JP2001321363A - Organism parameter measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily, safely and precisely measure a renal function, a hepatic function and a cardiorespiratory function for a short time. SOLUTION: The lights from a plurality of light sources 1, 2 and 3 are emitted to an organism tissue 5, and the transmitted lights are received by a light receiving element 6 and converted into electric signals. These signals are converted to digital signals for each wavelength by a multipexer 8, filters 9-11 and an A/D converter 12, and each of the signals is converted to a logarithm by a logarithm calculating circuit 14. A Φ calculating circuit 15 calculates the mutual ratio of these signals. A substance concentration calculating circuit 16 performs a calculation on the basis of this ratio to determine the concentration view of the indigocarmine injected to the blood. An organism parameter calculating circuit 17 performs a calculation on the basis of the concentration view to determine various parameters concerning renal function, hepatic function and cardiorespiratory function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to renal function, liver function,
The present invention relates to an apparatus for measuring a respiratory circulation function.

[0002]

2. Description of the Related Art A renal function test, that is, a test for glomerular filtration rate, includes a nuclear medicine test using radiation and a creatinine clearance test.

[0003]

The nuclear medicine examination needs to consider the exposure, and requires special facilities.
There is a disadvantage that it cannot be used at the bedside of an ICU or the like. On the other hand, the creatinine clearance test requires a long time (2 to 4 hours) for measurement, places a heavy burden on patients with renal failure, and has a drawback that accuracy is lacking because the calculation formula depends on the urine output value.

Since renal function is affected by circulatory dynamics such as cardiac output and circulating blood volume, it is desirable to measure both at the same time. No equipment was available. In some cases, the circulatory function is measured by injecting a dye into the blood of the subject and measuring the concentration diagram, but none is measured together with renal function. In addition, the dyes conventionally used for such measurement have difficulty in safety and handling.

The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to make it possible to measure a renal function, a liver function, and a respiratory circulatory function easily, in a short time, and more safely and accurately. That is.

[0006]

According to the first aspect of the present invention, there is provided an apparatus comprising:
It has a concentration measuring unit for measuring at least a concentration diagram of indigo carmine in data relating to the concentration of a light absorbing substance in blood, and a parameter detecting unit for obtaining a biological parameter based on the indigo carmine concentration diagram measured by the concentration measuring unit.
According to this, a biological parameter can be measured by injecting indigo carmine into a subject and measuring its blood concentration.

According to a second aspect of the present invention, in the device according to the first aspect, the concentration measuring section irradiates the living tissue with light and processes a signal corresponding to the intensity of light transmitted or reflected by the living tissue. And measuring an indigo carmine concentration diagram. According to this, non-invasive and accurate measurement can be performed.

According to a third aspect of the present invention, in the device according to the first aspect, the concentration measuring section irradiates the living tissue with light and processes a signal corresponding to the intensity of light transmitted or reflected by the living tissue. And measuring oxygen saturation together with the indigo carmine concentration diagram. According to this, an indigo carmine concentration diagram considering the oxygen saturation can be obtained.

According to a fourth aspect of the present invention, in the device according to the first aspect, the biological parameter includes cardiac output, liver clearance, kidney clearance, or body fluid volume.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described. First, the principle of the device of this embodiment will be described.

Indigo carmine (hereinafter referred to as IDG) is injected into the blood of a living tissue, and the living tissue is irradiated with light of three wavelengths. Then, signals I1, I2, and I3 corresponding to the light intensities of the respective wavelengths transmitted through the living tissue are obtained.
Is measured, the dimming degrees A1, A2 and A3 fluctuate due to blood pulsation. The change ΔA1, ΔA2, ΔA
3 is measured and their mutual ratio is determined. These ratios are expressed as Φ12 = ΔA1 / ΔA2, Φ13 = ΔA1 / ΔA3
Then, the following equation holds from Shaster's theory and experiment.

In the equations (1) and (2), RHb indicates the reduced hemoglobin concentration, O2Hb indicates the oxidized hemoglobin concentration, Cd indicates the IDG concentration, and Hb indicates the hemoglobin concentration. Eoi (i = 1, 2, 3) is the extinction coefficient of oxyhemoglobin, Eri (i = 1, 2, 3) is the extinction coefficient of reduced hemoglobin, Edi (i = 1, 2, 3) is the extinction coefficient of IDG, F indicates a scattering coefficient, and i = 1, 2, 3 is the light wavelength λ
1, λ2 and λ3.

In this case, the Eoi, Eri, Edi,
Since F is a known value, Φ12 = ΔA1 / Δ
A2, Φ13 = ΔA1 / ΔA3 are measured, and these are substituted into the above-mentioned equations (1) and (2) to solve the simultaneous equations. As a result, the concentration ratio of three blood substances of oxyhemoglobin, reduced hemoglobin, and IDG can be obtained. You can ask.

For example, if the ratio of the three concentrations O2Hb, RHb, and Cd of oxyhemoglobin, reduced hemoglobin, and IDG is 1: n: m,

O2Hb = 1 / (1 + n + m), RHb =
Since n / (1 + n + m) and Cd = m / (1 + n + m), the unknowns of the simultaneous equations of equations (1) and (2) can be two, n and m. Therefore, n,
By obtaining m, the concentration ratio of three blood substances of oxyhemoglobin, reduced hemoglobin, and IDG can be obtained.

Also, if the hemoglobin concentration Hb is known,
From Cd / Hb = m / (1 + n), the absolute concentration of IDG C
d can be calculated.

FIG. 1 is a block diagram showing a configuration of a biological parameter measuring device according to the present invention. In FIG. 1, light sources 1, 2, and 3 are composed of light emitting elements.
Are driven by the drive circuit 4 and have different wavelengths λ.
1, λ2 and λ3 are generated.
Here, λ1 = 620 nm, λ2 = 660 nm, λ3 = 9
40 nm. Light from the light sources 1, 2, 3 passes through the living tissue 5 and is received by the light receiving element 6, where it is converted into an electrical signal. These converted signals are amplified by an amplifier 7 and distributed by a multiplexer 8 to filters 9, 10 and 11 corresponding to the respective optical wavelengths.

The signals of the respective wavelengths distributed to the filters 9, 10, and 11, respectively, have high-frequency components removed therefrom.
A / D converter 12 converts the signal into a digital signal, and logarithmic calculation circuit 14 calculates a ratio Φ of a change in dimming degree Φ calculation circuit 1
5 and a substance concentration calculation circuit 16 for calculating an IDG concentration diagram
Are sequentially input.

The timing control circuit 13 includes a driving circuit 4,
A necessary timing signal is transmitted to each part of the multiplexer 8 and the A / D converter 12 to control the timing of their operation.

The Hb input circuit 19 is a circuit for storing an externally set blood hemoglobin concentration, and its contents are used as needed when the substance concentration calculation circuit 16 performs calculation.

The biological parameter calculating circuit 17 calculates the cardiac output CO, circulating blood volume V1, interstitial fluid volume V2, steady distribution volume Vdss, and excretion based on the IDG concentration diagram obtained by the substance concentration calculating circuit 16. Speed constant kel, clearance C
This is a circuit for calculating Ltot.

Here, generally, these parameters CO, V1, V2, Vdss, kel, CL
A method for obtaining tot will be described. The cardiac output CO can be obtained from the area D of the initial circulation in the pigment concentration diagram shown in FIG. That is, if the amount of the injected dye is C, These are calculated and found because of the relationship

Other parameters are obtained as follows.
FIG. 3 shows a dye density diagram expressed in semilogarithm. From this curve the distribution volume and clearance can be calculated. This density diagram can be represented by two extrapolated lines as shown in FIG. This indicates that the dye distribution volume in blood can be represented by two compartments. This 2
It is possible to calculate the circulating blood volume and the interstitial fluid volume by using the two volumes as the intravascular and interstitial fluid.

The two-compartment model is shown in FIG. Where V1 is the volume of the central compartment, V2
Is the volume of the peripheral compartment, k12, k21, ke
l is the rate constant, C1 is the pigment concentration in the central compartment, and C2 is the pigment concentration in the peripheral compartment.

Using the measured dye density map as the dye density of the central compartment, for example, the dye density map Cd (t) is expressed by the following equation of 2-exponential using the least square method or the like. At this time, the following formula is established. Dose is the amount of dye to be administered, and CLtot is the clearance. These equations provide the respective kinetic parameters. Here, V1 is the circulating blood volume, and V2 is the interstitial fluid volume.

In the present embodiment, the dye is IDG. Therefore, the biological parameter calculation circuit 17 compares the IDG concentration diagram obtained by the substance concentration calculation circuit 16 with the above equation (4).
Based on equation (11), cardiac output CO, circulating blood volume V
1, a circuit for calculating the interstitial fluid volume V2, the steady distribution volume Vdss, the excretion rate constant kel, and the clearance CLtot. Since IDG is mainly excreted by the kidney, the kel or CLtot of the IDG obtained by the above equation can be obtained.
Is mainly an indicator of the glomerular filtration rate of the kidney and the renal blood flow.

The Dose input circuit 18 is a circuit for storing an externally set IDG dose, and its contents are used as needed when the biological parameter calculation circuit 17 performs calculation.

In this apparatus, the light sources 1, 2, 3, the driving circuit 4, the light receiving element 6, the amplifier 7, the multiplexer 8, the filters 9 to 11, the A / D converter 12, the logarithmic calculation circuit 14,
The Φ calculation circuit 15, the substance concentration calculation circuit 16, the Hb input circuit 19, and the timing control circuit 13 constitute a concentration measurement unit, and the biological parameter calculation circuit 17 and the Dose input circuit 18 constitute a parameter detection unit.

Next, the operation of the thus configured apparatus will be described. When the apparatus starts operation, the light sources 1, 2, 3
The light of each wavelength generated by the above is transmitted through the living tissue 5.
The light receiving element 6 converts the light into an electric signal according to the intensity of the light. These signals are supplied to the amplifier 7, the filters 9, 10,
11 and an A / D converter 12 to reach a logarithmic calculation circuit 14. In the logarithmic calculation circuit 14, the output of the A / D converter 12 and the signals corresponding to the light intensities I 1, I 2, I 3 are calculated as
nI1, lnI2, and lnI3 are calculated and obtained. next,
The Φ calculation circuit 15 calculates Φ12 = ΔlnI1 / ΔlnI2,
Φ13 = ΔlnI1 / ΔlnI3 is calculated and obtained.

The substance concentration calculating circuit 16 comprises a Φ calculating circuit 15
Φ12 and Φ13 determined by the above and the simultaneous equations (1)
From the formula based on the formula (2), the oxygen saturation SpO2 and ID
A G density diagram Cd (t) is obtained. The oxygen saturation SpO
2 is determined from the ratio of the oxygenated hemoglobin concentration O2Hb to the reduced hemoglobin concentration RHb. The oxygen saturation SpO2 and the concentration diagram Cd (t) obtained here are displayed and recorded by a display and a recorder (not shown).

On the other hand, based on the IDG concentration diagram Cd (t) obtained by the substance concentration calculation circuit 16, the biological parameter calculation circuit 17 calculates the cardiac output CO, the circulating blood volume V1, the interstitial fluid volume V2, Distribution volume Vdss, excretion rate constant ke
1. Calculate the clearance CLtot. These are displayed and recorded by a display and a recorder (not shown).

In this embodiment, light of three wavelengths is used, and an equation taking into account the oxygen saturation is used when obtaining the IDG concentration diagram. Therefore, the influence of the oxygen saturation is eliminated, and the IDG concentration diagram can be obtained accurately. In addition,
If the measurement is performed on the assumption that the 100% gas is inhaled by the subject, the oxygen saturation can be regarded as 1, and the substance concentration calculation circuit 16 calculates any one of the above simultaneous equations.
An IDG density map can be obtained by the following equation.

According to the present embodiment, since the IDG is mainly excreted by the kidney, it is possible to accurately measure the renal function. Furthermore, in this embodiment, in addition to renal function parameters such as the excretion rate constant kel and clearance CLtot, circulatory function parameters such as cardiac output CO and circulating blood volume V1 can be obtained at the same time.

In this embodiment, it is sufficient that the wavelength λ1 is orange or red-orange, the wavelength λ2 is red, and the wavelength λ3 is infrared.
The peak of the wavelength λ1 is 610-630 nm,
If the peak of No. 3 is at 790-990 nm, a suitable measurement result can be obtained.

Next, a second embodiment will be described.
FIG. 5 shows the configuration of this device. In the present embodiment, the wavelengths λ1, λ of the light emitted from each of the light sources 1A, 2A, 3A
2, λ3 are λ1 = 620 nm, λ2 = 805 nm, λ
3 = 940 nm. Further, the Φ calculation circuit 15A according to the present embodiment calculates Φ13 = ΔlnI1 / ΔlnI3, Φ2
3 = ΔlnI2 / ΔlnI3.

Further, in the present embodiment, there is provided a judgment circuit 21 for judging whether the administered dye is IDG or indocyanine green (ICG). According to the characteristics of the extinction coefficient in FIG. 6, when IDG is administered, λ1 (620
nm), the largest light absorption change occurs in the transmitted light at λ3 (805 nm) when ICG is administered. The determination circuit 21 determines the type of the dye based on the value of Φ. That is, as shown in FIG. 7, appropriate thresholds are set for Φ13 and Φ23, and the respective thresholds are compared with Φ13 and Φ23 to determine which dye has been administered. .

Further, the substance concentration calculating circuit 16A in the present embodiment calculates an expression based on a simultaneous equation according to the judgment result of the judging circuit 21, and calculates the dye concentration map Cd (t) and Sd.
This is a circuit for obtaining pO2. In this case, the simultaneous equation is represented by the following equation, and the extinction coefficient Edi (i = 1, 2, 3)
Differs depending on whether it is an IDG or an ICG.

The other structure is the same as that of the first embodiment, and the same reference numerals are given in FIG. In this device,
Light sources 1A, 2A, 3A, drive circuit 4, light receiving element 6, amplifier 7, multiplexer 8, filters 9 to 11, A / D converter 12, logarithmic calculation circuit 14A, Φ calculation circuit 15A, substance concentration calculation circuit 16A, Hb The input circuit 19 and the timing control circuit 13 constitute a concentration measurement unit, and the biological parameter calculation circuit 17 and the Dose input circuit 18 constitute a parameter detection unit.

According to the present embodiment, when the IDG is administered, the judgment circuit 21 determines the Φ1 calculated by the Φ calculation circuit 15A.
3. It is determined that IDG has been administered with reference to Φ23, and that fact is output to the substance concentration calculation circuit 16A. The substance concentration calculation circuit 16A uses the extinction coefficient of IDG (1
Calculate the equation based on the simultaneous equations of 2) and (13) and calculate S
The pO2 and IDG concentration diagram CdD (t) is determined. These SpO2 and CdD (t) are displayed and recorded on a display and a recorder (not shown). Biological parameter calculation circuit 17
Is the IDG concentration diagram Cd obtained by the substance concentration calculation circuit 16A.
Based on D (t), cardiac output CO, circulating blood volume V1,
The interstitial fluid volume V2, the steady distribution volume Vdss, the excretion rate constant kel, and the clearance CLtot are calculated. These are displayed and recorded on a display and a recorder (not shown).

On the other hand, when ICG is administered, the decision circuit 2
1 refers to Φ13 and Φ23 obtained by the Φ calculation circuit 15A, determines that ICG has been administered, and outputs the fact to the substance concentration calculation circuit 16A. The substance concentration calculation circuit 16A
Formulas based on the simultaneous equations (12) and (13) using the extinction coefficient of ICG were calculated, and SpO2 and ICG were calculated.
A density diagram CdC (t) is obtained. Hereinafter, the same processing as in the case of IDG administration is performed in each unit.

The present embodiment is an apparatus using light of three wavelengths, and it can measure the pigment concentration diagram and the arterial oxygen saturation of any of the IDG and ICG dyes, regardless of whether they are administered. it can. However, a condition that both IDG and ICG are not administered into blood is necessary.

In this embodiment, whether the administered dye is IDG or ICG is automatically determined by using the determination circuit 21. This is performed by an operator using key input means or the like. May be performed.

Next, a third embodiment will be described. As in the second embodiment, in an apparatus using light of three wavelengths, it is possible to measure the carboxyhemoglobin concentration COHb under the condition where no dye is administered. The invention for measuring the carboxyhemoglobin concentration COHb using three wavelengths is as disclosed by the applicant in Japanese Patent Application No. 11-339605. In the present embodiment, arterial blood oxygen saturation SpO2, IDG concentration CdD, ICG concentration Cd
C, a device capable of measuring carboxyhemoglobin concentration COHb. However, it is assumed that IDG, ICG, and carboxyhemoglobin do not simultaneously exist in blood.

As shown in FIG. 8, the configuration of this apparatus is such that light generated from the light sources 1A, 2A and 3A passes through the living tissue 5 and is converted into an electric signal by the light receiving element 6, and this signal is The process is the same as that of the second embodiment until the signal is converted into a digital signal by the A / D converter 12 through the filters 9, 10, and 11, but the processing of this signal is performed by the data processing device 30 of the digital computer. Like that. Further, the present apparatus is provided with an input device 22 by which the operator inputs an IDG density C to the data processing device 30.
It instructs which of dD, ICG concentration CdC, and carboxyhemoglobin concentration COHb is to be measured.

The operation of the apparatus will be described with reference to the flowchart of FIG. When the power is turned on (step 10
1) Measure transmitted light (step 102). That is, light generated from the light sources 1A, 2A, and 3A and transmitted through the living tissue 5 is converted into an electric signal by the light receiving element 6. This signal is amplified by an amplifier 7, passed through a multiplexer 8, filters 9, 10 and 11, and converted into digital signals I 1, I 2 and I 3 by an A / D converter 12. Data processing device 30
Measures these signals continuously for a predetermined time and calculates the logarithm lnI
1, lnI2, ln3 are converted and stored.

Next, Φ calculation is performed based on the logarithmic value obtained in step 102 (step 103). That is, a change ΔlnI of lnI1, lnI2, ln3 for each pulsation.
1, ΔlnI2 and ΔlnI3 are obtained, and Φ13 = ΔlnI
1 / ΔlnI3, Φ23 = ΔlnI2 / ΔlnI3 are calculated.

Next, the data processing device 30 is connected to the input device 2
It is determined whether the instruction given from step 2 is an instruction for calculating the dye density (step 104).
And the designated dye concentration are calculated (step 10).
5). In this step, when the instruction means 20 instructs the measurement of the concentration CdD of IDGC, the expression (12) is used.
The oxygen saturation SpO2 and the IDG concentration diagram CdD (t) are obtained by performing a calculation based on a simultaneous equation in which Ed in the equation (13) is used as the extinction coefficient of IDG.

When the given instruction is to measure the ICG concentration CdC, Ed in the equations (12) and (13) is
The oxygen saturation SpO2 and the ICG concentration diagram CdC (t) are obtained by performing calculations based on simultaneous equations as extinction coefficients of CG. The hemoglobin concentration used in this calculation is given in advance from the input device 22. SpO2 and Cd determined
C (t) is displayed and recorded by a display and a recorder (not shown).

Next, the data processing device 30 determines the obtained CdD
Using (t) or CdC (t), cardiac output CO, circulating blood volume V1, interstitial fluid volume V2, steady distribution volume Vds
s, excretion rate constant kel, and clearance CLtot are calculated (step 106). The dose Vdose of each dye used in this calculation is given in advance from the input device 22. The obtained values are displayed and recorded by a display and a recorder (not shown).

On the other hand, the carboxyhemoglobin concentration COH
If the measurement of b is instructed, SpO2 and COHb are obtained by performing calculations based on the following simultaneous equations (step 107). Here, Eco is the extinction coefficient of carboxyhemoglobin.

The thus obtained SpO2 and COHb are displayed and recorded by a display and a recorder (not shown). In the present apparatus, the light sources 1A, 2A, 3A, the driving circuit 4, the light receiving element 6, the amplifier 7, the multiplexer 8, the filters 9-1.
1. The logarithmic calculation function, the Φ calculation function, and the density map calculation function of the A / D converter 12, the input device 22, and the data processing device 30 correspond to a concentration measuring unit, and the biological parameter calculation function and the input device of the data processing device 30. Reference numeral 22 corresponds to a parameter detection unit.

In place of the instruction from the input device 22, the data processing device 30 automatically determines which dye concentration diagram to use based on the change pattern of Φ, and calculates the dye concentration measurement. It may be executed. FIG.
The flowchart is shown in FIG. In this case, only the determination step 200 is different from the apparatus described in FIG.

In the measurement at the three wavelengths, if the dye concentration measurement and the carboxyhemoglobin concentration measurement are not performed, the data processing device 30 determines the SpO2 based on the following calculation formula. Can be improved.

Here, EX is a variable indicating light absorption generated by pulsation of tissues other than arterial blood, is an unknown, and has no wavelength dependence. Φ12 = ΔA1 / ΔA2, Φ1
By measuring 3 = ΔA1 / ΔA3 and substituting it into the above equation to solve the simultaneous equations, E which is an error component for SpO2 measurement is obtained.
X can be eliminated, and the concentration ratio SpO2 of oxyhemoglobin O2Hb and reduced hemoglobin RHb can be determined more accurately. If there is no injected dye, EX is obtained in this way. If there is an injected dye, this EX is used to obtain the injected dye concentration based on a simultaneous equation including EX and the dye concentration. The dye concentration can be determined more accurately.

Next, a fourth embodiment will be described. This apparatus, as shown in FIG. 11, processes the transmitted light intensity signal obtained by irradiating the living tissue 5 with light of four wavelengths, thereby simultaneously controlling the respective concentrations of IDG and ICG administered to the blood. It is a device for measuring. Light sources 41, 42, 43,
44 are driven by a drive circuit 54 and each has a wavelength λ
1 = 620 nm, λ2 = 660 nm, λ3 = 805n
m, λ4 = 940 nm. Light from the light sources 41, 42, 43, and 44 passes through the living tissue 5, is received by the light receiving element 56, is converted into an electric signal,
These converted signals are amplified by an amplifier 57, and are distributed by a multiplexer 58 to filters 59, 60, 61, and 62 corresponding to the respective optical wavelengths.

The signals distributed to the filters 59, 60, 61 and 62 are converted into digital signals by the A / D converter 52 after removing high-frequency components. This digital signal is processed by a data processing device 70 composed of a digital computer. The data processing device 70 also includes a driving circuit 54, a multiplexer 5
8. It is configured to control each part of the A / D converter 52.

The input device 23 is connected to the data processing device 70, and the blood hemoglobin concentration and the dye dose are input in advance.

Next, the operation of the above-configured apparatus will be described with reference to the flowchart of FIG. The operator first administers IDG and ICG into the blood of the subject. When the power is turned on (step 301), the apparatus measures transmitted light (step 302). That is, the light sources 41, 4
Light generated from 2, 43 and 44 and transmitted through the living tissue 5 is converted into an electric signal by the light receiving element 56. This signal is amplified by an amplifier 57, passes through a multiplexer 58, and filters 59, 60, 61, and 62, and is converted into digital signals I1, I2, I3, and I4 by an A / D converter 52. This signal is continuously measured for a predetermined time, and the data processing device 70
Given signals are logarithm lnI1, lnI2, lnI3,
is converted to lnI4, and the predetermined time is stored.

Next, the data processing device 70 executes step 3
Φ is calculated based on the data obtained in step 02 (step 303). That is, lnI1, lnI2,
changes ΔlnI1, ΔlnI2 of lnI3 and lnI4,
ΔlnI3 and ΔlnI4 are obtained, and Φ12 = ΔlnI1 /
ΔlnI2, Φ13 = ΔlnI1 / ΔlnI3, Φ14
= ΔlnI1 / ΔlnI4 is calculated.

Next, the data processing device 70 performs a predetermined calculation to perform the oxygen saturation SpO2 and the IDG concentration diagram CdD.
(T), an ICG density map CdC (t) is obtained (step 304). That is, the data processing device 70 performs a calculation based on the following simultaneous equations.

In the above formula, RHb is a reduced hemoglobin concentration, O2Hb is an oxyhemoglobin concentration, and CdD is I
DG concentration and CdC indicate ICG concentration. Eoi (i =
1, 2, 3, 4) is the extinction coefficient of oxyhemoglobin, Er
i (i = 1, 2, 3, 4) is the extinction coefficient of reduced hemoglobin, Eddi (i = 1, 2, 3, 4) is the extinction coefficient of IDG, and Edci (i = 1, 2, 3, 4) is The extinction coefficient of IDG, F indicates a scattering coefficient, and i = 1, 2, 3, 4 indicates light wavelengths λ1, λ2, λ3, λ4. In this case, the Eo
Since i, Eri, Eddi, Edci, and F are known values, Φ12 = ΔA1 / ΔA2 and Φ13 = ΔA
By measuring 1 / ΔA3, Φ14 = ΔA1 / ΔA4 and substituting these values to solve the simultaneous equations, it is possible to obtain the blood concentration ratio of the four substances of oxyhemoglobin O2Hb, reduced hemoglobin RHb, IDG and ICG. it can.

The data processing device 70 calculates the density ratio
From the value of the hemoglobin concentration Hb given in advance, I
The absolute densities CdD and CdC of DG and ICG are calculated, and the respective density maps CdD (t) and CdC (t) are obtained.

Next, the data processing device 70 uses the obtained dye concentration diagrams CdD (t) and CdC (t) to calculate the cardiac output CO, the circulating blood volume V1, the interstitial fluid volume V2, Steady distribution volume Vdss, excretion rate constant kel,
Calculate the clearance CLtot (Step 30)
5). These are displayed and recorded by a display and a recorder (not shown).

When IDG and ICG were administered simultaneously and measured, the IDG kel _idg and CLt in the same circulation were measured.
ot _idg and ICG's kel _icg and CLtot _icg
Can be obtained at the same time. IDG is mainly excreted by the kidney, but some excretion by the liver has been confirmed. Therefore, the rate constant kel _idg is the rate constant k of excretion into the kidney.
_Elidgr and the rate constant of elimination to the liver _kelidgh
Can be thought of as the sum of kel _idg = kel _idgr + kel _idgh (a) On the other hand, ICG is excreted only by the liver. Therefore, I
By CG's kel _icg and IDG's kel _idg ,
More accurate renal excretion ability can be calculated. For example, the rate constant of the excretion of ICG to the liver and the rate constant of the excretion of IDG to the liver are expressed by a certain relationship as in the following equation. kel _idgh = K * kel _icg (b) This equation need not be a linear equation. From the equations (a) and (b), the rate constant kel of excretion of IDG into the kidney is obtained.
_idgr can be calculated as: kel _idgr = kel _idg- K * kel _icg (c).

Then, the data processing device 70 uses the kel _idg and kel _icg obtained in step 305 to
Further, equation (c) may be calculated to obtain the rate constant kel _idgr of excretion of IDG into the kidney. Alternatively, the clearance CLtot _idgr may be obtained from the kel _idgr thus obtained.

In this apparatus, the light sources 41, 42, 43,
44, drive circuit 54, light receiving element 56, amplifier 57, multiplexer 58, filters 59 to 62, A / D converter 5
2. The logarithmic calculation function, the Φ calculation function, and the density diagram calculation function of the input device 23 and the data processing device 70 constitute a concentration measurement unit, and the biological parameter calculation function of the input device 23 and the data processing device 70 constitute a parameter detection unit. Constitute.

In this embodiment, the peak of the first wavelength λ1 is orange to red-orange, the peak of the second wavelength λ2 is red, the peak of the third wavelength λ3 is 790-810 nm, and the peak of the fourth wavelength λ4 is 810 nm. As long as it is a long wavelength infrared ray, the first
If the peak of the wavelength λ1 is 610 to 630 nm, a favorable measurement result can be obtained.

If four wavelengths are used as in the present invention,
It is possible to simultaneously measure the dye concentration diagrams of IDG and ICG with one injection, and obtain biological information that can be calculated from IDG and biological parameters that can be calculated from ICG in a short time at a time with one injection and device operation. Things become possible.
Further, if further calculation is performed using biological parameters obtained at the same time, such as kel _idg and kel _icg , it is possible to obtain further biological parameters such as kel _idgr .

Further, according to the apparatus using four wavelengths as described above, the arterial blood oxygen saturation was measured in the same manner as when the carboxyhemoglobin concentration COHb was measured under the condition where the dye was not administered using the apparatus using the three wavelengths. And the COHb concentration of carboxyhemoglobin can be measured simultaneously. Therefore, similarly to the above three wavelengths, by providing the selection means, it is possible to detect the dye concentration diagram and the oxygen saturation when the dye is injected, or to detect the hemoglobin monoxide concentration and the oxygen saturation when the dye is not injected. Can be selected for operation.

In each of the above embodiments, O
The method of calculating the concentration ratio of 2Hb, RHb, CdD, CdC, etc. may be a method of calculating, instead of calculating, referring to a table created in advance by calculation or based on experimental results.

In each of the above embodiments, the measurement is performed based on the transmitted light of the living tissue. However, the measurement may be performed based on the reflected light of the living tissue.

[0072]

According to the present invention, the renal function, liver function and respiratory circulatory function can be measured simply, in a short time, and more safely and accurately. Therefore, the device of the present invention can be used for routine examinations in urology and the like. Also,
The dye IDG used is excellent in safety because it does not contain iodine, is inexpensive, and can be supplied in ampoules, so that it is easy to handle. Further, according to the device of the present invention, important parameters for body fluid management, such as cardiac output and circulating blood volume, can be measured in a minimally invasive manner in a short time. Therefore, it is extremely useful for monitoring the progress of treatment for cardiovascular diseases.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of a first embodiment of the present invention.

FIG. 2 is a diagram for explaining a method of obtaining a cardiac output from a pigment concentration diagram.

FIG. 3 is a diagram for explaining a method for obtaining various parameters from a dye density diagram.

FIG. 4 is a diagram for explaining a method of obtaining various parameters from a dye density diagram.

FIG. 5 is a diagram showing an overall configuration of a second embodiment of the present invention.

FIG. 6 is a graph showing light absorption characteristics of IDG and ICG.

FIG. 7 is a diagram showing a pattern of Φ used to determine which of IDG and ICG has been administered.

FIG. 8 is a diagram showing an overall configuration of a third embodiment of the present invention.

FIG. 9 is a view for explaining the operation of the device shown in FIG. 8;

FIG. 10 is a diagram illustrating a modification of the third embodiment.

FIG. 11 is a diagram showing an overall configuration of a fourth embodiment of the present invention.

FIG. 12 is a view for explaining the operation of the device shown in FIG. 11;

[Explanation of symbols]

 1, 2, 3, 41, 42, 43, 44 Light source 6, 56 Light receiving element 14 Logarithmic calculation circuit 15, 15A Φ calculation circuit 30, 70 Data processing device 22, 23 Input device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takuo Aoyagi 1-31-4 Nishi-Ochiai, Shinjuku-ku, Tokyo Inside the Japan Optoelectronics Corporation (72) Inventor Naoki Kobayashi 1-31-Nishi-Ochiai, Shinjuku-ku, Tokyo No. 4 Inside Nihon Koden Kogyo Co., Ltd. (72) Inventor Park Takeda Park 1-31-4 Nishi-Ochiai Shinjuku-ku, Tokyo Japan Co., Ltd. (72) Inventor Masayoshi Fuse 1 Nishi-Ochiai Shinjuku-ku, Tokyo F-term (reference) No. 31-4 Nippon Koden Kogyo K.K.

Claims (4)

[Claims] 1. A concentration measuring unit for measuring at least a concentration diagram of indigo carmine in data relating to a concentration of a light absorbing substance in blood, and a parameter detection for obtaining a biological parameter based on data of the indigo carmine concentration diagram measured by the concentration measuring unit. Biological parameter measuring device having a part. 2. The method according to claim 1, wherein the concentration measuring unit irradiates the living tissue with light and processes a signal corresponding to the intensity of light transmitted or reflected by the living tissue to measure an indigo carmine concentration map. The biological parameter measurement device according to claim 1. 3. The concentration measuring unit irradiates a living tissue with light, processes a signal corresponding to the intensity of light transmitted or reflected by the living tissue, and measures oxygen saturation together with an indigo carmine concentration map. The biological parameter measurement device according to claim 1, wherein: 4. The biological parameter measuring device according to claim 1, wherein the biological parameters include cardiac output, liver clearance, renal clearance, or body fluid volume.