JPH0534979B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a liver function testing device, and in particular, a method for injecting into the blood a specific dye that is selectively taken in and excreted only by the liver to reach a specific dye concentration. The present invention relates to a liver function testing device that calculates correlated values, is also capable of measuring plasma disappearance rate and stagnation rate, and automatically performs measurement processing for testing and diagnosing liver function.

[Prior art] The conventional method for measuring the plasma disappearance rate and stagnation rate for testing and diagnosing liver function involves measuring blood sampling using indocyanine green (hereinafter referred to as ICG) as a specific dye. It was getting worse.

According to this method, after ICG is intravenously injected into a subject, blood is collected three times at 5, 10, and 15 minutes after the injection, and serum is separated after waiting for the clot to condense. , the absorbance at a wavelength of 805 nm was measured and a calibration curve obtained in advance (ICG blood corresponding concentration VS absorbance)
Accordingly, the ICG concentration in plasma after 5, 10, and 15 minutes is determined, and the plasma disappearance rate and stagnation rate are calculated from this concentration change.

In addition, a method for calculating the plasma disappearance rate and stagnation rate without drawing blood was developed in the Japanese Patent Publication No. 60-58649.
It was proposed in the No. According to this proposed method, the body surface is irradiated with light, and the amount of light transmitted or reflected from the living body at wavelengths for which ICG has high absorption sensitivity and wavelengths for which it is almost insensitive is measured, and this time change (pigment loss) is measured. Calculate the plasma disappearance rate and stagnation rate from the curve).

[Problems to be Solved by the Invention] In the conventional blood sampling method, it is necessary to accurately measure the time for blood sampling after injection. However, in actual inspections, the measurements were not performed with high precision and the measurement operations were complicated. In addition, blood sampling placed a large mental and physical burden on the subjects.

Furthermore, the R _MAX measurement method, which measures the plasma elimination rate several times by varying the ICG injection volume, has recently become popular, but this method requires blood sampling more than ten times. There was a problem that the burden on the subjects became even greater.

In addition, the above-mentioned Japanese Patent Publication No. 60-58649 and
In the method of measurement without blood sampling disclosed in Publication No. 61-162934, when the sensor is actually attached to a living body, blood flow disturbances due to blood vessel compression, shaking of the living body that is the object to be measured, pulsation within the living body, etc. Changes in blood flow within the body (for example, blood flow changes just up and down the arm)
Due to these factors, the output fluctuates, making it impossible to obtain an accurate pigment loss curve.

Therefore, the plasma disappearance rate and stagnation rate obtained from this curve cannot be said to be accurate.

Therefore, the main purpose of this invention is to provide a liver that can eliminate artifacts such as blood flow obstruction, vibration of the living body, pulsation in the living body, and changes in blood flow in the living body when the sensor is attached to the living body, and that enables accurate measurement. An object of the present invention is to provide a functional testing device.

[Means for Solving the Problems] The present invention is a liver function testing device for testing liver function, which detects light absorption by a specific dye that is administered into the blood of living tissue and taken in and excreted by the liver. a light source means for irradiating the living tissue with a first light having a wavelength that is absorbed and a second light having a wavelength that is not absorbed; and photoelectric conversion means for outputting first and second photoelectric conversion symbols corresponding to second light, sampling means for sampling the first and second photoelectric conversion outputs from the photoelectric conversion means, and the sampling said first and second samples sampled by means
determining means for determining a coefficient of a linear regression equation between the first and second photoelectric conversion signals based on a variation component in the living tissue included in the photoelectric conversion signal; calculation means for calculating a value correlated to the specific pigment concentration in the blood based on the sampling signal output of the sampling means over time and the coefficient of the linear regression equation determined by the determination means; It is characterized by

According to a more preferred embodiment of the present invention, means is provided for determining the plasma disappearance rate of a specific dye based on the determined coefficients of the simulation function.

Furthermore, according to a preferred embodiment of the present invention, means is provided for determining the stagnation rate of a specific dye over a predetermined time based on the determined coefficients of the simulation function.

[Function] The liver function testing device according to the present invention uses a first light having a wavelength that is absorbed by a specific pigment that is administered into the blood of a living tissue and is ingested and excreted by the liver, and a second light having a wavelength that is not absorbed. Light is irradiated into the living tissue, the first and second photoelectric conversion signals corresponding to the light obtained from the living body are sampled, and the in-vivo A value corresponding to the blood concentration of a specific pigment is calculated using a calculation that removes blood fluctuations, and a function of a simulation curve of the calculation result over time is calculated using the method of least squares. Furthermore, it is possible to determine the plasma disappearance rate K and T-minute stagnation rate R% of a specific dye based on that function, eliminating the need for blood sampling at all.
The burden on the subject can be reduced to intravenous injection of a specific dye, and the mental and physical burden on the subject can be significantly reduced. Furthermore, artifacts such as blood flow disturbances, shaking, and pulsation of the living body when the sensor is attached to the living body can be eliminated.

1 to 4 are diagrams for explaining the principle of this invention.

Let the amount of light incident on the living tissue at wavelength λ ₁ , which is largely absorbed by a specific pigment, and wavelength λ ₂ , which is not absorbed, be I ₁ and I ₂ , and the amount of light after passing through the predetermined optical path of the living tissue is T ₁ and T, respectively. ₂ . The relationship between I ₁ , I ₂ , T ₁ and T ₂ when the specific dye is injected is as follows.

logI ₁ /T ₁ = kg ₁・Cg・Vb＋f ₁ (Cb, Vb) + γ _t1 (1) logI ₂ /T ₂ = f ₂ (Cb, Vb) + γ _t2 (2) Each coefficient and variable is shown in Figure 1. It is shown. Here, f ₁ and f ₂ are functions determined by the characteristics of blood at wavelengths λ ₁ and λ ₂ .

On the other hand, I ₁ , I ₂ , T ₁ and
The relationship of T ₂ is logI ₁ /T ₁ = f ₁ (Cb, Vb) + γ _t1 (3) logI ₂ /T ₂ = f ₂ (Cb, Vb) + γ _t2 (4).

Here, T ₁ before actually injecting the specific dye
The relationship between T2 and _T2 is measured as shown in FIG. 2, and is a linear relationship as shown in FIG. This is data obtained when the sensor is attached to a living body and the blood volume within the living body is varied. It has been confirmed that this linearity has no individual differences and is highly reproducible.

Therefore, equations (3) and (4) become logT ₁ =A·logT ₂ +B (5). That is, it is expressed as logI ₁ - {f ₁ (Cb, Vb) + γ _t1 } = A [logI ₂ - {f ₂ (Cb, Vb) + γ _t2 }] + B (6).

Next, after injecting the specific dye, use equations (1) and (2) to find S=logT ₁ − [A・logT ₂ +B] (7); S=logI ₁ −Kg・Cg・Vb−f ₁ (Cb, Vb) + γ _t1 −A
[logI ₂ −{f ₂ (Cb, Vb) + γ _t2 ]] −B (8) Here, using equation (6), S=−Kg・Cg・Vb (9).

Therefore, it can be seen that if FIG. 3 is used as a biological calibration curve, a signal of S can be obtained.

However, in S, although Kg is constant, it fluctuates due to Vb, making it impossible to obtain accurate Cg. In other words,
Affected by the amount of blood in the body.

Therefore, in FIG. 4, is the calibration curve. When a specific dye is injected,
A fluctuation occurs in the signal of only logT ₁ , and comes to point E, for example. At this time, becomes S shown in equation (9).

Next, since _Vb in equation ₍ 9) _is considered to _be expressed as
+B)/logT ₁ 0(10).

Therefore, from equations (7) and (10), the signal Sg corresponding to Cg is Sg=logT ₁ - (A・logT ₂ +B)/1+logT ₁ − (A・log
T ₂ + B) / logT ₁ 0 = logT ₁ 0 [logT ₁ 0 - (A・logT ₂ + B)] / 2logT ₁ 0
−(A·logT ₂ +B) (11) is obtained.

[Embodiment] FIG. 5 is a schematic block diagram of an embodiment of the present invention.

In FIG. 5, the liver function testing device is a sensor section 1.
0 and a measurement processing section 20. The sensor section 10 includes a first light source 11 , a second light source 12 , a light receiving element 13 , and a preamplifier 14 .

The first light source 11 and the second light source 12 respectively generate light pulses at a wavelength λ ₁ where the specific dye has a high absorbance and a wavelength λ ₂ where the specific dye has no absorbance. The light receiving element 13 is
The living tissue 15 is irradiated from the light sources 11 and 12,
Receives light that has passed through a predetermined optical path. Note that the light sources 11 and 12 are driven by the measurement processing unit 20 so as to alternately emit light in pulse operation.

The measurement processing unit 20 uses the CPU 3 as a calculation means.
Contains 4. The CPU 34 provides a START signal to the oscillation circuit 24 and timing circuit 23 through the I/O port 32. The oscillation circuit 24 constantly oscillates a predetermined clock.

Using this clock and the START signal, the constant current circuit 21 outputs the first light source 11 and the second light source 1 through the timing circuit 23 and the decoder 122.
2, constant currents i ₁ and i ₂ , and the timing shown in Figure 6.
Give in TM ₁ ″ and TM ₂ ″.

The light emitted by the first light source 11 and the second light source 12 passes through a predetermined optical path of the living tissue 15 and enters the light receiving element 13 . The current generated from the light receiving element 13 is converted into a current − by the preamplifier 14.
undergoes voltage conversion and amplification.

This signal, which is amplified within a predetermined range by the amplifier 16 in the measurement processing section 20 and provides an output such as V _PD in FIG. 6, is generated by the timing circuit 23 and the decoder 225 at the timing shown in FIG. A sample and hold circuit (SHC) 28 driven by TM ₂ ' samples and holds the signal.

The voltages T ₁ and T ₂ shown in FIG. 6 are maintained, and the multiplexer (MPX) 29 and AD converter (ADC) 3
0 and a data latch circuit 31, respectively, and the data are latched after being converted into digital signals.
At this time, the timings of the multiplexer 29, AD converter 30, and data latch circuit 31 are controlled by the timing circuit 23 and decoder 226.

The latched data is I/O from the CPU 34.
Timing is taken from decoder 427 by the SELECT signal issued through port 32, and T ₁
and _T2 are taken into the RAM 35 as digital signals. In addition, a buzzer 33 is attached to the I/O port 32.
is connected and notifies the timing of injecting a specific dye. Furthermore, the CPU 34 has RAM 35 and
The ROM 36, display section 37, and operation section 28 are connected. The RAM 35 stores data as shown in FIG. 7, which will be described later, and the ROM 36 stores data as shown in FIG.
A program based on the flowcharts shown in FIGS. 1 to 8-3 is stored. The display section 37 displays data as shown in FIGS. 9 to 12, which will be described later. The printer 38 prints the liver function test results.

The operation unit 39 includes an alarm LED 40, a calibration key 41, a start key 42, and a print key 43. The alarm LED 40 is for displaying a warning when the reliability of the test result is low, and the calibration key 41 is for setting the calibration mode.
The start key 42 instructs to start the measurement mode, and the print key 43 instructs to print out the test results.

FIGS. 8-1 to 8-3 are flowcharts for explaining the specific operation of an embodiment of the present invention. FIG. 7 is a diagram showing data stored in the RAM 35 shown in FIG.
14 is a diagram showing an example of the disappearance curve of a specific dye measured by the present invention, and FIG.
The figure shows the results of the elimination curve, plasma elimination rate K, and T-minute stagnation rate measured using the present invention.

Next, the specific operation of one embodiment of the present invention will be described with reference to FIGS. 5 and 8 to 14.

First, steps SP11 to SP16 (abbreviated as SP in the figure) shown in FIG _.
Sample the amount of light after passing through the object to be measured at λ ₂ ,
It is stored in the RAM 35. That is,
At SP11, the CPU 34 outputs a START signal via the I/O port 23 from the line shown in FIG. As mentioned above by START signal
The values of T ₁ and T ₂ are data latched. In SP12, it waits until it is latched.

Next, in SP13, the CPU 34 is as shown in Figure 5.
via I/O port 32 to the SELECT line
A SELECT signal is output, and at SP14, data of _T1 is first read through the I/O port 32 and stored in the storage area 8a1 of the RAM 35 shown in FIG.

Similarly, T ₂ data in SP15 and SP16 is
The data is stored in the storage area 8a2 of the RAM 35.

Upon completion of the calculation at step SP16 described above, the CPU 34 returns to the original step.

This will be explained in Figure 8-2 which shows the calibration mode.

This calibration mode is activated when the calibration key 41 is pressed or when the
It starts at the end of the measurement mode operation shown in the figure.
In step SP21, the CPU 34
to calibration mode. This display, for example, as shown in FIG. 9, indicates that the calibration mode is entered and also instructs the mounting of the sensor section 10. Following this instruction, the measurer attaches the sensor section 10 to the object to be measured 13.

After that, the CPU 34 at step SP22
Wait until the calibration key 41 is operated. When the calibration key 41 is operated, the CPU 34 advances to step SP23 and executes the data sample subroutine shown in FIG. 8-1.

Next, T ₁ and T ₂ read by SP23 are stored in RAM35.
In FIG. 5, the CPU 34 controls the constant current circuit 21 using the Si ₁ and Si ₂ lines so as to fall within the range of T _MAX and T _MIN in 8b1 and 8b2. Then, the current setting values of Si ₁ and Si ₂ are stored in 8c ₁ and 8c ₂ in the RAM.

Thereafter, the currents of Si ₁ and Si ₂ constantly flow through the light sources 11 and 12.

Next, SP25 sounds a buzzer to notify that the power setting has been completed.

The following SP26 to SP29 are flowcharts for performing the above-mentioned biological calibration. in particular,
Sample the values of T ₁ and T ₂ n times with SP26 and SP27, respectively, and set them as CT ₁₍₁₎ to _{CT 1(o)} , and convert them to 8d1 to 8dn.
Then, set CT ₂₍₁₎ to _{CT 2(o)} and convert this to 8e1 to 8en.
to memory.

In the next SP28, logCT ₁ () and logCT ₂ ()
Perform two-variable statistical calculations for (=1 to n), and calculate the A and B values of logCT ₁ () = A・logCT ₂ () + B and the correlation coefficient r ₁ and CT ₁ () (I = 1 to
The maximum value of n) is determined as CT ₁ 0, and each RAM
The memory is stored in 8f1, 8f2, 8f3, and 8f4.

Next, in SP29, in order to test the reliability of the biological calibration, it is determined whether r ₁ is 0.998 or more, and if it is less than 0.998, the process moves to SP30, the LED of alarm 40 is lit, and the calibration is performed again. Return to SP22 for bracing. On the other hand, if it is 0.998 or more, the mode shifts to the measurement mode shown in FIG. 8-3. The value of 0.998 used here is just an example, and is determined by the performance of the entire device. Furthermore, during the n data samples of SP26, the subject raised and lowered their hand to change the amount of blood in the body.
In addition, pressure may be applied using a sensor.

Next, the measurement mode will be explained with reference to FIG. 8-3. In step SP41, CPU3
4 displays on the display section 37 a display for injecting a specific dye. Regarding this display, for example, as shown in FIG. 10, a display instructing to inject a specific dye, such as ICG, is performed. Following this display, the measurer makes preparations for injecting the specific dye into the subject. Next, in step SP42, the CPU 34 waits until the start key 42 is turned on. When the CPU 34 determines that the start key 42 has been operated, in step SP43,
In addition to displaying the timing of the specific dye, the buzzer 33 issues an alarm sound. This is displayed as, for example, 1→2→3→4→5 as shown in FIG. 11, and the measurer injects the specific dye when "5" is displayed. Also, CPU3
4 is the first when the display is “1”, “2”, “3”, “4”
The buzzer generates a sound, and when "5" is displayed, a different sound is generated from the buzzer 33.

The measurer injects the specific dye when this sound or display occurs. At step SP44, the CPU 34 sets "0" as the initial value of the timer.

Next, in step SP45, the CPU 34 executes the data sample program, which is the subroutine described in FIG. 8-1. Then,
T ₁ to 8a ₂ in storage area 8a 1 to 8a ₂ of RAM24
Each is stored as T ₂ . At step SP46, the CPU 34 uses A, B, CT ₁ 0 stored in the storage areas 8f1, 8f2, 8f3, and 8f4 of the RAM 35 in the calibration mode explained in FIG. 8-2 above to perform the next calculation. An operation based on the formula is performed and Cg() is stored in the storage area _8g1 of the RAM 35.

Cg () = logCT ₁ 0 [logT ₁ () - (A・logT ₂ (
)+B)]/2logCT ₁ 0-(A・logT ₂ ()+B) This value of Cg() is calculated as follows in step SP46.
For example, the display section 37 may be configured as shown in FIG.
will be displayed. In Figure 12, the horizontal axis shows the elapsed time after injection of the specific dye, and the vertical axis shows Cg()
is the value of Here, if the number of samples of the disappearance curve of a specific dye is m, I is an integer from 1 to m, and if the measurement time of the disappearance curve is T _s , then 1
The sampling time is ITM= _Ts /(m-1)
It is. Of course, when I=1, it corresponds to the injection of a specific dye. In step SP47,
The CPU 34 waits during this sampling time ITM.

After this waiting time has elapsed, the CPU 34 determines whether or not i is greater than n in step SP48. Step if i is greater than n
Proceed to SP49, but if it is smaller, return to step SP45 again and repeat sampling.
Here, the storage area of RAM24 is 8g1 to 8gm
The data Cg(I) stored in , for example, draws a disappearance curve of a specific dye as shown in FIG. 13, and this rising point is detected and step SP49
, subtract it from each Cg(I) using the previous data as the baseline, and re-open the storage area 8g1.
Or memorize it to 8gm. Of course, in order to improve the measurement accuracy, T ₁ or T ₂ of step SP45 should be
It may be the average value of times.

Next, in step SP51, the CPU 34 selects the time T ₁ to T ₂ (0< _{T 1 <} T ₂ <
Using the least squares method on the simulation curve of Cg( _t )=Cgo・e ^Bt t= _Ts /(n-1) (minutes), calculate the constants A and B. seek.

Next, in step SP52, the CPU 34 calculates K and R by calculating the plasma disappearance rate K=-B and the T minute stagnation rate R%=e ^Bt . And the K I asked for,
R is stored in the storage areas 8j1 and 8j2 of the RAM 35, respectively. At this time, the CPU 34 calculates the correlation coefficient r ₂ using the least squares method, and
r ₂ is stored in the storage area 8j3 of the RAM 35.
Further, at this time, the CPU 34 causes the buzzer 14 to generate an end buzzer sound.

Further, the CPU 34 displays the value of K and the value of R% on the display unit 26 in the manner shown in FIG. 12, for example. Next, in step SP53, the CPU 34 determines whether the correlation coefficient _r2 is smaller than, for example, -0.95. This means that the correlation coefficient r ₂ is −
The closer it is to 1, the better the correlation, so the degree of correlation is checked. However, the value of −0.95 is
It is a value between 0 and -1 and is provisional,
Of course, the closer it is to -1, the more reliable the device will be.

Here, if the correlation coefficient r ₂ is greater than, for example, -0.95, the reliability is determined to be low, and the alarm 40 is lit in step SP54, and in step SP53, the correlation coefficient r ₂ is greater than, for example, -0.95. , and the measurement is reliable, the step will not flash without flashing the alarm LED 281.
Proceed to SP55.

Then, in step SP55, the CPU 43
It is determined whether the print key 43 is operated or not, and if it is operated, the printer 38 prints the
The value of and the value of R% are printed.

Furthermore, if necessary, the characteristic pigment loss curve of Cg (I) stored in the storage areas 8g ₁ to 8g _o of the RAM 35 is also printed, and
Move to the calibration mode shown in the figure.

Further, when it is determined in step SP55 that the print key 43 is not operated, the process shifts to the calibration mode.

Next, FIG. 14 shows experimental results of measurements performed using the liver function testing apparatus shown in FIG. The experimental results shown in Figure 14 are based on a 14-year-old male liver patient (weight:
The sensor unit 10 was attached to the fingertip of the left hand of a human (48 kg), and an aqueous solution containing 24 mg of ICG (0.5 mg per 1 kg of body weight) was intravenously injected into the right anterior vein. Figure 15 shows the first light source 1
1 shows the change in Cg over time when a light emitting diode with a wavelength λ ₁ =810 nm is used and a light emitting diode with a wavelength λ ₂ =940 nm is used as the second light source. K calculated from this ICG disappearance curve
As shown in FIG. 15, the value of K was 0.1251 and the value of R% was 13%, and at the same time, the value of K measured by the conventional blood sampling method was 0.124 and R% was 12.8%, which were almost the same. At the same time, FIG. 15 shows the raw data of T ₁ and T ₂ . This clearly shows that the amount of blood in the body was changed. In this case, the first
As shown in Figure 4, since the values almost match the blood sample values, it can be seen that changes in blood flow have been sufficiently canceled.

Note that the present invention can also be extended to an apparatus for measuring R _MAX , which is calculated by determining the K value for various ICG doses using the K value obtained by the present invention.

[Effects of the Invention] As described above, according to the present invention, a living tissue is irradiated with a light pulse of a wavelength that is largely absorbed by a specific pigment and a light pulse of a wavelength that is not absorbed at a predetermined level, thereby producing a desired effect on the living tissue. The light pulse that has passed through the optical path is detected, and based on its output, the coefficients of the linear regression equation of the peak value of the light pulse of each wavelength are calculated, and after the specific dye is injected, it is Based on the received light output, the plasma disappearance rate and stagnation rate of a specific pigment are calculated and output according to a predetermined calculation formula, making it possible to accurately time-manage the disappearance curve of a specific pigment, resulting in accurate data. is obtained.

Furthermore, the plasma disappearance rate and stagnation rate can be determined from a large number of disappearance curve data, rather than from several samples obtained by conventional blood sampling methods.

Furthermore, the measurement method can be simplified compared to the conventional testing method in which the ICG injection amount is varied and measurements are taken several times to determine the plasma disappearance rate or stagnation rate.

In addition, it has been possible to eliminate artifacts such as blood flow disturbances, oscillations of the living body, pulsations in the living body, and changes in blood flow in the living body when the sensor is attached to a living body, which have been problems in the past, making accurate measurements possible. Therefore, it is effective when used in all fields of non-invasively measuring pigments in living organisms.

[Brief explanation of the drawing]

1 to 4 are diagrams for explaining the principle of the present invention. FIG. 5 is a schematic block diagram of one embodiment of the present invention. FIG. 6 is a timing diagram for detecting the amount of light at wavelengths λ ₁ and λ ₂ after passing through a predetermined optical path of the object to be measured. FIG. 7 is a diagram showing data stored in the RAM shown in FIG. 1. 8-1 to 8-3 are flowcharts for explaining the specific operation of an embodiment of the present invention, in particular, FIG. 8-1 shows a data sample subroutine; Figure 2 shows the calibration mode, and Figures 8-3 show the measurement mode. FIGS. 9 to 12 are diagrams showing display examples of the display unit shown in FIG. 5. FIG. 13 is a diagram showing an example of a disappearance curve of a specific dye measured according to the present invention. Figures 14 and 15 are diagrams showing the results of the elimination curve, plasma elimination rate, and 15-minute stagnation rate measured using the present invention. In the figure, 10 is a sensor section, 11 is a first light source, 12 is a second light source, 13 is a light receiving element, 14 is a preamplifier, 15 is an amplifier, 20 is a measurement processing section,
21 is a constant current circuit, 23 is a timing circuit, 24
is a clock generator, 28 is a sample hold circuit, 29 is a multiplexer, 30 is an A/D converter, 31 is a data latch circuit, 32 is an I/O port, 33 is a buzzer, 34 is a CPU, 35 is a RAM,
36 is a ROM, 37 is a display unit, 38 is a printer,
39 is the operation unit, 40 is the alarm LED, 41 is the calibration key, 42 is the start key, 4
3 indicates a print key.

Claims (1)

[Scope of Claims] 1. A liver function testing device for testing liver function, which detects a first wavelength of light that is absorbed by a specific pigment that is administered into the blood of a biological tissue and taken in and excreted by the liver. light source means for irradiating the biological tissue with light and second light having a wavelength that is not absorbed; photoelectric conversion means for outputting first and second photoelectric conversion symbols, sampling means for sampling the first and second photoelectric conversion outputs from the photoelectric conversion means; determining means for determining a coefficient of a linear regression equation between the first and second photoelectric conversion signals based on a variation component in the living tissue included in the first and second photoelectric conversion signals; and Calculating a value correlated to the specific dye concentration in the blood based on the sampling signal output of the sampling means and the coefficient of the linear regression equation determined by the determining means during a predetermined time from injection of the dye. A liver function testing apparatus, comprising a calculation means for calculating the first and second sampling means.
the first and second photoelectric conversion signals sampled multiple times by the sampling means; ₁ and T ₂ , linear regression analysis is performed according to the formula logT ₁ =AlogT ₂ +B to determine the constants A and B values, and the maximum of the photoelectric conversion signal T ₁ sampled multiple times. A liver function testing device equipped with a means for determining the value as T ₁ 0. 2. The method of claim 1, further comprising a coefficient calculating means for calculating a coefficient of a simulation function as a function of time using a least squares method based on a value correlated to the specific dye concentration calculated by the calculating means. The liver function testing device according to scope 1. 3. comprising means for determining the plasma disappearance rate of the specific dye based on the coefficients of the simulation function determined by the coefficient calculation means;
A liver function testing device according to claim 2. 4. The liver function testing device according to claim 3, further comprising means for outputting the plasma elimination rate determined by the means for determining the plasma elimination rate. 5. The liver function according to claim 2, further comprising means for determining the stagnation rate of the specific dye in the predetermined time T based on the coefficients of the simulation function determined by the coefficient calculation means. Inspection equipment. 6. The liver function testing device according to claim 5, further comprising means for outputting the stagnation rate determined by the stagnation rate determining means. 7 The calculation means calculates constants A and B determined by the determination means, when the sampled first and second photoelectric conversion signals are T ₁ and T ₂ .
2. The liver function testing device according to claim 1, further comprising means for calculating a value Cg correlated with the specific pigment based on the maximum value T ₁ 0 and the maximum value T 1 0 according to the following calculation formula. Mg=logT ₁ 0 [logT ₁ − (A・logT ₂
+B)]/2logT ₁ 0-(A・logT ₂ +B) 8 The coefficient calculation means calculates the coefficient based on the calculation formula of Cg=Cgo・e ^Bt , where t is the predetermined time after the injection of the specific dye. , constants Cgo, B, according to claim 2. 9. The liver function testing device according to claim 3, wherein the means for determining the plasma disappearance rate includes means for calculating the following equation: K=-B, where K is the plasma disappearance rate. 10. The liver function testing device according to claim 5, wherein the means for determining the stagnation rate comprises means for calculating the formula of T R%=e ^Bt .