JPH1156822A - Blood sugar measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make measurement accuracy to higher with an noninvasive or low invasive blood sugar value measuring instrument. SOLUTION: The spectrum of the living body is measured in a spectrum measuring section 1 and the estimation of a blood sugar value is executed in a blood sugar estimating section 2 by using the spectrum. On the other hand, the information on meals, exercise, insulin injection, etc., is inputted in an information inputting instrument 3 and is stored into a blood sugar information storage memory 4. A physiological blood sugar change is estimated in accordance with various kinds of the information in a blood sugar value information calculating section 5 by using the preserved information and the range and distribution that the present blood sugar value can attain is calculated. The validity of the estimated blood sugar value determined in the blood sugar estimating section 2 is evaluated in a blood sugar studying section 6 in accordance with the range and distribution that the present blood sugar value can attain. If the estimated blood sugar value is valid, the value is outputted as it is by a blood sugar value display and output section 7 and is stored into an output blood sugar information storage memory 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood glucose measuring device for measuring a blood glucose level in a living body non-invasively or minimally invasively.

[0002]

2. Description of the Related Art As a blood glucose measuring device for non-invasively measuring blood glucose in a living body, a spectroscope that irradiates a living body with visible light, near infrared light or infrared light, and analyzes the spectrum of transmitted or reflected light. Analytical devices are known. For example, JP-A-3-1
In JP-A-73535 and JP-A-5-176917, a human body is irradiated with near-infrared light, and the intensity of the transmitted light is measured to estimate the glucose concentration in a living body. Further, Japanese Patent Application Laid-Open Nos.
In Japanese Patent No. 144545, as a system for measuring blood glucose in a living body in a minimally invasive manner, a system is used in which a body fluid is exuded from a living body and the glucose concentration in the body fluid is measured. In addition to these methods, various devices for non-invasively or minimally invasive measurement of blood glucose have been invented, but there have been no examples of practical use.

[0003]

The non-invasive or minimally invasive blood glucose measurement device is one of the reasons behind the delay in the practical use of blood glucose concentration control in diabetic patients. This is considered to be because the measurement accuracy assumed by the devices invented so far does not sufficiently increase. Because of the problem of the measurement accuracy, it can be said that the devices invented so far have not been put into practical use.

For example, in a non-invasive measurement using light, a glucose value is only estimated from a light transmission amount without measuring a biochemical blood glucose amount. For this reason, due to the influence of disturbance light, fluctuations in the state of a living body, and the like, a negative blood sugar level may be obtained depending on the result of the calculation, and a numerical value that is impossible as the amount of glucose in the living body will appear. Further, even when blood glucose is measured in a minimally invasive manner, measurement errors may increase due to a small amount of body fluid or a low sugar concentration.

An object of the present invention is to provide a non-invasive or minimally-invasive blood glucose measuring device with improved measurement accuracy, focusing on the above-mentioned problem of a large measurement error.

[0006]

SUMMARY OF THE INVENTION A blood glucose measuring device of the present invention is a non-invasive or minimally invasive blood glucose measuring device for measuring blood glucose in a living body. A blood sugar level correcting means for correcting the calculated blood sugar level based on the obtained information, and / or a means for prompting re-measurement based on the input information.

In general, the blood glucose level of a living body shows a sudden change after a meal or after exercise, but does not show a sudden change at most other times. Therefore, by taking in advance the information of the factors that change the blood sugar level, such as meal time and exercise time, into the device and correcting the blood sugar measurement (estimated) value using this information, or by prompting re-measurement, Blood glucose measurement with high measurement accuracy becomes possible. Specific examples of this information include when and how much food was consumed,
When and how much you exercised, there are recent blood sugar levels actually measured invasively, and the pathological condition of diabetes of the measured patient. Also,
Specific examples of means for inputting such information into the device include:
Input by key operation, input by voice, transfer of blood glucose level from simple invasive blood glucose meter, information transfer from simple exercise monitor,
Such a method is used.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to embodiments. FIG. 1 is a block diagram showing a configuration of a noninvasive blood glucose measuring device according to an embodiment of the present invention. In this embodiment, the blood glucose measuring device includes a spectrum measuring unit 1.
A blood sugar estimating unit 2, an information input device 3, a blood sugar information storage memory 4, a blood sugar level information calculating unit 5, a blood sugar examining unit 6,
It comprises a blood sugar level display / output unit 7 and an output blood sugar level storage memory 8. FIG. 2 is an external view of the blood glucose measuring device.

This blood glucose measuring device has a spectrum measuring section 1
Then, the spectrum of the living body is measured, and the blood sugar estimating unit 2 estimates the blood sugar level using the spectrum. On the other hand, information for blood sugar estimation is input from the key input unit 31, the voice input unit 32 of the information input device 3, the information transfer / transmission unit 33 from another device, and the like, and is stored in the blood sugar information storage memory 4. Using the information stored in the blood sugar information storage memory 4, the blood sugar level information calculating unit 5 estimates a physiological blood sugar change based on various types of information and determines the range and distribution of the current blood sugar level. calculate. Based on the range and distribution of the blood sugar level calculated in this way, the blood sugar examination unit 6 evaluates the validity of the estimated blood sugar level obtained by the blood sugar estimation unit 2. As a result, if the blood sugar estimated value is appropriate, the blood sugar level display / output unit 7 outputs the value as it is. If the estimated blood sugar level is not appropriate, re-measurement is prompted or the output value is corrected. The blood sugar level finally estimated in this way is output using the blood sugar level display / output unit 7. The last output blood sugar level is stored in the output blood sugar level storage memory 8.

The measurement of the biological spectrum in the spectrum measuring section 1 and the estimation of the blood glucose level using the spectrum in the blood glucose estimation 2 are described in detail in JP-A-3-173535 and JP-A-5-176917. And
Since it is already generally well known, a detailed description is omitted here. As the key input unit 31 and the voice input unit 32 of the information input device 3, those generally well known are used.
The information transfer unit 33 automatically receives and transfers information from another device and inputs the information. There are the following two types. One is
As shown in FIG. 3, an input from another invasive blood glucose meter to the main body 11 is provided. The blood glucose level and the measurement time measured by the invasive blood glucose meter 12 can be taken into the apparatus 11 by a method such as a wired method, a wireless method, or an infrared communication 13. The invasive blood glucose meter 12 has a built-in transmitter and the device 11 has a built-in receiver. When the invasive blood glucose meter 12 is mounted on the device 11, information is transmitted. The other is input of meal time and exercise information as shown in FIG. With the simple exercise monitor 14, the living state of the monitor wearer can be estimated to some extent from the state and amount of exercise and the state of body movement. For this reason, after the monitor 14 is attached to the patient, information such as meal time and amount, exercise time and exercise amount are stored in the monitor 14 in advance, and this information is transferred to the present apparatus 11 so that the information is transferred. Can be automatically entered. As the information transfer means, known methods such as the above-mentioned wired type, wireless type, and infrared communication type 13 can be considered. Simple exercise monitor 1
For example, a pedometer calorimeter is used as 4. When the calorimeter 14 is brought close to the apparatus 11 and a button is pressed, information is transmitted to the apparatus 11.

Various types of information input from the information input device 3 are stored in the memory 4 in the form shown in FIGS. 5, 6, and 7. Information input as a time series is stored with time as shown in FIG. This information is sequentially deleted from the oldest information after 24 hours have passed. The exercise time and the meal time are end times. Also, since the diabetic state of the patient does not change, it is stored as shown in FIG.
Further, by combining the memory contents of FIG. 5 with the current time, information as shown in FIG. 7 is constructed. For this information, for example, blood glucose measurement, exercise, insulin administration, meals, and the like, the time and amount are arranged from the latest time. This is to facilitate the next blood sugar level information calculation process. Further, the data in FIG. 5 may be a simplified version of only the presence / absence information without an amount.

Next, information calculation processing in the blood sugar level information calculation section 5 will be described. Fluctuations in the blood sugar level of a living body depend on the amount of meal, the dose of insulin, the amount of exercise, the state of diabetes, and the like, and the change is physiologically defined. For this reason,
As information for blood sugar level measurement, the previous invasive blood sugar level and its measurement time, the amount of meal and its meal time, the amount of insulin dose and its administration time, the amount of exercise and its exercise time, and the condition of diabetes are considered. From these information and the current time, it is possible to statistically infer the possibility of blood glucose rise and fall based on the previous blood sugar information.

Hereinafter, a specific example of the blood sugar level information calculation processing will be described with reference to the flowchart of FIG. First, various information is input (ST1). The input information is stored in the information storage memory 4 in a form as shown in FIGS. If the blood glucose level has not been measured for at least 24 hours since the last blood glucose measurement time, it is difficult to estimate the current blood glucose level distribution from the blood glucose information, so that the distribution is not estimated (ST3). If no meal, exercise, administration of insulin, or the like is performed when t minutes have elapsed, it is generally assumed that blood sugar levels will be approximately the same due to the homeostasis of the living body. In practice, the variance is f
(T) is expected (FIG. 9
reference).

If 24 hours have not elapsed since the last blood glucose measurement time, the nearest blood glucose value before measurement is assumed to be temporary μ, and the variance (σ) is determined based on the time after blood glucose measurement ( ST4). On the other hand, the blood glucose level decreasing effect by exercise and the blood glucose level decreasing effect by insulin contribute to the decrease of the central value and the increase of the variance from the previously measured blood glucose level, respectively (FIG. 10).
reference). Therefore, after the determination of the variance (σ), it is determined whether or not exercise has been performed from the previous blood glucose measurement to the current time (ST
5) If it is exercising, μ = μ−momentum × coefficient is calculated (ST6). If it is not exercising, nothing is performed, and the process proceeds to the next step.

Furthermore, the meal time and the elapsed time are used for estimating a change leading to an increase in blood sugar. At this time, the condition of the patient's diabetes greatly affects the blood sugar change (FIG. 1).
1, see FIG. 14). By summing up these changes, the distribution of the blood sugar estimated value at the present time is obtained. Judgment of the presence or absence of exercise,
Then, it is determined whether or not insulin has been injected from the previous blood glucose measurement to the current time (ST7).
If an insulin injection has been made, a calculation of μ = μ−insulin injection amount (unit) × coefficient is performed (ST8), and the process proceeds to the next ST9. If no insulin has been injected, do nothing and move to the next ST9. In ST9, it is determined whether or not a meal has been taken since the last blood glucose measurement. If a meal has been made, μ = μ + meal amount × time coefficient is calculated (ST10), and the process proceeds to the next ST11. The time coefficient at this time differs depending on the degree of diabetes. This is because, as shown in FIG. 14, the time when the blood sugar level increases after a meal and the time to return to the state before a meal increase as the degree of diabetes increases. If not eating, determination N in ST9
In O, the process moves to ST11, where the distribution information (μ, σ) calculated from the blood sugar information is output.

Finally, a flowchart of a specific example of the blood glucose level correcting process and the process of giving a re-measurement instruction (FIG. 12)
This will be described with reference to FIG. First, the current estimated blood sugar level distribution calculated from the information for blood sugar measurement and the blood sugar level estimated by actual measurement using light are input (ST21) and compared (ST22). As shown in FIG. 13, the measured blood sugar level (x) is calculated based on the variance of the distribution estimated from the information.
If the value falls within 1.5σ, this value is output as a reliable value. That is, in FIG. 12, in ST22,
μ−2.5σ <x <μ + 2.5σ? Is YES,
In ST23, is μ-1.5σ <x <μ + 1.5σ? Is also YES, and the measured blood sugar level (x) is output (ST26).

When the measured blood sugar level (x) falls within 2.5σ, the correction is made using the central value (μ) and the variance value (σ) so as to be close to the central value. That is, this is the case where the determination in ST22 is YES and the determination in ST23 is NO.
In this case, in ST24, μ−2.5σ <x <μ
−1.5σ? Is determined, and in the case of YES, (x + μ
−1.5σ) / 2 is output (ST27). This is Figure 1
This corresponds to the correction (1) shown in FIG. The determination in ST24 is N
In the case of O, it means that μ + 1.5σ <x <μ + 2.5σ, and (x + μ + 1.5σ) / 2 is output (S
T28). This corresponds to the correction (2) shown in FIG.

If the distance is further 2.5 σ or more, this value is regarded as unreliable, and re-measurement is instructed (ST2).
5). As another equation for correcting the estimated blood sugar level, | x
−μ | <2.5σ,

[0019]

(Equation 1)

The following is also conceivable. In this way, by correcting the blood glucose level to a degree that can be understood from the change in the living body, a large blood glucose outlier does not appear, and the blood glucose measurement accuracy is improved. FIG.
This is an example of a change in blood glucose when exercise is administered, insulin is administered, and then a meal is taken.A decrease in blood glucose due to the effect of insulin and an increase in blood glucose due to the effect of the diet appear in the change in blood glucose. I have.

[0021]

According to the present invention, the calculated blood glucose level is corrected based on the information relating to the blood glucose measurement and the input information,
And / or to encourage re-measurement, the device can compare the measured (estimated) blood glucose level with a physiological change in blood glucose level. For this reason, when a numerical value that cannot be inferred from a physiological change appears, it is possible to correct the output blood glucose level using the information and to prompt a re-measurement. As a result, the blood glucose level measurement accuracy of the device can be improved as compared to a case where such information is not used.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a blood glucose measuring device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an appearance of the blood glucose measurement device of the embodiment.

FIG. 3 is a diagram illustrating information transfer from another invasive blood glucose meter to the blood glucose measurement device of the embodiment.

FIG. 4 is a diagram for explaining information transfer from another calorimeter to the blood glucose measurement device of the embodiment.

FIG. 5 is a diagram showing an example of time information stored in a blood glucose information storage memory of the blood glucose measurement device of the embodiment.

FIG. 6 is a diagram showing an example of patient information stored in a blood glucose information storage memory of the blood glucose measurement device of the embodiment.

FIG. 7 is a diagram showing an example of estimated information stored in a blood glucose information storage memory of the blood glucose measurement device of the embodiment.

FIG. 8 is a flowchart illustrating a blood glucose information calculation process of the blood glucose measurement device of the embodiment.

FIG. 9 is a diagram showing a time transition of a blood sugar level.

FIG. 10 is a graph showing the time course of blood glucose level after insulin administration or exercise.

FIG. 11 is a diagram showing a time transition of a blood glucose level after a meal.

FIG. 12 is a flowchart illustrating a process of examining a blood glucose level of the blood glucose measuring device according to the embodiment.

FIG. 13 is a diagram showing a blood sugar level-distribution probability for explaining the blood sugar level correcting process.

FIG. 14 is a diagram showing a difference in blood sugar level change depending on a diabetic state.

FIG. 15 is a diagram showing a change in blood glucose when exercise, meal, and insulin administration are combined.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spectrum measurement part 2 Blood glucose estimation part 3 Information input part 4 Blood glucose information storage memory 5 Blood glucose information calculation part 6 Blood glucose examination part 7 Blood glucose level display / output part 8 Output blood glucose level storage memory

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinichi Hirako 24 Yamanouchi Yamanoshitacho, Ukyo-ku, Kyoto City Omron Life Science Research Institute, Inc.

Claims (13)

[Claims] 1. A blood glucose measuring device for measuring a blood glucose level in a living body in a non-invasive or minimally invasive manner, comprising: an information input means for inputting information relating to blood glucose measurement; and a calculation based on the input information. A blood glucose measuring device comprising: a blood glucose level correcting means for correcting a blood glucose level; and / or a means for prompting re-measurement based on the input information. 2. The blood glucose measurement device according to claim 1, wherein the information relating to the blood glucose measurement is a blood glucose value measured most recently and a measurement time thereof. 3. The blood sugar according to claim 2, wherein the information input means for inputting the blood sugar level and the measurement time automatically receives the blood sugar level and the measurement time measured using another invasive blood glucose meter. measuring device. 4. The blood glucose measuring device according to claim 1, wherein the information relating to the blood glucose measurement is the most recently injected insulin and its injection time. 5. The blood glucose measurement device according to claim 1, wherein the information relating to the blood glucose measurement is a latest meal time and a meal amount. 6. The blood glucose measuring device according to claim 5, wherein the means for inputting the most recent meal time of the measurer automatically receives a time estimated as a meal time by using another simple body movement measuring means. . 7. The blood glucose measurement device according to claim 1, wherein the information relating to the blood glucose measurement is a measurer's exercise amount and exercise time. 8. A means for inputting a measurer's exercise amount and exercise time includes: an exercise amount measured by another simple exercise measurement means;
The blood glucose measurement device according to claim 7, wherein the exercise time is automatically received. 9. The information relating to the blood glucose measurement is whether the measurer is a diabetic patient or a normal person, and whether the condition is insulin-dependent diabetes mellitus or non-insulin-dependent diabetes mellitus. The blood glucose measurement device according to claim 1. 10. The blood glucose measuring device according to claim 1, wherein the information relating to the blood glucose measurement preliminarily describes information of an oral glucose tolerance test. 11. The blood glucose measuring device according to claim 1, wherein said information input means for inputting information relating to blood glucose measurement inputs information using a keyboard or voice input on the device. 12. The blood glucose measuring device according to claim 1, wherein said blood glucose level correcting means performs correction based on a predetermined correction formula. 13. The blood glucose measurement device according to claim 1, wherein the means for prompting re-measurement based on information relating to blood glucose measurement displays an instruction on a blood glucose level display screen.