amplifier section 11 into an input for a recorder. Reads the on/off status of a plurality of switches t5 that set the upper and lower limits of the measured value for warning, a switch that controls the generation of alarm sounds, and a switch that controls the display section 1111 lr Switch input section 2 consisting of a control circuit (, measured Sad
, and a display section 25 that displays pulse rate. Control method (1
6 part 2 includes first to third double-wave rectifying parts 1=1. ．． ]5. I
Control of G, analog multiplexer 18, AD conversion section 20, display section 25, switch input section 24, etc., and S a
Perform 4 calculations of O2 and pulse rate. Furthermore, this device is a screen copy part 2 for hard copying the display contents of the display unit 25.
7. Digital output section 28 for connecting to an external printer, etc. It has an alarm generating section 30 that emits an alarm sound, and a power source 31 that supplies power to each section.

In this embodiment, a microcomputer is used as the control calculation section 26, and a halogen lamp is used as the light source 1 that emits light to the measurement section. A portion of the light from the light source is incident on the light receiving element of the reference light section 3, and the light is guided to the measuring section through an optical fiber or the like (not shown). The light that has passed through the measuring section is guided to the light receiving section 2 by another optical fiber or the like (not shown), where the light is divided into the first to third wavelength ranges.
, and the separated lights are sent to the first and third light receiving elements 36.
It enters at ゜37138. Reference 11 (the light receiving element in the light receiving section 3 and the first to third light receiving elements f3G, 3' of the light receiving section 2)
7.38 each outputs a current proportional to the likely intensity incident on it. The output of the light receiving element of the reference tail section 3 is converted into a voltage by a reference charging current voltage converting section 4. Charging current to reference j1)i
- The output of the conversion unit 4 is the first and the month number conversion unit S +
6 + '7 will be man-powered.

The first to third month number converters 5+0+7 convert the outputs of the first to third light-receiving elements and the reference fiBH>',;electric;A voltage converters 4 into the first to third monthly converters. The receiver outputs a signal zero proportional to the logarithm of the output of the prime r. Each month conversion unit 5, 6.7 has a light (to be described later)) 41ノ, :, ji,
j, there is a fluctuation correction circuit, which allows the output 1 of each month number converter to
has been removed. 1st/j) month number conversion part, “+
, (i, '7 are connected to the first to third low-pass filters ji, Inj: and fjs I = third differential amplifier 31111.+2.I:(), respectively. 1 to 3rd low-pass filter 819.](1
The output of 1st - 1st :( differential amplifier 11.] 2, 1 :(
are connected to each. First...Third differential amplifier section 1
], 42.1:'! are the differences between the outputs of the first to jth logarithmic conversion units 5, 6.7 and the outputs of the first to jth low-pass filters 8, 9, and 10, respectively.
Only the charge volume pulse wave signal υ in the wavelength range corresponding to 1=+ can be obtained from the output of t3. This pulse wave signal is generated by a change in the volume of arterial blood at the measurement site, and contains information about the 1-light coefficient of the arterial blood. The outputs of the first to third differential amplifiers N, 12° 13 are output to the j-th to third double-wave rectifiers 14, . 15.16 is connected to Jt. 1st~
Each of the third double-wave rectifiers includes a half-wave rectifier circuit and a differential integrator. The outputs of the first to third differential amplifiers 11, 12, and 13 are each double-wave rectified by the first to third double-wave rectifiers under the control of the control wave 1 section 26. The signal is integrated by an integrator in the wave rectifier and then held for a predetermined period of time. The first to third double-wave rectifiers 14 and 15 held
．． 16 and the output of the light amount measuring section 1'7, which will be described later, are sequentially selected by the analog multiplexer 18 and output to the AI'
) is input to the double integrator 19a of the converter 2( ). Which input the analog multiplexer 18 selects is controlled by the control calculation unit 26.

Double integrator 1! 1.) The signal input to the double integrator 19a is formed by a converter and a counter built in the microcomputer 26. is converted to Al1). One conversion of ノ~/() is 211 ropes.
3rd double-wave rectifier] ・1.15, J (The integrator of i is discharged., 2nd, 1st to 2nd:) double-wave 4. 14. ] The integrator at +5.16 repeats integration, holding, and discharging at a constant cycle, and when the A/[) conversion is performed, the A-, +1j output of the measuring section 1゛7 is A/I).
Conversion is also repeated at regular intervals. A/l',) converted first and third wave rectifying 1ift part] -'I I
J 5 , :1. From the output of G to A / D
The converted and stored offset voltages of the first and third double-wave rectifiers are subtracted, and the first to third pulse wave amplitude values proportional to the amplitude of the pulse wave (No. 11) are calculated. , by a predetermined calculation from the first and second pulse wave amplitude values.
The oxygen saturation SaO, (]) is calculated. Also, the first
The second oxygen saturation 5aO2(2) is determined by a predetermined operation τγ from the pulsation amplitude values of
iii", times % - Sad, (1) is used to detect the presence or absence of noise due to vibration of the AlI3 constant part,
This will be discussed later. 5aO2(1,) and 5a
02 (2> is calculated one after another at regular intervals, or the latest Sad, (2) and a certain number of previous SaO, (2)
5a02 average value is calculated according to a predetermined method, and the result is displayed on the display section 25. S a (',) 2
The calculation of the average value will be explained in detail later. Also,
The output of the first differential amplifier section 11 is transmitted to a pulse wave shaping section 21, a pulse wave signal converting section 22. It is also connected to the pulse wave output section 23.

The pulse wave shaping section 21 binarizes the output signal of the first differential amplification section 11 depending on whether it is larger or smaller than a certain threshold value, converts it into a pulse signal, and inputs it to the control calculation section 26 . The control calculation unit 26 detects the rising edge J5 and falling edge of this human pulse signal, calculates the period, and calculates the pulse rate per minute based on the period. The calculation of the pulse rate is repeated at regular intervals in the same way as 5aO2 (1) and SaO2 (2). Calculation of pulse rate will also be described later. The calculated pulse rate is displayed on the display section 25. The pulse wave signal converter 22 converts the output signal of the first differential amplifier 11 into a pulse wave display ammeter 29.
Convert it so that it is suitable for the input. This can be determined by checking whether a pulse wave signal is being obtained normally using a pulse wave display ammeter. The pulse wave output section 23 is for adapting the output signal of the first differential amplification section 11 to the human power of the recorder. The display contents of the display section 25 are hard-copied by the screen copy section 27 when the switch of the switch manual section 24 is pressed, and
The average value of aO7, pulse rate, etc. are recorded graphically.

The average value of S a O and the signal of the pulse rate are outputted via the dino signal output section 23.

When the 5aO7 and pulse rate are out of a certain range, it is necessary to issue an alarm because the patient is in danger and requires some kind of treatment. In the device of the present invention, the upper and lower limits of 5aO7 and pulse rate at which an alarm should be issued are respectively set to 1 and 1hi by switches in the switch manual section 24. The set value is displayed on the display section 25.

Is the warning displayed on the display unit 25? The alarm is also emitted by sound from the alarm and alarm generator 30. Whether or not to emit an alarm sound when an alarm occurs can be selected using a switch provided in the switch input section 24.

Furthermore, if the generation of an alarm is to be prohibited when the measured value is less than or equal to the upper limit value and/or when the measured value is less than or equal to the lower limit value, this can be done by setting a specific value.

The light amount measuring section 17 is a circuit that converts the output of the month number converting section 7 to match the A/l) conversion human power. The output of the charge measurement unit 17 is converted into A/l) at regular intervals and is used to check whether the light amount of the light source 1 is appropriate.

If the amount of light is very large, the light receiving element and logarithmic conversion circuit 5,
6.7 becomes saturated and the accuracy of pulse wave pickling deteriorates. Also, when the measuring part is deviated from the predetermined position, the amount of light becomes very large, and accurate 5a02 measurement is impossible. Similarly, when the amount of light is low, the light receiving element and the month number conversion circuit 5. The characteristics of I3.7 become worse and only accurate S a 02 measurement is possible. Therefore, in order to constantly monitor whether the amount of light is appropriate, the output of the photoelectric measuring section 17 is subjected to /D conversion, and it is checked whether the value is within a certain range.

Next, we will explain a method for removing noise due to /1 amount fluctuations of the light source 1. In FIG. 2, the beam from the halo tube lamp 32 as the light source 1 is an optical fiber 3.
:) is concentrated on the end face. , :(, 1 is a receiving element of lf, which receives and receives light from a halloween lamp as a reference light, and is provided in the 7-board 34a.

A person on the end face of optical fiber 33! :IJ・j
Unique spectral characteristics and light-receiving element-34! ] J4-ru (4's division C!1.j property is approximately 1-1, and the strength of each older brother is 11 [There is a proportional relationship. In Figure 2, the light receiving element 3...1 that receives the reference light. The BHB beam incident on the 1. optical fiber 3: ) passes through the 2.4 optical fiber 33 and enters the measuring section. 1.1, and the light transmitted through the measuring section is guided to the light receiving section 2 (FIG. 1). The light incident on the light receiving section 2 is 11
: As mentioned above, the light is separated into the first to third wavelength ranges and the first to third wavelength ranges are
The jth receiver is input to the element 36.3'7.38. The output of the first to third light receiving elements and the output of the light receiving element r'1 of the reference light section 3 are connected to the third circuit, which outputs only the attenuation of light by the measuring section without receiving the photoelectric fluctuation of the source. As shown in the figure 1-. The light receiving element 34 of the reference light section 3 is connected to the human power of the converter 35.The light receiving element J of the first-fiS3 of the light receiving section
'3 G+3 L: 3 '+'r are respectively ■/\・°
Converter 39° I/V converter 4.0. I/\i converter 41
is connected to the input of Each I/V converter 35, 39
, 4.0.

Reference numeral 41 converts the output current of each light receiving element into a voltage. 42, 43, and 4.1 are monthly number amplifiers each having two input terminals A and F3 and outputting the number of months of the ratio of input A to input B.

To simplify the explanation, the first light receiving element 36 of the light receiving section 2
I will only explain the circuit that is dazzling.

The light incident on the first light-receiving element 36 is light in the first wavelength range separated by the light-receiving part 2, and the light-receiving element 34 of the reference light part 3
The spectral characteristics are different from the light incident on the

Therefore, the ratio of the change in light intensity due to a change in the light amount of the light source to the intensity of light incident on the light receiving element 36 is the proportion of the change in light intensity due to a change in the light amount of the light source in accordance with the intensity of light incident on the light receiving element 34. Not equal to percentage. Therefore■／＼・
Even if you calculate the logarithm of the ratio of the output of the ° converter 39 and the I/V converter 35, the sl 1" caused by the change in the light amount of the light source can be completely removed. I/V converter:) ( ) output and I
/V-hen 1! f'! By calculating the logarithm of the ratio of the output of l:ζ35, the likelihood of the light source is +7. To remove the 1: shoulder 1 tone in the variable ratio, the light receiving element 1'3 of the reference light section 3 = 1! 11.1 It is necessary to match the spectral distribution of the light that is likely to be incident on the first light receiving element r-:F (i. 1) The light source 3 requires as many spectroscopic elements as the number of wavelength ranges to be separated by the light receiving part 2. 1) It must have a very complicated configuration. Must be. The present invention is based on processing the output of one or more reference light receiving elements! ! (This is to eliminate the influence of changes in the light intensity of the light source without using a spectroscopic element in the light source 3.The ratio of the change in light intensity due to photoelectric changes in the light source to the likely intensity incident on the light receiving element R-34 is l!, which is the ratio of the change in light intensity due to a change in the light amount of the light source to the likely intensity incident on the light receiving element 36;
There is a certain relationship between the two. 1, that is, the ratio of the alternating current component due to the photoelectric change of the light source to the direct) optical component of the output voltage of the converter 35, and 1/~.
)5] There is a certain relationship between the ratio of the AC component due to the photoelectric change of the light source to the DC component of the output voltage.

1/\・“Converter 3” so that they match
What is necessary is to change the ratio of the AC component due to the photoelectric change of the light source to the DC component of the output of No. 5. This also applies to light in the second and third wavelength ranges. Is that circuit 4 in Figure 3?
5, 4G, and 4.7 AC/DC conversion circuits. The ratio of the AC component due to the change in the light amount of the light source to the DC component in the output of the AC/DC conversion circuits 45, 413, and 47 is as follows: Converter 39°4, o,
The ratio of the AC component due to the change in the light amount of the original light (i=J to the DC component in the output of the amplifier 41) matches the proportion of the AC component due to the change in the light amount of the light source. Noise is removed.

Figure 1 shows an example of the fittings. In FIG. 4, the first to third light receiving elements 3G, 37.38 of the light receiving section 2 are outputting!
It uses a circuit that converts XC to ir (continuous month number. 11th
In order to simplify the explanation, only the circuit provided monthly to the first light-receiving element 36 of the light-receiving section will be described.

The collector current of the transistor l[)) of the logarithmic amplifier 42 is equal to the output photocurrent IL of the light receiving element 36 of the light receiving section 2.

1 is expressed as the product of the light intensity 1oλ and the transmittance or reflectance ratio of the measuring section, and 10λ is the IU flow component 1oλgc and the alternating current due to changes in the light intensity of the light source. Consisting of noise components 1oλ11, 1=(lo
λI)c−tloλn)F=Ioλpc(l +Nλmonth−゛.Here, − is Nλ−−!−9, 3,, +1
1(lλp(·1') is a redundancy determined by the sensitivity of the light receiving element and the transmission chamber of the measuring section.

Output current Irl:l of the light receiving elements 3...1 of the reference light section 3:
It is proportional to the emission intensity of the light source over the wavelength range 10,
o is the DC component and the change in the light intensity of the light source, J is the intersection of 1'
Since j: consists of f component Jon, Ir=, (Iopc+Ion)=K 11opc(
1+N). Here, N −=,
, ! , (il+IoDc' is a constant. Light receiving element f of reference light section 3:', I/V converter that converts the output of 4 into voltage;) (output intermediate voltage Vr of 3
is expressed by the following equation.

Vr=RoK, Ioc+c(1+N) The current flowing through the resistor R1 is Vr/IL =4. u=T
opc(] + N) 1 (1) The current flowing through the resistor R2 is an alternating current component or canted.Here, R is the parallel combined resistance of R2 and R1.Thereby, the collector current of the lannostar 51 is different from 1X. Therefore, the first term of the output '0LIL of the monthly amplifier 42 includes information from the measuring section, and the second term includes only noise due to changes in the i amount of the light source.

522 ゛, N/(1+-,,,----Re±shishiri L----)=N λR2(R+R, 10R,) Add 71 ruJ to 1. <,,R2,lza,,R1
By selecting , it is possible to eliminate the component containing the layer 11° due to the change in the amount of light in the VouL.

Output type jJlf of receiving gear C element j'-3=1 of reference light section 3:
Middle direct: If you want to increase the ratio of the alternating current component due to the change in the light amount of the light source to the DC component in the collector current of the transistor 51 from the ratio of the alternating current component due to the change in the light amount of the light source to the intervening component, ,,R,,,coni”nri(
'.

It is better to use a bypass filter instead of the low-pass filter in 1. Second. 11th Month Amplifier +
i, 3, . 1. ．． The same is true for 1 (there is also T3).

Next, I will explain Ryounami 4 Raku; Ikobu. Both wave y flow section 1
．． 4, 15.16 is 111 from the fan that passed through the measuring section.
This is the part that converts the pulse wave signal, which is an AC signal, into a DC signal. Since the frequency of the pulse wave signal is usually low, conventionally a circuit combining a small wave rectifier circuit and an integrator as shown in FIG. 5 has been used.

(When the sine wave signal 3 is manually applied to the circuit shown in Figure 3, the small wave rectifier circuit) Peak 11) 1
and the negative side peak ■1)2 becomes ■1)1≠11]2.

This is due to the difference in offset voltage between the half-wave rectifier circuit and the integrator. This is due to the bias current of the half-wave rectifier circuit and integrator that flows through the current flowing through the resistor 1<6.

The integrator in FIG. 5 also includes two switches Sl.

S2 is provided, and the input is integrated when the switch S1 is ON and the switch S2 is OFF, and then the input is integrated when the switch S1 is ON and the switch S2 is OFF.
is turned OFF to stop manual integration and place the integrator in a hold state. After holding for a certain period of time, switch S2 is turned on.
The integrator capacitor C,1 is discharged. The integrator repeats this operation. Since a capacitor C2 and a resistor R8 which are connected in series are connected to the integrator's power, a transient change occurs in the voltage 'l+QI2, resulting in an error. In addition, when measuring only the off-sect voltage of the circuit shown in Fig. 5, turn on switch S3 to short-circuit the human power and switch S3.
1 is ON, switch S2 is OFF, and only one voltage is integrated. However, the offset voltage that is generated when the switch S3 is turned on does not match the offset voltage when the switch S3 is turned on and an alternating signal is input.

When a sine wave signal ＼・=a−another 110 is input into the circuit shown in FIG.
If R6=R7, then \.1 becomes according to the input voltage (■). , where oFF1 and \+OFl: are the input offset voltages of the half-wave rectifier circuit and the integrator, respectively.

Therefore, if sufficient time has elapsed since the switch S1 was turned on, the current 12 is T 2''--3--a ・5ioQ month R0 ゛.If R, = 2R8, then the integrator's The current flowing into the capacitor C2 is I, +L. This is shown in Figure 6. When I, +I2 are integrated by an integrator, the output of the integrator and the amplitude of the sine wave signal are 111 ga.
There is no linear relationship between the two. Therefore, even if you measure and store only the offset voltage without inputting the sine wave signal, and subtract it from the external output when the signal is input, the value proportional to the amplitude of the signal will not be 1). This is because a current flows through Y(7) due to the difference in voltage between the half-wave rectifier circuit and the integrator input off-celler 1. To prevent this,
-\7 OFF~ or \'OFF+≠VOFF2, but no current flows through the resistor I<7. Also, since the integrator repeats charging, holding, and discharging (1),
The inner S1 is turned on at predetermined intervals, and the monthly pad is repeated. At this time, the current flowing through %C2 and R1 changes transiently, and an error occurs in the output of the integrator.

Therefore, in the dual-wave -°r flow section of the present invention, as shown in FIG. Buffer circuit 5) prevents current from flowing through the resistor 1<7 even if there is a difference in the manual offset voltage.In the circuit shown in Figure 7, the switches S3-1 and S
The output voltage of the half-wave rectifier circuit 10 ( ) at 1 o'clock when an AC signal is input with 3-2 turned OFF is as follows. However, here, it is assumed that RIi=R, and the bias current of the buffer circuit 53) and the half-wave rectifier circuit ioO is 1-minute smaller and can be ignored. and switch 53-
When switch S1 is turned on after a sufficient period of time has elapsed since switch S1 was turned on, the integrator's manual power supply 51. '+l,'
The output of the integrator has a linear relationship with the input signal oscillation 1 of the double-wave rectifier. Therefore, the signal can be obtained by subtracting the value of the human power ω4 from the integrator output when the signal is human power to obtain a value proportional to the human power signal.

When measuring only the offset voltage, is it necessary to prevent the signal from being input? 5a02 During measurement, offset voltage drift) occurs, so only the offset voltage of both wave rectifiers must be measured once every few minutes. When using a method of short-circuiting the inputs of the double-wave rectifier using switch S3 as shown in the circuit of Figure 5, a transient response occurs immediately after switch S3 is closed, and the correct offset voltage is maintained until a steady state is reached. There is no difference in measurement. Since it is necessary to wait until the steady state is reached, it takes a long time until the measurement of 5ad2 is restarted next time. In this embodiment, as shown in FIG. 7, the switch 53-1 and the switch 53-2 are inserted so as to shorten the time from when these switches are turned on until the steady state is reached.

When measuring only the offset voltage of the double-wave rectifier, the switch 53-1 and the switch 53-2 are turned on, and the buffer circuit 57 and the buffer circuit! The output of 3;; is integrated.

The time from when the switch 53-1 (-) is turned on to when the input to the amplifier circuit 5°7 reaches a steady state is determined by the on-resistance of the capacitor C2 and the switch S: (-). Is the ON resistance resistance 1'?
, , is very small compared to , , so the time period of 11.9 to reach a steady state is very short. In addition, the switch 53-2 is turned on.
When N is applied, resistance I<, , from voltage source 1 to 1.

A current flows through the diode DI through the switch 53-2, and the current flowing through the resistor 1 is set to be sufficiently large, so that the output of the half-wave rectifier circuit becomes VoFFl. Therefore, it is possible to measure the offset voltage immediately after the switches 53-1 and 53-2 are turned on.
The time required to restart 5aO7 measurement can be shortened.

By using the circuit that eliminates noise caused by changes in the charge of the light source as described above, and by using a flow section for both wave forces that can accurately adjust the offset voltage to 11, it is possible to achieve high accuracy even with a minute signal level <5aO7t; and to reduce the pulse rate to 1111r. :J
f−·k 7° Next, the motion archiator 72 detection method according to the present invention will be described. The motion artifact detection method according to the embodiment of the present invention is characterized in that continuous or periodic motion artifacts can be detected and there is little influence due to differences in subjects. In the present invention, 3
The photoplethysmogram is measured for one type of wavelength.
The first to third differential amplifier sections 11, 12 . i3 are obtained as the respective outputs. SaO2 is different 2
Since pulse wave signals at three different wavelengths are obtained in the present invention, Sa○ can be calculated from pulse wave signals at three different wavelengths.

Or calculate it. The multiple SaO2 values obtained here match if there is no motion artifact, or if there is motion artifact, these multiple 5a
A difference occurs in the d2 value. In one embodiment of the present invention, 2981 values of 5ad2 are calculated from pulse wave signals at three different wavelengths using two different calculation formulas, and the values of S a O2
It is determined that there is a motion artifact when the absolute value of the difference in values is greater than or equal to the value i (I: value or greater).

The reference value varies depending on the 5ao2 value obtained by calculation. This is because even if the magnitude δ of the motion artifact is the same, the difference between a plurality of Sads and value openings differs depending on the 5ad2 value. This point will be explained in more detail.

Charge volume pulse waves in three different wavelength ranges are obtained at the light receiving section 2 as outputs of the first and third differential amplifier sections 11, 12, and 13, respectively. These pulse wave signals are respectively j~
third double-wave rectifier], 4. , i 5 , 16, the two waves are rectified and integrated for a certain period of time, and then the Hall IS is applied. and the first to seventh double-wave rectifiers 14, ]5.
1 (The voltage held at 5 is sequentially A/]
One is converted and recorded. Then, the stored PH of 111j to Ho/1 of the third double-wave rectifier 14, 15.16,
The first to third double-wave rectifiers 14, which have been roughly measured and stored from the 1/value. ．． ]! 5. After the offset voltage values of 16 are subtracted, respectively, "' l + '
l' 21Y. Y l l Y21
Yl are the first to third differential amplifier sections 11, 12 .
It is proportional to the amplitude of the pulse wave signal which is the output of 13.

And YIY21Y3 or each wavelength 8 (,15111
m1 '710 m111+ 65 ('l 1III
For light near +1 (when Q is applied, Yl and Y, 5aO7(1)=A+('l'2/Yl)"+B+.

Y, and Y3 to 5aO2(2)=A2(Ys/ )'l
)'+B2 is calculated and stored.

SaO2 (1) and (Y2/Y, )2 and SaO, (2
) and ('l'3/Y, )2 is shown in FIG. If there is no motion artifact, the values of 5ad2(1) and 5a02(2) match. When there is a motion artifact, the noise caused by it is almost unrelated to the wavelength, so (Y, /Y,)'' and 0', /Y, )2 have values close to 1, and 5aO2 (1) and SaO, (2) are For example, if there is no motion artifact when the true 5ad2 is 95%, then (Y 2/"1' l
)' = 0.

437'+(Y3/Y+)2=o, 671, or if there is a motion artifact, almost the same noise is superimposed on Yl l Y 2ha'3 and (Y, /Y,)2=1
．． (Y.

/Y1) approaches 2-1, 5aO2(]); and 5a
Since O7(2) approaches 64.5% and 89.7%, respectively, the difference between 5a(-), (1) and 5aO2(2) becomes large. Therefore 1saO7(]) Sa(,),,(
2) Compare l with ノ + K i (1, l1rf, and if it is hotter than the reference value, it is determined that there is a motion artifact. l 5aO = (1) 5aO7 (2) Is l the angle of 11° 1° due to motion artifact? Even if they are the same, they differ depending on the true S a ('), so the above J, l
, ? The il value should be set differently depending on the true Sad. Is it a motion artifact?
Since it is not possible to know the true Sa(',) when the value is 5a02(],) and 5ad2(2), different reference values are set. Y 1lY21)'+1 respectively wavelength; Shoulder+! ') 111111.7](l
mJ 65 (If it is a pulse wave for a value near -1+nm, it is true 5aO if there is no motion artifact.
1 or 1a 5%, 80%, 70% respectively 11th
In the diagram, lay J3 and lie on 5aO7 (1), then point A, ,
l'3,.

C1, and for 5a02(2) the point A,,1
It is expressed as 3°C7. If there are three types of S a (,) 3 and there are motion artifacts of the same type, then A
I+lil+01 respectively move to Jtl)1+E11c, and Δ.

137. C7 moves to I), ,C7,F,. If there is a motion artifact in the case of the true value of 5ad2 for each of this and b, then lsa○2(1)-SaO7
(2) l is △1 in Figure 11. △2. It is indicated by △3, and the true value of 5a02 (or 5aO2(]) or 5a
O2(2)). This situation is shown in FIG.

Detection of motion artifacts above a certain level is performed using l SaO,, (]) -3aO7 (2) l and the reference value (
When comparing f(SaO2(ILSaO7(2))), a value approximately the same as that shown in FIG. 8 may be used as the reference value r(SaO2(1)+5aO7(2)).

As described above, since the motion artifact detection method of the present invention does not detect changes in the waveform or amplitude of the pulse wave signal, there is little difference in detection sensitivity between subjects, and periodic motion artifacts can also be detected.

Measure the pulse wave for the likelihood of 3 or more wavelengths, then 3
When calculating the S a O2 of the species, each other's 5aO
A difference of 7 is calculated by 2 or more. Those 2 or more 5a
As an example of detecting motion artifacts from the difference in O7, a standard value is set for each absolute value of the difference in 5ad2, and these standard values are compared with the absolute value of the corresponding difference in 5a(-)2. , at least one Sad, or the corresponding value (a method of determining that there is a motion artifact when it exceeds the threshold value, or two or more). There is a method of determining that a motion artifact exists when all values exceed the base 7 (1) value corresponding to one of them.

Next, the method of calculating Sad and the average value will be explained.

In the apparatus of the present invention, 5aO7(1,) and 5ao2(2) are calculated at a certain time interval, totaling 9 times. Calculated 5aO2(1
) or 5aO7(2) is displayed sequentially each time it is calculated. Therefore, the measurement accuracy of 5aO=(]) or 5aO7(2) can be maintained.
If it is not 1E, for example, the intensity reaching the light receiving part is not appropriate, or the amplitude of the pulse wave signal is excessive or too small, the calculated Sad, (1) or SaO, (2)
contains many errors, so it is not recommended to display it. When such measured viscosity cannot be guaranteed or is relatively common, the conventional example often fails to display S a O2, making it extremely difficult to use. 5aO2(]) and 5
For example, if the calculation of ad2 (2) is performed every second, if a situation occurs where the measured viscosity is not guaranteed once every few seconds, Sad will not be displayed once every few seconds, making the display very difficult to see. .

Conventionally, the following methods have been used to solve this problem.

Normally it is sad, but it is extremely rare for it to change suddenly in 1 second. Therefore, if a situation arises in which the measurement accuracy of 5aO7 is not guaranteed at time i, then SaO2 at time i
If the value calculated and displayed at time i-] is continuously displayed, the problem that there is a time when tir is not displayed can be resolved.

However, with this method, the measurement accuracy of Sad is not guaranteed.If the condition continues for several seconds, the same value or 5ad
If the measurement accuracy of 2 is not guaranteed or it is displayed only for a continuous period of time, and the true SaO2 changes during that time, the difference between the displayed 5aO7 and the true Sad may become hot and cause an incorrect diagnosis. There is a strong possibility that the

Therefore, in the device of the present invention, 1llllllll of Sad, .
Even if the condition is not specified or occurs sporadically, the display will not disappear frequently and the accuracy will not be maintained.If the condition continues, the display will be erased to avoid making a wrong diagnosis. There is. How to do it.

Explain to the body. In the apparatus of the present invention, 5aOz(]) and Sad, (2) are successively grouped into 11 groups at regular intervals and stored. At a certain time 1, Sad, (2) (i) or ' is calculated and written as 1. If there is a certain number of items calculated and recorded before that time including time I, 1 (+1 Sa□, (2) is guaranteed to be 5a02 (2) is a certain number, therefore C) I”
- Check whether it exists (Tatashi, 1 (+1≧ρ).

Specifically, time 1-1 (back to S.

0, (2> is checked, and it is also measured 1'i'i degree or 1ill 5aO7(2) or 5a02(2)(i)
C or more including -1] If there is, SaO, (2) or 0 are taken out from the one closest to time i, which is not guaranteed due to measurement accuracy,
The average value of those (1) is calculated and the value is displayed on the display.The accuracy is guaranteed among 1 (+1 5ao2 (2)) from time 1 to the previous time 1-1 (. If there are fewer than !Sad, the display is erased and a warning is issued.At the next time i+], 3a(L(L( 2)
5aO7(2) is examined and its accuracy is guaranteed.
It is checked whether there are I or more /, and if there is one or more, I4, Sad, (2) are taken from the one closest to time i + 1 and the average value is calculated and displayed, and if there are less than β, it is displayed or blank. A warning will be issued.

The same operation as above is repeated. According to this method, k
−, (SaO with g+2 or more 4-side constant accuracy not guaranteed,
Since the SaO2 display is not blanked unless (2) continues, the SaO2 display will not be blanked even if a situation occurs sporadically where measurement accuracy cannot be guaranteed.

Furthermore, if the accuracy is not guaranteed and the SaO7 display continues for -p+2 or more times, the SaO7 display is erased, so an incorrect SaO2 display will not be held for a long time, and there is little possibility of making an incorrect diagnosis.

As an example, 'SaO, (2) is 110 in 1 second ju
1. 1 (is 71. e is selected as 5. In this case, SaO whose viscosity cannot be guaranteed, (2) is 44 or more
The display will not be erased except for continuous flashes, and the accuracy is not guaranteed.If Sa(',),, (2) or (2) is continuously displayed, the SaO2 display will not be displayed in bold for more than 1 second. None. Also: 8a02 (2) where accuracy is not guaranteed for only 3 seconds, or if it continues, the same value is displayed as 5aO =... S a O, does not change rapidly enough to become a problem in 1 second, leading to an incorrect diagnosis. There's no fear.

Next, the display function of the apparatus of this embodiment will be explained. In the conventional SaO2 measuring apparatus, the measurement value (Jl) was displayed digitally or by the deflection of the ammeter. Although a device that can continuously measure SaO has the advantage of being able to see moment-to-moment changes in the measured value, the digital display of the measured value or the display by the swing of the ammeter does not show the time of the measured value. Is it necessary to understand the changes in the S?
A 02 measurement device; 6 has a built-in pen recorder and is equipped with a terminal that outputs measured values or voltage, so that constant values can be recorded with a pen recorder. However, when measuring continuously over a long period of time, recording measured values on a pen reflex requires a large amount of recording paper, of which only a small amount is important, and most of the recording paper is wasted. Further, even if it is not necessary to record the changes but want to examine short-term changes, recording must be done with a pen recorder, which wastes recording paper.

In order to solve the following two problems, the device of the present invention uses a two-dimensional display element 130 in the display section as shown in FIG.
The average value of a'o 2 and the pulse rate are displayed numerically and graphically with time as the horizontal axis.

In FIG. 9, for example, a color CRT (cathode ray tube) is used as the two-dimensional display element 80, and the Sa○2 display section 81 digitally displays the average value of 5a02 calculated by the control calculation section 26. The section 82 displays the measured pulse rate in digitals, the graph section 83 displays 5a02, and the graph section 84 displays the pulse rate as time changes.

59 is an increase key for setting the limit value for S a 02 alarm, 60 is a decrease key, 61 is an increase key for setting the lower limit value for S a O, 62 is a decrease key, G 'A, G 4 are -1-Eye setting increase key and decrease key for pulse rate alarm; 65 + 6 b is increase key and decrease key for pulse rate F limit setting; each of these keys is used in the normal display mode, which will be described later. The selection key '7.1 is included together with the corresponding key as well as the key input section 2111 of FIG.

7 () is the setting of S a Oy - limit value display element r - 1°7
1 is a set lower limit value display element for Sad, '72 is a set upper limit value display element for pulse rate r, 7;) is a set lower limit value display element for pulse rate, and each display element is a two-dimensional display element. 0 and is included in the display section 25 in FIG.

During normal measurement, keys 7 and 4 are pressed, and the latest S
a ('), and the pulse rate is displayed numerically, 1rlS
01 and 82, and is displayed at Toso 1 at the left end of I-1 at the position corresponding to each value. Each time a new S a O2 and pulse rate is displayed, the dot corresponding to the S a O2 and pulse rate measured in The direction is shifted sequentially, for example, toward the top of FIG. ,
7], 72, and 73 as numbers, and is also displayed as a broken line near the graphs 83 and 84. The time axis of the graph display can be set using the switch 75. Innocia G also selects whether or not to display the 4-limit and 11-ft lower limit graphically for warning. 5a02
If the measured value of 5a02 or pulse rate is outside the set upper and lower limit ranges, the dot corresponding to 5a02 or pulse rate at that time will be distinguished from the dot when the measured value is within the upper and lower limit range. It will be displayed in a different style. Specifically, the color or Al11 degree will be changed and displayed. For example, SaO
If the pulse rate is within the range between the upper limit and the lower limit, it will be displayed as a green dot, and if it is Sad or the pulse rate measurement is lower than the upper limit, it will be displayed in red. If the measured value of 5ad2 or pulse rate is below the lower limit value, it is displayed as a blue dot. Furthermore, switch ゛7
7 and the lever 78 can be used to view the display at the previous caution time 3, and by pressing the switch 7':] the display can be hard-copied. When making a hard copy, mark the numbers! Not f. Further, the dinotal output section outputs Sad, value, and pulse rate at predetermined intervals.

Next, the operation of the apparatus of the present invention will be explained using the flowchart shown in FIG. In one embodiment of the invention, Sao 2
(IL Sao 2(2), pulse rate fil calculation t・1
- is performed every second. Power 47 switch IJ () is O
When the CRT 8f-,1 of the display section 25 is turned on, "1-CAL" is displayed on the CRT 8f-,1 of the display section 25 to notify that the ohming annope state is in effect. In addition, by operating keys 5≦]-66, values commonly used as the 1-limit value J9 and lower limit value of Sad and pulse rate are set and displayed on the display sections 70+7] and +'72+73. be done. For example, if the key 59 is held down, the value of the counter in the control calculation section 26 increases at regular intervals, the display on the display section 70 increases, and the limit value of 5aO7 increases by 1. If you press key 60, the upper limit value of 5a02 is 1
It grows up little by little. The keypad keys 60 to 66 are operated in the same manner. Next, the first to third double-wave rectifiers] 4
, 15.16 or the offset voltage is output by the microprocessor.
4. , ]5.16 switch groups are controlled. In this state, the integral switch S of the first to third double-wave rectifiers
l.

53-1 and 53-2 are turned on and the discharge switch S2 is turned off, and each double-wave rectifier is integrated and held.

The held offset voltages of the first to third double-wave rectifiers are sequentially A/D converted by the A/D converter 20,
It is stored in the memory of the control calculation unit 2G. A/D conversion is performed by a double integrator, a comparator, and a counter built into the microcomputer, and input switching is performed by a multiplexer=18. Then, the discharge switches of the first to third double-wave rectifying sections are controlled by the control calculation section 26 via the switch control line, and each integrating capacitor is discharged. The above integration of the offset voltage, A/I conversion of the held voltage, storage, and both wave rectification; and the discharge of the integral capacitor in the A section are repeated in sequence as shown in FIG. It is determined whether the circuit is stable from the outputs of the double-wave rectifiers 14, 15, and 16 that have been sequentially A/1) converted and stored. In this case, the output offset voltage values of the first to third double-wave rectifiers that have been converted and stored; Third
It is determined that the circuit is stable if all the differences between the output voltage values of the two-wave rectifying section 7) and the respective voltage values are less than a predetermined value.

Integration and holding of the offset voltages of the first to third double-wave rectifier sections, A/D conversion of the held voltages, storage, and discharging of the integration capacitors are repeated until the circuit is stabilized and 1 is added. The output offset voltage values of the first to third double-wave rectifiers stored immediately before it was determined that the circuit was stable are used as the first to third offset values, and from then on, the A of the signal is
/ I) Used to subtract the offset from the converted value. When it is determined as 1' that the circuit is stable, the ICALJ display disappears and execution is performed until 11 or less.

In II, it is first determined whether only the offset voltages of the first to third double-wave rectifiers are to be measured. This is because when the offset voltages of the first to third double-wave rectifiers drift during measurement, the offset voltages are newly measured and stored. The offset voltage measurement here is performed once every few minutes. Re-measuring the offset voltage means:
The first to third double-wave rectifiers 14, 15, 16 are set to the offset input state, and the first to third double-wave rectifiers 14, 15
．． 16 offset voltages are integrated and held, and these voltages are sequentially converted into A/I) converter 20.
The data is converted into D and stored in the memory of the control calculation unit 26.

Then jump to II'. If the offset voltage is not to be measured again, directly execute steps II' and subsequent steps.

The operations below TI are repeated at regular intervals.

In II', first, in order to check whether the intensity that has passed through the measurement section does not affect the measurement accuracy, the output of the light intensity measurement circuit 17 is selected by the multiplexer 18, converted into \/D, and stored in the memory.

The output of the light amount measurement circuit is transmitted to the third light receiving element T-38 of the light receiving unit 2.
It is related to the intensity of light incident on the A/I) It is determined whether the converted output value of the light intensity measurement circuit 1-7 is less than or equal to a second light intensity setting value that has been set after a preset first setting value. . If the output value of the light amount measuring circuit 17 is outside the range of the two light amount setting values listed in 1iij, the following operation is performed; if not, the output value of the light amount measuring circuit 17 is set to the second set value in n1li. It is checked whether the elapsed time has elapsed since the light intensity changed from a value less than the charge setting value -1 to a value between the two light intensity setting values. The elapsed time or the predetermined time 1i! If it is below J, the pulse wave signal is also not stable, so in this case as well, it jumps to III.

The operations following IJJ will be described later. Predetermined time L11
Since the pulse wave signal is stable in υ, −, the first
- The output of the third double-wave rectifier 2 is sequentially A/1) converted and stored. Stored fjs] □ = Sth (from the output values of the two-wave rectifiers 14, 15, 16, respectively, the offset voltage force n calculated by I and stored in advance is calculated by 1, and the first The pulse wave amplitude values in each of the first to third wavelength ranges are stored as pulse wave amplitude values in each of the first to third wavelength ranges. Next, all values of YllY2+)'3 are determined to be 1' if they are greater than the preset third setting value and less than the preset fourth setting value. When all three are greater than or equal to the third set value and less than or equal to the first set value, the pulse wave amplitude is within the range 1i1i that can guarantee measurement accuracy. At this time, the following operations are performed.

time! The first and second pulse wave amplitude values Y11 and Y21 at
5ad2(1)i at time 1 from 5ao2(])
i=A, (Y2i/Y,i)'+I3. Then, the first and third pulse wave amplitude values Y11 and Y, i at time 1 are calculated as 5aO2(2)i=A2(Y,i/Y,i)2+B2 at time 1 and stored. Also Y 1 + + Y 21
If at least one of 1 Y 3 i is below the third set value or above the fourth set value, the pulse wave amplitude cannot be measured due to saturation of the measurement circuit, S/N ratio problem, etc. Since the accuracy cannot be maintained, the above SaO;(])it; and Sa
O.

(2)+ノ1il17,+112b,INrNawaJLsu,5iI(J,,(2)ilJ: It is remembered that it is invalid and it is not recorded in Iv 4-1゜)'l;l Y, iH
All values of 'l'31 are correct11. 5aOp(] )i
+5a(-,)2(2)i is calculated, written, and hidden, then 1' of the presence or absence of motion archia7ri1 is 1.
j-to be made.

In other words, the absolute monthly value reference value 1'(SaO2(1)i, 5aO2(
2) The comparison of i) is made.

As an example, f(SaOz(1)1,5a(L(2-1)=6(%)
; S80. (2) When i≧1〕o%, 71vlf
=18.8(%) ””””””-1(%): SaO,
(2) Explain the case when i <90% 4-. 5aO7(2) When i is 1- than (j()%, then l SaO, (1)i-8ad, (2)i
l is C; %]-So, I.

That's 1'1 with motion artifact.
1 fixed 4-ru. Yota5ad2(2)i <9+1% and b
is 1sao2(])i−8aO, (2)i l > ]
2i, 'J-3aO; (2) If it is i/7, it is determined that there is a motion artifact.

If there is a motion artifact, this time i
5aO7(2) is marked as invalid because the measurement accuracy is not guaranteed, and jumps to IV, and if there is no motion artifact, the operation below Iv is performed as is.

■ In \l, the average value of 5ad2 (2) is calculated.

5aO7(2)i from 5aO2(2)i −'? The eight pieces of data up to 8 are sequentially checked to see if they are valid or invalid, and if they are valid, they are added to the SS. k is incremented by 1 each time it is added. If there are 5 or more non-invalid 5aO7(2)s, that is, k or 5, the average value of 5S15 or 5aO7(2) is summed up and stored in the S a O7 display memory. When there are no 5 or more non-invalid 5aO7(2) (value Sa○ from time i to i+7th, (2)
After examining everything from i to 5ad2(2)i7, the value of k becomes less than or equal to 5, and this step jumps to III'.

When k becomes 5 and the average value of 5aC)z(2) is calculated and stored, the pulse rate is then calculated.

The pulse rate is calculated from the interval between the rising and falling pulses of the pulse wave shaping section 21. The output pulses of the pulse wave shaping unit 21 are constantly checked by the control calculation unit 2G at the rising edge and the rising edge 1, and the times of the rising and falling pulses are stored in 11M times. When the pulse rate is calculated, the time of the rise or fall of the membrane force 1, which is 8 pulses before the rise or fall of the membrane force 1, is checked. and the time of the latest rise or fall and the rise 8 pulses ago.
The pulse rate per minute is calculated from the difference between 20 and the falling time.

When the pulse rate is calculated, it is stored in the pulse rate display memory. Next, the average value of the calculated SaO, (2) is displayed on the display section 7f, which is set for warning. ” are compared with the respective S a O2 upper limit and S a O2 lower limit.

The average value of 5aO2(2) is 1-. Or, if F is below the lower limit value, it is stored in 1 or S a 02 high alarm memory or 5 a (-) or low alarm memory, and is counted. S a (',), (
When the average value of 2) is between its upper and lower limits,
Sad, High Alarm Memory and SaO,o~Alarm Memo It is determined whether the pulse rate is less than or equal to the pulse rate upper limit set for warning or less than the pulse rate lower limit. When the pulse rate is below the set upper limit, 1 is stored in the pulse rate high alarm memory, and when the pulse rate is below the lower limit, 1 is stored in the pulse rate low alarm memory.
Jump to I. When the pulse rate is within the range between the two upper limit values and the lower limit value, the pulse rate high alarm memory and pulse rate low alarm memory are stored automatically and jump to \.

When \='1 or less, 5ad2, pulse rate, etc. are displayed on the two-dimensional display element and the screen is copied depending on the state of the switches 4 to 75]. First, it is checked whether the display mode, normal mode, or preview mode. If switch A 4 is ON, the mode becomes normal mode IS, and if switch A 7 is ON, the mode becomes prefew mode. In the normal mode, among the contents stored in the SaO1 display memory and the pulse rate display memory, the latest Sad and pulse rate are displayed numerically on the display section 82. And 5a02. on the left edge of the screen. A dot will be displayed at the position corresponding to the pulse rate, and the contents of the 1ii4 SaO7 display memory and pulse rate display memory will be changed to the old value.
7 items are displayed. The tile and scale of the graph display are set by a switch 75. In addition, when switch 76 is ON, the SaO2 high alarm memory display stores and stores the contents of the limit values for each SaO = 13 and the measured pulse rate and r. Memory, Sad, low alarm memory display memory,
The contents of the pulse rate high alarm display memory, pulse rate low alarm display memory, and display memory are displayed on the two-dimensional display element -)) () with broken lines. When switch 76 is pressed, the contents of each alert memory corresponding to 5a02 and pulse rate displayed in the graph are checked, and SaO,
The content of Hireer 1\memory 1 is indicated by the corresponding SaO,, is displayed as a red i・n1, and Sa(
, ) 20-Alarm memory contents 1 and 5a02 corresponding to it are displayed in blue, and both alarms 1 and 1 are displayed in blue.
When the memory was filled with (), I was stunned;
l Ijntsqsu()-lJuki1+ /Aγ λ',
-1 be J. The same applies to pulse failure. When the switch 76 is set to 1, the contents of each high alarm display memory are displayed graphically.The color of the pulse rate dots is changed depending on the contents of each alarm memory. No changes are made and everything is displayed as a green dot. Also, if the latest Sa (') or pulse rate is not within the range of each upper limit and 1ζ limit, IJ old, El) will flash, and if Sui, Chiro 8 is ON, an alarm will sound. It will be done. In addition, the latest S a 02 meter (when the error is not available, the display during operation is 1N0PJ, 1 gloss or fish light is displayed, the 5aO3 stripe and the pulse rate numerical display and the dots for it are blank, Sui, 7S 68 is ON
Then? r-report f7 is issued.

Then jump to II.

The following describes the display of 1, ie, Sui, Cheer 7, and 5 when the mode or preview mode is ON.

In this mode, instead of the latest Sad and pulse rate on the left edge of the screen, a dot is displayed at a height representing the previously 1 Sad and pulse rate, and is also displayed as a number. Switch to °75↓hi switch tf'i6
ノJj9. i#li/-Marumo l'toi'lshite'. Lever 73) is used to set whether to display the current 5aOJi and pulse rate on the left edge of the screen. While the lever 78 is moved to the left, the previous value will be displayed on the left edge of the screen, and the graph will be displayed. Yes, move in the direction of J. Lever 78 has been moved to the right until 1.1:, the graph is displayed at the right end of both sides with newer values, and the graph is displayed on the right side] 111
Move one place. Lever 7)) When cents are placed on h.11 history, the graph stops moving. The functions of switch 75 and switch 7G are the same as the 7-mal mode. When switch 75 and switch 7G are turned on with lever 78 set to medium heat in the preview mode, both 1
rri is copied onto an appropriate sheet 1- by a printing device (not shown). Then jump to II. The preview mode is processed while the first to third double-wave rectifiers in 11 are performing integration, or while the time is being adjusted in III, so in this mode, j, l
t sequentially new 5ad2 and pulse rates are calculated and stored.

When the AID conversion value of the output of light amount measurement circuit] is less than the light amount setting value of il or less than the second light amount setting value, or the AID conversion value of the output of the light amount measurement circuit is the second light amount measurement circuit. - When the value becomes between the first light intensity setting value and the second light intensity setting value and the predetermined time has not elapsed, 5aO3 (2) or 4 or more consecutive invalid Then jump to III'. In III and below, the following operation is performed.

In III, first, in order to keep the period of calculation of S a O and pulse rate constant, a waiting time is performed for approximately the same time as the integration time of the first to third double wave rectifiers, and then the operation in III' and below is performed. Do the following. In Ill, the operating state is stored in the 5a02 display memory and the pulse rate display memory. Then jump to \・■.

[Effect of the Invention 1] As detailed below, the present invention compensates for the fluctuation of the advance light passing through the Δ1 line due to the fluctuation of the light amount of the light source by using the output of one reference light-receiving element. :.

Since it is simple, the configuration is extremely simple, and as a result of this correction, the light source can be driven by commercial power, making the power source inexpensive.

[Brief explanation of drawings]

FIG. 1 is a 70 block diagram showing one embodiment of the present invention, and FIG. 2 is a 70 block diagram showing an embodiment of the present invention. source p;c,at
3 and 4 are detailed block diagrams of main parts in the embodiment of FIG. 1, FIG. 5 is a circuit diagram showing an example of a conventional double-wave rectifier circuit, and FIG. is a waveform diagram showing the defects that occur in the circuit of FIG. 5, FIG. (,),, Difference between measured values and true 5aO=
Graphs showing which relationships, (159 diagrams show operations 1-70
-Na, 1--1., Fig. 1() is a front view showing the display i'Fb of the device of this invention, and Fig. 11 is 1 in this invention.
(1', /"l',)', i', /"l',)
” is a graph showing the relationship between 5a02 and 11...
Light source, 2... Light receiving section, I='l, ] 5,
I C')...both waves, 1≦lA section, 2...9 section before control, 25...display section;) 2...light source, t'1.
Reference photodetector, 4! 'i, ,'L 6. ．． 47
,. AC/l')C change circuit. Fig. 2 Fig. 4 gt+ 5Q021 long r+1saoz+2+ +6th
Figure 10 To+ ha”7-hhJ

Claims (1)

[Claims] (1) Using a light source with a continuous wavelength tη, Y ・I'l:, irradiate the part to be measured with t emitted from the light source, and reflect or transmit light from the part to be measured. The light is split into multiple wavelength ranges, the split light is received by multiple receivers provided for each wavelength range, and the part to be measured is detected from the output of each light-receiving element. '1.1 In a photometric device that measures the characteristics, there is a single illumination receiving element that passes the light from the light source through the part to be measured and directly receives the light, and a direct current output of the reference 11J light receiving element. A component ratio change F stage for changing the ratio of 1 & minute and AC component to the ratio of 1/j current component and AC component predetermined for each wavelength range. For each wavelength range, the output and component ratio changes of each photodetector J'-
It has an operator η stage for calculating the ratio with the output of the first stage J′,
'A'
= 7-:1lllI:'-+'! j'-? -IL(-
A photometric device characterized by: