JP2008253438A - Non-invasive biological information measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-invasive biological information measuring device for accurately estimating the feature quantity with low power consumption. <P>SOLUTION: The non-invasive biological information measuring device comprises at least one light source 210, a control means 270 for controlling the light source 210, a biological information sensor 220 for measuring biological information, an amplification means 230 for amplifying output signals from the biological information sensor 220, an A/D converting means 240 for converting the amplified analogue signals to digital signals, a storing means 250 for storing the digital data after the A/D conversion, and a feature quantity estimating means 260 for estimating the feature quantity of the biological information by analyzing the digital data in the storing means 250. With this structure, the low power consumption can be achieved by changing the content of the control of the light source 210 according to the feature quantity estimated by the feature quantity estimating means 260. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a non-invasive living body information measuring apparatus capable of measuring living body information without invading a living body, and more specifically, a non-light source capable of varying the amount of measurement light in accordance with a feature amount of a measuring object. The present invention relates to an invasive biological information measuring device.

  The number of patients with diabetes, a typical lifestyle-related disease, is increasing worldwide. Diabetic patients require routine glycemic control to reduce complications from diabetes and improve the quality of life of patients. Therefore, patients must measure blood glucose regularly every day under the guidance of a doctor.

  As a typical method for measuring a blood glucose level, there is an invasive blood glucose measuring device that punctures a patient's finger to collect blood and measure the blood glucose level. In an invasive blood glucose measuring device, it is troublesome and painful when blood is collected by puncturing a finger, and there is also a risk of infection, etc. Measuring devices have already been proposed.

  As an example of this non-invasive blood glucose measurement device, a “biological measurement system” using a photoacoustic effect has been proposed (for example, Patent Document 1).

  A “biological measurement system” using a photoacoustic effect irradiates a part of a living body, such as a fingertip, from the biological measurement system with light having a wavelength absorbed by glucose. The light is focused on a relatively small focal area. In general, the collected light is absorbed by glucose and converted into kinetic energy in the tissue in the region adjacent to the focal region.

  The kinetic energy converted in the tissue increases the temperature and pressure of the region of the tissue where the irradiation light is absorbed by glucose (hereinafter referred to as the absorbing tissue region), and generates a sound wave. This sound wave is hereinafter referred to as “photoacoustic wave signal”. The photoacoustic wave signal is emitted from the absorbing tissue region and detected by an acoustic sensor included in the biological measurement system. The acoustic sensor is mounted in contact with the living body surface. The intensity of the photoacoustic wave signal is a function of the amount of glucose in the absorbing tissue region, and the intensity measured by the sensor is used to examine the blood glucose level.

  As another non-invasive type diabetes diagnosis apparatus, “measurement of molecular change in eye lens” using Raman spectroscopy has already been proposed (for example, Patent Document 2).

This "measurement of molecular changes in the lens of the eye" irradiates the lens of the eyeball with excitation light, receives the backscattered light, and separates it into fluorescent light and Rayleigh light using a spectroscope or dichroic beam splitter. In this method, information capable of diagnosing diabetes is obtained from a value obtained by normalizing the fluorescence intensity with the Rayleigh light intensity, and based on the information, diabetes, cataract and other diseases are diagnosed. The relative amount of backscattered fluorescence and Rayleigh emission is a reliable value for the onset and progression of the disease in the body.
Special table 2001-526557 gazette Japanese National Patent Publication No. 7-500030

  However, with the techniques described in Patent Document 1 and Patent Document 2, photoacoustic waves, fluorescent light, and Rayleigh light obtained from a living body are very weak, and a feature amount can be estimated only by a weak signal change. A sufficient amount of light is output from the light source. Therefore, there is a problem that it requires a large amount of power consumption and is not suitable for putting a portable product into practical use.

  Moreover, in the technique described in the said patent document 1, in order to minimize the influence of noise and the influence of a body motion, a measurement is performed in multiple times and a series of measurement results are averaged. Therefore, there is a problem that not only power consumption but also measurement time increases.

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a non-invasive living body information measurement apparatus that can reduce power consumption and shorten measurement time.

  In order to solve the conventional problems, a non-invasive living body information measuring apparatus according to claim 1 of the present invention includes at least one light source, a living body information sensor that measures living body information, and an output signal from the living body information sensor. Amplifying means for amplifying; A / D converting means for A / D converting the amplified signal; feature quantity estimating means for estimating a feature quantity of biological information based on the A / D converted digital data; The control content of the light source is changed in accordance with the control of the light source and the control means for controlling the activation of the amplification means and the A / D conversion means, and the feature quantity estimated by the feature quantity estimation means. And a light source control content changing means for controlling the control means.

  The noninvasive living body information measuring apparatus according to claim 2 of the present invention is the noninvasive living body information measuring apparatus according to claim 1, wherein the control content of the light source is control of the light amount of the light source. It is what.

  A non-invasive living body information measuring apparatus according to claim 3 of the present invention is the non-invasive living body information measuring apparatus according to claim 1, wherein the control content of the light source is control of the lighting time of the light source. It is a feature.

  The noninvasive living body information measuring device according to claim 4 of the present invention is the noninvasive living body information measuring device according to claim 1, wherein the feature amount estimating means is configured such that the estimated feature amount value is It has a region determination means for determining which one of a plurality of regions obtained by dividing a possible range corresponds.

  The noninvasive living body information measuring apparatus according to claim 5 of the present invention is the noninvasive living body information measuring apparatus according to claim 4, wherein the region determining means has a register which can be written from the outside, and the register The threshold value can be changed by changing the value of.

  The noninvasive living body information measuring apparatus according to claim 6 of the present invention is the noninvasive living body information measuring apparatus according to claim 4, wherein the region determining means has a short-term difference between the estimated feature values between the regions. It is characterized by having a low-pass filter that performs filtering so that the value of the feature value can be regarded as not moving when moving between, and ignoring an event that has moved in a short period.

  The noninvasive living body information measuring apparatus according to claim 7 of the present invention is the noninvasive living body information measuring apparatus according to claim 6, wherein the low-pass filter determines that the period of movement between the regions is a short period. The time can be individually set according to the direction of movement between the regions.

  The noninvasive living body information measuring apparatus according to claim 8 of the present invention is the noninvasive living body information measuring apparatus according to claim 6, wherein the low-pass filter has a register writable from the outside, and the register By writing a new value, it is possible to change a time range for ignoring a change in the feature value when the estimated feature value value moves between regions in a short period of time. .

  A noninvasive living body information measuring apparatus according to claim 9 of the present invention is the noninvasive living body information measuring apparatus according to claim 1, wherein the control means outputs a feature value value output from the feature quantity estimating means. It is characterized by having a region-specific light amount changing means for controlling the light amount of the light source according to which region corresponds to.

  The noninvasive living body information measuring apparatus according to claim 10 of the present invention is the noninvasive living body information measuring apparatus according to claim 9, wherein the region-specific light amount changing means is at least one first writable from outside. The light quantity value of the light source corresponding to the region can be changed by writing a new value in the first register group.

  The noninvasive living body information measuring apparatus according to claim 11 of the present invention is the noninvasive living body information measuring apparatus according to claim 9, wherein the region-specific light amount changing means has an input port for inputting a signal. The light quantity of the light source can be changed by a signal input to the input port.

  A non-invasive living body information measuring apparatus according to claim 12 of the present invention is the non-invasive living body information measuring apparatus according to claim 11, wherein the region-specific light amount changing means includes a second register writable from the outside. And by writing a new value to the second register, it is possible to set the light amount value of the light source to be changed by a signal input to the input port.

  According to a thirteenth aspect of the present invention, in the noninvasive living body information measuring device according to the first aspect, the control means outputs the feature value value output from the feature quantity estimating means. A region invariant detecting means for detecting whether or not the region to which the light belongs has changed for a certain period and outputting a light amount change request signal for requesting a change in the light amount of the light source when the region has not changed. To do.

  A noninvasive living body information measuring apparatus according to a fourteenth aspect of the present invention is the noninvasive living body information measuring apparatus according to the thirteenth aspect, wherein the region invariant detecting means has a first register writable from the outside. Then, by writing a new value to the first register, it is possible to change the certain period for detecting whether or not the region to which the feature value output from the feature value estimation unit belongs has changed. It is characterized by being.

  The noninvasive living body information measuring apparatus according to claim 15 of the present invention is the noninvasive living body information measuring apparatus according to claim 13, wherein the region invariant detecting means has a second register writable from the outside. Then, by writing a new value in the second register, a detection target region that is a target for detecting whether or not the region to which the feature amount value output by the feature amount estimation means belongs is a region that does not change for a certain period of time. It can be selected.

  According to a sixteenth aspect of the present invention, in the noninvasive biological information measuring device according to the thirteenth aspect, the region invariant detecting means has a third register which can be written from the outside. The time for outputting the light quantity change request signal can be changed by writing a new value in the third register.

  A noninvasive living body information measuring device according to claim 17 of the present invention includes at least one light source, a living body information sensor that measures living body information, an amplifying unit that amplifies an output signal from the living body information sensor, A / D conversion means for A / D converting the amplified signal, storage means for storing the A / D converted digital data, and lighting until the light source is turned on and the digital data is recorded in the recording means A series of measurement operations are repeated a predetermined number of times, and the measurement operation is repeated a predetermined number of times to average the digital data for a predetermined number of times stored in the storage means, and the averaged data is analyzed to obtain the feature amount of the biological information. Feature quantity estimation means to be estimated, control means for controlling the lighting timing of the light source, and activation of the amplification means and A / D conversion means, and features estimated by the feature quantity estimation means It is characterized in that a repetition count changing means for controlling said control means to change the number of repetitions of the series of measuring operations according to.

  The noninvasive living body information measuring device according to claim 18 of the present invention is the noninvasive living body information measuring device according to claim 17, wherein the feature amount estimating means is configured such that the estimated feature amount value is It has a region determination means for determining which one of a plurality of regions obtained by dividing a possible range corresponds.

  The noninvasive living body information measuring apparatus according to claim 19 of the present invention is the noninvasive living body information measuring apparatus according to claim 18, wherein the region determining means has a register which can be written from the outside, and the register The boundary between the plurality of areas can be changed by writing a new value to the field.

  Further, the noninvasive living body information measuring apparatus according to claim 20 of the present invention is the noninvasive living body information measuring apparatus according to claim 18, wherein the region determining means is configured such that the estimated feature value is short-term between regions. It is characterized by having a low-pass filter that performs filtering so that the value of the feature value can be regarded as not moving when moving between, and ignoring events that have moved in the region in a short time.

  The noninvasive living body information measuring apparatus according to claim 21 of the present invention is the noninvasive living body information measuring apparatus according to claim 20, wherein the low-pass filter determines that the period of movement between the regions is a short period. The time can be individually set according to the direction of movement between the regions.

  A noninvasive living body information measuring apparatus according to claim 22 of the present invention is the noninvasive living body information measuring apparatus according to claim 20, wherein the low-pass filter has a register writable from the outside, By writing a new value, it is possible to change a time range for ignoring a change in the feature value when the estimated feature value value moves between regions in a short period of time. .

  The noninvasive living body information measuring apparatus according to claim 23 of the present invention is the noninvasive living body information measuring apparatus according to claim 17, wherein the control means outputs the feature value value output from the feature quantity estimating means. It is characterized by having an area-specific repetition number changing means for changing the number of repetitions of the measurement operation according to which area corresponds to.

  The noninvasive living body information measuring apparatus according to claim 24 of the present invention is the noninvasive living body information measuring apparatus according to claim 23, wherein the region-specific repetition number changing means has a register which can be written from the outside. The value of the number of repetitions can be changed for each region by writing a new value to the register.

  The noninvasive living body information measuring apparatus according to claim 25 of the present invention is the noninvasive living body information measuring apparatus according to claim 23, wherein the region-specific repetition number changing means includes an input port for inputting a signal. And the number of repetitions can be changed by a signal input to the input port.

  A non-invasive living body information measuring apparatus according to claim 26 of the present invention is the non-invasive living body information measuring apparatus according to claim 25, wherein the region-specific repetition number changing means is a second register writable from the outside. And by writing a new value to the second register, it is possible to set the number of repetitions to be changed by a signal input to the input port.

  A non-invasive living body information measuring apparatus according to claim 27 of the present invention is the non-invasive living body information measuring apparatus according to claim 25, wherein the control means outputs the feature value value output from the feature quantity estimating means. And a region invariant detecting means for controlling the control means to increase the number of times the measurement operation is repeated when the area to which the signal belongs does not change for a certain period of time. Is.

  A noninvasive living body information measuring apparatus according to a twenty-eighth aspect of the present invention is the noninvasive living body information measuring apparatus according to the twenty-seventh aspect, wherein the region invariant detecting means has a first register writable from the outside. The time during which the area does not change can be changed by writing a new value to the first register.

  A noninvasive living body information measuring apparatus according to a twenty-ninth aspect of the present invention is the noninvasive living body information measuring apparatus according to the twenty-seventh aspect, wherein the region invariant detecting means has a second register writable from the outside. In addition, by writing a new value in the second register, it is possible to select a region for detecting whether or not the region to which the feature value output from the feature amount estimation means belongs does not change for a certain period of time. It is characterized by.

  A non-invasive living body information measuring apparatus according to claim 30 of the present invention is the non-invasive living body information measuring apparatus according to claim 27, wherein the region invariant detecting means has a third register writable from the outside. In addition, by writing a new value to the third register, it is possible to change the time for outputting the repeat count change request signal for requesting the change of the repeat count of the measurement operation.

  According to the noninvasive living body information measuring apparatus of the present invention, the range of values that can be taken by the feature value of the estimated biological information is divided into a plurality of regions, and it is determined which region the estimated feature value belongs to. By changing the amount of light from the next time or the number of measurements when the area has not changed for a certain period of time, it becomes possible to realize a measurement device with low power consumption and short measurement time. Continuous measurement time can be improved.

Embodiments of the noninvasive living body information measuring apparatus of the present invention will be described below in detail with reference to the drawings.
(Embodiment 1)
In Embodiment 1 of the present invention, a noninvasive blood glucose measurement device 110 using a photoacoustic method is assumed as a noninvasive living body information measurement device.

FIG. 1 is a diagram showing a system configuration according to Embodiment 1 of the present invention.
In FIG. 1A, 110 is a non-invasive blood glucose measuring device, 120 is the surface of a living body, 111 is irradiation light, 130 is a blood vessel, and 131 is a photoacoustic wave signal.
1B is a start signal 282, FIG. 1C is a lighting timing 281, FIG. 1D is a photoacoustic wave signal 131, FIG. 1E is an end signal 283, and FIG. The estimated blood glucose level output timing is shown.

FIG. 2 is a diagram showing a block configuration of the noninvasive blood glucose measurement device 110 according to Embodiment 1 of the present invention.
In FIG. 2, reference numeral 110 denotes a noninvasive blood glucose measurement device. In this non-invasive blood glucose measurement device 110, 210 is a light source, 220 is a biological information sensor for measuring biological information, 230 is an amplification means for amplifying an output signal from the biological information sensor 220, and 240 is a signal amplified by the amplification means 230. A / D conversion means for A / D converting, 250 a storage means for storing digital data A / D converted by the A / D conversion means 240, 260 for analyzing the digital data stored in the storage means 250 270 is a control means for controlling the light source 210 and activation of the amplifying means 230 and the A / D conversion means 240, and 400 is estimated by the feature quantity estimating means 260. The light source control content changing unit controls the control unit 270 to change the control content of the light source 210 according to the feature amount.

  The feature amount estimation unit 260 includes an area determination unit 261. The region determination unit 261 includes a region threshold value register 262 and a low-pass filter 263, and determines whether the estimated blood glucose level corresponds to any of a plurality of regions obtained by dividing a range that the value can take. The low-pass filter 263 has an LPF upper register 264 and an LPF lower register 265, and performs filtering so that the estimated blood glucose level can be regarded as not moving when the estimated blood glucose level has moved between a plurality of regions for a short period. .

  The control unit 270 includes a region invariance detecting unit 271 and a region-specific light amount changing unit 276. The region invariance detecting unit 271 has an invariant range register 272, an invariant region register 273, and a request time register 274, and detects whether or not the correction region signal 266 output from the feature amount estimating unit 260 does not change for a certain time. When not, a light amount change request signal 275 requesting a change in the light amount of the light source 210 is output to the region-specific light amount changing means 276.

  The region-specific light amount changing means 276 includes a first region light amount register 277, a second region light amount register 278, and a region invariant light amount register 279, and outputs a light amount 280 corresponding to the region to which the estimated blood glucose level belongs to the light source 210. . More specifically, the light quantity of the light source 210 is controlled in accordance with the correction area signal 266 output from the feature quantity estimation means 260 and the light quantity change request signal 275 output from the area invariance detection means 271.

  The light source control content changing unit 400 includes a region determining unit 261, a region invariant detecting unit 271, and a region-specific light amount changing unit 276, and changes the light amount of the light source 210 according to the estimated blood sugar level estimated by the feature amount estimating unit 260. The control means 270 is controlled as follows.

FIG. 3 is a diagram in which the estimated blood sugar level 267 of the noninvasive blood sugar measuring device 110 according to Embodiment 1 of the present invention is plotted on the time axis.
3, (a) is an estimated blood sugar level 267, (b) is a real area signal, (c) is a correction area signal 266, (d) is a light quantity change request signal 275, and FIG. (E) is the light quantity 280.

Hereinafter, the operation when the noninvasive blood glucose measurement device 110 performs continuous blood glucose measurement will be described with reference to FIGS. 1, 2, and 3.
By mounting the non-invasive blood glucose measurement device 110 so as to be in contact with the surface 120 of the living body, the irradiation light 111 emitted from the light source 210 is incident on the living body. The incident irradiation light 111 propagates in the living body and is absorbed by glucose in the blood vessel 130 to generate a photoacoustic wave signal 131. The photoacoustic wave signal 131 generated by glucose in the blood vessel 130 is detected by the non-invasive blood glucose measurement device 110, and an estimated blood glucose level 267 that is a feature amount of biological information is estimated.

  The region determination unit 261 determines which region the estimated blood glucose level 267 belongs to, and the light source control content changing unit 400 changes the light amount of the light source 210 according to the region to which the estimated blood glucose level 267 belongs.

  Then, by setting the light amount of the light source 210 to be small in the region to which the large estimated blood glucose level belongs, and to increase the light amount of the light source 210 in the region to which the small estimated blood glucose level belongs, the low power consumption and the measurement time can be reduced. A non-invasive blood glucose measurement device that can be shortened can be realized.

  More specifically, the non-invasive blood glucose measurement device 110 includes at least one light source 210, and irradiation light 111 having a wavelength equal to the wavelength absorbed by glucose is emitted from the light source 210. The photoacoustic wave signal 131 generated in the living body is converted into a voltage signal 221 by the living body information sensor 220.

  The activation signal 282 from the control means 270 activates the amplification means 230, the voltage signal 221 is amplified by the amplification means 230, and the amplified signal 231 is output. The activation signal 282 from the control unit 270 activates the A / D conversion unit 240, A / D conversion is performed by the A / D conversion unit 240, the amplified signal 231 is converted into sampling data 241, and stored in the storage unit 250. Written.

  The sampling data 241 stored in the storage unit 250 is read as the storage data 251 by the feature amount estimation unit 260, and an estimated blood sugar level 267 is estimated, and this is output as a measurement result.

  At that time, a possible value of the estimated blood sugar level that is the feature amount is divided into a plurality of regions with a threshold value set in advance in the region threshold register 262, and the region to which the region to which the estimated blood glucose level currently belongs is the feature amount. The determination is made by the region determination means 261 in the estimation means 260.

  Further, when the period in which the estimated blood glucose level exceeds the boundary of the region is a short period, a low pass in the feature amount estimation unit 260 is set so that the estimated blood glucose level does not exceed the estimated blood glucose level in the period exceeding the boundary. Filtering of the estimated blood glucose level is performed by the filter 263, and a correction region signal 266 is output.

  The control means 270 controls the light quantity 280 and lighting timing 281 of the light source 210, the start signal 282 of the amplification means 230 and the A / D conversion means 240, the amplification means 230, the A / D conversion means 240, and the feature amount estimation means 260. An end signal 283 is output.

  That is, when the correction region signal 266 indicates that the region is a region to which a small estimated blood glucose level belongs, the region-specific light amount changing means 276 changes the light amount of the light source 210 to be large, and conversely, the estimated blood glucose level is large. When indicating that the value belongs to the region, the region-specific light amount changing unit 276 changes the light amount of the light source 210 to be small.

  In addition, when the region invariance detecting unit 272 detects that the corrected region signal 266 belongs to the region to which the large estimated blood glucose level belongs for a long time, the region invariant detecting unit 272 sporadically increases the light amount of the light source 210. By controlling the area-specific light amount changing means 276, deterioration of measurement accuracy is prevented.

Below, it demonstrates using a specific numerical example.
In the present embodiment, the measurement is performed 120 times at intervals of 3 minutes, that is, 6 hours.
Here, the following values are set as initial values of the register that can be written from the outside.
That is,
(I) Area threshold value register 262: 150 (mg / dl) is set as the threshold value of the area determination means 261.
(Ii) LPF upper register 264: 2 (measurement cycle) is set as a time value to be ignored when the low pass filter 263 of the area determination means 261 rises.
(Iii) LPF lower register 265: 0 (measurement cycle) is set as a time value to be ignored when the low-pass filter 263 falls.
(Iv) First area light quantity register 277: 1.5 (μJ) is set as the light quantity value of the area-specific light quantity changing means 276 in the first area.
(V) Second area light quantity register 278: 1.0 (μJ) is set as the light quantity value of the area-specific light quantity changing means 276 in the second area.
(Vi) Area invariant light quantity register 279: 1.5 (μJ) is set as the light quantity value when the light quantity change request signal 275 is input.
(Vii) Invariant range register 272: 20 (measurement cycle) is set as the region invariant range of the region invariant detecting means 271.
(Viii) Invariant area register 273: 2 (area) is set as the detection area,
(Ix) Request time register 274: 1 (measurement cycle) is set as the light amount change request time.

  After the above initial setting is completed, first, the noninvasive blood glucose measuring device 110 is mounted on the surface 120 of a living body such as a patient's arm as shown in FIG. Thereafter, when the patient activates a blood glucose level measurement start switch (not shown) provided in the non-invasive blood glucose measurement device 110, an activation signal is output to the amplification unit 230 and the A / D conversion unit 240 by the control unit 270, The amplification means 230 and the A / D conversion means 240 are activated. The lighting timing 281 and the light quantity 280 of the light source 210 are controlled at the same timing when the amplification means 230 and the A / D conversion means 240 enter a stable operation, and the light source 210 is turned on.

The light 111 incident on the living body from the light source 210 propagates in the living body and is absorbed by glucose in the blood vessel 130, and a photoacoustic wave signal 131 is generated.
The photoacoustic wave signal 131 is converted into a voltage signal 221 corresponding to the pressure by the biological information sensor 220.

  The voltage signal 221 converted by the biological information sensor 220 is amplified by the amplification unit 230 with a preset gain, and is output to the A / D conversion unit 240 as an amplification signal 231.

  Here, the reason why the start signal 282 and the end signal 283 are input to the amplifying unit 230 is that an element such as an operational amplifier that is a constituent element of the amplifying unit 230 is operated only at the timing when the photoacoustic wave signal 131 is generated. Therefore, the power consumption of the amplifying unit 230 is reduced. Therefore, it is possible to realize an equivalent operation regardless of these signals.

  The activation signal 282 from the control unit 270 activates the A / D conversion unit 240. The amplified signal 231 output from the amplifying unit 230 is A / D converted at specific intervals by the A / D converting unit 240, and sampling data 241 as the A / D conversion result is written in the storage unit 250.

  Here, the end signal 283 is input to the A / D conversion unit 240 only when the photoacoustic wave signal 131 is generated, such as an element such as an AD converter that is a component of the A / D conversion unit 240. Is intended to reduce the power consumption of the A / D conversion means 240. Therefore, it is possible to realize an equivalent operation regardless of this signal.

  The end signal 283 from the control unit 270 is received by the feature amount estimation unit 260, the stored data 251 recorded in the storage unit 250 is read by the feature amount estimation unit 260, and the feature amount estimation unit 260 estimates the blood sugar level. 267 is calculated and output to the outside.

  At that time, the region determination unit in the feature amount estimation unit 260 uses the low-pass filter 263 to ignore the data exceeding the short-term region and determine which region the estimated blood glucose level 267 corresponds to. The correction area signal 266 is output.

  In the first embodiment, the estimated blood glucose level 267 is calculated by once writing the sampling data 241 of the A / D conversion unit 240 into the storage unit 250 and reading it by the feature amount estimation unit 260. It is obvious that the estimated blood glucose level 267 may be calculated by the estimation unit 260 receiving the sampling data 241 directly from the A / D conversion unit 240.

  A period from when the control unit 270 outputs the activation signal to the amplification unit 230 and the A / D conversion unit 240 until the estimated blood glucose level 267 is calculated by the feature amount estimation unit 260 and output to the outside is defined as a measurement basic cycle. Repeat this every 3 minutes.

  However, in order to minimize errors in the estimated blood glucose level 267 due to body movements such as breathing and pulse, and the influence of external noise, the above measurement basic cycle is repeatedly operated a specified number of times in a cycle of about 10 μs to 100 ms, and the measurement basic cycle There is also a method of calculating an estimated blood sugar level 267 as follows.

  Further, when the region invariance detecting unit 271 detects that the region to which the correction region signal 266 has not changed for a certain period of time, a light amount change request signal 275 is output to the region-specific light amount changing unit 276. While the light quantity change request signal 275 is output, the light quantity of the light source 210 is changed according to the value set in the area invariant light quantity register 279 by the area-specific light quantity changing means 276.

FIG. 3 shows how the light amount of the light source 210 is changed over time.
The real area signal shown in FIG. 5B is a signal generated by the area determination means 261 discriminating the estimated blood glucose level 267 with the area threshold value. In the present embodiment, “150” is set in the region threshold register 262 from the outside, and the Lo level is output if the estimated blood glucose level 267 is “150” or less, and the Hi level is output if it is greater than “150”.

  In this embodiment, the case where there are two areas has been described. However, when there are three or more areas, a plurality of area threshold registers 262 are provided, and a plurality of real area signals (multi-bit) are obtained. It is clear that it can be handled.

A corrected area signal 266 shown in FIG. 6C is a signal obtained by filtering the real area signal obtained by the area determining unit 261 by the low-pass filter 263. This is a signal for minimizing the change in the light amount and improving the measurement accuracy when the estimated blood glucose level 267 moves at short intervals near the boundary where the light amount is changed.
Note that the filtering function can be eliminated by setting both the upper LPF register 264 and the lower LPF register 265 of the area determination means 261 to “0”.

  In this embodiment, “2” is set in the LPF upper register 264 and “0” is set in the LPF lower register 265 from the outside, and the low-pass filter 263 has a signal level of 2 when the real area signal rises. When stable for a time longer than the period, filtering is performed so that the signal level of the real area signal at that time is output.

  The light quantity change request signal 275 shown in FIG. 6D is monitored by the region invariance detecting unit 271 of the control unit 270 for the correction region signal 266 output from the feature amount estimating unit 260, and the region has not changed for a certain period of time. Sometimes it is a signal for requesting a change in the amount of light. That is, it is a signal for periodically confirming whether or not the measurement accuracy has deteriorated by generating the light amount change request signal 275 when the measurement period continues for a long time with the light amount decreased. .

  Further, by setting the value of the region invariant light amount register 279 to be larger than the value of the second region light amount register 278, it is possible to increase the light amount only at the time of confirmation. Further, by setting a plurality of areas in the invariant area register 273, it is possible to periodically change the light quantity even in the normal light quantity measurement area. Furthermore, by setting “0” in the invariant area register 273 or setting the maximum value in the invariant area register 272, it is possible to eliminate the function of changing the light amount when the area has not changed for a certain period of time. It is.

  In the present embodiment, “20” is set in the invariant range register 272, “2” is set in the invariant region register 273, and “1” is set in the request time register 274, which are output from the feature amount estimation unit 260. When the signal of the correction area signal 266 is stabilized for a time longer than 20 measurement periods in the area 2, the Hi level is output for one measurement period. Further, when the region 2 continues, the Hi level is output for one measurement period every 20 measurement periods thereafter.

  FIG. 4 shows waveforms when it is assumed that 2.0 μJ is set in the region invariant light amount register 279 and regions 1 and 2 are set in the invariant region register 273 at the time of measurement according to the present embodiment. In this case, the light amount change request signal 275 is output even when the region 1 has not changed by 20 measurement cycles (near 340 minutes).

  A light amount 280 shown in FIG. 6D is the light amount of the light source 210, and while the light amount change request signal 275 is not output, according to the region of the correction region signal 266 output from the feature amount estimating means 260, The value of the light quantity register in the corresponding area set in the area-specific light quantity changing means 276 is output. While the light amount change request signal 275 is being output, the value set in the area invariant light amount register 279 is output.

  In the present embodiment, the first area light quantity register 277 is set to 1.5, the second area light quantity register 278 is set to 1.0, and the area invariant light quantity register 279 is set to 1.5 from the outside. When the signal of the correction area signal 266 output from 260 is the area 1, 1.5 is obtained when the signal is the area 2, and 1.5 when the light quantity change request signal 275 is outputted. , Respectively.

  In the example of FIG. 4, when the signal of the correction area signal 266 output from the feature amount estimation unit 260 is the area 1, 1.5 is output when the signal is the area 2, and the light amount change request signal 275 is output. If it is, 2.0 is output.

  First, at time 0 minutes, the estimated blood glucose level 267 is 90 mg / dl. At this time, the correction area signal 266 of the area determination unit 261 belongs to the area 1 and the light quantity at this time is 1.5 μJ.

  When the estimated blood glucose level 267 gradually increases and the estimated blood glucose level 267 reaches 148 mg / dl at time 27 minutes, the correction area signal 266 of the area determination means 261 remains at area 1 at this time. Is 1.5 μJ.

  Further, when the estimated blood sugar level 267 rises and the value of the estimated blood sugar level 267 reaches 160 mg / dl at time 30 minutes, the real area signal of the area determination means 261 becomes Hi level at this time, but the correction area signal 266 Is cut by the low-pass filter 263 and remains at the Lo level, and the amount of light is 1.5 μJ.

  At time 33 minutes, the estimated blood glucose level 267 is 135 mg / dl. At this time, the real area signal of the area determination means 261 becomes Lo level, and the amount of light is 1.5 μJ.

  At time 51 minutes, when the estimated blood glucose level 267 rises again and the estimated blood glucose level 267 reaches 153 mg / dl, the real area signal of the area determination means 261 again becomes Hi level, but the correction area signal 266 is cut by the low-pass filter 263 and remains at the Lo level, and the amount of light is 1.5 μJ.

  At time 54 minutes, the estimated blood glucose level 267 is 155 mg / dl. At this time, the real area signal of the area determination unit 261 becomes Hi level, but the correction area signal 266 is cut by the low-pass filter 263 and remains at Lo level, and the light amount is 1.5 μJ.

  At time 57 minutes, the estimated blood sugar level 267 is 158 mg / dl. At this time, the Hi level of the real area signal of the area determination unit 261 is 3 measurement cycles. For this reason, the correction area signal 266 becomes Hi level without being cut by the low-pass filter 263, and the light amount becomes 1.0 μJ.

  At time 117 minutes, the estimated blood glucose level 267 is 200.5 mg / dl. At this time, the real area signal of the area determination unit 261 remains at the Hi level, the correction area signal 266 is continuously cut at the Hi level without being cut by the low-pass filter 263, and the light quantity change request signal 275 is one. The measurement period is output, and the amount of light is 1.5 μJ.

  At time 120 minutes, the estimated blood glucose level 267 is 200 mg / dl. At this time, the real area signal of the area determination unit 261 remains at the Hi level, and the correction area signal 266 is continuously at the 21 measurement period Hi level without being cut by the low-pass filter 263. The region invariant detecting unit 271 starts measuring the continuous period of the region 2 again. The light quantity change request signal 275 is at Lo level, and the light quantity is 1.0 μJ.

  At time 177 minutes, the estimated blood glucose level 267 is 178 mg / dl. At this time, the real area signal of the area determination unit 261 remains at the Hi level, the correction area signal 266 is continuously cut at the Hi level for 40 measurement cycles without being cut by the low-pass filter 263, and the light quantity change request signal 275 is one. The measurement period is output, and the amount of light is 1.5 μJ.

  At time 180 minutes, the estimated blood sugar level 267 is 175 mg / dl. At this time, the real area signal of the area determination unit 261 remains at the Hi level, and the correction area signal 266 is continuously cut into the 41 measurement cycle Hi level without being cut by the low-pass filter 263. The region invariant detecting unit 271 starts measuring the continuous period of the region 2 again. The light quantity change request signal 275 is at Lo level, and the light quantity is 1.0 μJ.

  At time 195 minutes, the estimated blood glucose level 267 is 149 mg / dl. At this time, the real area signal of the area determination means 261 becomes Lo level, and 0 is set in the LPF lower register 265. Therefore, the correction area signal 266 is set to Lo level without being cut by the low pass filter 263, and the light amount is 1 .5 μJ.

  At time 231 minutes, the estimated blood glucose level 267 rises again, and the estimated blood glucose level 267 becomes 151 mg / dl. At this time, the real area signal of the area determination unit 261 becomes Hi level again, but the correction area signal 266 is cut by the low-pass filter 263 and remains at the Lo level, and the light amount is 1.5 μJ.

  At time 234 minutes, the estimated blood glucose level 267 is 153 mg / dl. At this time, the real area signal of the area determination unit 261 becomes Hi level, but the correction area signal 266 is cut by the low-pass filter 263 and remains at Lo level, and the light amount is 1.5 μJ.

  At time 237 minutes, the value of the estimated blood glucose level 267 is 156 mg / dl. At this time, the real area signal of the area determination means 261 has a Hi level of 3 measurement cycles, the correction area signal 266 is at the Hi level without being cut by the low pass filter 263, and the light quantity is 1.0 μJ.

  At time 273 minutes, the estimated blood glucose level 267 is 148 mg / dl. At this time, the real area signal of the area determination means 261 becomes Lo level, and 0 is set in the LPF lower register 265. Therefore, the correction area signal 266 is set to Lo level without being cut by the low pass filter 263, and the light amount is 1 .5 μJ.

  Further, the estimated blood glucose level 267 rises, and at time 318 minutes, the estimated blood glucose level 267 becomes 152 mg / dl. At this time, the real area signal of the area determination unit 261 becomes Hi level, but the correction area signal 266 is cut by the low-pass filter 263 and remains at Lo level, and the light amount is 1.5 μJ.

  At time 321 minutes, the estimated blood glucose level 267 is 148 mg / dl. At this time, the real area signal of the area determination means 261 becomes Lo level, and the amount of light is 1.5 μJ.

  At time 333 minutes, the estimated blood glucose level 267 is 135 mg / dl. At this time, the real area signal of the area determination means 261 remains at the Lo level, and the correction area signal 266 remains at the continuous 20 measurement period Lo level. However, since the invariable area register 273 does not set the area 1, the light amount is changed. The request signal 275 is not output, and the amount of light is 1.5 μJ.

  At time 360 minutes, the estimated blood glucose level 267 is 111 mg / dl. At this time, the real area signal of the area determination unit 261 remains at the Lo level, and the amount of light is 1.5 μJ.

  As described above, according to the first embodiment of the present invention, the region determination unit that determines to which region the estimated feature amount belongs is provided, and the determined region is a region where a large estimated feature amount can be obtained. Decreasing the measurement accuracy of the non-invasive blood glucose measurement device by setting the light amount of the light source to change according to the determined region so that the light amount is smaller than the region where a small estimated feature amount is obtained Therefore, low power consumption can be realized, and the continuous measurement time can be greatly extended when a portable non-invasive blood glucose measurement device is realized.

  In addition, if the area to which the estimated feature amount does not change for a certain period of time, it is possible to confirm whether the measurement accuracy has deteriorated by changing the light amount so that the light amount of the light source temporarily increases. It is possible to prevent deterioration of measurement accuracy.

  In the first embodiment of the present invention, the light amount of the light source is changed. However, the same result can be obtained by changing the lighting time of the light source.

  In the first embodiment of the present invention, the non-invasive blood glucose measurement device using the photoacoustic method has been described as an example. However, other biological information measurement devices of the photoacoustic method, Raman spectroscopy, OCT (optical The present invention can also be applied to other noninvasive living body information measuring apparatuses using coherence tomography, optical rotation angle, light absorption and transmission.

  Further, in Embodiment 1 of the present invention, the estimated blood sugar level 267 is calculated by writing the sampling data 241 of the A / D conversion unit 240 into the storage unit 250 once and reading it by the feature amount estimation unit 260. The estimated blood glucose level 267 may be calculated by the feature quantity estimation unit 260 receiving the sampling data 241 directly from the A / D conversion unit 240.

(Embodiment 2)
In the second embodiment of the present invention, the noninvasive biological information measurement device is assumed to be a noninvasive blood glucose measurement device 110.
In this second embodiment, in order to minimize the error of the estimated blood sugar level 267 due to the influence of body movement such as breathing and pulse, and external noise, the above measurement basic cycle is repeated a specified number of times at a cycle of about 10 μs to 100 ms. The estimated blood glucose level 267 is calculated as the measurement basic cycle, thereby reducing power consumption and the number of measurements.

FIG. 5 is a diagram showing a system configuration according to Embodiment 2 of the present invention.
In FIG. 5A, 110 is a non-invasive blood glucose measuring device, 120 is the surface of a living body, 111 is light, 130 is a blood vessel, and 131 is a photoacoustic wave signal.

  5B is the start signal 282, FIG. 5C is the lighting timing 281, FIG. 5D is the photoacoustic wave signal 131, FIG. 5E is the end signal 283, and FIG. The estimated blood glucose level output timing is shown.

FIG. 6 is a diagram showing a block configuration of the noninvasive blood glucose measurement device 110 according to Embodiment 2 of the present invention.
In FIG. 6, reference numeral 110 denotes a non-invasive blood glucose measurement device. In this non-invasive blood glucose measurement device 110, 210 is a light source, 220 is a biological information sensor for measuring biological information, 230 is an amplification means for amplifying an output signal from the biological information sensor 220, and 240 is a signal amplified by the amplification means 230. A / D conversion means for A / D converting, 250 a storage means for storing digital data A / D converted by the A / D conversion means 240, 260 for analyzing the digital data stored in the storage means 250 270 is a control means for controlling the light source 210 and activation of the amplification means 230 and the A / D conversion means 240, and 500 is a feature quantity estimation means 260 for estimating the feature quantity of the biological information. It is a repetition number changing unit that controls the control unit 270 so as to change the number of repetitions of a series of measurement operations according to the feature amount.

  The feature amount estimation unit 260 includes an area determination unit 261. The region determination unit 261 includes a region threshold value register 262 and a low-pass filter 263, and determines whether the estimated blood glucose level corresponds to any of a plurality of regions obtained by dividing a range that the value can take. The low-pass filter 263 has an LPF upper register 264 and an LPF lower register 265, and performs filtering so that the estimated blood glucose level can be regarded as not moving when the estimated blood glucose level has moved between a plurality of regions for a short period. .

  The control unit 270 includes a region invariance detecting unit 271 and a region-specific light amount changing unit 276. The region invariance detecting unit 271 has an invariant range register 272, an invariant region register 273, and a request time register 274, and detects whether or not the correction region signal 266 output from the feature amount estimating unit 260 does not change for a certain time. If not, a repetition number change request signal 675 for requesting a change in the number of repetitions of the estimated blood sugar level measurement operation is output to the region-specific light amount changing means 276.

  The repetition number changing means 676 includes a first region repetition number register 677, a second region repetition number register 678, and a region invariant repetition number register 679, and the measurement operation can be performed at the number of repetitions corresponding to the region to which the estimated blood glucose level belongs. Control means 270 is controlled to take place. More specifically, the control unit 270 is controlled in accordance with the correction region signal 266 output from the feature amount estimation unit 260 and the repeat count change request signal 675 output from the region invariance detection unit 271.

  The repetition number changing unit 500 includes an area determination unit 261, an area invariance detecting unit 271, and an area-specific repetition number changing unit 676, and changes the number of repetitions of the measurement operation according to the estimated blood glucose level estimated by the feature amount estimating unit 260. The control means 270 is controlled to do so.

FIG. 7 is a diagram in which the estimated blood sugar level 267 of the noninvasive blood sugar measuring device 110 according to Embodiment 2 of the present invention is plotted on the time axis.
7, (a) is an estimated blood glucose level 267, (b) is a real area signal, (c) is a correction area signal 266, (d) is a repeat count change request signal 675, FIG. (E) shows the number of repetitions.

Hereinafter, the operation when the noninvasive blood glucose measurement device 110 performs continuous blood glucose measurement will be described with reference to FIGS. 5, 6, and 7.
By mounting the non-invasive blood glucose measurement device 110 so as to be in contact with the surface 120 of the living body, light 111 emitted from the light source 210 enters the living body. The incident light 111 propagates in the living body and is absorbed by glucose in the blood vessel 130 to generate a photoacoustic wave signal 131. The photoacoustic wave signal 131 generated by glucose in the blood vessel 130 is detected by the non-invasive blood glucose measurement device 110, and an estimated blood glucose level 267 that is a feature amount of biological information is estimated.

  The region determination unit 261 determines which region the estimated blood glucose level 267 belongs to, and the light amount of the light source 210 is changed by the repetition number changing unit 500 according to the region to which the estimated blood glucose level 267 belongs.

  And by setting so that the number of repetitions of the measurement operation decreases in the region to which the large estimated blood glucose level belongs, and the region to which the small estimated blood glucose level belongs, the number of repetitions of the measurement operation is increased. A noninvasive blood glucose measurement device capable of shortening the time can be realized.

  More specifically, the non-invasive blood glucose measurement device 110 includes at least one light source 210, and irradiation light 111 having a wavelength equal to the wavelength absorbed by glucose is emitted from the light source 210. The photoacoustic wave signal 131 generated in the living body is converted into a voltage signal 221 by the living body information sensor 220.

  The activation signal 282 from the control unit 270 activates the amplification unit 230, the voltage signal 221 is amplified by the amplification unit 230, and the amplification signal 231 is output. The activation signal 282 from the control unit 270 activates the A / D conversion unit 240, A / D conversion is performed by the A / D conversion unit 240, the amplified signal 231 is converted into sampling data 241, and stored in the storage unit 250. Written.

  Sampling data 241 stored in the storage means 250 is estimated as the stored blood data 251 by the feature amount estimation means 260 by the feature amount estimation means 260, and this is output as a measurement result.

The storage unit 250 records the sampling data 241 written by the A / D conversion unit 240.
The sampling data 241 stored in the storage unit 250 is read as the storage data 251 by the feature amount estimation unit 260, and an estimated blood sugar level 267 is estimated, and this is output as a measurement result.

  At that time, a possible value of the estimated blood sugar level that is the feature amount is divided into a plurality of regions with a threshold value set in advance in the region threshold register 262, and the region to which the region to which the estimated blood glucose level currently belongs is the feature amount. This is determined by the area determination means 261 in the estimation means 260.

  Further, when the period in which the estimated blood glucose level exceeds the boundary of the region is a short period, a low pass in the feature amount estimation unit 260 is set so that the estimated blood glucose level does not exceed the estimated blood glucose level in the period exceeding the boundary. Filtering of the estimated blood glucose level is performed by the filter 263, and a correction region signal 266 is output.

  The control unit 270 controls the light amount 280 of the light source 210 and the lighting timing 281 corresponding to the number of repetitions. The activation signal 282 of the amplification unit 230 and the A / D conversion unit 240, the amplification unit 230, the A / D conversion unit 240, An end signal 283 is output to the feature quantity estimation means 260.

  That is, when the correction area signal 266 indicates that the estimated blood glucose level belongs, the area-specific repetition number changing means 676 changes the measurement operation repetition number to increase, and conversely the correction area signal 266 is large. When indicating that the estimated blood glucose level belongs, the region-specific repetition number changing unit 676 changes the number of repetitions so that the number of repetitions of the measurement operation is reduced.

  In addition, when the region invariance detecting unit 272 detects that the corrected region signal 266 belongs to the region to which the estimated blood glucose level that is large for a long time belongs, the region invariant detecting unit 272 sporadically increases the number of measurement operations. In addition, by controlling the region-specific repetition number changing means 676, the measurement accuracy is prevented from deteriorating.

Below, it demonstrates using a specific numerical example.
In the present embodiment, the measurement is performed 120 times (6 hours) at intervals of 3 minutes.
Here, the following values are set as initial values of the register that can be written from the outside.
That is,
(I) Region threshold value register 262: 150 (mg / dl) is set as the threshold value of the region determining means 261. (ii) LPF register 264: 1 (as the value of the time to be ignored when the low pass filter 263 of the area determining means 261 rises. (Iii) LPF lower register 265: 1 (measurement cycle) is set as a time value to be ignored when the low-pass filter 263 falls. (Iv) First area repetition count register 677: Repeat count change means for each area 300 (times) is set as the repeat count value of 676. (v) Second area repeat count register 678: 100 (times) is set as the repeat count value of the repeat count changing means 676 for each area. (Vi) Area invariant repeat count register 679: 200 (times) as the number of repetitions when the repetition number change request signal 675 is input (Vii) Invariable range register 272: 15 (measurement cycle) is set as the region invariable range of the region invariant detecting means 271, (viii) Invariant region register 273: 2 (region) is set as the detection region,
(Ix) Request time register 274: 2 (measurement cycle) is set as the light quantity change request time.

  After the above initial setting is completed, first, the noninvasive blood glucose measurement device 110 is mounted on the surface 120 of a living body such as a patient's arm as shown in FIG. Thereafter, when the patient activates a blood glucose level measurement start switch (not shown) provided in the non-invasive blood glucose measurement device 110, an activation signal is output to the amplification unit 230 and the A / D conversion unit 240 by the control unit 270, The amplification means 230 and the A / D conversion means 240 are activated. The lighting timing 281 and the light quantity 280 of the light source 210 are controlled at the timing when the amplification means 230 and the A / D conversion means 240 enter a stable operation, and the light source 210 is turned on.

The light 111 incident on the living body from the light source 210 propagates in the living body and is absorbed by glucose in the blood vessel 130, and a photoacoustic wave signal 131 is generated.
The photoacoustic wave signal 131 is converted into a voltage signal 221 corresponding to the pressure by the biological information sensor 220.

  The voltage signal 221 converted by the biological information sensor 220 is amplified by the amplification unit 230 with a preset gain, and is output to the A / D conversion unit 240 as an amplification signal 231.

  Here, the reason why the start signal 282 and the end signal 283 are input to the amplifying unit 230 is that an element such as an operational amplifier that is a constituent element of the amplifying unit 230 is operated only at the timing when the photoacoustic wave signal 131 is generated. Therefore, the power consumption of the amplifying unit 230 is reduced. Therefore, it is possible to realize an equivalent operation regardless of these signals.

  The activation signal 282 from the control unit 270 activates the A / D conversion unit 240. The amplified signal 231 output from the amplifying unit 230 is A / D converted at specific intervals by the A / D converting unit 240, and sampling data 241 as the A / D conversion result is written in the storage unit 250.

  Here, the end signal 283 is input to the A / D conversion means 240 because an element such as an AD converter that is a constituent element of the A / D conversion means 240 only at the timing when the photoacoustic wave signal 131 is generated. Is intended to reduce the power consumption of the A / D conversion means 240. Therefore, it is possible to realize an equivalent operation regardless of this signal.

  The end signal 283 from the control unit 270 is received by the feature amount estimation unit 260. The stored data 251 recorded in the storage unit 250 is read by the feature amount estimation unit 260. After the measurement for the number of repetitions is completed, the estimated blood glucose level 267 is calculated by the feature amount estimation unit 260 and output to the outside. .

  At that time, the region determination unit in the feature amount estimation unit 260 uses the low-pass filter 263 to ignore the data exceeding the short-term region and determine which region the estimated blood glucose level 267 corresponds to. The correction area signal 266 is output.

  A series of measurement operations from when the control unit 270 outputs the first activation signal to the amplification unit 230 and the A / D conversion unit 240 until the estimated blood glucose level 267 is calculated by the feature amount estimation unit 260 and output to the outside. This period is the basic measurement cycle, and this is repeated every 3 minutes.

  When the region invariance detecting unit 271 detects that the region to which the correction region signal 266 has not changed for a certain period of time, a repeat count change request signal 675 is output to the repeat count change unit 676 for each region. While the repetition number change request signal 675 is output, the control unit 270 changes the number of repetitions of the basic measurement cycle according to the value set in the region invariant repetition number register 679 by the region-specific repetition number changing unit 676. .

FIG. 7 shows how the number of repetitions is changed over time.
The real area signal shown in FIG. 5B is a signal generated by the area determination means 261 discriminating the estimated blood glucose level 267 with the area threshold value. In the present embodiment, “150” is set in the region threshold register 262 from the outside, and the Lo level is output if the estimated blood glucose level 267 is “150” or less, and the Hi level is output if it is greater than “150”.

  In this embodiment, the case where there are two areas has been described. However, when there are three or more areas, a plurality of area threshold registers 262 are provided, and a plurality of real area signals (multi-bit) are obtained. It is clear that it can be handled.

A corrected area signal 266 shown in FIG. 6C is a signal obtained by filtering the real area signal obtained by the area determining unit 261 by the low-pass filter 263. This is a signal for minimizing the change in the light amount and improving the measurement accuracy when the estimated blood glucose level 267 moves at short intervals near the boundary where the light amount is changed.
The filtering function can be eliminated by setting both the LPF upper register 264 and the LPF lower register 265 to “0”.

  In the present embodiment, “1” is set in the LPF upper register 264 and “1” is set in the LPF lower register 265 from the outside, and the low pass filter 263 outputs a signal at both the rise time and fall time of the real area signal. When the level is stable for a period longer than one measurement period, filtering is performed so that the signal level of the real area signal at that time is output.

  The repeat number change request signal 675 shown in FIG. 6D is monitored by the region invariance detecting unit 271 of the control unit 270 for the correction region signal 266 output from the feature amount estimating unit 260, and the region does not change for a certain period of time. Is a signal for requesting a change in the number of repetitions. That is, it is a signal for periodically confirming whether or not the measurement accuracy has deteriorated when the measurement period continues for a long time by reducing the number of repetitions.

  In addition, by setting the value of the area invariant repeat count register 679 to be larger than the value of the second area repeat count register 678, the repeat count can be increased only at the time of confirmation. Furthermore, by setting a plurality of areas in the invariant area register 273, it is possible to periodically change the number of repetitions even in the measurement area of the normal number of repetitions. Also, by setting “0” in the invariant area register 273 or setting the maximum value in the invariant area register 272, it is possible to eliminate the function of changing the number of repetitions when the area has not changed for a certain period of time. Is possible.

  In the present embodiment, “15” is set in the invariant range register 272, “2” is set in the invariant region register 273, and “2” is set in the request time register 274, which are output from the feature amount estimation unit 260. When the signal of the correction area signal 266 is stabilized for a time longer than 15 measurement periods in the area 2, the Hi level is output for 2 measurement periods. Further, when the region 2 continues, the Hi level is output for two measurement periods every 15 measurement periods thereafter.

  The number of repetitions shown in FIG. 5E indicates the number of activation signals 282 in the measurement basic cycle of the light source 210. The amount of light 280 is constant in the present embodiment. While the repetition number change request signal 675 is not output, the corresponding region set in the region-specific repetition number changing unit 676 is repeated according to the area of the correction region signal 266 output from the feature amount estimation unit 260. The value of the count register is output. While the repeat count change request signal 675 is being output, the value set in the area invariant repeat count register 679 is output.

  In the present embodiment, “300” is set in the first area repeat count register 677, “100” is set in the second area repeat count register 678, and “200” is set in the area invariant repeat count register 679, respectively. When the signal of the correction area signal 266 output from the feature amount estimation unit 260 is the area 1, “300” is output, when the signal is the area 2, 100 is output, and when the repetition number change request signal 675 is output. “200” is output.

  First, at time 0 minutes, the estimated blood glucose level 267 is 90 mg / dl. At this time, the correction area signal 266 of the area determination unit 261 is the area 1 and the number of repetitions is 300 times.

  When the estimated blood glucose level 267 gradually increases and the estimated blood glucose level 267 reaches 148 mg / dl at time 27 minutes, the correction area signal 266 of the area determination means 261 remains at area 1 at this time. The number of times is 300 times.

  Further, the estimated blood glucose level 267 rises, and the estimated blood glucose level 267 becomes 160 mg / dl at 30 minutes. At this time, the real area signal of the area determination unit 261 becomes Hi level, but the correction area signal 266 is cut by the low-pass filter 263 and remains at Lo level, and the number of repetitions is 300 times.

  At time 33 minutes, the estimated blood glucose level 267 is 135 mg / dl. At this time, the real area signal of the area determination means 261 becomes Lo level, and the number of repetitions is 300 times.

  At time 51 minutes, when the estimated blood glucose level 267 rises again and the estimated blood glucose level 267 reaches 153 mg / dl, the real area signal of the area determination means 261 again becomes Hi level, but the correction area signal 266 is cut by the low-pass filter 263 and remains at the Lo level, and the number of repetitions is 300.

  At time 54 minutes, the estimated blood glucose level 267 is 155 mg / dl. At this time, the real area signal of the area determination means 261 has a Hi level of 2 measurement cycles, and the correction area signal 266 becomes Hi level without being cut by the low-pass filter 263, and the number of repetitions is 100 times.

  At time 99 minutes, the estimated blood glucose level 267 is 197.5 mg / dl. At this time, the real area signal of the area determination means 261 remains at the Hi level, the correction area signal 266 is continuously cut at the Hi level without being cut by the low-pass filter 263, and the repeat count change request signal 675 is The Hi level is output for two measurement cycles, and the number of repetitions is 200.

  At time 102 minutes, the estimated blood glucose level 267 is 198 mg / dl. At this time, the real area signal of the area determination unit 261 remains at the Hi level, and the correction area signal 266 is continuously cut at the Hi level without being cut by the low-pass filter 263. The region invariant detecting unit 271 starts measuring the continuous period of the region 2 again. Since the repeat count change request signal 675 is output for two measurement cycles, it remains at the Hi level, and the repeat count is 200.

  At the time of 105 minutes, the value of the estimated blood sugar level 267 is 198.5 mg / dl. At this time, the real area signal of the area determination unit 261 remains at the Hi level, and the correction area signal 266 is continuously cut into 17 measurement periods Hi level without being cut by the low-pass filter 263. The light quantity change request signal 275 becomes Lo level, and the number of repetitions is 100 times.

  At time 144 minutes, the estimated blood glucose level 267 has a value of 199.5 mg / dl. At this time, the real area signal of the area determination unit 261 remains at the Hi level, and the correction area signal 266 is continuously at the 30 measurement period Hi level without being cut by the low-pass filter 263, and the repetition number change request signal 675 is The Hi level is output for two measurement cycles, and the number of repetitions is 200.

  At time 147 minutes, the estimated blood glucose level 267 is 199 mg / dl. At this time, the real area signal of the area determination unit 261 remains at the Hi level, and the correction area signal 266 is continuously at the 31 measurement period Hi level without being cut by the low-pass filter 263. The region invariant detecting unit 271 starts measuring the continuous period of the region 2 again. Since the repeat count change request signal 675 is output for two measurement cycles, it remains at the Hi level, and the repeat count is 200.

  At time 150 minutes, the estimated blood glucose level 267 is 198 mg / dl. At this time, the real area signal of the area determination unit 261 remains at the Hi level, and the correction area signal 266 is continuously at the 32 measurement period Hi level without being cut by the low-pass filter 263. The light quantity change request signal 275 becomes Lo level, and the number of repetitions is 100 times.

  At time 189 minutes, the estimated blood glucose level 267 is 160 mg / dl. At this time, the real area signal of the area determination unit 261 remains at the Hi level, and the correction area signal 266 becomes the continuous 45 measurement cycle Hi level without being cut by the low-pass filter 263, and the repetition number change request signal 675 is The Hi level is output for two measurement cycles, and the number of repetitions is 200.

  At time 192 minutes, the value of the estimated blood glucose level 267 is 155 mg / dl. At this time, the real area signal of the area determination unit 261 remains at the Hi level, and the correction area signal 266 is continuously cut at the Hi measurement level without being cut by the low-pass filter 263. The region invariant detecting unit 271 starts measuring the continuous period of the region 2 again. Since the repeat count change request signal 675 is output for two measurement cycles, it remains at the Hi level, and the repeat count is 200.

  At time 195 minutes, the estimated blood glucose level 267 is 149 mg / dl. At this time, the real area signal of the area determination unit 261 becomes Lo, but the correction area signal 266 is cut by the low-pass filter 263 and remains at the Hi level because “1” is set in the LPF lower register 265. . The light quantity change request signal 275 becomes Lo level, and the number of repetitions is 100 times.

  At time 198 minutes, the estimated blood glucose level 267 is 145 mg / dl. At this time, the real area signal of the area determination unit 261 remains Lo, and the correction area signal 266 is at the Lo level without being cut by the low-pass filter 263, and the number of repetitions is 300 times.

  At time 231 minutes, the estimated blood glucose level 267 rises again, and the estimated blood glucose level 267 becomes 151 mg / dl. At this time, the real area signal of the area determination means 261 becomes Hi level again, but the correction area signal 266 is cut by the low-pass filter 263 and remains at the Lo level, and the number of repetitions is 300 times.

  At time 234 minutes, the estimated blood glucose level 267 is 153 mg / dl. At this time, the real area signal of the area determination means 261 becomes Hi level, but the correction area signal 266 becomes Hi level without being cut by the low-pass filter 263, and the number of repetitions is 100 times.

  At time 273 minutes, the estimated blood glucose level 267 is 148 mg / dl. At this time, the real area signal of the area determination unit 261 becomes Lo, but the correction area signal 266 is cut by the low-pass filter 263 and remains at the Hi level because 1 is set in the LPF lower register 265, and is repeated. The number of times is 100.

  At time 276 minutes, the estimated blood glucose level 267 is 146 mg / dl. At this time, the real area signal of the area determination unit 261 remains Lo, and the correction area signal 266 is at the Lo level without being cut by the low-pass filter 263, and the number of repetitions is 300 times.

  Further, the estimated blood glucose level 267 rises, and at time 318 minutes, the estimated blood glucose level 267 becomes 152 mg / dl. At this time, the real area signal of the area determination unit 261 becomes Hi level, but the correction area signal 266 is cut by the low-pass filter 263 and remains at Lo level, and the number of repetitions is 300 times.

  At time 321 minutes, the estimated blood glucose level 267 is 148 mg / dl. At this time, the real area signal of the area determination means 261 becomes Lo level, and the number of repetitions is 300 times. At this time, the correction area signal 266 is at the level of 15 continuous measurement periods Lo, but since the invariable area register 273 does not set the area 1, the repeat count change request signal 675 is not output.

  At time 360 minutes, the estimated blood glucose level 267 is 111 mg / dl. At this time, the real area signal of the area determination unit 261 remains at the Lo level, and the number of repetitions is 300.

  In the second embodiment, the feature amount estimation unit 260 reads the stored data 251 stored in the storage unit 250 for each end signal 283, and after the measurement for the number of repetitions is completed, the estimated blood glucose level 267 is obtained. Although the calculation is repeated, it is clear that after the measurement for the number of repetitions is completed, the stored data 251 for the repeated measurement may be read out collectively, an averaging process may be performed, and the estimated blood glucose level 267 may be calculated. .

  As described above, according to the second embodiment of the present invention, the region determination unit that determines to which region the estimated feature amount belongs is provided, and the determined region is a region where a large estimated feature amount can be obtained. The number of repetitions in the measurement basic cycle is changed according to the determined area according to the determined area so that the number of repetitions in the measurement basic cycle is smaller than the area where the small estimated feature amount is obtained. By setting it, it is possible to reduce power consumption and shorten measurement time without degrading the measurement accuracy of the noninvasive blood glucose measurement device, greatly increasing the continuous measurement time when realized with portable devices. Can be stretched.

  In addition, if the region to which the estimated feature quantity does not change for a certain period of time, it is determined whether the measurement accuracy has decreased by changing the number of repetitions so that the number of measurement repetitions temporarily increases. It can be confirmed and deterioration of measurement accuracy can be prevented.

  In the second embodiment of the present invention, the non-invasive blood glucose measurement device using the photoacoustic method has been described as an example. However, other biological information measurement devices of the photoacoustic method, Raman spectroscopy, OCT (optical The present invention can also be applied to other noninvasive living body information measuring apparatuses using coherence tomography, optical rotation angle, light absorption and transmission.

  As described above, the noninvasive living body information measurement device according to the present invention realizes a device with low power consumption and short measurement time by changing the light source control method and the number of measurement repetitions according to the estimated feature amount. It is possible to improve the continuous measurement time of a portable non-invasive biological information measuring device.

The figure which shows the system configuration | structure in Embodiment 1 of this invention. The figure which shows the block structure of the noninvasive blood-glucose measuring apparatus 101 in Embodiment 1 of this invention. The figure which plotted the estimated blood glucose level 267 of the noninvasive blood glucose measuring device 110 in Embodiment 1 of this invention on the time axis The figure which plotted the estimated blood glucose level 267 of the noninvasive blood glucose measuring device 110 in Embodiment 1 of this invention on the time axis The figure which shows the system configuration | structure in Embodiment 2 of this invention. The figure which shows the block configuration of the noninvasive blood glucose measuring device 101 in Embodiment 2 of this invention. The figure which plotted the estimated blood glucose level 267 of the noninvasive blood glucose measuring device 110 in Embodiment 2 of this invention on the time axis

Explanation of symbols

DESCRIPTION OF SYMBOLS 110 Non-invasive blood glucose measuring device 111 Light 120 Living body 130 Blood vessel 131 Photoacoustic wave signal 210 Light source 220 Biological information sensor 221 Voltage signal 230 Amplifying means 231 Amplified signal 240 A / D conversion means 241 Sampling data 250 Storage means 251 Storage data 260 Features Estimating means 261 Area determining means 262 Area threshold register 263 Low pass filter 264 LPF upper register 265 LPF lower register 266 Correction area signal 267 Feature value 267 Estimated blood glucose level 270 Control means 271 Area invariant detecting means 272 Invariable area register 273 Invariant area register 274 Request Time register 275 Light quantity change request signal 276 Area-specific light quantity changing means 277 First area light quantity register 278 Second area light quantity register 279 Area invariant light quantity register 280 Light Amount 281 Lighting timing 282 Start signal 283 End signal 400 Light source control content changing means 500 Repeat count changing means 675 Repeat count change request signal 676 Repeat count change means by area 677 First area repeat count register 678 Second area repeat count register 679 Area Invariant repeat count register

Claims (30)

At least one light source;
A biological information sensor for measuring biological information;
Amplifying means for amplifying an output signal from the biological information sensor;
A / D conversion means for A / D converting the amplified signal;
Feature quantity estimation means for estimating the feature quantity of the biological information based on the A / D converted digital data;
Control means for controlling the light source and the activation of the amplification means and the A / D conversion means;
A light source control content changing unit that controls the control unit to change the control content of the light source according to the feature amount estimated by the feature amount estimation unit,
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 1,
The control content of the light source is control of the light amount of the light source.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 1,
The control content of the light source is control of the lighting time of the light source.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 1,
The feature amount estimation means includes region determination means for determining which of the plurality of regions obtained by dividing the estimated value of the feature amount into a range that the value can take.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 4,
The area determination means has a register writable from the outside,
The threshold value can be changed by changing the value of the register.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 4,
The region determination means includes a low-pass filter that performs filtering so that the estimated feature value can be regarded as not moving when the estimated feature value moves between regions in a short period of time.
Ignore events that move in a short period of time,
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 6,
The low-pass filter can individually set the time for determining the period of movement between the regions as a short period according to the direction of movement between the regions,
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 6,
The low-pass filter has a register writable from the outside,
By writing a new value to the register, it is possible to change the width of time for ignoring the change in the feature value when the estimated feature value value moves between regions in a short period of time.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 1,
The control unit includes a region-specific light amount changing unit that controls the light amount of the light source according to which region the value of the feature amount output from the feature amount estimation unit corresponds to.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 9,
The region-specific light amount changing means has at least one first register group writable from the outside,
By writing a new value to the first register group, it is possible to change the light amount value of the light source according to the region.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 9,
The region-specific light amount changing means has an input port for inputting a signal,
The light quantity of the light source can be changed by a signal input to the input port.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 11,
The region-specific light amount changing means has a second register writable from the outside,
By writing a new value to the second register,
It is possible to set the light quantity value of the light source to be changed by a signal input to the input port.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 1,
The control means detects whether or not the region to which the value of the feature value output from the feature quantity estimation means belongs has not changed for a certain period, and when it has not changed, requests to change the light amount of the light source A region invariant detecting means for outputting a light quantity change request signal
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 13,
The region invariance detecting means has a first register writable from the outside,
By writing a new value to the first register, it is possible to change the certain period for detecting whether or not the region to which the feature value output from the feature value estimation unit belongs has changed.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 13,
The region invariant detecting means has a second register writable from the outside,
By writing a new value to the second register, it is possible to select a detection target region that is a target for detecting whether or not the region to which the feature amount value output by the feature amount estimation means belongs is a region that does not change for a certain period of time. Is,
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 13,
The region invariance detecting means has a third register writable from the outside,
By writing a new value to the third register, the time for outputting the light amount change request signal can be changed.
A noninvasive living body information measuring device characterized by the above. At least one light source;
A biological information sensor for measuring biological information;
Amplifying means for amplifying an output signal from the biological information sensor;
A / D conversion means for A / D converting the amplified signal;
Storage means for storing the A / D converted digital data;
A series of measurement operations until the light source is turned on and the digital data is recorded in the recording means is repeated a predetermined number of times, and the digital data for a predetermined number of times stored in the storage means is averaged by repeating the measurement operation a predetermined number of times. A feature amount estimation means for analyzing the averaged data and estimating a feature amount of biological information;
Control means for controlling lighting timing of the light source, and activation of the amplification means and A / D conversion means;
A repetition number changing unit that controls the control unit to change the number of repetitions of the series of measurement operations according to the feature amount estimated by the feature amount estimation unit;
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 17,
The feature amount estimation means includes region determination means for determining which of the plurality of regions obtained by dividing the estimated value of the feature amount into a range that the value can take.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 18,
The area determination means has a register writable from the outside,
By writing a new value to the register, the boundary of the plurality of areas can be changed.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 18,
The region determination means includes a low-pass filter that performs filtering so that the estimated feature value can be regarded as not moving when the estimated feature value moves between regions in a short period of time.
Ignore events that move in a short time,
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 20,
The low-pass filter is
The time for judging the period of movement between the areas as a short period can be individually set according to the direction of movement between the areas,
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 20,
The low-pass filter has a register writable from the outside,
By writing a new value to the register, it is possible to change the width of time for ignoring the change in the feature value when the estimated feature value value moves between regions in a short period of time.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 17,
The control unit includes a region-specific repetition number changing unit that changes the number of repetitions of the measurement operation according to which region the value of the feature amount output from the feature amount estimation unit corresponds.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 23,
The region-specific repetition number changing means has a register writable from the outside,
By writing a new value to the register, the value of the number of repetitions can be changed for each region.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 23,
The region-specific repetition number changing means has an input port for inputting a signal,
The number of repetitions can be changed by a signal input to the input port.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 25,
The region-specific repetition number changing means has a second register writable from the outside,
By writing a new value to the second register,
The number of repetitions to be changed according to a signal input to the input port can be set.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 25,
The control means includes
Detecting whether the region to which the feature value output from the feature amount estimation unit belongs does not change for a certain period of time, and when the region has not changed, the control unit is configured to increase the number of repetitions of the measurement operation. Having a region invariant detection means to control,
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 27,
The region invariance detecting means has a first register writable from the outside,
By writing a new value to the first register, the time during which the area does not change can be changed.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 27,
The region invariant detecting means has a second register writable from the outside,
By writing a new value to the second register, it is possible to select an area for detecting whether or not the area to which the feature value output from the feature quantity estimation unit belongs does not change for a certain period of time.
A noninvasive living body information measuring device characterized by the above. The noninvasive living body information measuring device according to claim 27,
The region invariance detecting means has a third register writable from the outside,
By writing a new value to the third register, it is possible to change the time for outputting the repeat count change request signal for requesting the change of the repeat count of the measurement operation.
A noninvasive living body information measuring device characterized by the above.

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