JP2014001946A - Concentration measurement device and control method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To propose a new concentration measurement device or the like capable of performing calibration and concentration measurements of a predetermined component even in a usage state where the concentration measurement device or the like is mounted on a predetermined portion of a living body.SOLUTION: Measurement light generated by a multiple wavelength light source 10 is caused to branch at a branch section 20, and first measurement light is irradiated to a living body by a first irradiation section 30A. An observed scattered light time-resolved waveform acquisition section 120 acquires an observed scattered light time-resolved waveform on the basis of light intensity of scattered light from a living body detected by a first light intensity detection section 70A. On the other hand, second measurement light caused to branch at the branch section 20 is irradiated to a reflection mirror 40. A device function time-resolved waveform acquisition section 130 acquires a device function time-resolved waveform on the basis of light intensity of reflection light detected by a second light intensity detection section 70B at the time of detection of the first light intensity detection section 70A. A scattered light time-resolved waveform correction section 140 performs deconvolution processing of the observed scattered light time-resolved waveform by the device function time-resolved waveform and calculates a scattered light time-resolved waveform. Further, a concentration calculation section 150 calculates the glucose concentration of the dermis layer of the skin by using the scattered light time-resolved waveform.

Description

  The present invention relates to a concentration measuring device for measuring the concentration of a predetermined component contained in a living body.

  Conventionally, a concentration measuring method for measuring the concentration of a predetermined component contained in a living body has been devised. As one of them, for example, a technique has been devised in which blood glucose is measured by collecting blood from a fingertip or the like and measuring enzyme activity for glucose in the blood.

  However, the blood glucose level measurement method as described above is an invasive measurement method in which blood is collected from a fingertip or the like, and has a problem that it is accompanied by pain and discomfort for the subject. Therefore, as a non-invasive measurement method, a technique has been devised in which near infrared light is irradiated from the surface of a part of a human body (for example, a hand) and a blood glucose level is measured from the amount of light absorption.

  For example, Patent Document 1 describes a technique for calculating the glucose concentration of the dermis layer using a time-resolved waveform of reflected light (scattered light) of light irradiated on the skin. Patent Documents 2 and 3 describe methods for measuring time-resolved waveforms using a streak camera. Patent Documents 4 and 5 disclose a method for acquiring internal information of a scattering medium based on an apparatus function and a measurement value of the scattering light absorber.

JP 2010-237139 A JP 2004-219426 A JP 2001-133396 A JP 2000-146828 A JP-A-9-61343

  Among the above-described conventional examples, the techniques disclosed in Patent Documents 4 and 5 consider that the measurement system error caused by the measurement system when measuring the component concentration is superimposed on the time-resolved waveform. This is a technique for correcting a time-resolved waveform of scattered light using an apparatus function representing an error. This technique is based on the premise that calibration is performed in advance to obtain an apparatus function in a state where a measurement target is not arranged, and then measurement is performed after the measurement target is arranged.

  By the way, a diabetic patient can be considered as a representative example of a subject who needs to measure a blood glucose level. For diabetic patients, daily blood glucose level management is an important matter, and therefore a measuring device that is supposed to be always worn is desired. That is, there is a demand for an apparatus that can perform both calibration and blood glucose level measurement at all times or at any time with the measurement apparatus attached. However, the conventional non-invasive measuring apparatus that has been devised has not been based on such usage.

  In addition, although the component of a measuring object was demonstrated as a blood glucose level, it is not a problem restricted to a blood glucose level. Of course, the living body to be measured may be not only a human but also an animal. For example, it is well known that diabetes is a dog disease.

  The present invention has been made in view of the above-described problems, and is a new non-invasive concentration measuring apparatus that can perform calibration and measure the concentration of a predetermined component even if it is in a use state attached to a predetermined part of a living body. It is to propose.

  A first form for solving the above problems is a concentration measuring device attached to a predetermined part of a living body, and detects an irradiation unit that irradiates the living body with measurement light, and scattered light from the living body. Based on a detection unit, a first acquisition unit that acquires a time-resolved waveform of scattered light based on the light intensity of the scattered light detected by the detection unit, and based on the light intensity of the measurement light when attached to the predetermined part A second acquisition unit that acquires a device function time-resolved waveform; and a calculation unit that calculates a concentration of a predetermined component contained in the living body using the scattered light time-resolved waveform and the device function time-resolved waveform. It is the concentration measuring apparatus provided.

  According to another aspect, there is provided a method for controlling a concentration measuring device attached to a predetermined part of a living body, wherein the living body is irradiated with measurement light, scattered light from the living body is detected, and the detection Obtaining a scattered light time-resolved waveform based on the light intensity of the scattered light, obtaining a device function time-resolved waveform based on the light intensity of the measurement light when attached to the predetermined part, and the scattering It is good also as comprising the control method including calculating the density | concentration of the predetermined component contained in the said biological body using an optical time-resolved waveform and the said apparatus function time-resolved waveform.

  According to this 1st form etc., measurement light is irradiated to a living body by an irradiation part. The detection unit detects scattered light from the living body, and the first acquisition unit acquires the scattered light time-resolved waveform based on the light intensity of the scattered light detected by the detection unit. In addition, the second acquisition unit acquires the device function time-resolved waveform based on the light intensity of the measurement light when attached to the predetermined part. And a calculation part calculates the density | concentration of the predetermined component contained in the biological body using a scattered light time-resolved waveform and an apparatus function time-resolved waveform.

  The concentration measuring device and the control method of the concentration measuring device of this embodiment are non-invasive, and it is possible to acquire the scattered light time-resolved waveform and the device function time-resolved waveform with the concentration measuring device attached to a predetermined part of the living body. . The fact that the apparatus function time-resolved waveform can be acquired in the mounted state means that calibration can be performed in the mounted state. Of course, it is also possible to measure the concentration of the predetermined component contained in the living body at a desired timing in a worn state.

  Further, as a second form, the concentration measurement apparatus in which the calculation unit in the concentration measurement apparatus of the first form includes a deconvolution processing unit that deconvolves the scattered light time-resolved waveform with the device function time-resolved waveform. It is good also as comprising.

  According to the second embodiment, it is possible to obtain a scattered light time-resolved waveform in which errors caused by the measurement system are compensated by performing a deconvolution process on the scattered light time-resolved waveform with the device function time-resolved waveform. .

  Further, as a third mode, in the concentration measuring apparatus according to the first or second mode, the measuring device further includes a measurement light detection unit that detects the measurement light, and the second acquisition unit performs the measurement at the time of detection by the detection unit. A concentration measurement device that acquires the device function time-resolved waveform based on the light intensity of the measurement light detected by a light detection unit may be configured.

  According to the third aspect, by acquiring the device function time-resolved waveform based on the light intensity of the measurement light detected by the measurement light detection unit at the time of detection by the detection unit, the acquisition of the scattered light time-resolved waveform, Acquisition of the device function time-resolved waveform can be performed simultaneously.

  Further, as a fourth mode, in the concentration measuring apparatus according to the first or second mode, a light guide unit for inserting a light guide unit for guiding the measurement light to the detection unit is inserted between the irradiation unit and the living body. A second mechanism, wherein the second acquisition unit obtains the device function time-resolved waveform based on the light intensity of the light detected by the detection unit when the light guide unit is inserted by the light guide unit insertion mechanism. It is good also as comprising the density | concentration measuring apparatus to acquire.

  According to the fourth aspect, the device function time-resolved waveform is acquired based on the light intensity of the light detected by the detection unit when the light guide unit is inserted between the irradiation unit and the living body by the light guide unit insertion mechanism. By doing so, it is possible to acquire the device function time-resolved waveform in a time division manner with one optical path.

  Further, as a fifth form, in the concentration measuring apparatus according to the fourth form, the light guide part is inserted by the light guide part insertion mechanism and the second acquisition part is used based on the number of times of calculation of the density. It is good also as comprising a density | concentration measuring apparatus further provided with the control part which performs control which performs acquisition of an apparatus function time-resolved waveform.

  According to the fifth aspect, the insertion of the light guide unit by the light guide unit insertion mechanism and the acquisition of the device function time-resolved waveform by the second acquisition unit are executed based on the number of times of density calculation. For example, when the density calculation count reaches a predetermined number, it is possible to periodically update the device function time-resolved waveform by executing insertion of the light guide and acquisition of the device function time-resolved waveform. .

  Further, as a sixth aspect, in the concentration measuring apparatus according to the fourth aspect, based on the elapsed time from the last calculation of the concentration, the insertion of the light guide by the light guide insertion mechanism, and the first It is good also as comprising a concentration measurement apparatus further provided with the control part which performs control which performs the acquisition of the said apparatus function time-resolved waveform by 2 acquisition parts.

  According to the sixth aspect, based on the elapsed time from the last calculation of the concentration, the light guide unit is inserted by the light guide unit insertion mechanism, and the device function time-resolved waveform is acquired by the second acquisition unit. Let For example, when the elapsed time from the last calculation of the concentration reaches a predetermined time, the apparatus function time-resolved waveform is periodically updated by inserting the introduction unit and acquiring the apparatus function time-resolved waveform. Is possible.

The block diagram which shows an example of a function structure of a 1st density | concentration measuring apparatus. The figure which shows an example of the data structure of model data. The figure which shows an example of the data structure of time-resolved waveform corresponding | compatible data. The figure which shows an example of a data structure of correction | amendment scattered light time-resolved waveform data. The flowchart which shows the flow of a 1st density | concentration measurement process. The figure which shows the structural example of the optical system of the 1st optical apparatus in a modification. The block diagram which shows an example of a function structure of a 2nd density | concentration measuring apparatus. The flowchart which shows the flow of a 2nd density | concentration measurement process. The flowchart which shows the flow of an apparatus function time-resolved waveform acquisition process. The flowchart which shows the flow of an observation scattered light time-resolved waveform acquisition process.

  Hereinafter, an example of a preferred embodiment of the present invention will be described with reference to the drawings. The concentration measurement apparatus according to the present embodiment is a wearable measurement apparatus in which a probe including at least an irradiation unit to a light collection unit is attached to a predetermined part (for example, a finger or a wrist) of a living body. In the present embodiment, a case where the concentration measuring apparatus measures the glucose concentration contained in the dermis layer of the skin as the concentration of the predetermined component contained in the living body will be described as an example. However, it goes without saying that embodiments to which the present invention can be applied are not limited to the embodiments described below.

1. 1. First embodiment 1-1. Configuration FIG. 1 is a block diagram illustrating an example of a functional configuration of a first concentration measurement apparatus 1A in the first embodiment. The first concentration measuring apparatus 1A includes, as main components, a first optical device 3A, a control unit 100, an operation unit 200, a display unit 300, a sound output unit 400, a communication unit 500, and a storage unit 600. It is comprised.

  The first optical device 3A includes a multi-wavelength light source 10, a branching unit 20, a first irradiation unit 30A, a second irradiation unit 30B, a reflecting mirror 40, a first light collecting unit 50A, and a second light collecting unit. 50B, the first relay unit 60A, the second relay unit 60B, the first light intensity detection unit 70A, and the second light intensity detection unit 70B. In the present embodiment, the light path from the first irradiation unit 30A to the first light intensity detection unit 70A is referred to as a “first light path”, and reaches from the second irradiation unit 30B to the second light intensity detection unit 70B. The light path up to is referred to as a “second light path”.

  In the present embodiment, the first irradiation unit 30A and the first light collecting unit 50A are built in a probe, and the probe is attached to a predetermined part (finger or wrist) of a subject who is a living body. The probe may be configured as, for example, a clip type or a patch type. Further, since the second optical path is an optical path for obtaining a device function time-resolved waveform to be described later, it is preferable that the second optical path is composed of the same member as the first optical path. That is, the second irradiation unit 30B, the second light collection unit 50B, the second relay unit 60B, and the second light intensity detection unit 70B are respectively the first irradiation unit 30A, the first light collection unit 50A, the first relay unit 60A, and The first light intensity detector 70A is composed of the same member. The second relay unit 60B has the same length as the first relay unit 60A.

  The multi-wavelength light source 10 is a light source configured to be able to generate and output pulsed light having a plurality of wavelengths, and includes, for example, a multi-wavelength semiconductor laser. The multi-wavelength light source 10 generates and emits pulsed light of the instructed wavelength based on the light source control signal output from the control unit 100. Further, after emitting the pulsed light, the multi-wavelength light source 10 outputs a trigger signal for instructing the light intensity detection timing to the first light intensity detecting unit 70A and the second light intensity detecting unit 70B, respectively.

  The branching unit 20 is an optical branching device that branches the pulsed light output from the multi-wavelength light source 10, and has, for example, a half mirror. One of the lights branched by the branching unit 20 is irradiated to the living body by the first irradiation unit 30A as the first measurement light. Further, the other of the branched lights is irradiated onto the reflecting mirror 40 by the second irradiation unit 30B as the second measurement light.

  Human skin is roughly divided into three layers, an epidermis layer, a dermis layer, and a subcutaneous tissue layer. Among them, capillaries are developed in the dermis layer, and the glucose concentration of the dermis layer changes so as to follow the glucose concentration in blood. Therefore, an object of the present embodiment is to estimate the blood glucose level of the subject by measuring the glucose concentration contained in the dermis layer.

  50 A of 1st condensing parts condense the emitted light from the biological body by irradiating 1st measurement light toward the biological body from 30 A of 1st irradiation parts. Specifically, backscattered light (hereinafter simply referred to as “scattered light”) when the first measurement light is applied to the living body is collected as emitted light and guided to the first relay unit 60A. The second condensing unit 50B condenses the reflected light from the reflecting mirror 40 when the second measurement light is irradiated from the second irradiating unit 30B toward the reflecting mirror 40. These condensing parts can be said to be light incident parts that receive scattered light from the living body or reflected light from the reflecting mirror 40.

  The first relay unit 60A is a relay that relays the scattered light collected by the first light collecting unit 50A to the first light intensity detecting unit 70A. The second relay unit 60B is a relay that relays the reflected light collected by the second light collecting unit 50B to the second light intensity detecting unit 70B. These relay units are configured to include optical fibers, for example.

  The first light intensity detection unit 70A is a detector that detects the light intensity of scattered light from the living body relayed by the first relay unit 60A. The second light intensity detector 70B is a detector that detects the light intensity of the reflected light from the reflecting mirror 40 relayed by the second relay unit 60B. These light intensity detection units include, for example, a photoelectric tube, a photomultiplier tube, various photodiodes, a streak camera, and the like, and output a light detection signal including the detected light intensity to the control unit 100. The first light intensity detection unit 70A corresponds to a detection unit that detects scattered light from a living body. The second light intensity detection unit corresponds to a measurement light detection unit that detects measurement light.

  The control unit 100 is a control device and an arithmetic device that collectively control each unit of the concentration measurement device and the optical device according to various programs such as a system program stored in the storage unit 600. For example, a CPU (Central Processing Unit) And a processor such as a DSP (Digital Signal Processor).

  The control unit 100 includes, as main functional units, a light source control unit 110, an observed scattered light time-resolved waveform acquisition unit 120, an apparatus function time-resolved waveform acquisition unit 130, a scattered light time-resolved waveform correction unit 140, and a concentration calculation. Part 150. However, these functional units are only described as one embodiment, and all the functional units are not necessarily essential components.

  The light source controller 110 controls the generation of pulsed light by the multi-wavelength light source 10. Specifically, the light source control signal for instructing the wavelength of the pulsed light and the generation of the pulsed light is output to the multi-wavelength light source 10, and the multi-wavelength light source 10 generates and emits the pulsed light having a plurality of wavelengths.

  The observed scattered light time-resolved waveform acquisition unit 120 calculates and acquires the scattered light time-resolved waveform based on the light detection signal indicating the light intensity of the scattered light from the living body output from the first light intensity detection unit 70A. . The scattered light time-resolved waveform acquired by the observed scattered light time-resolved waveform acquisition unit 120 (hereinafter referred to as “observed scattered light time-resolved waveform”) is a time-resolved waveform on which a measurement system error is superimposed. The observed scattered light time-resolved waveform acquisition unit 120 corresponds to a first acquisition unit.

  Ideally, it is desirable that the measurement light, which is pulsed light applied to the living body, is light having a complete impulse shape (which can be regarded as a delta function). However, the pulsed light generated by the multi-wavelength light source 10 actually has a constant pulse width. Ideally, it is desirable that the response characteristic of the light intensity detector also exhibits an impulse response characteristic, but in reality, the time resolution of the light intensity detector is also finite. Measurement system errors resulting from the measurement light irradiation system and the scattered light detection system are superimposed on the scattered light time-resolved waveform acquired by the observed scattered light time-resolved waveform acquisition unit 120.

  The device function time-resolved waveform acquisition unit 130 calculates and acquires a device function time-resolved waveform based on the light detection signal indicating the light intensity of the reflected light from the reflecting mirror 40 output from the second light intensity detection unit 70B. To do. Measurement light, which is pulsed light emitted from the multi-wavelength light source 10, enters the second light intensity detection unit 70B through a second light path configured as a path substantially the same as the first light path. However, in the second optical path, measurement light is irradiated to the reflecting mirror 40 instead of the living body. In this case, the time-resolved waveform acquired by the device function time-resolved waveform acquisition unit 130 (hereinafter referred to as “device function time-resolved waveform”) is a time-resolved waveform representing the measurement system error. A function approximation of the measurement system error is called an apparatus function. The device function time-resolved waveform acquisition unit 130 corresponds to a second acquisition unit.

  The scattered light time-resolved waveform correction unit 140 uses the observed scattered light time-resolved waveform acquired by the observed scattered light time-resolved waveform acquisition unit 120, using the device function time-resolved waveform acquired by the device function time-resolved waveform acquisition unit 130. To correct. The observed scattered light time-resolved waveform acquired by the observed scattered light time-resolved waveform acquisition unit 120 is a convolution (convolution) between the time-resolved waveform of scattered light from the living body and the device function time-resolved waveform. Therefore, the scattered light time-resolved waveform correcting unit 140 performs a deconvolution process that deconvolutes (deconvolves) the observed scattered light time-resolved waveform with the device function time-resolved waveform, so that the scattered light time in which the measurement system error is compensated for. Get the decomposition waveform.

  The measurement system error can vary depending on the use environment (for example, temperature) of the apparatus and the use time. Therefore, the device function time-resolved waveform acquisition unit 130 acquires the device function time-resolved waveform at an arbitrary timing, so that the measurement system error can be correctly compensated at any time. It can be said that the device function time-resolved waveform acquisition unit 130 acquires the device function time-resolved waveform is equivalent to performing a kind of calibration. The scattered light time-resolved waveform corrected by the scattered light time-resolved waveform correcting unit 140 is referred to as “corrected scattered light time-resolved waveform” and is expressed as “R (t)”. The scattered light time-resolved waveform correcting unit 140 functions as a deconvolution processing unit.

  The concentration calculation unit 150 uses the scattered light time-resolved waveform corrected by the scattered light time-resolved waveform correcting unit 140 to calculate the glucose concentration contained in the dermis layer of the skin. The concentration calculation unit 150 corresponds to a calculation unit that calculates the concentration of a predetermined component contained in the living body using the scattered light time-resolved waveform and the device function time-resolved waveform.

  The measurement light incident on the living body follows various paths due to its scattering characteristics, and the light emitted as reflected light (scattered light) is collected by the first light collecting unit 50A. At this time, the path | route which the photon (photon) traced the biological body is various. That is, the light captured as scattered light becomes light including photons with different traced paths. Therefore, when considered on the time axis, it is represented by a waveform of the time distribution of the number of captured photons. The waveform of this time distribution is a scattered light time-resolved waveform. It can be considered that the light reaching the first light intensity detection unit 70A selectively passes through a predetermined portion (each layer of skin) in the living body depending on the detection time. That is, it is considered that the propagation path of photons propagated in the living body is characterized by the light scattering coefficient, and the light intensity change along the optical path is characterized by the light absorption coefficient.

  In the scattered light time-resolved waveform, light detected at an earlier time passes only through a shallower portion from the surface, and conversely, light detected at a later time reaches a deeper region from the surface. Thus, the intensity of the detection light at different detection times corresponds to the light components that have passed through different path distributions. That is, the light intensity at a certain detection time includes light absorption information in the light path distribution corresponding to the time. Therefore, if the optical path for each detection time of the time-resolved waveform is obtained in advance by actual measurement, the distribution of the light absorption coefficient can be calculated by the inverse problem solving method.

  Based on the above principle, the concentration calculation unit 150 calculates the light absorption coefficient of each layer in the skin based on the corrected scattered light time-resolved waveform calculated by the scattered light time-resolved waveform correcting unit 140, and the light absorption The glucose concentration of the dermal layer of the skin is calculated using the coefficient. A calculation formula relating to the calculation of the glucose concentration will be described later.

  The operation unit 200 is an input device configured to include, for example, a button switch, and outputs a pressed button signal to the control unit 100. By operating the operation unit 200, various instructions such as input of various data and an instruction to start measurement of glucose concentration are made.

  The display unit 300 is a display device that performs various displays based on display signals output from the control unit 100, and includes, for example, an LCD (Liquid Crystal Display). The display unit 300 displays information such as the glucose concentration calculated by the concentration calculation unit 150.

  The sound output unit 400 is a sound output device that outputs a sound based on the sound output signal output from the control unit 100, and includes, for example, a speaker. The sound output unit 400 outputs sound guidance, alarm sound, and the like related to glucose concentration measurement.

  The communication unit 500 is a communication device for transmitting / receiving information used inside the device to / from an external information processing device under the control of the control unit 100. As a communication method of the communication unit 500, a form in which a wired connection is made through a cable compliant with a predetermined communication standard, a form in which a connection is made through an intermediate device that is also used as a charger called a cradle, or short-range wireless communication is used. Various systems such as a wireless connection type can be applied.

  The storage unit 600 includes a storage device (memory) such as a ROM (Read Only Memory), a flash ROM, or a RAM (Random Access Memory), and includes a system program of the control unit 100 and a scattered light time-resolved waveform acquisition function. In addition, various programs and various data for realizing various functions such as a density measuring function are stored. In addition, it has a work area for temporarily storing data being processed and results of various processes.

  The storage unit 600 stores, as a program, a first concentration measurement program 610 that is read by the control unit 100 and executed as a first concentration measurement process (see FIG. 5). The first concentration measurement program 610 includes a scattered light time-resolved waveform correction program 610A executed as a scattered light time-resolved waveform correction process (see FIG. 5) as a subroutine. These processes will be described later in detail using a flowchart.

  Further, in the storage unit 600, for example, model data 620, time-resolved waveform correspondence data 630, modified scattered light time-resolved waveform data 640, component absorption information data 650, and layered light absorption coefficient data 660 are included as data. And measured concentration data 670 are stored.

  The model data 620 is data relating to a model generated by performing a simulation process such as a Monte Carlo simulation, and an example of the data configuration is shown in FIG. The model data 620 stores candidate wavelengths, propagation optical path length distributions, and non-absorbed scattered light intensity time characteristics in association with each other.

  The candidate wavelength is selected from a plurality of wavelengths and is a candidate for the wavelength of the pulsed light used in the calculation of the component concentration. It is effective to select, as a candidate wavelength, a wavelength at which the orthogonality of the light absorption spectrum is high for the main component of skin. Specifically, it is preferable to select, as a candidate wavelength, a wavelength at which the orthogonality of light absorption spectra of water, protein, lipid and glucose, which are the main components of the dermis layer of the skin, is increased.

  For example, the light absorption coefficient of glucose becomes maximum when the wavelength is 1600 nm (nanometers), and the light absorption coefficient of water becomes maximum when the wavelength is 1450 nm. For this reason, it is preferable to obtain the propagation optical path length distribution and the scattered light time-resolved waveform for the wavelength where the orthogonality of the absorption spectrum of the main component of the skin such as 1450 nm and 1600 nm is high.

The propagation optical path length distribution is a model in which the propagation optical path length of a photon of pulsed light when the number of incident photons is “N _in ” is obtained by, for example, Monte Carlo simulation. Specifically, the propagation optical path length distribution “L _m (t)” of each layer of the skin when the number of incident photons is “N _in ” is calculated by performing a simulation (Monte Carlo simulation) using the Monte Carlo method.

More specifically, a skin model having a light absorption coefficient of zero is configured in advance, and the distance and direction to the next point where a photon advances in each layer of the skin model is repeated using a random number every unit time. This simulation is performed for a predetermined number of photons, and each movement path of the photons reaching the light intensity detection unit is classified for each layer through which the movement path passes. Then, by calculating the average length of the movement path of the photons reached per unit time for each classified layer, for example, the propagation optical path length distribution “L _m (t) for each skin layer as shown in FIG. Get.

The non-absorption scattered light intensity time characteristic is a model obtained by, for example, Monte Carlo simulation, calculating the scattered light intensity when the light absorption coefficient is zero and the number of incident photons is “N _in ”. Specifically, for the above skin model having a light absorption coefficient of zero, the number of photons detected by the light intensity detection unit when the skin model is irradiated with measurement light is calculated per unit time. The non-absorbing scattered light intensity time characteristic “N (t)” as shown in FIG. The scattered light intensity on the vertical axis is synonymous with the number of photons (number of photons) detected by the light intensity detector.

  The time-resolved waveform correspondence data 630 is data in which two types of time-resolved waveforms are stored in association with each other, and an example of the data configuration is shown in FIG. The time-resolved waveform correspondence data 630 stores candidate wavelengths, observed scattered light time-resolved waveforms, and device function time-resolved waveforms in association with each other. The time-resolved waveform correspondence data 630 is used by the scattered light time-resolved waveform correcting unit 140 to calculate the scattered light time-resolved waveform.

  The modified scattered light time-resolved waveform data 640 is data in which the modified scattered light time-resolved waveform calculated by the scattered light time-resolved waveform correcting unit 140 is stored, and an example of the data configuration is shown in FIG. In the scattered light time-resolved waveform data, the candidate wavelength and the modified scattered light time-resolved waveform “R (t)” are stored in association with each other.

The concentration calculation unit 150 stores the propagation optical path length distribution “L _m (t)” and the non-absorbed scattered light time-resolved waveform “N (t)” stored in the model data 620 and the corrected scattered light time-resolved waveform data 640. Using the stored modified scattered light time-resolved waveform “R (t)”, the glucose concentration of the dermal layer of the skin is calculated.

  The component absorption information data 650 is data in which absorption information relating to components contained in the dermis layer of the skin is stored. Specifically, for example, light absorption coefficients and molar absorption coefficients of four components of water, protein, lipid, and glucose are stored as absorption information. Such absorption information needs to be measured in advance and stored in the storage unit 600. The component absorption information data 650 is used to calculate the glucose concentration of the dermis layer of the skin.

  The layered light absorption coefficient data 660 is data of light absorption coefficients of the skin epidermis layer, dermis layer, and subcutaneous tissue layer. These values are calculated by solving a predetermined simultaneous equation when calculating the component concentration of each component of the dermis layer. A specific method for calculating the layered light absorption coefficient will be described later.

  The measured concentration data 670 is data in which the calculation result of the concentration of the predetermined component contained in the living body calculated by the concentration calculation unit 150 is stored. For example, this includes the glucose concentration of the dermal layer of the skin.

1-2. Process Flow FIG. 5 is a flowchart showing a flow of a first concentration measurement process executed by the control unit 100 according to the first concentration measurement program 610 stored in the storage unit 600.

  First, the control unit 100 determines whether or not it is the concentration measurement timing (step A1). Assuming that the blood glucose level is regularly measured with a diabetic patient as the subject, for example, the timing for each predetermined time interval (for example, once every 3 hours) can be set. . In addition, the concentration may be measured using the timing when the measurement execution instruction operation is performed by the user via the operation unit 200 as a measurement timing so that the diabetic patient can check the blood glucose level at any time.

  If it is determined that it is the measurement timing (step A1; Yes), the control unit 100 executes the scattered light time-resolved waveform correction process according to the scattered light time-resolved waveform correction program 610A stored in the storage unit 600.

  In the scattered light time-resolved waveform correction process, the control unit 100 executes the process of loop A for each predetermined candidate wavelength (steps A3 to A15). In the process of loop A, the light source control unit 110 outputs a light source control signal to the multi-wavelength light source 10 in order to generate and emit pulse light of the candidate wavelength to the multi-wavelength light source 10 (step A7).

  Next, the observed scattered light time-resolved waveform acquisition unit 120 performs an observed scattered light time-resolved waveform calculation process (step A9). Specifically, a process for analyzing the light intensity of the scattered light from the living body is performed based on the light detection signal output from the first light intensity detection unit 70A, and the scattered light time-resolved waveform is acquired. Then, the acquired scattered light time-resolved waveform is stored in the time-resolved waveform correspondence data 630 of the storage unit 600 as an observed scattered light time-resolved waveform.

  Further, the device function time-resolved waveform acquisition unit 130 performs device function time-resolved waveform calculation processing (step A11). Specifically, processing for analyzing the light intensity of the reflected light from the reflecting mirror 40 is performed based on the light detection signal output from the second light intensity detection unit 70B, and the device function time-resolved waveform is acquired. The acquired device function time-resolved waveform is stored in the time-resolved waveform correspondence data 630 of the storage unit 600 in association with the observed scattered light time-resolved waveform.

  Next, the scattered light time-resolved waveform correcting unit 140 performs a deconvolution process (step A13). Specifically, the observed scattered light time-resolved waveform stored in association with the time-resolved waveform correspondence data 630 is deconvolved with the device function time-resolved waveform. As an algorithm for realizing the deconvolution, a conventionally known algorithm can be applied.

  According to experiments conducted by the present inventor, it was confirmed that the scattered light time-resolved waveform can be corrected with high accuracy by performing deconvolution using the Lucy Richardson method. The scattered light time-resolved waveform correcting unit 140 stores the time-resolved waveform obtained by the deconvolution process in the modified scattered light time-resolved waveform data 640 of the storage unit 600 as a corrected scattered light time-resolved waveform.

  Thereafter, the control unit 100 shifts the processing to the next candidate wavelength. And if the process of step A7-A13 was performed about all the candidate wavelengths, the control part 100 will complete | finish the process of the loop A (step A15).

Next, the density calculation unit 150 performs density calculation processing (step A17). In the concentration calculation process, the same number of wavelengths as the number of principal components of the skin are selected from a plurality of candidate wavelengths. The main components of the dermis layer are the four components of water, protein, lipid and glucose. Therefore, four wavelengths “(λ ₁ , λ ₂ , λ ₃ , λ ₄ )” are selected from the candidate wavelengths.

Also, the same number of different times as the number of layers of the living body are selected. The skin consists of three layers, an epidermis layer, a dermis layer and a subcutaneous tissue layer. Therefore, three different times “t _k = (t ₁ , t ₂ , t ₃ )” are selected. The three selected times “t _k = (t ₁ , t ₂ , t ₃ )” are preferably times when the propagation optical path length distribution of each layer of the skin shows a peak. That is, it is preferable to calculate the time obtained by adding the time when the optical path length is maximized in the propagation optical path length distribution of each layer of the skin shown in FIG.

For each of the four wavelengths “(λ ₁ , λ ₂ , λ ₃ , λ ₄ )” selected as described above, according to the following equations (1) and (2), the three selected times “t _k = (t ₁ , T ₂ , t ₃ ) ”, the epidermal layer light absorption coefficient“ μ _a1 ”, the dermis layer light absorption coefficient“ μ _a2 ”, and the subcutaneous tissue layer light absorption coefficient“ μ _a3 ”. Is calculated.

In equation (1), “μ _am ” represents the light absorption coefficient for each layer, and the subscript “m” represents the skin layer number. For convenience, the skin layer number is “m = 1”, the dermis layer number is “m = 2”, and the subcutaneous tissue layer number is “m = 3”. That is, “μ _a1 ” is the light absorption coefficient of the epidermis layer, “μ _a2 ” is the light absorption coefficient of the dermis layer, and “μ _a3 ” is the light absorption coefficient of the subcutaneous tissue layer. “M” is the number of skin layers, and “M = 3” in this embodiment.

“L _m (t)” indicates the propagation optical path length distribution in the m-th layer of the skin. For example, “L _m (t ₁ )” indicates the total distance that photons detected at time “t ₁ ” propagated through the m-th layer. “N _in ” is the total number of photons of pulsed light (number of incident photons) and is known. “I _in ” is the intensity of the pulsed light (incident light intensity) and is known.

Although detailed description is omitted in this specification, the expression (1) approximately expresses the scattered light intensity “R (t)” detected at the time “t” as the following expression (3). This is an expression derived based on what can be done.

式（４）を用いて式（３）を変形すると、式（１）が導出される。 In Expression (3), “L ′ _m (t)” is an average value per one photon of the distance propagated through the m-th layer of the skin. This is a value obtained by dividing the total propagation distance “L _m (t)” by “N ′ (t)” and is given by the following equation (4).

When equation (3) is transformed using equation (4), equation (1) is derived.

In solving the simultaneous equations of Equation (2), the propagation optical path lengths “L _m (t _k )” of the skin layers at the three selected times “t _k = (t ₁ , t ₂ , t ₃ )”, The absorption scattered light intensity “N (t _k )” and the modified scattered light intensity “R (t _k )” are required. These values are stored in the propagation optical path length distribution “L _m (t)” and the non-absorption scattered light time-resolved waveform “N (t)” stored in the model data 620 and the modified scattered light time-resolved waveform data 640. Each of the corrected scattered light time-resolved waveforms “R (t)” can be calculated by substituting the selected time “t _k ”.

By solving the simultaneous equations of equation (2) for each of the _four selected wavelengths “(λ ₁ , λ ₂ , λ ₃ , λ ₄ )”, the light absorption coefficient “μ _a1 ” of the epidermis layer and the light absorption of the dermis layer If the coefficient “μ _a2 ” and the light absorption coefficient “μ _a3 ” of the subcutaneous tissue layer are calculated, these calculated values are stored in the layer-by-layer light absorption coefficient data 660.

Next, the component concentration of the dermis layer of the skin is calculated using the layered light absorption coefficient. The equation for _obtaining the volume fraction “c _vi ” of each component when the total number of components is “N” is given by the following equation (5).

The main components of the dermis layer are the four components of water, protein, lipid and glucose (N = 4). Therefore, when Expression (5) is expressed as a four-component expression, the following Expression (6) is obtained. According to this formula (6), the volume fractions of water, protein, lipid and glucose are calculated.

However, “μ _ai ” represents the light absorption coefficient for each component, and the subscript “i” represents the symbol of the component. For convenience, “i = w” for water, “i = p” for protein, “i = 1” for lipid, and “i = g” for glucose. That is, “μ _aw ”, “μ _ap ”, “μ _al ”, and “μ _ag ” indicate the light absorption coefficients of water, protein, lipid, and glucose, respectively. These light absorption coefficients differ for each wavelength, and the light absorption coefficients corresponding to each of the four selected wavelengths “(λ ₁ , λ ₂ , λ ₃ , λ ₄ )” are “μ _aw (λ ₁ ) to μ _aw (λ ₄₎ "," _{μ ap (λ 1) ~μ ap} (λ 4) "," _{μ al (λ 1) ~μ al} (λ 4) "and" _{μ ag (λ 1) ~μ ag} (λ 4) Is. These values are stored in advance in the component absorption information data 650 of the storage unit 600 as absorption information.

“C _vi ” represents the volume fraction of each component, and the subscript “i” is the same as above. That is, “c _vw ”, “c _vp ”, “c _vl ”, and “c _vg ” indicate the volume fractions of water, protein, lipid, and glucose, respectively. These volume fractions are unknown. The light absorption coefficients “μ _a2 (λ ₁ )” and “μ _a2 ” of the dermis layer (i = 2) calculated previously for the _four selected wavelengths “(λ ₁ , λ ₂ , λ ₃ , λ ₄ )”. By using (λ ₂ ) ”,“ μ _a2 (λ ₃ ) ”and“ μ _a2 (λ ₄ ) ”and the above absorption information, the simultaneous equations of Equation (6) can be solved. Accordingly, the volume fractions “c _vw ”, “c _vp ”, “c _vl ”, and “c _vg ” of each component can be calculated.

After calculating the volume fractions “c _vw ”, “c _vp ”, “c _vl ”, and “c _vg ” of each component, the volume fraction is converted into a weight volume concentration or the like according to a known conversion formula, The component concentration of each component of the dermis layer is calculated. For example, the glucose concentration of the dermis layer is stored in the storage unit 600 as the measured concentration data 670.

  After performing the concentration calculation process, the control unit 100 performs control to display the calculated glucose level of the dermis layer on the display unit 300 (step A19). Then, it is determined whether or not to end the process (step A21). When it is determined that the process is to be continued (step A21; No), the process returns to step A1. If it is determined that the process is to be terminated (step A21; Yes), the first density calculation process is terminated.

1-3. Operational Effect In the first concentration measurement apparatus 1A, measurement light that is pulse light generated by the multi-wavelength light source 10 is branched by the branching unit 20, and the living body is irradiated with the first measurement light by the first irradiation unit 30A. The observed scattered light time-resolved waveform acquisition unit 120 acquires the observed scattered light time-resolved waveform based on the light intensity of the scattered light from the living body detected by the first light intensity detector 70A. On the other hand, the second measurement light branched by the branching unit 20 is applied to the reflecting mirror 40. The device function time-resolved waveform acquisition unit 130 obtains the device function time-resolved waveform based on the light intensity of the reflected light from the reflecting mirror 40 detected by the second light intensity detection unit 70B at the time of detection by the first light intensity detection unit 70A. get. Thereby, acquisition of a scattered light time-resolved waveform and acquisition of an apparatus function time-resolved waveform can be performed simultaneously.

  The scattered light time-resolved waveform correction unit 140 deconvolves the observed scattered light time-resolved waveform acquired by the observed scattered light time-resolved waveform acquisition unit 120 with the device function time-resolved waveform acquired by the device function time-resolved waveform acquisition unit 130. By processing, a scattered light time-resolved waveform in which the measurement system error is compensated is acquired. Therefore, acquisition of the device function time-resolved waveform can be said to be a kind of calibration. Then, the concentration calculation unit 150 calculates the glucose concentration of the dermis layer of the skin using the corrected scattered light time-resolved waveform calculated by the scattered light time-resolved waveform correcting unit 140.

  The concentration measurement method in the present embodiment is a non-invasive method, and the observation scattered light time-resolved waveform and the device function time-resolved waveform can be simultaneously acquired with the device mounted on a predetermined part of the living body. The fact that the apparatus function time-resolved waveform can be acquired in the mounted state means that calibration can be performed in the mounted state. In addition, as the measurement timing of the glucose concentration, a periodic timing, a timing when a measurement execution instruction operation is performed by the user, or the like can be set, and the glucose concentration is measured at a desired timing, and the measurement result Can be notified to the user.

1-4. Modification The first optical device 3A described in the above embodiment may be configured as shown in FIG. Specifically, in the first optical device 3A of FIG. 6, the reflecting mirror 40 is not provided in the second light path, and the second measurement light branched by the branching unit 20 is transmitted to the second light collecting unit 50B and the second light collecting unit 50B. It is configured to be guided to the second light intensity detection unit 70B via the two relay unit 60B. 1 is different from the first optical device 3A in FIG. 1 in that the measuring light is directly received without using the reflecting mirror 40.

2. Second Embodiment The embodiment to which the present invention is applicable is not limited to the first embodiment described above.
Hereinafter, a second embodiment to which the present invention is applied will be described. In addition, about the same component as 1st Embodiment, and the same step of a flowchart, the same code | symbol is attached | subjected and description for the second time is abbreviate | omitted.

2-1. Configuration FIG. 7 is a block diagram showing an example of the configuration of the second concentration measurement apparatus 1B in the second embodiment. The second concentration measuring device 1B includes a second optical device 3B, a control unit 100, an operation unit 200, a display unit 300, a sound output unit 400, a communication unit 500, and a storage unit 600. Is done.

  The second optical device 3B includes a multi-wavelength light source 10, an irradiation unit 30, a reflecting mirror 40, a condensing unit 50, a relay unit 60, a light intensity detecting unit 70, and a reflecting mirror advance / retreat mechanism 80. Configured. In the present embodiment, the irradiation unit 30, the reflecting mirror 40, the light collecting unit 50, and the reflecting mirror advance / retreat mechanism 80 are built in the probe, and the probe is attached to a predetermined part (finger or wrist) of a subject who is a living body. .

  The irradiation unit 30 irradiates the living body or the reflecting mirror 40 with measurement light that is pulsed light generated by the multi-wavelength light source 10. When the reflecting mirror 40 is inserted between the irradiation unit 30 and the living body by the reflecting mirror advance / retreat mechanism 80, the reflected light reflected by the reflecting mirror 40 is collected by the light collecting unit 50. On the other hand, when the reflected light is retracted, the scattered light scattered by the living body is collected by the light collecting unit 50.

The condensing unit 50 condenses scattered light from the living body or reflected light from the reflecting mirror 40.
The relay unit 60 guides the light collected by the light collecting unit 50 to the light intensity detecting unit 70.
The light intensity detection unit 70 detects the light intensity of scattered light or reflected light guided through the relay unit 60.

  The reflecting mirror advance / retreat mechanism 80 performs control to insert / retract the reflecting mirror 40 between the irradiation unit 30 and the living body according to the reflecting mirror advance / retreat control signal output from the control unit 100. As this reflecting mirror advance / retreat mechanism 80, for example, a sliding mechanism that allows the reflecting mirror 40 to be slidably inserted / retracted by an ultra-small actuator can be employed. In this embodiment, the reflecting mirror 40 corresponds to a light guide unit that guides measurement light to the light intensity detection unit 70, and the reflecting mirror advance / retreat mechanism 80 guides the light guide unit to be inserted between the irradiation unit 30 and the living body. It corresponds to an optical part insertion mechanism.

  The control unit 100 includes, as main functional units, a light source control unit 110, an observed scattered light time-resolved waveform acquisition unit 120, an apparatus function time-resolved waveform acquisition unit 130, a scattered light time-resolved waveform correction unit 140, and a concentration calculation. Unit 150 and reflecting mirror advance / retreat control unit 160.

  The reflecting mirror advance / retreat control unit 160 controls the advance / retreat operation of the reflecting mirror 40 by the reflecting mirror advance / retreat mechanism 80. Specifically, at the acquisition timing of the device function time-resolved waveform, a reflecting mirror insertion control signal for inserting the reflecting mirror 40 is output to the reflecting mirror advance / retreat mechanism 80, and the reflecting mirror 40 is moved between the irradiation unit 30 and the living body. Insert it. Then, after acquiring the device function time-resolved waveform, a reflecting mirror retract control signal for retracting the reflecting mirror 40 is output to the reflecting mirror advance / retreat mechanism 80, and the inserted reflecting mirror 40 is retracted.

  The storage unit 600 stores, as a program, a second concentration measurement program 612 that is read by the control unit 100 and executed as a second concentration measurement process (see FIG. 8). The second concentration measurement program 612 is executed as an apparatus function time-resolved waveform acquisition program 612A executed as an apparatus function time-resolved waveform acquisition process (see FIG. 9) and an observed scattered light time-resolved waveform acquisition process (see FIG. 10). The observed scattered light time-resolved waveform acquisition program 612B is included as a subroutine. These processes will be described later in detail using a flowchart.

  Further, in the storage unit 600, as data, for example, model data 620, corrected scattered light time-resolved waveform data 640, component absorption information data 650, layered light absorption coefficient data 660, measured concentration data 670, Device function time-resolved waveform data 680 and observed scattered light time-resolved waveform data 690 are stored.

The device function time-resolved waveform data 680 stores a device function time-resolved waveform acquired by performing device function time-resolved waveform acquisition processing.
The observed scattered light time-resolved waveform data 690 stores the observed scattered light time-resolved waveform acquired by performing the observed scattered light time-resolved waveform acquisition process.

2-2. Process Flow FIG. 8 is a flowchart showing the flow of the second concentration measurement process executed by the control unit 100 in accordance with the second concentration measurement program 612 stored in the storage unit 600.

  First, the control unit 100 determines whether it is the measurement timing of the component concentration (step A1). If it is determined that it is the measurement timing (step A1; Yes), the control unit 100 determines whether or not the concentration calculation has been performed a predetermined number of times (for example, three times) (step B3).

  When it is determined that the concentration calculation has been executed a predetermined number of times (step B3; Yes), the control unit 100 performs device function time-resolved waveform acquisition processing according to the device function time-resolved waveform acquisition program 612A stored in the storage unit 600. (Step B5).

FIG. 9 is a flowchart showing a flow of apparatus function time-resolved waveform acquisition processing.
First, the reflecting mirror advance / retreat control unit 160 outputs a reflecting mirror insertion control signal instructing insertion of the reflecting mirror 40 to the reflecting mirror advance / retreat mechanism 80, and performs control for inserting the reflecting mirror 40 between the irradiation unit 30 and the living body. Perform (Step C1).

  Next, the control unit 100 performs loop B processing for each candidate wavelength (steps C3 to C9). In the process of loop B, the light source control unit 110 outputs a light source control signal instructing generation of pulse light of the candidate wavelength to the multi-wavelength light source 10 so as to generate and emit pulse light of the candidate wavelength. Control (step C5).

  Next, the device function time-resolved waveform acquisition unit 130 performs device function time-resolved waveform calculation processing (step C7). Specifically, processing for analyzing the light intensity of the reflected light from the reflecting mirror 40 is performed based on the light detection signal output from the light intensity detection unit 70, and the device function time-resolved waveform is calculated and acquired. Then, the acquired device function time-resolved waveform is stored in the storage unit 600 as device function time-resolved waveform data 680.

  If the control unit 100 has performed the processes of steps C5 and C7 for each candidate wavelength, the control unit 100 ends the process of loop B (step C9). Next, the reflecting mirror advance / retreat control unit 160 outputs a reflecting mirror retracting control signal for instructing the retracting of the reflecting mirror 40 to the reflecting mirror advance / retreat mechanism 80, and performs control to retract the reflecting mirror 40 inserted in step C1 ( Step C11). And the control part 100 complete | finishes an apparatus function time-resolved waveform acquisition process.

  Returning to FIG. 8, after performing the device function time-resolved waveform acquisition process, or when it is determined in step B3 that the calculation of the concentration has not been executed a predetermined number of times (step B3; No), the control unit 100 Observed scattered light time-resolved waveform acquisition processing is performed in accordance with the observed scattered light time-resolved waveform acquisition program 612B stored in the storage unit 600 (step B7).

FIG. 10 is a flowchart showing the flow of observed scattered light time-resolved waveform acquisition processing.
The control unit 100 performs loop C processing for each candidate wavelength (steps D1 to D7). In the process of loop C, the light source control unit 110 outputs a light source control signal instructing generation of pulse light of the candidate wavelength to the multi-wavelength light source 10 so as to generate and emit pulse light of the candidate wavelength. Control (step D3).

  Thereafter, the observed scattered light time-resolved waveform acquisition unit 120 performs an observed scattered light time-resolved waveform acquisition process (step D5). Specifically, based on the light detection signal output from the light intensity detection unit 70, processing for analyzing the light intensity of the scattered light from the living body is performed to obtain the observed scattered light time-resolved waveform. Then, the acquired observed scattered light time-resolved waveform is stored in the storage unit 600 as observed scattered light time-resolved waveform data 690.

  If the control unit 100 has performed the processing of steps D3 and D5 for each candidate wavelength, the control unit 100 ends the processing of loop C (step D7). Then, the control unit 100 ends the observed scattered light time-resolved waveform acquisition process.

  Returning to FIG. 8, after performing the observed scattered light time-resolved waveform acquisition processing, the scattered light time-resolved waveform correcting unit 140 performs deconvolution processing (step B9). Specifically, an operation is performed to deconvolve the observed scattered light time-resolved waveform stored in the observed scattered light time-resolved waveform data 690 with the device function time-resolved waveform stored in the device function time-resolved waveform data 680. . Then, the calculation result is stored in the storage unit 600 as corrected scattered light time-resolved waveform data 640.

  After performing the deconvolution process, the control unit 100 proceeds to Step A17. The subsequent processing is the same as the first concentration measurement processing.

  When it is determined in step A1 that the measurement timing is not reached (step A1; No), the control unit 100 determines whether or not an operation instruction to acquire the device function time-resolved waveform has been performed by the user via the operation unit 200 ( Step B11). When it is determined that the acquisition instruction operation has not been performed (step B11; No), the process returns to step A1. If it is determined that an acquisition instruction operation has been performed (step B11; Yes), the control unit 100 performs the device function time-resolved waveform acquisition process described in FIG. 9 (step B5). Then, the control unit 100 returns to Step A1.

2-3. Action Effect In the second concentration measuring apparatus 1B, the apparatus function time is based on the light intensity detected by the light intensity detecting unit 70 when the reflecting mirror 40 is inserted between the irradiation unit 30 and the living body by the reflecting mirror advance / retreat mechanism 80. The decomposed waveform acquisition unit 130 acquires a device function time-resolved waveform. Therefore, it is possible to acquire the device function time-resolved waveform in a time division manner with one optical path. Although the instrument function time-resolved waveform cannot be obtained at the same time as the concentration measurement, the instrument function time-resolved waveform related to the optical path used for concentration measurement can be obtained, so the instrument function that more accurately represents the measurement system error related to the measurement component It is possible to obtain a time-resolved waveform.

  Further, in the second concentration measurement apparatus 1B, based on the number of times of density calculation, the reflection mirror 40 is advanced and retracted by the reflection mirror advance / retreat mechanism 80, and the apparatus function time-resolved waveform acquisition unit 130 acquires the apparatus function time-resolved waveform. Let Specifically, when the number of density calculations reaches a predetermined number (for example, three times), insertion of the reflecting mirror 40 and acquisition of a device function time-resolved waveform are executed. This makes it possible to periodically update the device function time-resolved waveform.

  Further, in the second concentration measurement apparatus 1B, the acquisition of the device function time-resolved waveform is executed even when the device function time-resolved waveform acquisition instruction operation is performed via the operation unit 200. The data for correcting the scattered light time-resolved waveform at the timing can be updated to the latest data.

2-4. In the second embodiment, based on the number of density calculations, the reflecting mirror 40 is advanced and retracted by the reflecting mirror advance / retreat mechanism 80, and the device function time-resolved waveform acquisition unit 130 acquires the device function time-resolved waveform. However, instead of this, it may be performed based on the elapsed time from the last calculation of the concentration.

  Specifically, for example, the elapsed time from the last calculation of the concentration is measured, and when the elapsed time reaches a predetermined time (for example, 2 hours), insertion of the reflecting mirror 40 by the reflecting mirror advance / retreat mechanism 80, In addition, the device function time-resolved waveform acquisition unit 130 may acquire the device function time-resolved waveform.

3. Other Examples 3-1. Light Source The light source described in the above embodiment need not be a multi-wavelength light source, and a plurality of light sources that generate pulsed light of one type of wavelength may be arranged. The light source may be a light source that repeatedly generates pulsed light. In this case, it is preferable that the light intensity detection unit 70 integrates the light intensity for a certain period of time and includes the integrated value of the light intensity in the light detection signal and outputs it to the control unit 100.

3-2. Detection of light intensity When the intensity of the measurement light is weak, the light intensity may be detected by counting the number of photons by photon counting detection.

3-3. Calculation of Light Absorption Coefficient In the above embodiment, the light absorption coefficient of each layer of the skin is calculated according to the equation (2). However, the light absorption coefficient of each layer of the skin may be calculated using the following equation (7) obtained by developing the equation (1) into an integral type instead of the equation (2).

3-4. Calculation of Component Concentration In the above embodiment, the concentration of each component of the dermis layer of the skin was calculated according to equations (5) and (6) determined by the relationship between the light absorption coefficient and the volume fraction. However, the concentration of each component of the dermis layer of the skin may be calculated according to the following equations (8) and (9) determined by the relationship between the molar extinction coefficient and the molar concentration.

  In addition to these, as a method for calculating the light absorption coefficient and the concentration of each component, for example, a method based on multivariate analysis such as principal component analysis or PLS (Partial Least Squares) method may be used.

3-5. Others The target component of concentration measurement has been described as a blood glucose level, but it is needless to say that the present invention is not limited to the blood glucose level, and other components may be targeted. Of course, the living body to be measured may be not only a human but also an animal.

  DESCRIPTION OF SYMBOLS 1A 1st density | concentration measuring apparatus, 1B 2nd density | concentration measuring apparatus, 3A 1st optical apparatus, 3B 2nd optical apparatus, 10 multiwavelength light source, 20 branching part, 30 irradiation part, 30A 1st irradiation part, 30B 2nd irradiation part , 40 reflector, 50 condensing unit, 50A first condensing unit, 50B second condensing unit, 60 relay unit, 60A first relay unit, 60B second relay unit, 70 light intensity detection unit, 70A first light Intensity detection unit, 70B second light intensity detection unit, 80 reflecting mirror advance / retreat mechanism, 100 control unit, 200 operation unit, 300 display unit, 400 sound output unit, 500 communication unit, 600 storage unit

Claims (7)

A concentration measuring device attached to a predetermined part of a living body,
An irradiation unit for irradiating the living body with measurement light;
A detection unit for detecting scattered light from the living body;
A first acquisition unit that acquires a scattered light time-resolved waveform based on the light intensity of the scattered light detected by the detection unit;
A second acquisition unit that acquires a device function time-resolved waveform based on the light intensity of the measurement light when attached to the predetermined part;
Using the scattered light time-resolved waveform and the device function time-resolved waveform, a calculation unit that calculates the concentration of a predetermined component contained in the living body,
Concentration measuring device with The calculation unit includes a deconvolution processing unit that deconvolves the scattered light time-resolved waveform with the device function time-resolved waveform.
The concentration measuring apparatus according to claim 1. Further comprising a measurement light detector for detecting the measurement light,
The second acquisition unit acquires the device function time-resolved waveform based on the light intensity of the measurement light detected by the measurement light detection unit at the time of detection by the detection unit.
The concentration measuring apparatus according to claim 1 or 2. A light guide part insertion mechanism for inserting a light guide part for guiding the measurement light to the detection part between the irradiation part and the living body;
The second acquisition unit acquires the device function time-resolved waveform based on the light intensity of light detected by the detection unit when the light guide unit is inserted by the light guide unit insertion mechanism.
The concentration measuring apparatus according to claim 1 or 2. The apparatus further includes a control unit that performs control to execute insertion of the light guide unit by the light guide unit insertion mechanism and acquisition of the device function time-resolved waveform by the second acquisition unit based on the number of times of calculation of the density. The
The concentration measuring apparatus according to claim 4. Based on the elapsed time from the last calculation of the density, control is performed to execute insertion of the light guide unit by the light guide unit insertion mechanism and acquisition of the device function time-resolved waveform by the second acquisition unit. A control unit;
The concentration measuring apparatus according to claim 4. A method for controlling a concentration measuring device attached to a predetermined part of a living body,
Irradiating the living body with measurement light;
Detecting scattered light from the living body;
Obtaining a scattered light time-resolved waveform based on the light intensity of the detected scattered light;
Obtaining a device function time-resolved waveform based on the light intensity of the measurement light when mounted on the predetermined part;
Using the scattered light time-resolved waveform and the device function time-resolved waveform to calculate the concentration of a predetermined component contained in the living body;
Control method.

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