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EP-3275363-B1 - APPARATUS AND METHOD FOR ESTIMATING BIOLOGICAL SUBSTANCE, APPARATUS FOR ACQUIRING UNIT SPECTRUM, AND WEARABLE DEVICE

EP3275363B1EP 3275363 B1EP3275363 B1EP 3275363B1EP-3275363-B1

Inventors

  • LEE, SO YOUNG
  • PARK, JIN YOUNG

Dates

Publication Date
20260513
Application Date
20170111

Claims (10)

  1. A computer-implemented method for acquiring a unit spectrum, comprising the steps of: emitting (512) a first light, by a spectrometer (110), to a storage (212) of a receptor (121) when the storage contains a first serum solution without a biological substance, wherein the first serum solution flows into the storage through an inlet (211) of the receptor and is discharged through an outlet (213) of the receptor, wherein the spectrometer includes a light source (111) including a light-emitting diode or a laser diode; detecting (513) the first light passing through the first serum solution and being reflected from a reflector (122), wherein the reflector is formed of a reflective material and is disposed at a rear surface of the receptor; obtaining, by the spectrometer (110), a first spectrum from the detected first light; emitting (515) a second light, by the light source, to the storage when the storage contains a second serum solution comprising the biological substance, wherein the second serum solution flows into the storage through the inlet of the receptor and is discharged through the outlet of the receptor; detecting (516) the second light passing through the second serum solution and being reflected from the reflector; obtaining, by the spectrometer (110), a second spectrum from the detected second light; and obtaining a unit spectrum by subtracting the first spectrum from the second spectrum and dividing by a sugar concentration and dividing by a light traveling path, wherein the light traveling path is estimated in the second serum solution by converting the spectral intensity acquired on the basis of the light traveling path in an aqueous solution.
  2. The computer-implemented method of claim 1, further comprising estimating the biological substance by: emitting a light to a skin of a user; detecting the light returned from the skin; measuring a skin spectrum of the user from the detected light; and estimating the biological substance in the user based on the measured skin spectrum and the unit spectrum.
  3. The computer-implemented method of claim 2, wherein the measuring the skin spectrum comprises measuring the skin spectrum based on at least one of infrared spectroscopy and Raman spectroscopy, wherein the first and second serum solutions comprise a scatterer that stimulates a light scattering phenomenon in biological tissue and at least one of gelatin, silica and intralipid.
  4. The computer-implemented method of claim 2 or 3, wherein the estimating the biological substance comprises: collecting a background spectrum of the user as learning data; creating a prediction model of the biological substance using the collected learning data; and estimating the biological substance using the prediction model.
  5. The computer-implemented method of claim 4, further comprising measuring the background spectrum from the user's skin with the user in a fasting state, in a preset calibration cycle or upon receiving a request from the user, or wherein the step of estimating comprises estimating the biological substance based on a reference value of the biological substance, the unit spectrum, and an output result of the prediction model.
  6. An apparatus for acquiring a unit spectrum, the apparatus comprising: a receptor (121) configured to receive a biological tissue simulation solution being either a first serum solution without a biological substance or a second serum solution with the biological substance, wherein the receptor comprises: an inlet (211) configured to input the first or second serum solution; a storage (212) configured to store the first or second serum solution flowing in through the inlet; and an outlet (213) configured to discharge the first or second serum solution stored in the storage; a reflector (122) configured to reflect a light incident onto the receptor, wherein the reflector is disposed at a rear surface of the receptor; a spectrometer (110) configured to emit the light into the receptor, detect the light reflected by the reflector, and measure a spectrum from the detected light for each of the first and second serum solutions, wherein the spectrometer includes a light source (111) including a light-emitting diode or a laser diode; and a processor (130) configured to acquire a unit spectrum for the biological substance by subtracting the spectrum obtained with the first serum solution from the spectrum obtained with the second serum solution and dividing by a sugar concentration and dividing by a light traveling path, wherein the light traveling path is estimated by the processor in the second serum solution by converting the spectral intensity acquired on the basis of the light traveling path in an aqueous solution.
  7. The apparatus of claim 6, wherein the biological tissue simulation solution comprises at least one of gelatin, silica and intralipid, and further comprising: a scatterer for scattering the light emitted by the spectrometer.
  8. The apparatus of claim 6 or 7, wherein the reflector is formed of a reflective material with a reflectance of 100%, or wherein the spectrometer is further configured to measure the spectrum based on at least one of infrared spectroscopy and Raman spectroscopy.
  9. The apparatus of claim 6, wherein the spectrometer is configured to measure the first spectrum when the first serum solution flows in through the inlet and is stored in the storage, and the spectrometer is configured to measure the second spectrum when, after the first spectrum is measured, the second serum solution flows in through the inlet for a predetermined time, the first serum solution is discharged through the outlet, and the second serum solution is stored in the storage.
  10. The apparatus of claim 6, wherein the processor is further configured to correct at least one of a spectral intensity, an offset, and a slope of the first spectrum and the second spectrum and acquire the unit spectrum based on the corrected first spectrum and second spectrum.

Description

BACKGROUND 1. Field Apparatuses and methods consistent with exemplary embodiments relate to estimating a biological substance in a non-invasive way, and more particularly, to acquiring a unit spectrum for estimating a biological substance and estimating the biological substance using the acquired unit spectrum. 2. Description of Related Art Diabetes mellitus is a chronic disease that causes various complications and cannot be easily treated. Thus, the complications should be prevented by regularly checking blood sugar levels. In addition, those who take insulin shots need to check their blood sugar levels because they are at risk for low blood sugar levels and therefore adjustment of insulin dose may be necessary. Generally, an invasive method is used to measure the blood sugar level due to the high reliability of the method. However, there may be pain, inconvenience, and a risk of infection with a disease when blood is collected using a syringe. In recent years, research has been conducted on a method of measuring a blood sugar level in a non-invasive manner using a spectrometer Instead of directly collecting blood. K. Yamakoshi, Y. Yamakoshi: "Pulse Glucometry: A New Approach for Noninvasive Blood Glucose Measurement Using Instantaneous Differential Near-Infrared Spectrophotometry", Journal of Biomedical Optics, vol. 11, no. 5, September 1, 2006 describes a new optical method for noninvasive blood glucose (BGL) measurement. Optical methods are confounded by basal optical properties of tissues, especially water and other biochemical species, and by the very small glucose signal. These problems are addressed by using fast spectrophotometric analysis in a finger, deriving 100 transmittance spectra per second, to resolve optical spectra (900 to 1700 nm) of blood volume pulsations throughout the cardiac cycle. Difference spectra are calculated from the pulsatile signals, thereby eliminating the effects of bone, other tissues, and non-pulsatile blood. A partial least squares (PLS) model is used with the measured spectral data to predict BGL levels. WO 97/36540 relates to the determination of concentrations of biological substances using Raman spectroscopy and artificial neural network discriminator. The concentration of a substance, such as glucose, in a biological sample, such as human tissue (e.g. the skin of an index finger) is non-invasive determined by directing the output beam of a laser diode onto and into the skin so as to cause Raman scattering. The output of a charge coupled device, upon which the scattered light is spatially dispersed according to frequency is digitized and applied to a processor. The processor compares the Raman scattering intensity characteristics of the sample with a comparative model, in particular, an artificial neural network discriminator (ANND). The ANND is trained with a plurality of Raman spectral characteristics from biological fluids or tissue, possessing known Raman scattered light intensities versus wavelength characteristics at known concentrations. A preferred implementation of the ANND employs fuzzy adaptive resonance theory mapping (ARTMAP), which has robust noise rejection capabilities and can readily handle nonlinear phenomena. WO 2016/035626 A1 discloses quantitative spectrometry performed by using a quantitative spectrometry apparatus. SUMMARY OF THE INVENTION It is the object of the present invention to provide an improved method and apparatus for acquiring a unit spectrum. This object is solved by the subject matter of the independent claims. Preferred embodiments are defined in the dependent claims. SUMMARY OF THE DISCLOSURE Exemplary embodiments address at least the above problems and/or disadvantages and other disadvantages not described above. Also, the exemplary embodiments are not required to overcome the disadvantages described above, and may not overcome any of the problems described above. According to an aspect of an exemplary embodiment, there is provided an apparatus for estimating a biological substance including: a spectrometer configured to emit a light to a skin of a user, detect the light returned from the skin, and measure a skin spectrum of the user from the detected light, and a processor configured to estimate a biological substance in the user based on the measured skin spectrum and a unit spectrum acquired using biological tissue simulation solution. The spectrometer may measure the skin spectrum based on at least one of infrared spectroscopy and Raman spectroscopy. The biological tissue simulation solution may include a scatterer that stimulate a light scattering phenomenon in biological tissue and at least one of gelatin, silica, intralipid, and a serum solution. The processor may be further configured to acquire the unit spectrum by subtracting a pure spectrum from a bio substance spectrum. The pure spectrum may be measured from the biological tissue simulation solution to which the biological substance is not added, and the bio subst