JP2007105331A - Measuring instrument of metabolic amount - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an instrument capable of measuring a metabolic amount by a noninvasive technique based on physiological parameter measurement by a simple instrument constitution and a signal processing technique. <P>SOLUTION: A simple metabolic amount is calculated by using metabolic amount calculation formula (6) considering the thermal balance of the body from parameters of the surface temperature of fingers, the temperature, environmental temperature, a blood flow, oxygen saturation, etc. (a metabolic amount [thermogenic amount] of the whole body)=α(T<SB>a</SB>-T<SB>c</SB>)+β(T<SB>FS</SB>-T<SB>R</SB>) (6). In this formula, arterial blood temperature T<SB>a</SB>, the temperature T<SB>C</SB>, a heat capacity effective value α, the skin temperature T<SB>FS</SB>of the fingers, a room temperature T<SB>R</SB>and a convective heat conductivity effective value β are used. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a metabolic rate measuring apparatus that measures a plurality of physiological parameters in a living body without collecting blood and calculates a metabolic rate from the plurality of physiological parameters.

There are several ways to measure metabolism. Among them, indirect calorimetry is a method for measuring the amount of oxygen consumed to produce the metabolic amount, not directly measuring the metabolic amount. Among indirect calorimetry, there is an open circuit indirect calorimetry method in which a human face is covered with a mask, breathing air is collected, and oxygen and carbon dioxide consumption are measured. This method is used to measure changes in metabolic rate during exercise and rest, but it is difficult to keep the mask on for a long time, so it is limited to short-term metabolic rate measurement. In order to measure the amount of metabolism for a longer period of time, there is an indirect calorimetry method of a closed circuit system in which the amount of oxygen and carbon dioxide produced in a sealed room is measured. This method can measure the amount of metabolism at rest or during sleep, and can be measured for a long time because there is less burden on humans. In addition, there is a method of measuring energy consumption during the period by drinking water containing stable isotopes of hydrogen and oxygen that are harmless to the human body and measuring the course of stable isotopes excreted in urine. In this measurement, the average energy consumption in a person's daily life is measured. Japanese Patent Application Laid-Open No. 2004-329542 describes a method for calculating a blood glucose level using a relationship between a parameter corresponding to a plurality of temperatures derived from the body surface and the amount of oxygen in the blood and the blood glucose level. Yes.
JP 2004-329542 A

  In measuring the amount of metabolism, a large-scale device has been conventionally required, and it has not been easy for an individual to measure in daily life.

  An object of this invention is to provide the method and apparatus which an individual can measure a metabolic rate simply at home.

  Much of the heat generated by metabolism is spent on maintaining body temperature, and excess heat is released outside the body. That is, the amount of heat generated by metabolism (the amount of heat produced) is equal to the sum of the amount of heat stored in the body (the amount of stored heat) and the amount of heat released outside the body (the amount of heat released). From this heat control mechanism of the human body, the metabolic rate can be calculated based on the heat storage amount and the heat release amount.

  The metabolic rate measuring device according to the present invention includes an environmental temperature measuring device that measures the environmental temperature, a finger temperature measuring device that measures the temperature of the finger surface, a body temperature capturing unit that captures body temperature information, and information on the blood flow of the finger Authentication is performed by using a blood flow volume capturing unit that captures the image, an image capturing unit for finger authentication, an image storage unit that stores an image for authentication, an image captured by the image capturing unit, and an image stored in the image storage unit The authentication unit, the storage unit storing the relationship between the environmental temperature, the finger surface temperature, the body temperature, the blood flow rate and the metabolic rate, the environmental temperature measured by the environmental temperature measuring device, and the finger measured by the finger temperature measuring device A computing unit that calculates the metabolic rate by applying the surface temperature, the body temperature taken in by the body temperature taking-in unit, and the blood flow taken in by the blood flow taking-in unit to the relationship stored in the storage unit, and is calculated by the computing unit Tayu And a display unit for displaying. The body temperature capturing unit is a thermometer, and the output of the thermometer may be supplied to the calculation unit, or may be an operation unit for inputting a separately measured body temperature as a numerical value. If authentication by the authentication unit fails, the process ends.

The metabolic rate measuring apparatus according to the present invention also includes an environmental temperature measuring device for measuring the environmental temperature, a finger surface contact portion that contacts the finger surface, a cylindrical member that contacts the finger surface contact portion and opens at one end. A radiation thermometer that is provided in the vicinity of the other end of the tubular member and that measures radiant heat from the surface of the finger; a blood flow obtaining unit that obtains information on the blood flow of the finger; and toward the one end of the tubular member A light source that emits light of at least two different wavelengths, a photodetector that detects light interacting with a finger in contact with the finger surface contact portion, a body temperature capturing portion that captures body temperature information, and finger authentication Measured by an imaging unit for image processing, an image storage unit for storing an image for authentication, an authentication unit for performing authentication using an image captured by the imaging unit and an image stored in the image storage unit, and an environmental temperature measuring instrument Measured ambient temperature, finger measured by radiation thermometer Metabolism by applying the surface temperature, the body temperature captured by the body temperature capturing unit, the blood flow captured by the blood flow capturing unit, and the photodetection result measured by the photodetector to the relationship with the prestored metabolic rate A calculation unit that calculates the quantity and a display unit that displays a result output from the calculation unit are provided.
In addition, a storage unit that stores the results output from the calculation unit may be provided, and the data stored in the storage unit may be displayed in time series on the display unit.

  According to the present invention, a simple metabolic rate measuring device can be obtained.

Based on the principle of the human body's thermal control mechanism, the amount of heat generated by metabolism (the amount of heat produced) is equal to the sum of the amount of heat stored in the body (the amount of stored heat) and the amount of heat released to the outside of the body (the amount of heat released). .
(Total body metabolism [amount of heat production]) = (total body heat storage) + (total body heat release)… (1)

The body internal temperature at the site r _i of the body T, the tissue temperature T _T in the region r _i of the body, when the heat capacity at the site r _i of the body and alpha _i, the heat storage amount of the entire body is the heat storage amount in each part of the body And can be expressed by the following equation.

Although equation (2) are those dealing with the amount of each part of the body, the body temperature as a valid value using the arterial blood temperature T _a of the body deep as an effective value representing the body portion temperature, representative of the tissue temperature of the body Use _Tc . As for the heat capacity, α is used as an effective value representing the heat capacity of the whole body. This α is a value that depends on the body composition, density, weight, etc. of each individual. From the above, the heat storage amount of the whole body can be expressed by the following formula.
Total amount of heat stored in the body = α (T _a −T _c ) (3)

In general, heat radiation is performed by conduction, radiation, convection, and evaporation, but conduction and radiation have a small amount of heat and can be ignored when a person is wearing clothes. Evaporation can be ignored assuming a room condition where temperature control is performed without sweating. When this order is considered only heat dissipation by convection between the body surface and the air, convection skin temperature at the surface region r _j of the body T _S, the external temperature in contact with the surface sites r _j of the body T _OUT, in the surface region r _j of the body If the heat transfer coefficient is β _j , the heat dissipation amount of the entire body is the sum of the heat dissipation amounts from the surface parts of the body, and can be expressed by the following equation.

Equation (4) deals with the amount of each part of the body, but the finger skin temperature T _FS is used as an effective value representing the body surface temperature of the body, and the room temperature T _R is used as an effective value representing the external temperature. Is used. As for the convective heat transfer coefficient, β is used as an effective value representing the convective heat transfer coefficient of the entire body surface region. This β is a value that depends on the surface area and clothes of each individual. As described above, the amount of heat released from the entire body can be expressed by the following equation.
Total heat dissipation = β (T _FS -T _R ) (5)

  In this example, the finger is used as a representative part of the heat dissipation of the entire body because the finger is sensitive to changes in the external temperature, the skin temperature and the amount of heat release appear to be large, and the muscles are few so that it is local. This is because the amount of heat produced is small and reflects well the whole body phenomenon.

From the formulas (1), (3), and (5), the metabolism amount of the whole body can be expressed by the following formula.
(Metabolic rate of whole body [heat _{production]) = α (T a -T} c) + β (T FS -T R) ... (6)

From the heat flow conservation rule with fingers, it can be considered that the amount of heat entering the finger and the amount of heat released from the finger are balanced. For the finger tissue, let T _{Fa be} the arterial temperature of the deep part of the finger, λ be the thermal conductivity of the finger tissue, ω _{b be} the blood flow in the finger tissue, c _{b be} the specific heat of the blood, and the convective heat transfer coefficient κ Then, the heat flow conservation law of a finger can be expressed by the following formula. In this equation, χ is a proportional coefficient.
_{λ (χω b c b T Fa} -T FS) = κ (T FS -T R) ... (7)

The left-hand side represents the heat transfer from the artery to the finger surface to the tissue, and Penn's biological heat transfer equation (Pennes HH, “Analysis of tissue and arterial blood temperatures in the resting human forearm” J. applied physiology, 1, 93-122 (1984)).

Here, assuming that the arterial temperature T _{Fa in} the deep part of the finger is proportional to the arterial blood temperature T _{a in} the deep part of the body, and T _Fa = σT _a + τ, Equation (7) is as follows.

この式(8)を式(6)に代入すると、式(9)が得られる。

Substituting this equation (8) into equation (6) yields equation (9).

  In order to use Equation (9), it is necessary to determine proportional coefficients a to e that are different for each individual. For this purpose, it is possible to take a method in which a person's metabolic rate is measured and a coefficient of each individual is obtained by multiple regression analysis from Equation (9) and the measured metabolic rate.

According to the above model equation, finger surface temperature T _FS , room temperature T _R as an effective value representing the body surface temperature of the body, body temperature T _c as an effective value representing the body tissue temperature, and blood flow ω _b are measured, By using the proportionality coefficient measured separately, the metabolic rate can be measured. Here, the representative measurement point of the body is the fingertip, but other body surfaces can be used. The representative point of body tissue temperature corresponds to the tissue temperature inside the body by measuring the temperature of the part different from the temperature measurement part as the effective value representing the body surface temperature of the body, such as sublingual, armpit, rectum, etc. Temperature to be obtained. In addition, as a temperature measurement site | part as an effective value representing the body surface temperature of a body, the site | part of an extremity can also be utilized besides a finger surface.

In addition, since measuring the amount of metabolism requires a large-scale device, the amount of metabolism corresponding to the glucose concentration can be obtained by using the relationship between the blood glucose concentration and the amount of metabolism, which is a human energy source. You can also. Relationship metabolic rate and the glucose concentration of the whole body, part r _k QG (r _j) the amount of heat generated by the glucose heat production in the body, Qpai the amount of heat generated by the heat production by glucose substances other than such fatty and amino acids If (r _j) to, metabolic rate of the entire body becomes a heat summation occurring in each part of the body, it can be shown by the following equation.

Equation (10) is, which treats heat of each part of the body, the average intracellular glucose concentration G _c in the entire body is proportional to the metabolic rate by glucose in cells, the average of the whole body Assuming that the intracellular concentration の of substances other than glucose is proportional to the amount of metabolism due to other than intracellular glucose, and the proportionality coefficients are A and B, the amount of metabolism of the whole body can be expressed by the following equation.
Total body metabolism = AG _c + BΠ… (11)
From the equations (9) and (11), the following equation is established.

According to the above model equation, finger surface temperature T _FS , room temperature T _R as an effective value representing the body surface temperature of the body, body temperature T _c as an effective value representing the body tissue temperature, and blood flow ω _b are measured, By using the separately measured proportionality coefficient, the metabolic rate AG _c corresponding to blood glucose can be measured.

When it is desired to improve accuracy, tissue oxygen saturation is taken into consideration. Since the heat radiation amount of the whole body is proportional to the amount of oxygen used, the relationship of G _c + Π∝ [O ₂ consumption amount] is established. Since tissue oxygen saturation StO ₂ is synonymous with O ₂ consumption, it can be expressed by the following equation.
StO ₂ = a′G _c + b′Π (13)
Equation (14) is established from Equation (12) and Equation (13).

According to the above model formula, finger surface temperature T _FS , room temperature T _R as effective values representative of body surface temperature of body, body temperature T _c as effective values representative of body tissue temperature, blood flow ω _b , tissue oxygen saturation By measuring the degree StO ₂ and using a separately measured proportionality coefficient, it is possible to measure ((ab′−a′b) / b ′) G _c which is a metabolic amount corresponding to blood glucose.

  Further, when the coefficients of the equation (14) are arranged, the equation (15) is obtained, and the glucose concentration can be calculated.

Embodiments of the present invention will be described below with reference to the drawings.
First, the finger surface temperature and room temperature can be measured relatively easily by using, for example, a resistance temperature detector or a radiation thermometer that measures radiation heat. Regarding body temperature, sublingual body temperature, armpit body temperature, rectal temperature, and eardrum temperature can be measured relatively easily with an electronic thermometer using a resistance thermometer or an ear thermometer using a radiation thermometer. The blood flow rate can be measured by a laser blood flow meter using the Doppler effect as an example, and can also be measured by a method in which a minute amount of heat is applied to the finger and the temperature change is measured. The tissue oxygen saturation can be measured non-invasively with a pulse oximeter or a tissue oxygen saturation meter having a function of obtaining an optical oxygen saturation.

FIG. 1 is an explanatory diagram illustrating the relationship between measured values obtained by various sensors and parameters derived therefrom. Using radiation thermometer measures the surface temperature T _FS finger, measuring the room temperature T _R with the thermistor. The body temperature T _c is measured using a thermometer connected to the main body or commercially available. Further, the light intensity I is measured at a wavelength related to the absorption of hemoglobin, and the blood flow ω _b is calculated. A parameter relating to the arterial blood temperature is calculated from the finger surface temperature _TFS and the blood flow ω _b . Further, the absorbances A ₁ and A ₂ are measured at at least two wavelengths related to the absorption of hemoglobin, and a parameter relating to the degree of oxygen saturation of the hemoglobin is calculated.

  FIG. 2 is a top view of a metabolic meter according to the present invention. In this device, the skin of the belly of the fingertip is used as the body surface, but other body surfaces can be used on the principle of measurement.

  The apparatus is divided into a body temperature measuring unit 1 for measuring body temperature and a body unit 2 for measuring room temperature, finger surface temperature, blood flow volume and tissue oxygen saturation, and the body temperature measuring unit 1 and body unit 2 are connected by a wiring unit 3. Has been. In this embodiment, the body temperature measurement unit 1 and the body unit 2 are connected, and the body temperature data measured by the body temperature measurement unit 1 is transmitted to the body unit 2, but a commercially available thermometer is used. The body temperature data may be input using the operation unit 10 of the main body unit 2. Further, the blood flow volume and tissue oxygen saturation may be input using a commercially available device, and the blood flow data and tissue oxygen saturation data may be input using the operation unit 10 of the main body 2. . FIG. 3 shows a top view of a metabolic meter according to the present invention when body temperature and blood flow are measured with a general device.

  For example, body temperature data can be input on a screen as shown in FIG. In this example, 36.50 ° C. is displayed as a specified value, and an underline is displayed at the first place, indicating that it is an input target. Here, the numerical values are changed using the operation buttons 10b and 10c. That is, when the displayed numerical value is increased, the operation button 10b is pressed, and when it is decreased, the operation button 10c is pressed to input the measured body temperature. After that, the operation button 10d is pressed and the unit of the body temperature is pressed. To decide. After that, the first place and the second place of the decimal point are inputted by the same operation, and the body temperature data is inputted. If the operation button 10d is accidentally pressed, the input can be performed again by pressing the operation button 10a.

  On the upper surface of the apparatus, the operation unit 10, the measurement unit 12 on which a finger to be measured is placed, the display of the measurement result, the display unit 11 for displaying the state of the apparatus and the measurement value, and the finger on the measurement unit 12 with appropriate pressure Push pressure display light emitting diodes 15a and 15b are provided for indicating whether they are placed. The operation unit 10 is provided with four push buttons 10a to 10d for operating the apparatus. The measurement unit 12 is provided with a cover 14, and when the cover 14 is opened (the figure shows a state in which the cover is opened), there is a finger placement unit 13 having an elliptical periphery. The finger placement unit 13 includes an opening end 22 of the radiation temperature sensor unit, an optical sensor unit 30, and a temperature sensor unit 20.

  FIG. 5 shows the operation procedure of the apparatus. When the device is turned on by pressing the button on the operation unit 10, "warming up" is displayed on the display unit 11, and the electronic circuit in the device is warmed up. At the same time, a check program runs and automatically checks the electronic circuit. When “warming up” is completed, “Authenticate. Please place your finger” is displayed on the liquid crystal display unit 11 for personal authentication by vein authentication. An image photographed by a camera provided in the measurement unit 12 is pattern-matched with an image registered in the database, and authentication of a registered user or a non-registered user is performed. If it cannot be authenticated by pattern matching, it is determined whether or not to re-authenticate. When the vein authentication pattern matching is completed, “Please place your finger” is displayed on the display unit 11 for measurement.

  When a finger is placed on the finger placement unit 13, measurement starts and a countdown is displayed on the display unit 11. During the countdown, at the same time, whether or not the pressing pressure with which the finger presses the finger placement unit 13 is an appropriate pressing pressure is displayed by the pressing pressure display units 15a and 15b. For example, when the pressing pressure is appropriate, both the pressing pressure display light emitting diodes 15a and 15b are lit. When the pressing pressure is smaller than the proper range, only the light emitting diode 15a is lit, and when the pressing pressure is larger than the proper range, only the light emitting diode 15b is lit. The color of the light emitting diodes 15a and 15b may be changed. When the countdown ends, “Please release your finger” is displayed on the display unit 11. When the finger is removed from the finger placement unit 13, “data processing in progress” is displayed on the display unit 11. Thereafter, the metabolic rate corresponding to the blood glucose concentration is displayed on the display unit 11. At this time, a coefficient for a user who is authenticated by vein authentication is used as a coefficient applied to an expression for obtaining blood glucose. At this time, the displayed blood glucose level is stored for each user together with the date / time and stored in the measurement data DB in the apparatus. When a user IC card is installed in the apparatus, measurement data is stored in the IC card together with the date and time. Stored in the IC card. After reading the displayed metabolic rate, press the button on the operation unit. After about 1 minute, the device is in a state where “Authenticate. Put your finger” is displayed on the display unit 11 for the next authentication.

  When viewing a past history stored in the device, only the history of the user who has performed vein authentication is displayed. Further, when the apparatus is used by one user or when measured data may be shared, the vein authentication function can be canceled.

  6A and 6B are diagrams showing details of the measurement unit, in which FIG. 6A is a top view, FIG. 6B is an XX sectional view thereof, and FIG. 6C is a YY sectional view thereof.

  First, temperature measurement using the metabolic meter of the present invention will be described. An infrared lens 25 is arranged at a position inside the apparatus where the test part (finger's belly) placed on the finger placement unit 13 can be seen, and a pyroelectric detector 27 is arranged below the infrared lens 25 via an infrared transmission window 26. Has been. The thermistor 23 is used to measure the room temperature, and the temperature immediately before placing the finger is the room temperature. Further, a small camera 28 is incorporated in the sensor body for finger vein authentication.

As described above, the temperature sensor unit of the present embodiment has three temperature sensors and measures the following three types of temperatures.
(1) Radiation temperature of finger (pyroelectric detector 27): T _FS
(2) room temperature (thermistor 23): T _R
(3) Body temperature (body temperature measurement unit 1): T _c

  FIG. 7 is a schematic diagram of the pressing pressure detection mechanism. A spring 29 and switches 50a and 50b are attached to the housing and a moving distance measuring bar 51 is attached to the sensor cover 30 in order to tell the user whether or not the pressure is being pressed with an appropriate pressing pressure. There is a spring 29 at the bottom of the sensor cover. Light emitting diodes 15a and 15b are connected to the switches 50a and 50b. Assuming that the spring constant of the spring 29 is k and the springs are attached to the four corners of the bottom of the sensor cover, the total spring constant is 4k. If the pressing pressures m1 to m2 are appropriate, the spring contraction distance h1 = 4k / m1 to h2 = 4k / m2 indicates an appropriate pressing pressure. A switch 50a is installed when the spring 29 is contracted by h1, and a switch 50b is installed when the spring 29 is contracted by h2. When the sensor is pressed with a force less than m1, the moving distance measuring bar 51 does not pass through the switch 50a, so that only the light emitting diode 15a is turned on. When the sensor is pressed with a force of m1 or more and m2 or less, since the moving distance measuring bar 51 passes through the switch 50a, the light emitting diodes 15a and 15b are turned on. When pressed with a force greater than m2, the moving distance measuring bar 51 passes through the switch 50b, the light emitting diode 15a is turned off, and only 15b is lit to notify that an appropriate pressing pressure has been exceeded.

  Next, the optical sensor unit 30 will be described. The optical sensor unit is for measuring the hemoglobin concentration and the hemoglobin oxygen saturation necessary for obtaining the tissue oxygen saturation. In order to measure the hemoglobin concentration and the hemoglobin oxygen saturation, it is necessary to measure the absorbance at a minimum of two wavelengths. FIG. 6C shows a two-wavelength measurement using two light sources 33 and 34 and one detector 35. An example of the configuration is shown.

  The ends of the two optical fibers 31 and 32 are located in the optical sensor unit 30. The optical fiber 31 is an optical fiber for irradiating light, and the optical fiber 32 is an optical fiber for receiving light. As shown in FIG. 6C, the optical fiber 31 is connected to fibers 31a and 31b serving as branch lines, and light emitting diodes 33 and 34 having two wavelengths are arranged at the ends of the fibers. A photodiode 35 is disposed at the end of the light receiving optical fiber 32. The light emitting diode 33 emits light having a wavelength of 830 nm, and the light emitting diode 34 emits light having a wavelength of 780 nm. Using these two near-infrared lights, the oxygenated and reduced hemoglobin concentration changes, and the total hemoglobin concentration change corresponding to the blood volume, which is the sum thereof, are measured.

  In the optical sensor unit 30, user authentication is performed using the small camera 28. The two light emitting diodes 33 and 34 emit light, and the light is transmitted and scattered to the measurement unit such as a finger. When the light emitting diodes 33 and 34 irradiate the measurement unit, the small camera 28 takes an image of the measurement unit. The user is authenticated by matching the video taken at this time with the video registered in advance.

The two light emitting diodes 33 and 34 emit light in a time-sharing manner, and the light generated from the light emitting diodes 33 and 34 is applied to the subject's finger from the optical fiber 31 for light irradiation. The light applied to the finger is diffusely reflected by the finger skin, enters the light receiving optical fiber 32, and is detected by the photodiode 35. When light irradiated on the finger is diffusely reflected by the skin of the finger, the light penetrates into the tissue through the skin and is absorbed by hemoglobin in the blood flowing through the capillaries. The data measured by the photodiode 35 is the reflectance R, and the absorbance is approximately calculated by log (1 / R). By irradiating light with a wavelength of 830 nm and light with a wavelength of 780 nm, measuring the reflectance R for each, and calculating log (1 / R), the absorbance A _{1 at} a wavelength of 830 nm and the absorbance A _{2 at a} wavelength of 780 nm are measured. The

Assuming that the reduced hemoglobin concentration is [Hb] and the oxygen-binding hemoglobin concentration is [HbO ₂ ], the absorbance A ₁ and absorbance A ₂ are expressed by the following equations.

A _Hb (830 nm), A _Hb (780 nm), A _{HbO 2} (830 nm) and A _{HbO 2} (780 nm) are molar extinction coefficients of reduced hemoglobin and oxygen-binding hemoglobin, respectively, and are known at each wavelength. a is a proportionality coefficient. The hemoglobin concentration [Hb] + [HbO ₂ ] and the hemoglobin oxygen saturation [HbO ₂ ] / ([Hb] + [HbO ₂ ]) are obtained from the above equation as follows.

  Although an example of measuring hemoglobin concentration and hemoglobin oxygen saturation by measuring absorbance at two wavelengths has been described here, measuring the absorbance at three wavelengths or more reduces the influence of interfering components and increases the measurement accuracy. Is also possible.

  The blood flow rate can be obtained from the frequency spectrum of 780 nm light of the light emitting diode 34 among the light scattered and reflected by the finger in the same manner as follows.

Here, k ₁ is a proportionality constant, ω is an angular frequency, P (ω) is a power spectrum of the signal, and I is an amount of light received at a wavelength of 780 nm.

  FIG. 8 is a conceptual diagram showing the flow of data processing in the apparatus. The apparatus of this example includes a sensor including a body temperature measuring unit 1, a thermistor 23, a pyroelectric detector 27, a photodiode 35, a vein authentication camera 28, and pressing pressure check switches 50a and 50b. The photodiode 35 measures the absorbance at a wavelength of 830 nm and the absorbance at a wavelength of 780 nm. The vein authentication camera 28 also images a measurement site irradiated with light having a wavelength of 830 nm and a wavelength of 780 nm. Further, the moving distance measuring bar 51 acts on the pressing pressure check switches 50 a and 50 b according to the vertical movement of the sensor cover 30. These measurements are input to the device.

  Nine kinds of analog signals are converted into digital signals by analog / digital converters AD1 to AD6 via amplifiers A1 to A6, respectively. Five physiological parameters (body temperature, room temperature, finger surface temperature, blood flow, tissue oxygen saturation) are calculated from the digitally converted values.

  With these five physiological parameters, a conversion calculation into a metabolic rate for final display is performed. FIG. 9 shows a functional block diagram of the apparatus. This apparatus is driven by a battery 41. A signal measured by the sensor unit 43 including the temperature sensor and the optical sensor enters an analog / digital converter 44 (analog / digital converters AD1 to AD6) installed corresponding to each signal, and is converted into a digital signal. Is done. As peripheral circuits of the microprocessor 45, there are analog / digital converters AD1 to AD6, a liquid crystal display 11, a RAM 42, and pressing pressure display light emitting diodes 15a and 15b, which are accessed from the microprocessor 45 through each bus line 46. Is done. The push buttons 10a to 10d are connected to the microprocessor 45, respectively. The microprocessor 45 has a built-in ROM 47 for storing software. The microprocessor 45 can receive a command from the outside by pressing the buttons 10a to 10d.

A ROM 47 built in the microprocessor 45 stores a program and an authentication program necessary for processing calculation. The authentication program performs authentication by pattern matching using the finger vein image captured by the small camera and the image stored in the authentication image storage unit. The microprocessor 45 further includes a hemoglobin oxygen saturation constant storage unit 48 for storing hemoglobin oxygen saturation constants and a blood flow constant storage unit 29 for storing blood flow constants. The calculation program calls the optimum constants from the Hb / O ₂ constant storage part and the blood flow constant storage part after the finger measurement is completed and calculates. Similarly, a memory area necessary for processing calculation is secured in the RAM 42 incorporated in the apparatus. The result of the calculation process is displayed on the liquid crystal display unit 11.

  In this embodiment, the metabolic rate is calculated in the apparatus. However, physiological parameters can be stored in the IC card, and the metabolic rate can be calculated by reading the IC card data with another PC, for example.

The ROM contains a function for obtaining a metabolic rate as a program component necessary for processing calculation. This function is defined as follows. First, the metabolic rate is expressed by equation (9). Counts a to e in Equation (9) are determined in advance from a plurality of measurement data. The procedure for obtaining a to e (a _i (i = 0,1,2,3,4)) is as follows.
(1) Create a multiple regression equation showing the relationship between physiological parameters and metabolic rate measured separately.
(2) A normal equation (simultaneous equation) relating to physiological parameters is obtained from an equation obtained by the method of least squares.
(3) The values of the coefficients a _i (i = 0, 1, 2, 3, 4, 5) are obtained from the normal equation and substituted into the multiple regression equation.

Further, the glucose concentration is expressed by the formula (15). The counts a to f in the equation (15) are determined in advance from a plurality of measurement data. The procedure for obtaining a to f (a _i (i = 0,1,2,3,4,5)) can be performed in the same manner as the above metabolic rate. Here, an example of glucose concentration is shown.

_First , blood glucose concentration G _c and physiological parameters X ₁ = (T _FS −T _R ) / ω _b , X ₂ = T _FS / ω _b , X ₃ = (T _FS −T _R ), X ₄ = T _The following regression equation (19) representing the relationship of _c , X ₅ = StO ₂ is made.

Subsequently, the least square method is used to obtain a multiple regression equation that minimizes an error from the blood glucose concentration measurement value G _c by the enzyme electrode method. When the sum of squares of the residual is D, D is expressed by the following equation (20).

The square sum D of the residual is minimized, wherein the _{(20) a 0, a 1} , ..., because when a zero partial differentiation with a _5, the following equation is obtained.

When the average values of C and X _{1 to} X ₅ are C _mean and X _{1mean to} X _5mean , X _imean = 0 (i = 1 to 5), and thus Expression (22) is obtained from Expression (19).

Further, the fluctuation / covariation between the normalization parameters is expressed by Expression (23), and the covariation between the normalization parameter X _i (i = 1 to 5) and C is expressed by Expression (24).

If equation (22) (23) (24) organized into Equation (21), simultaneous equations (normal equation) (25) is obtained, a ₁ ~a ₅ is obtained by solving this.

The constant term a ₀ is obtained using equation (22). The a _i (i = 0, 1, 2, 3, 4, 5) obtained as described above are stored in the ROM when the apparatus is manufactured. In the actual measurement by the apparatus, the glucose concentration is calculated by substituting the normalization parameters X _{1 to} X ₅ obtained from the measurement values into the regression equation (19). Further, a _i (i = 0, 1, 2, 3, 4, 5) can be obtained for each individual to be used after the sale, not at the time of manufacturing the device, and can be stored in the IC card.

  Below, the specific example of the calculation process of metabolic rate is shown. The coefficient of equation (9) is determined from a large number of data measured in advance for the number of adults, and the following formula for calculating the metabolic rate is stored in the ROM of the microprocessor.

As an example of the measured value, if the measurement data T _c = 36.70, T _FS −T _R = 4.70, (T _FS −T _R ) / ω _b = 10.00, and T _FS / ω _b = 61.80 are substituted into the above formula, 8.4 kJ It becomes. The metabolic rate by the indirect calorimetry of the closed circuit system at this time is 8.5 kJ. In addition, measurement data T _c = 37.10, T _FS −T _R = 7.20, (T _FS −T _R ) / ω _b = 8.60, T _FS / Substituting ω _b = 38.10 into the above equation yields 7.7 kJ.

  FIG. 10 plots the measured values for a plurality of subjects, with the vertical axis representing the calculated metabolic rate by the method of the present invention and the horizontal axis representing the measured metabolic rate by the closed circuit indirect calorimetry method. FIG. As in this method, a good correlation can be obtained by measuring the body temperature, finger temperature, and blood flow of a person and calculating the metabolic rate (correlation coefficient = 0.82).

  Below, the specific example of the calculation process of glucose concentration is shown. The coefficient of equation (15) is determined from a large number of data measured in advance for the large number of people, and the following formula for calculating the glucose concentration is stored in the ROM of the microprocessor.

As an example of the measured value, the measurement data T _c = 36.55, T _FS −T _R = 7.91, (T _FS −T _R ) / ω _b = 16.27, T _FS / ω _b = 64.96, StO ₂ = 0.36 Substituting for yields 141.2. The blood glucose concentration at this time is 138.0 mg / dl. In addition, when the blood glucose concentration is 100.0 mg / dl, the measurement data T _c = 36.85, T _FS −T _R = 8.02, (T _FS −T _R ) / ω _b = 11.74, T _FS / ω _b = 46.97, Substituting StO ₂ = 0.38 into the above equation yields 95.7 mg / dl.

  FIG. 11 is a diagram in which the measured values are plotted for a plurality of subjects, with the vertical axis representing the glucose concentration calculated by the method of the present invention and the horizontal axis representing the glucose concentration measured value by the enzyme electrode method. As in this method, a good correlation can be obtained by measuring the human body temperature, finger temperature, oxygen supply amount, blood flow volume and calculating blood glucose concentration (correlation coefficient = 0.84).

  Further, by multiplying the calculated glucose concentration by the coefficient A in the equation (11), the metabolic rate corresponding to the blood glucose concentration can be calculated.

  In the examples, the amount of metabolism corresponding to the glucose concentration was determined, but there are metabolic amounts of substances other than glucose such as neutral fat and cholesterol, and a calculation formula was created from these blood concentrations and measured values. In addition, the amount of metabolism corresponding to the neutral fat or cholesterol concentration can also be determined.

  In addition, the tendency of the accumulated measurement value of the metabolic amount corresponding to the calculated metabolic amount, glucose concentration, blood glucose concentration, etc. shows that the healthy person and metabolic disease such as arteriosclerosis, heart disease, glucose intolerance etc. Since these are different from the affected patients, these calculated values can also be used as an index for understanding the disease state. By displaying the accumulated metabolic rate in time series, it becomes easy to judge the tendency.

Explanatory drawing which shows the relationship between the measured value by various sensors, and the parameter derived | derived from it. 1 is a top view of a metabolic meter according to the present invention. FIG. 1 is a top view of a metabolic meter according to the present invention. FIG. The figure which shows the input operation of a numerical value. The figure which shows the operation procedure of an apparatus. Detailed drawing of a measurement part. The schematic diagram of a pressing-pressure detection mechanism. The conceptual diagram which shows the flow of the data processing in an apparatus. The conceptual diagram which shows the data storage place in an apparatus. The plot figure of the metabolic rate measured by the calculated value of the metabolic rate by this invention and the conventional method. The plot figure of the calculated value of the glucose concentration by this invention, and the measured value of the glucose concentration by the enzyme electrode method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Body temperature measurement part, 2 ... Main part, 3 ... Wiring part, 10 ... Operation part, 11 ... Display part, 12 ... Measurement part, 13 ... Finger placing part, 22 ... Opening end of radiation temperature sensor part, 20 ... Temperature Sensor unit, 30 ... Optical sensor unit, 21 ... Plate, 23 ... Thermistor, 25 ... Infrared lens, 26 ... Infrared transmission window, 27 ... Pyroelectric detector, 31, 32 ... Optical fiber, 33, 34 ... Light source, 35 ... Photo diode

Claims (15)

An environmental temperature measuring device for measuring the environmental temperature;
A finger temperature measuring device for measuring the temperature of the finger surface;
A body temperature capturing section that captures body temperature information;
A blood flow capturing unit that captures information about the blood flow of the finger;
An imaging unit for finger authentication;
An image storage unit for storing an authentication image;
An authentication unit that performs authentication using an image captured by the imaging unit and an image stored in the image storage unit;
A storage unit storing a relationship between an environmental temperature, a finger surface temperature, a body temperature, and a blood flow rate and a metabolic rate;
The environmental temperature measured by the environmental temperature measuring device, the finger surface temperature measured by the finger temperature measuring device, the body temperature captured by the body temperature capturing unit, and the blood flow captured by the blood flow capturing unit are A calculation unit that calculates a metabolic rate by applying the relationship stored in the storage unit;
A metabolic rate measuring apparatus comprising: a display unit that displays a result calculated by the calculation unit.   2. The metabolic rate measuring apparatus according to claim 1, wherein the body temperature taking-in unit comprises a thermometer, and an output of the thermometer is supplied to the arithmetic unit.   2. The metabolic rate measuring apparatus according to claim 1, wherein the body temperature taking-in unit has an operation unit for inputting a body temperature numerically.   2. The metabolic rate measurement device according to claim 1, wherein the blood flow volume capturing unit includes a light source that irradiates light on the surface of the finger, and a photometer that measures a frequency spectrum of light scattered and reflected from the surface of the finger; A metabolic rate measuring apparatus characterized by comprising:   2. The metabolic rate measuring apparatus according to claim 1, wherein the blood flow rate taking-in unit has an operation unit for inputting a numerical value of the blood flow rate.   The metabolic rate measuring apparatus according to claim 1, further comprising an oxygen saturation capturing unit that captures information related to the oxygen saturation of the finger, wherein the storage unit includes the temperature of the finger surface, the body temperature, the blood flow rate, and the blood flow. The relationship between oxygen saturation and metabolic rate is stored, and the calculation unit is configured to measure the environmental temperature measured by the environmental temperature measuring device, the temperature of the finger surface measured by the finger temperature measuring device, and the body temperature capturing unit. Calculating the metabolic rate by applying the captured body temperature, the blood flow volume captured by the blood flow volume capturing unit, and the oxygen saturation level captured by the oxygen saturation capturing unit to the relationship stored in the storage unit. A featured metabolic rate measuring device.   7. The metabolic rate measuring apparatus according to claim 6, wherein the oxygen saturation intake unit detects light from the light source unit that irradiates at least two different wavelengths of light and the light source unit scattered on the body surface. A metabolic rate measuring apparatus comprising: a blood vessel; and means for calculating hemoglobin oxygen saturation from a detection result of the detector.   7. The metabolic rate measuring apparatus according to claim 6, wherein the oxygen saturation intake unit includes an operation unit for inputting a numerical value of the oxygen saturation.   2. The metabolic rate measuring apparatus according to claim 1, wherein the finger temperature measuring device includes a finger placement unit and a sensor that measures a radiation temperature of the finger placed on the finger placement unit. apparatus.   2. The metabolic rate measuring apparatus according to claim 1, wherein when the authentication by the authenticating unit fails, the process is terminated. An environmental temperature measuring device for measuring the environmental temperature;
A finger surface contact portion with which the finger surface contacts;
A cylindrical member in contact with the finger surface contact portion and having one end open;
A radiation thermometer that is provided in the vicinity of the other end of the cylindrical member and measures radiant heat from the surface of the finger;
A blood flow acquisition unit for acquiring information on the blood flow of the finger;
A light source that emits light of at least two different wavelengths toward the one end of the cylindrical member;
A photodetector for detecting light interacting with a finger in contact with the finger surface contact portion;
A body temperature capturing section that captures body temperature information;
An imaging unit for finger authentication;
An image storage unit for storing an authentication image;
An authentication unit that performs authentication using an image captured by the imaging unit and an image stored in the image storage unit;
The environmental temperature measured by the environmental temperature measuring device, the temperature of the finger surface measured by the radiation thermometer, the body temperature captured by the body temperature capturing unit, the blood flow captured by the blood flow capturing unit, and the light A calculation unit that calculates the metabolic rate by applying the light detection result measured by the detector to the relationship with the metabolic rate stored in advance;
A metabolic rate measuring apparatus comprising: a display unit that displays a result output from the arithmetic unit.   12. The metabolic rate measuring apparatus according to claim 11, wherein the body temperature intake unit is a thermometer.   12. The metabolic rate measuring apparatus according to claim 11, wherein the body temperature taking-in unit is an operation unit for inputting a body temperature numerically.   12. The metabolic rate measuring apparatus according to claim 11, wherein when the authentication by the authentication unit fails, the process is terminated.   12. The metabolic rate measuring apparatus according to claim 11, further comprising: a storage unit that stores results output from the calculation unit, and displays data stored in the storage unit in time series on the display unit. Metabolite measurement device.

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