JP2000235028A - Blood component measuring device and blood component measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely measure the concentration of a blood component in a short time by estimating the reflected light quantity after a fixed time (equilibrated state) by use of the reflected light quantity data up to the equilibrium state of the reflected light quantity. SOLUTION: After a chip having a test paper is mounted, a power source switch is ON, and it is confirmed that the device is normally operated, a light measurement part 10 is operated to measure the reflected light quantity. The measurement is continued at fixed time intervals until the measurement end is judged by a control means 2. The reflected light quantity measured first after the confirmation of the normal operation of the device is taken as a reference reflected light quantity, and the reflected light quantities measured at fixed time intervals thereafter are stored in a data memory part 15. The control means 2 calculates the ratio of the reference reflected light quantity to the measured reflected light quantity (herein referred to as absorbance) as occasion demands, and stores the result in the data memory part 15. The blood glucose value is determined from a preset calibration curve stored in the data memory part 15 and the estimated absorbance, and displayed on a display means 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood component measuring apparatus and a blood component measuring method for measuring the concentration of a minute amount of blood components collected by puncturing a living body surface such as a fingertip.

[0002]

2. Description of the Related Art In recent years, with the increase in the number of diabetic patients, autologous blood glucose measurement in which patients monitor daily fluctuations in blood glucose levels has been recommended. At present, as one of the methods of measuring blood glucose level, a test paper that develops a color according to the amount of glucose in blood is mounted, blood is supplied to the test paper, developed, and the degree of color development is measured optically. 2. Description of the Related Art A method of using a blood glucose measuring device for quantifying a blood glucose level by performing (color measurement) has been performed. To detect the blood glucose level based on this coloration, wait until the color reaction between glucose in blood and the reagent in the test paper is completed, and then optically measure the degree of coloration to measure the blood glucose level. calculate. For this reason, currently available blood glucose measuring devices require a measuring time of about 20 seconds or more, and therefore a blood glucose measuring device capable of performing measurement more quickly has been desired.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a blood component measuring apparatus and a blood component measuring method for measuring a blood glucose level in a short time and with high accuracy in view of the above-mentioned problems of the prior art. And

[0004]

The above object is achieved by the present invention described below. (1) The present invention relates to a blood component measuring device that measures a minute amount of blood collected by puncturing the skin, which is detachably provided to the blood component measuring device and performs a color reaction with a specific component in blood. A chip provided with a test paper containing a reagent, irradiation means for irradiating the test paper with light, and measurement means for detecting the intensity of reflected light or transmitted light of light applied to the test paper from the irradiation means, When power is supplied to the blood component measuring device, at regular time intervals, control means for causing the irradiating means to irradiate light and cause the measuring means to detect the intensity of reflected light or transmitted light; and Storage means for storing the intensity of the reflected light or transmitted light detected by the means; measurement end time determining means for determining a measurement end time from a temporal change in the intensity of the reflected light or transmitted light; and the reflected light or transmitted light. of Means for calculating a prediction coefficient for predicting the intensity of the reflected light or transmitted light after the measurement end time determined by the measurement end time determination means from the temporal change of the degree, and the prediction coefficient and the reflected light or transmitted light. Prediction calculation means for predicting the intensity of the reflected light or transmitted light after the measurement end time determined by the measurement end time determination means from the change over time of the intensity; and the reflected light or transmitted light predicted by the prediction calculation means. A blood component measuring device comprising: a concentration calculating means for obtaining a blood component concentration from intensity.

(2) According to the present invention, a power supply of the blood component measuring device is inputted, and the control means controls the irradiation of the test paper with the light by the irradiating means and the measuring means by the measuring means at regular time intervals. While detecting the intensity of the reflected light or transmitted light from the test paper, the collected blood is developed on the test paper and subjected to a color reaction with the reagent, and the detected intensity of the reflected light or transmitted light is stored in storage means. The measurement end time is determined by the measured end time determining means from the stored temporal change of the reflected light or transmitted light intensity, and the prediction coefficient is obtained from the stored temporal change of the reflected light or transmitted light intensity. Means for determining a prediction coefficient for predicting the intensity of the reflected light or transmitted light after the determined measurement end time, and then, by the prediction calculation means, calculates the prediction coefficient and the counter value. The intensity of reflected light or transmitted light after the measurement end time determined by the measurement end time determination means is predicted from the temporal change in the intensity of light or transmitted light, and is predicted by the concentration calculation means by the prediction calculation means. The blood component measuring device according to the above (1), wherein the concentration of the blood component is measured from the intensity of the reflected light or transmitted light.

(3) According to the present invention, the intensity of the reflected light or transmitted light is stored in a storage means as an absorbance, and the absorbance (ab (t)) is obtained as the intensity of the reflected light or transmitted light after the determined measurement end time. ) Is calculated by the following equation 1
The blood component measuring device according to the above (1) or (2), which is obtained by:

[0007]

(Equation 5)

[0008]

(Equation 6)

[0009] b is obtained from equation (2). AB (1) in the formula,
AB (2) and AB (3) measure the intensity of the reflected light or transmitted light at a certain time interval (T) stored in the storage means from the absorbance after a predetermined time interval in the measurement end time determination means. (M, where m = 1, 2, 3,... (Integer)) absorbance (ab (m)) and the immediately preceding interval (m−
The change rate (V (m) = (a) of the absorbance (ab (m-1)) of 1)
b (m) -ab (m-1)) / T) and its rate of change (A (l) = (V (l) -V (1-1)) / T, where l =
m + 1), and when A (l) -A (l-1) <0 is defined as AB (1), A (l) -A (l-) is determined after AB (1) is determined. 1)> 0 and A (l) * A (l-2)>
When the value is 5, AB (2) (= ab (11)) is defined as ab
Measurement end time AB (3) when (l2 + (l2-l1))
Asking. Let M = l2-l1. k and a are AB from b and ab (0) in the means for calculating the prediction coefficient.
Using the absorbance data up to (3), a multiple regression analysis is performed in Equation 1 to determine the value.

(4) The present invention is such that the control means can change a fixed time interval for causing the irradiating means to irradiate light and the measuring means to detect the intensity of reflected light or transmitted light during detection. The blood component measurement device according to any one of (1) to (3) above.

(5) The present invention is the blood component measuring device according to any one of the above (1) to (4), wherein the prediction calculation means uses a logistic curve.

(6) According to the present invention, the concentration calculating means uses a calibration curve drawn by a change in intensity of reflected light or transmitted light actually measured from a change in blood component concentration, and a correction term for correcting the calibration curve. The blood component measuring device according to any one of the above (1) to (5), wherein the blood component concentration is determined by the following method.

(7) The present invention relates to a method for measuring a small amount of blood components collected by puncturing the skin, comprising: a test paper containing a reagent that causes a color reaction with a specific component in blood; Irradiating means for irradiating the test paper with light, measuring means for detecting the intensity of reflected light or transmitted light of the light irradiating the test paper from the irradiating means, and irradiating the irradiating means with light at regular time intervals. And control means for causing the measuring means to detect the intensity of the reflected light or transmitted light; storage means for storing the intensity of the reflected light or transmitted light detected by the measuring means; and the intensity of the reflected light or transmitted light Measurement end time determining means for determining the measurement end time from the change over time of the reflected light or transmitted light after the measurement end time determined by the measurement end time determination means from the change over time of the intensity of the reflected light or transmitted light. Strength Means for obtaining a prediction coefficient for prediction, and the intensity of the reflected light or transmitted light after the measurement end time determined by the measurement end time determination means, based on the change over time of the prediction coefficient and the intensity of the reflected light or transmitted light. Inputting a power supply for operating each of the means by the prediction operation means for predicting the above, and a concentration operation means for obtaining the blood component concentration from the intensity of the reflected light or transmitted light predicted by the prediction operation means; The blood collected is subjected to the test while irradiating the test paper with light by the irradiating means and detecting the intensity of reflected light or transmitted light from the test paper by the measuring means at regular time intervals by the means. The intensity of the reflected light or transmitted light is stored in storage means, and the intensity of the stored reflected light or transmitted light is stored in storage means. The measurement end time is determined by the measurement end time determining means from the temporal change, and the reflected light after the determined measurement end time is determined by the means for determining the prediction coefficient from the stored temporal change of the intensity of the reflected light or transmitted light. Or, after obtaining a prediction coefficient for predicting the intensity of the transmitted light, the prediction operation means determines the prediction coefficient and the intensity of the reflected light or transmitted light over time, and the measurement end time determining means determines the time. A blood component measurement method for predicting the intensity of reflected light or transmitted light after the measurement end time and measuring the concentration of blood components from the intensity of reflected light or transmitted light predicted by the prediction operation means by the concentration calculation means. is there.

(8) In the present invention, the intensity of the reflected light or the transmitted light is stored in a storage means as an absorbance, and the intensity of the reflected light after the determined measurement end time is determined as an absorbance (ab (t)).
Is a blood component measurement method according to the above (7), which is obtained by the predictive calculation means by the following equation 1.

[0015]

(Equation 7)

[0016]

(Equation 8)

B is obtained from equation (2). AB (1) in the formula, A
B (2) and AB (3) are obtained by measuring the intensity of the reflected light or transmitted light at a certain time interval (T) stored in the storage means from the absorbance at a predetermined time interval in the measurement end time determining means. (M, where m = 1, 2, 3,... (Integer)) absorbance (ab (m)) and the immediately preceding interval (m−
The change rate (V (m) = (a) of the absorbance (ab (m-1)) of 1)
b (m) -ab (m-1)) / T) and its rate of change (A (l) = (V (l) -V (1-1)) / T, where l =
m + 1), and when A (l) -A (l-1) <0 is defined as AB (1), A (l) -A (l-) is determined after AB (1) is determined. 1)> 0 and A (l) * A (l-2)>
When the value is 5, AB (2) (= ab (11)) is defined as ab
The time when (l2 + (l2-l1)) is reached is the measurement end time AB
Calculate as (3). Let M = l2-l1. k and a are
In the means for calculating the prediction coefficient, multiple regression analysis is performed in Equation 1 using the absorbance data from b and ab (0) to AB (3).

(9) The present invention is the blood component measuring method according to any one of (7) to (8), wherein said prediction calculation means uses a logistic curve.

(10) In the present invention, the density calculation means includes:
The above (7) to (9) are obtained by using a calibration curve drawn by a change in intensity of reflected light or transmitted light actually measured from a change in blood component concentration and a correction term for correcting the calibration curve. )).

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [1] Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram showing a configuration of a blood component measuring device 1 which is an example of the present invention, and FIG. 2 is a flowchart showing an example of an operation of the blood component measuring device 1.

In the blood component measuring device 1, the control means 2
Is composed of a microcomputer and controls various operations of the blood component testing apparatus 1. The control means 2 has a built-in arithmetic unit for calculating the concentration of a blood component (eg, glucose) in the blood to be measured based on a signal from the photometric unit 10.

The photometric section 10 has a light emitting element 8 and a light receiving element 9, which are housed and held in one block. The light emitting element 8 is electrically connected to the control means 2, and the light receiving element 9 is electrically connected to the control means 2 via the amplifier 11 and the A / D converter 12.

The light emitting element 8 is activated by a signal from the control means 2 and emits pulse light at predetermined time intervals. The pulse light has, for example, a cycle of about 0.5 to 3.0 msec and a light emission time of one pulse of about 0.05 to 0.3 msec. Further, the control means 2 can change the light emission cycle of the light emitting element 8 during operation. The wavelength of the pulse light is preferably about 500 to 720 nm, more preferably 580 to 650 nm.
It is about nm.

When the light emitting element 8 is turned on with the chip provided with the test paper attached to the blood component measuring device 1, light emitted from the light emitting element 8 is irradiated on the test paper, and the reflected light is received by the light receiving element. The light is received by the element 9 and photoelectrically converted. An analog signal corresponding to the amount of received light is output from the light receiving element 9, amplified as desired by the amplifier 11, converted to a digital signal by the A / D converter 12, and input to the control means 2.

The blood component measuring device 1 includes a power supply unit 4,
Power supply voltage detector 5, power switch 6, switch circuit 7,
A control oscillating unit 13, a clock oscillating unit 14, a data storage unit 15,
It has a buzzer output unit 16, an external output unit 17, and a temperature measurement unit 18.

The power supply unit 4 is loaded with a battery. The power supply voltage detection unit 5 detects the voltage of the battery and outputs the detected value to the control unit 2. Thereby, the remaining amount of the battery can be checked.

The switch circuit 7 detects the input of the power switch 6 and various switches described below, and inputs the signal to the control means 2. The types of switches include a power switch, a storage data read switch, a time setting /
There are a change switch, a reset switch, a buzzer operation / non-operation switch, a 50 Hz / 60 Hz commercial power frequency selection switch, and the like.

The power switch 6 can switch between an input state and a disconnected state by pressing an operation button. Alternatively, for example, when a chip is attached to the blood component analyzer 1, a mechanism in which power is automatically input in a handling procedure of the blood component analyzer 1 may be used.

The control oscillating unit 13 constitutes a timer, oscillates clock pulses at regular time intervals, and supplies a reference signal for operation of the microcomputer of the control means 2.

The clock oscillating unit 14 constitutes a clock for specifying an absolute time (date and time), oscillates clock pulses at fixed time intervals, and supplies a reference signal for operation of a clock control circuit incorporated in the control unit 2. I do.

The buzzer output section 16 activates a buzzer based on a signal from the control means 2 and emits a sound.

The external output section 17 is for outputting data such as the obtained blood sugar level to an external device such as a personal computer. In this case, the external output unit 17 has a built-in communication driver such as RS232C.
When performing infrared communication, the external output unit 17
It has an infrared light emitting element and a driving circuit for the infrared light emitting element.

The temperature measuring section 18 includes a temperature sensor (for example, a thermistor) that can measure the environmental temperature. The temperature measurement unit 18 measures the temperature as needed, and the temperature information is stored in the data storage unit 15. The temperature information read from the data storage unit 15 is input to the control unit 2 and used for calculating a blood sugar level.

Next, an example of the operation of the blood component measuring device 1 will be described with reference to the flowchart of FIG. After attaching the chip provided with the test paper to the blood component measuring device 1, the power switch 6 is turned on. At this time, the chip may be attached after the power is turned on. It is desirable that the power switch 6 has a mechanism in which the power is automatically turned on before and after the procedure by mounting the chip on the blood component measuring device 1. After the power is input, if it is confirmed that the blood component measuring device 1 is operating normally, the photometric unit 10 is operated to measure the amount of reflected light. The measurement of the reflected light amount is continuously performed at regular time intervals until the control means 2 determines that the measurement has been completed. Here, the predetermined time interval is preferably within one second.

After confirming the normal operation of the blood component measuring device 1, the first measured reflected light amount is stored in the data storage unit 15 as a reference reflected light amount (R (0)). The reflected light amount (R (n), n = 1, 2,...) Measured at regular time intervals thereafter is also stored in the data storage unit 15 as needed.

After the start of the measurement, the control means 2 calculates a ratio (ab (n)) (hereinafter referred to as absorbance) between the reference reflected light amount and the measured reflected light amount shown in Expression 3 as needed, and calculates the result. The data is stored in the data storage unit 15.

[0037]

(Equation 9)

In the equation, n = 0, 1, 2, 3,...

When the relationship between ab and time is drawn on a graph, this graph is approximately represented by the function shown in Equation 1. here,
k and a are coefficients, e is an index, and t is time. Also b
Is represented by Equation 2.

[0040]

(Equation 10)

[0041]

[Equation 11]

M is AB (1) and AB (2) as described later.
Is determined after selecting. Even if the reaction between the specific component in the blood and the reagent reaches equilibrium and the absorbance does not reach a certain value, solving equation 1 using the absorbance data up to the point in the middle of the reaction gives the absorbance and time. Can be obtained.

Next, the solution of Equation 1 will be described. Equation 1
Three data AB satisfying the coefficient b (determined by equation 2)
(1), AB (2) and AB (3) are selected. Ab shown in equation 3
(n) is calculated and stored, and the rate of change in absorbance (V (m)) shown in equation 4 and the rate of change (A
(l)) is calculated, and the obtained V (m) and A (l) are stored in the data storage unit 15.

[0044]

(Equation 12)

[0045]

(Equation 13)

In the equation, T is the interval of the measurement time, m = 1, 2,
.., 1 = 2, 3,.

Here, when A (l) -A (l-1) is calculated and A (l) -A (l-1) <0 for the first time, AB (1) = ab in equation (2). (l) (= ab (l1)). Next, in the measurement data after AB (1) is determined, A (l)
When A (l-1)> 0 and A (l) * A (l-2)> 5, AB (2) = ab (l) (= ab (l2)). Finally, AB (3) = ab (l2 + (l2-l1)). Further, for M in Equation 2, M = 12−11. The measurement point of AB (3) is set as the measurement end point of the reflected light amount, and the measurement of the reflected light amount is performed up to AB (3). Selected AB (1), AB (2), AB
Calculate b from (3). 3 points, AB (1), AB
The selection method of (2) and AB (3) may not be the method described above, but since the selection method of three points greatly affects the accuracy of the prediction calculation, the time of reflected light depending on the type of test paper and reagent The selection method is changed at any time according to the change.

Using the obtained b and the absorbance data from ab (0) to AB (3), multiple regression analysis is performed in equation 1 to obtain k and a. As a result, Equation 1 can be expressed as a function of time alone, and as a result, the prediction calculation of the absorbance at an arbitrary time after the measurement point AB (3) (for example, a time at which the amount of reflected light is constant) is performed. Can be done. In addition to the function represented by the above-described formula 1, it is also possible to use an appropriate function in accordance with the change in the reflected light ratio with time, the reaction speed, and the like depending on the type of the test paper and the reagent. For example, a jigmoid curve or the like in addition to the logistic curve of Equation 1 is given.

The blood glucose level is obtained from the preset calibration curve stored in the data storage unit 15 and the predicted absorbance. The blood sugar level is displayed on the display means 3. Here, the calibration curve may be set at the time of performing the prediction calculation, and is not particularly limited to the case where the values of the reflected light amount and the absorbance become constant.

[2] The predicted calculated value obtained by the above-described method was compared with the actually measured value. An adult male's blood was adjusted with a glucose solution to prepare eight types of blood glucose level blood samples (all hematocrit values were 40%). Measure the amount of reflected light for each blood (measurement time interval is 1
Seconds). AB used for calculation of Equation 2 for each data
Table 1 shows the results of the predicted calculation of the absorbance after 30 seconds obtained from 1, AB2, AB3 and Equation 1. In addition, the blood glucose level (mg / dl) in Table 1 was measured by Glucorder-GXT (manufactured by Shinotest Co., Ltd.), and the absorbance data for performing the measured absorbance and the prediction calculation was measured using Medisafe (manufactured by Terumo Corporation). The reflected light quantity data obtained by
The one taken out through the converter was used.

[0051]

[Table 1]

When the measured value of the absorbance was compared with the predicted value, the error was within ± 3%, and a highly accurate predicted value could be calculated regardless of the blood sugar level. The measurement time is 7-1
The blood glucose level could be measured in a shorter time of 3 seconds.

[0053]

As described above, according to the blood component measuring apparatus and the blood component measuring method of the present invention, the reflected light amount after a certain period of time (equilibrium state) is obtained by using the reflected light amount data before the reflected light amount reaches the equilibrium state. Therefore, the blood component concentration can be measured with high accuracy in a short time.

[Brief description of the drawings]

FIG. 1 is a block diagram of an internal configuration of a blood component measurement device 1.

FIG. 2 is a flowchart illustrating an example of the operation of the blood component measurement device 1.

Claims (10)

[Claims] 1. A blood component measuring device for measuring a minute amount of blood collected by puncturing the skin, comprising: a reagent which is detachably provided to the blood component measuring device and which performs a color reaction with a specific component in blood. A chip provided with a test paper including: an irradiation unit for irradiating the test paper with light; a measurement unit for detecting an intensity of reflected light or transmitted light of light irradiated on the test paper from the irradiation unit; and the blood. When power is input to the component measuring device, at regular time intervals, control means for causing the irradiating means to perform light irradiation and the measuring means to detect the intensity of reflected light or transmitted light, and the measuring means Storage means for storing the detected intensity of the reflected light or transmitted light; measurement end time determining means for determining a measurement end time from a temporal change in the intensity of the reflected light or transmitted light; Means for obtaining a prediction coefficient for predicting the intensity of the reflected light or transmitted light after the measurement end time determined by the measurement end time determination means from the temporal change of the intensity; and the prediction coefficient and the reflected light or transmitted light. Prediction calculation means for predicting the intensity of the reflected light or transmitted light after the measurement end time determined by the measurement end time determination means from the temporal change of the intensity, and the reflected light or transmitted light predicted by the prediction calculation means A blood component measuring device comprising: a concentration calculating means for obtaining a blood component concentration from intensity. 2. A power supply of the blood component measuring device is inputted, and the control means irradiates the test paper with the light at regular time intervals and reflects the light from the test paper by the measurement means. While detecting the intensity of light or transmitted light, the collected blood is spread on the test paper and caused to undergo a color reaction with the reagent, and the detected intensity of the reflected light or transmitted light is stored in storage means. The measurement end time is determined by the measurement end time determining means from the temporal change in the intensity of the reflected light or the transmitted light, and the determination is performed by the means for obtaining the prediction coefficient from the stored temporal change in the intensity of the reflected light or the transmitted light. After obtaining a prediction coefficient for predicting the intensity of the reflected light or transmitted light after the measured measurement end time, the prediction operation means calculates the prediction coefficient and the reflected light or transmitted light. The intensity of reflected light or transmitted light after the measurement end time determined by the measurement end time determining means is predicted from the temporal change of the light intensity, and the reflected light predicted by the prediction calculation means by the density calculating means. The blood component measuring device according to claim 1, wherein the concentration of the blood component is measured from the intensity of the transmitted light. 3. The intensity of the reflected light or transmitted light is stored in a storage means as an absorbance, and the absorbance (ab (t)) is obtained as the intensity of the reflected light or transmitted light after the determined measurement end time.
The blood component measuring apparatus according to claim 1, wherein the following formula (1) is obtained by the predictive calculation means. (Equation 1) (Equation 2) b is obtained from Equation 2. AB (1), AB (2), AB
(3) In the measurement end time determining means, the intensity of the reflected light or the transmitted light at each fixed time interval (T) stored in the storage means is calculated from the absorbance after a predetermined time interval (m,
Here, m = 1, 2, 3,... (Integer)) and the absorbance (ab (m-1)) at the preceding interval (m-1). Change rate (V (m) = (ab (m) -ab
(m-1)) / T) and the difference in the rate of change (A (l) =
(V (l) -V (l-1)) / T, where l = m + 1) is obtained, and when A (l) -A (l-1) <0, AB
As (1), after AB (1) is determined, A
When (l) -A (l-1)> 0 and A (l) * A (l-2)> 5, AB (2) (= ab (l1)) is defined as ab (l2 +
The time when (l2-l1)) is obtained as the measurement end time AB (3). Let M = l2-l1. k and a are obtained by performing a multiple regression analysis in Equation 1 using the absorbance data from b and ab (0) to AB (3) in the means for obtaining the prediction coefficient. 4. The apparatus according to claim 1, wherein said control means is capable of changing a fixed time interval for causing said irradiation means to irradiate light and said measuring means to detect the intensity of reflected light or transmitted light during detection. 4. The blood component measurement device according to any one of items 1 to 3. 5. The blood component measuring device according to claim 1, wherein said predictive calculation means uses a logistic curve. 6. A method according to claim 1, wherein said concentration calculating means calculates a blood component concentration using a calibration curve drawn by a change in intensity of reflected light or transmitted light measured from a change in blood component concentration and a correction term for correcting the calibration curve. 6. The blood component measuring device according to claim 1, which is to be obtained. 7. A method for measuring a component of a trace amount of blood collected by puncturing skin, comprising: a test paper containing a reagent that undergoes a color reaction with a specific component in blood; and irradiating the test paper with light. Irradiating means, measuring means for detecting the intensity of reflected light or transmitted light of the light radiated on the test paper from the irradiating means, and irradiating the irradiating means with light and measuring the light at predetermined time intervals. Control means for detecting the intensity of the reflected light or transmitted light; storage means for storing the intensity of the reflected light or transmitted light detected by the measuring means; and measurement from the temporal change in the intensity of the reflected light or transmitted light A measurement end time determining means for determining an end time, and the intensity of the reflected light or the transmitted light after the measurement end time determined by the measurement end time determining means is predicted from the temporal change of the intensity of the reflected light or the transmitted light. Means for determining a prediction coefficient for predicting the intensity of the reflected light or transmitted light after the measurement end time determined by the measurement end time determination means from the temporal change of the prediction coefficient and the intensity of the reflected light or transmitted light. And a concentration calculating means for obtaining a blood component concentration from the intensity of the reflected light or transmitted light predicted by the predicting calculation means, wherein the control means controls the test by the irradiation means at regular time intervals. While irradiating the paper with light and detecting the intensity of the reflected light or transmitted light from the test paper by the measuring means, the collected blood was developed on the test paper and caused to undergo a color reaction with the reagent to detect the blood. The intensity of the reflected light or the transmitted light is stored in a storage unit, and the measurement end time determination unit determines the end of the measurement from the stored temporal change of the intensity of the reflected light or the transmitted light. A prediction coefficient for predicting the intensity of the reflected light or transmitted light after the determined measurement end time by means for determining a time and calculating the prediction coefficient from the stored temporal change of the intensity of the reflected light or transmitted light. Is calculated by the prediction calculation means, and the intensity of the reflected light or transmitted light after the measurement end time determined by the measurement end time determination means is determined from the change over time of the prediction coefficient and the intensity of the reflected light or transmitted light. A blood component measuring method for measuring the concentration of the blood component from the intensity of the reflected light or transmitted light predicted by the concentration calculating means. 8. The prediction calculation means stores the intensity of the reflected light or transmitted light in a storage means as an absorbance, and calculates the absorbance (ab (t)) of the reflected light intensity after the determined measurement end time. The blood component measurement method according to claim 7, wherein the blood component measurement method is obtained by the following equation (1). (Equation 3) (Equation 4) b is obtained from Equation 2. AB (1), AB (2), AB
(3) In the measurement end time determining means, the intensity of the reflected light or the transmitted light at each fixed time interval (T) stored in the storage means is calculated from the absorbance after a predetermined time interval (m,
Here, m = 1, 2, 3,... (Integer)) and the absorbance (ab (m-1)) at the preceding interval (m-1). Change rate (V (m) = (ab (m) -ab
(m-1)) / T) and the difference in the rate of change (A (l) =
(V (l) -V (l-1)) / T, where l = m + 1) is obtained, and when A (l) -A (l-1) <0, AB
As (1), after AB (1) is determined, A
When (l) -A (l-1)> 0 and A (l) * A (l-2)> 5, AB (2) (= ab (l1)) is defined as ab (l2 +
The time when (l2-l1)) is obtained as the measurement end time AB (3). Let M = l2-l1. k and a are obtained by performing a multiple regression analysis in Equation 1 using the absorbance data from b and ab (0) to AB (3) in the means for obtaining the prediction coefficient. 9. The blood component measuring method according to claim 7, wherein said prediction calculation means uses a logistic curve. 10. The concentration calculating means calculates a blood component concentration using a calibration curve drawn by a change in intensity of reflected light or transmitted light actually measured from a change in blood component concentration, and a correction term for correcting the calibration curve. The blood component measuring method according to claim 7, which is obtained.