Optical sensor, calibration method and device for estimating biological information

Abstract

An optical sensor, a calibration method, and an apparatus for estimating biological information are disclosed. According to one embodiment, a method of calibrating an optical sensor can include acquiring a first characteristic of an external light source by a detector of the optical sensor when an internal light source of the optical sensor is turned off, driving the internal light source, acquiring a second characteristic of the internal light source and the external light source by the detector, and acquiring a reference characteristic of the internal light source for calculating absorbance of an object based on the first characteristic and the second characteristic.

Description

[0001] This application claims the benefit of Korean Patent Application No. 10-2020-0058975, filed on May 18, 2020, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. Technical Field

[0002] The following description relates to methods for calibrating optical sensors, optical sensors, and techniques for estimating biological information using optical sensors. Background Technology

[0003] Recently, techniques for non-invasive analysis of various components of a subject (specifically, human tissue) using optical sensors have been developed. Typically, optical sensors use a separate scattering reflector to measure the spectrum of a light source before measuring human skin, and the optical sensor is calibrated using the measured spectrum. However, the accuracy of bioinformatics estimation can be reduced because the spectrum or intensity can vary due to heat from the light source, temperature changes caused by skin contact, changes in ambient temperature, and degradation of the light source's performance. Furthermore, when using multiple light sources, it is difficult to calibrate the sources due to the different thermal characteristics of each. Summary of the Invention

[0004] The present invention is provided in a simplified form to describe the choice of concepts further described in the following detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter.

[0005] In one general aspect, a method for calibrating an optical sensor includes: acquiring a first characteristic of an external light source by means of a detector of the optical sensor when the internal light source of the optical sensor is turned off; driving the internal light source; acquiring a second characteristic of the internal light source and the external light source by means of the detector; and acquiring a reference characteristic of the internal light source for calculating the absorbance of an object based on the first and second characteristics.

[0006] The reference characteristics may include at least one of the intensity and spectral characteristics of the light emitted from the internal light source and reflected on the internal reflective surface of the optical sensor.

[0007] The steps to obtain a reference characteristic may include: obtaining the reference characteristic by subtracting the first characteristic from the second characteristic.

[0008] The step of driving the internal light source may include modulating at least one of the amplitude and phase of the internal light source, and the step of obtaining the reference characteristics may include using a lock-on detection technique to obtain the reference characteristics.

[0009] The method may further include: comparing a reference characteristic with an initial characteristic and determining whether to perform a remeasurement.

[0010] The method may also include guiding the user when it is determined that a remeasurement is required.

[0011] The method may further include: performing an initial calibration to obtain initial characteristics.

[0012] The steps for performing initial calibration may include: driving an internal light source in a shaded environment and acquiring initial characteristics by detecting light reflected from the internal reflective surface of an optical sensor via a detector.

[0013] The steps for performing initial calibration may include: obtaining a third characteristic by detecting light reflected from the external reflective surface via a detector in a shielded environment, and obtaining a spectral transmission constant for calculating the absorbance of the object based on the initial characteristic and the third characteristic.

[0014] The steps to obtain the spectral transmission constant may include: normalizing the third characteristic and the initial characteristic, and obtaining the ratio of the normalized values ​​as the spectral transmission constant.

[0015] In another general aspect, a method for calibrating an optical sensor includes: driving an internal light source of the optical sensor; acquiring characteristics of the internal and external light sources through a detector of the optical sensor; and acquiring reference characteristics of the internal light source for calculating the absorbance of an object based on the acquired characteristics.

[0016] The step of driving the internal light source may include modulating at least one of the amplitude and phase of the internal light source, and the step of obtaining the reference characteristics may include obtaining the reference characteristics using a lock-on detection technique.

[0017] In another general aspect, a method for calibrating an optical sensor includes: driving an internal light source when an object comes into contact with the optical sensor; modulating the reflectivity of the internal reflective surface by applying a voltage to a reflective surface modulator of the optical sensor; detecting light reflected by the object and the internal reflective surface from the internal light source by a detector of the optical sensor; and using a lock-on detection technique based on the detected light to obtain reference characteristics of the internal light source for calculating the absorbance of the object.

[0018] The method may further include: comparing reference characteristics of the internal light source with initial characteristics and determining whether to perform a remeasurement; and guiding the user when it is determined that a remeasurement is required.

[0019] The method may further include: performing an initial calibration to obtain reference characteristics.

[0020] In another general aspect, an optical sensor is provided, the optical sensor comprising: an internal light source disposed on a substrate; a detector disposed on the substrate and spaced apart from the internal light source; a partition disposed between the internal light source and the detector to block light from the internal light source; and an internal reflective surface configured to reflect light from the internal light source toward the detector.

[0021] An internal light source may be positioned between the light source and the detector, and the optical sensor may also include a covering surface made of a transparent material.

[0022] The optical detector may further include a modulator configured to modulate at least one of the amplitude and phase of the internal light source.

[0023] The optical detector may further include a reflective surface modulator configured to modulate the reflectivity of the inner reflective surface when a voltage is applied to the reflective surface modulator.

[0024] In another general aspect, an apparatus for estimating biological information includes: an optical sensor comprising: an internal light source configured to emit light; an internal reflective surface configured to reflect a portion of the light emitted from the internal light source toward a detector; and a detector configured to detect the light; and a processor configured to acquire reference characteristics of the internal light source by performing calibration of the optical sensor, and configured to estimate biological information based on the reference characteristics when light scattered or reflected from an object is detected.

[0025] The processor can acquire a first characteristic based on the light from an external light source when the internal light source is off, acquire a second characteristic based on the light from both the internal and external light sources by driving the internal light source, and acquire a reference characteristic based on the first and second characteristics, according to a calibration request.

[0026] The processor can obtain the reference characteristic by subtracting the first characteristic from the second characteristic.

[0027] The processor can modulate at least one of the amplitude and phase of the internal light source when driving the internal light source, and can use lock-on detection technology to obtain reference characteristics based on the acquired first and second characteristics.

[0028] The processor can compare the initial characteristics of the internal light source with the reference characteristics obtained through calibration, and can determine whether to perform recalibration based on the comparison results.

[0029] The processor can perform initial calibration by driving the internal light source in a shaded environment to obtain the initial characteristics and spectral transmission constant of the internal light source based on the light reflected by the internal reflective surface and the light reflected by the external reflective surface.

[0030] The processor can acquire spectral absorbance based on the light, spectral transmission constant, and reference characteristics detected from the object, and can use the acquired spectral absorbance and bioinformatics estimation model to estimate bioinformatics.

[0031] Bioinformation may include one or more of the following: antioxidants, blood sugar, triglycerides, cholesterol, proteins, carotenoids, lactic acid, and uric acid.

[0032] The optical sensor may also include a reflective surface modulator that modulates the reflectivity of the inner reflective surface when a voltage is applied to the reflective surface modulator.

[0033] The processor can modulate the reflectivity of the inner reflective surface by applying a voltage to the reflective surface modulator when the optical sensor comes into contact with the object, and can obtain reference characteristics based on the light reflected by the inner reflective surface and the object through lock-on detection technology.

[0034] The processor can continuously perform calibration and estimation of biometric information while the object is in contact with the optical sensor. Attached Figure Description

[0035] Figure 1 This is a block diagram illustrating an apparatus for estimating biological information according to one embodiment.

[0036] Figure 2 This is a diagram illustrating an optical sensor according to one embodiment.

[0037] Figure 3 This is a diagram used to describe the initial calibration.

[0038] Figure 4 This is a diagram illustrating an embodiment of calibration performed during bioinformatics estimation.

[0039] Figure 5 This is a diagram used to describe bioinformatics estimation.

[0040] Figure 6 This is a diagram used to illustrate an optical sensor and calibration method according to another embodiment.

[0041] Figure 7 This is a diagram used to describe an optical sensor and calibration method according to yet another embodiment.

[0042] Figure 8 This is a block diagram illustrating an apparatus for estimating biological information according to another embodiment.

[0043] Figures 9 to 13 This is a flowchart illustrating a method for calibrating an optical sensor according to an embodiment.

[0044] Figure 14 This is a diagram illustrating a wearable device according to one embodiment.

[0045] Figure 15 This is a diagram illustrating a smart device according to one embodiment.

[0046] Throughout the accompanying drawings and detailed embodiments, unless otherwise described, the same reference numerals will be understood to denote the same elements, features, and structures. For clarity, illustration, and convenience, the relative dimensions and depictions of these elements may be exaggerated. Detailed Implementation

[0047] The following detailed description provides details of exemplary embodiments with reference to the accompanying drawings. The disclosure will be more readily understood with reference to the detailed description and accompanying drawings of the exemplary embodiments below. However, the disclosure may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that the disclosure will be thorough and complete, and will fully convey the inventive concept to those skilled in the art, and the disclosure will be defined only by the appended claims. The same reference numerals denote the same elements throughout the specification.

[0048] It will be understood that although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. Furthermore, unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. In the specification, unless explicitly stated otherwise, the word "comprising" and variations such as "including" will be understood to imply inclusion of the stated elements, but not exclusion of any other elements. Terms (such as "unit" and "module") denote units that perform at least one function or operation, and they may be implemented using hardware, software, or a combination of hardware and software.

[0049] In the following, embodiments of the biometric information estimation device, optical sensor, and method for calibrating the optical sensor will be described in detail with reference to the accompanying drawings.

[0050] Figure 1 This is a block diagram illustrating an apparatus for estimating biological information according to one embodiment. Figures 2 to 7 This is a diagram used to describe the optical sensor and the calibration of the optical sensor according to an embodiment.

[0051] Reference Figure 1 The device used to estimate biological information includes an optical sensor 110 and a processor 120.

[0052] The optical sensor 110 can emit light toward an object and detect light signals scattered or reflected from the object.

[0053] Figure 2 This is a diagram illustrating an optical sensor according to one embodiment.

[0054] Reference Figure 1 and Figure 2 The optical sensor 110 includes an internal light source 24 and a detector 25. The internal light source 24 and the detector 25 may be disposed on the substrate 21 and spaced apart from each other. The internal light source 24 may include, but is not limited to, a light-emitting diode (LED), a laser diode, a phosphor, etc. The detector 25 may include, but is not limited to, a photodiode, a phototransistor, an image sensor, a spectrometer, etc.

[0055] The internal light source 24 and detector 25 can be configured as one or more arrays and arranged in various forms (such as concentric circles, rectangles, triangles, and linear shapes). For example, multiple LED arrays can be arranged around photodiodes in concentric circles, rectangles, etc., or conversely, multiple photodiodes can be arranged around a light source in concentric circles, rectangles, etc. The number and arrangement of the internal light source 24 and detector 25 are not specifically limited and can be modified in various ways depending on the type of biological information to be analyzed or the computational performance of the device 100 used to estimate the biological information.

[0056] The internal light source 24 and detector 25 can be formed on the substrate 21 by wire bonding or flip-chip bonding, or can be patterned on the substrate 21 by microfabrication techniques.

[0057] The optical sensor 110 may include a partition 26 disposed between the internal light source 24 and the detector 25 to block light emitted from the light source 24 from directly propagating to the detector 25.

[0058] Optionally, the optical sensor 110 may also include an internal reflective surface 27 that reflects a portion of the light emitted from the internal light source 24 toward the object to guide it to the detector 25. The internal reflective surface 27 may be disposed on the partition wall 26 between the internal light source 24 and the detector 25, as shown in the figures. The internal reflective surface 27 may be formed as a light-reflecting object (such as a mirror or a metallic object) or a light-reflecting material may be applied to the object.

[0059] The optical sensor 110 may have a cover surface 23 formed on the surface in contact with the object, and an inner reflective surface 27 may be disposed on the cover surface 23. In this case, the cover surface 23 may be made of a transparent material (such as glass) so that light emitted from the internal light source 24 and light reflected by the object can be transmitted. The space 22 between the substrate 21 and the cover surface 23 may be molded.

[0060] Processor 120 may be electrically connected to optical sensor 110. Processor 120 may control optical sensor 110 in response to a request for estimating biological information and estimate the biological information based on the characteristics of the signal received from optical sensor 110. In this case, the biological information may include one or more of antioxidant components, blood glucose, triglycerides, cholesterol, proteins, carotenoids, lactic acid, and uric acid. However, the biological information is not limited to these.

[0061] To improve the accuracy of bioinformatics estimation, the processor 120 may perform initial calibration during the manufacture of the device 100 used for estimating bioinformatics or when the user first uses the processor 120.

[0062] Figure 3 This is a diagram used to describe the initial calibration.

[0063] Reference Figure 3 The processor 120 can first drive the internal light source 24 to emit light with optical properties I(λ) in a shielded environment. When the light emitted by the internal light source 24 is reflected by the internal reflective surface 27, the detector 25 can detect the light reflected by the internal reflective surface 27, and the processor 120 can store the optical properties I detected by the detector 25. r0 (λ) serves as the initial characteristic of the internal light source 24. In this case, the optical characteristics detected by the detector 25 can represent the wavelength, light intensity, or spectral characteristics depending on the configuration of the detector 25, and for ease of description, can be described as light intensity, absorbance, etc.

[0064] The processor 120 can then drive the internal light source 24 to emit light toward the external reflective surface 31 in a shielded environment, and can obtain the spectral transmission constant based on the optical properties detected by the detector 25. In this case, the detected optical properties may include the light reflected by the external reflective surface 31 and the internal reflective surface 27.

[0065] For example, the spectral transmission constant k(λ) can be obtained by referring to Equation 1 below.

[0066] (1)

[0067] Processor 120 can subtract the initial optical property I from the optical property I1(λ) of the light reflected from the outer reflecting surface 31 and the inner reflecting surface 27. r0 (λ) is used to obtain the optical properties of the light reflected by the external reflecting surface 31. spec (λ). In this case, if the optical properties of the light reflected by the inner reflecting surface (i.e., the initial optical properties I) r0 If (λ) is very small, then the optical properties of the light reflected by the external reflecting surface 31 are Ispec (λ) can converge to a value similar to the optical properties I0(λ) of the light emitted by the internal light source 24.

[0068] Processor 120 can acquire the optical properties I of the light reflected by the external reflective surface. spec (λ) and the initial optical properties I of the light reflected by the inner reflecting surface 27 r0 The ratio between (λ) is taken as the spectral transmission constant. In this case, the optical properties I of the light reflected by the outer and inner reflecting surfaces are respectively... spec (λ) and I r0 (λ) can be normalized, and the spectral transmission constant can be obtained using the normalized optical property I. spec norm (λ) and I r0 norm (λ) is used to obtain the value. At this point, normalization can be performed so that the optical properties (e.g., light intensity) have values ​​in the range of 0 to 1.

[0069] The processor 120 can store the acquired initial characteristics and spectral transmission constants as initial calibration information, and utilize the stored initial calibration information when estimating biometric information.

[0070] On the other hand, as described above, when an optical characteristic is detected by detector 25, processor 120 can obtain the initial characteristic and spectral transmission constant using the detected optical characteristic value itself. However, it can also obtain the initial characteristic and spectral transmission constant by subtracting the optical characteristic I detected by detector 25 in a shielded environment without driving an internal light source from the optical characteristic value. dark The value obtained.

[0071] The initial calibration process described above can be omitted. For example, the initial characteristics and spectral transmission constant can be obtained using values ​​acquired through preprocessing in other devices or similar environments.

[0072] Meanwhile, when bioinformation estimation is repeated, the spectral characteristics or intensity of the light signal of the optical sensor 110 may change due to changes in the measurement environment (such as heating of the internal light source 24, temperature changes due to object contact, changes in ambient temperature, and degradation of the performance of the internal light source 24), and changes in the optical characteristics of the internal light source may reduce the accuracy of bioinformation estimation.

[0073] The processor 120 may additionally perform calibration to correct for changes in optical properties caused by repeated bioinformatic estimation. For example, the processor 120 may perform calibration each time, such as upon user request, at predetermined intervals, or before bioinformatic estimation.

[0074] Optionally, the processor 120 may perform calibration based on whether the environment used for bioinformatics estimation has changed drastically or whether the accuracy of the bioinformatics estimation results has decreased. For example, the device 100 for estimating bioinformatics may also include a temperature sensor for measuring the contact temperature of an object or the heat generated by an internal light source. When the temperature measured by the temperature sensor falls outside the normal range, the processor 120 may determine that the environment has changed drastically. Optionally, when the bioinformatics estimation results deviate from the normal range by more than a predetermined threshold or when the number of times the bioinformatics estimation results deviate from the normal range exceeds a predetermined threshold, the processor 120 may determine that the accuracy of the bioinformatics estimation has decreased. However, these are merely examples, and the conditions used for determination may be set differently.

[0075] Figure 4 This is a diagram illustrating one embodiment of additional calibrations performed during bioinformatics estimation. (Refer to...) Figure 4 A calibration method according to one embodiment is described.

[0076] The processor 120 can shut down the internal light source 24 of the optical sensor and control the detector 25 to acquire the optical characteristics I of the external light source. amb (λ).

[0077] Then, the processor 120 can drive the internal light source 24 and detect light from the external light source and light reflected onto the internal reflective surface 27 via the detector 25. Furthermore, the processor 120 can use the detected light to determine the optical characteristics I2(λ)=I of the internal light source 24 and the external light source. amb (λ)+I r (λ).

[0078] Processor 120 can, as shown in Equation 2 below, subtract the optical characteristic I of the external light source from the optical characteristic I2(λ) of the internal light source 24 and the external light source. amb (λ) is used to obtain the reference characteristic I for calculating absorbance. r (λ). The processor 120 can perform preprocessing, including smoothing, on the acquired reference characteristics and store the preprocessed reference characteristics.

[0079] (2)

[0080] When a reference characteristic is acquired, the processor 120 can compare the reference characteristic with the initial characteristic acquired during the initial calibration process and determine whether to perform a remeasurement. For example, if the difference between the initial characteristic and the reference characteristic exceeds a predetermined threshold, it can be determined that the optical characteristics of the internal light source have changed to a degree that affects the accuracy of the bioinformatics estimation, and guidance can be provided to the user.

[0081] When a request to estimate biological information is received, the processor 120 can use reference characteristics obtained through calibration to estimate the biological information. In this case, the request to estimate biological information can be received through predetermined intervals, user input, or external devices.

[0082] Figure 5 This is a diagram used to describe bioinformatics estimation.

[0083] Reference Figure 5 When the object OBJ comes into contact with the optical sensor 110, the processor 120 can drive the internal light source 24 to emit light with optical properties I(λ) toward the object OBJ. The detector 25 can detect the light emitted by the internal light source 24 and scattered or reflected by the internal reflective surface 27, the surface of the object OBJ, or a measurement location (e.g., a blood vessel) within the object OBJ.

[0084] The processor 120 can calculate absorbance based on the characteristics of the light detected by the detector 25 and the reference characteristics and spectral transmission constant obtained through calibration, and use the absorbance to calculate bioinformatics estimates.

[0085] For example, an example of the absorbance calculation formula based on the Lambert-Beer law is shown in Equation 3 below, but it is not limited to this.

[0086] (3)

[0087] here, Y This represents the absorbance at wavelength λ. abs Represents absolute value. I r Indicates reference characteristics, k This represents the spectral transmission constant obtained through initial calibration. I sam This represents the optical properties detected by detector 25 after light is emitted towards the object. The intensity of light scattered or reflected from the object can be determined from the detected optical properties. I sam Subtract reference property I r To obtain.

[0088] When absorbance is calculated as described above, processor 120 can use absorbance to estimate biological information. For example, the biological information estimate can be obtained using a biological information estimation model that defines the correlation between absorbance and biological information.

[0089] Figure 6 This is a diagram used to illustrate an optical sensor and calibration method according to another embodiment.

[0090] Reference Figure 6The optical sensor 110 may also include a modulator 28 for modulating the amplitude or phase of the internal light source 24. In one example, the processor 120 may acquire the optical characteristics I of the external light source when the internal light source 24 is off. amb (λ). The processor 120 can drive the internal light source 24 and control the modulator 28 to perform quadrature amplitude modulation, phase modulation, etc., of the internal light source 24. Furthermore, reference characteristic I... r (λ) can be obtained using the optical property I2 detected by detector 25. mod (λ)=I amb (λ)+I r mod (λ) is obtained through lock-in detection. In another example, processor 120 can acquire the characteristics of both the internal and external light sources while directly modulating the internal light source under an external light source, and use lock-in detection to acquire reference characteristics based on the acquired optical characteristics. In this case, lock-in detection is a known technique, so its detailed description will be omitted. Processor 120 can compare the reference characteristics acquired as described above with the initial characteristics and determine whether to perform a remeasurement.

[0091] Figure 7 This is a diagram used to describe an optical sensor and calibration method according to yet another embodiment.

[0092] In this embodiment, calibration can be performed before bioinformatics estimation when the user brings the object OBJ into contact with the overlay surface of the optical sensor used for bioinformatics estimation. Then, once calibration is complete, bioinformatics can be estimated using signals continuously detected from the object OBJ. However, the embodiment is not limited to this, and only the calibration process may be performed, omitting the bioinformatics estimation process.

[0093] Reference Figure 7 The optical sensor 110 may also include a reflective surface modulator 29 that modulates the reflectivity of the inner reflective surface 27. For example... Figure 7 As shown, the reflective surface modulator 29 may be attached to the inner reflective surface 27, or integrally formed with the inner reflective surface 27. The reflective surface modulator 29 may be a liquid crystal light modulator.

[0094] The processor 120 can modulate the signal reflected by the inner reflective surface 27 by applying a voltage to the reflective surface modulator 29 via the modulator 28, and acquire reference characteristics using the signal detected by the detector 25 through a lock-on detection technique. The processor 120 can compare the reference characteristics acquired as described above with the initial characteristics and determine whether to perform a remeasurement.

[0095] Figure 8 This is a block diagram illustrating an apparatus for estimating biological information according to another embodiment.

[0096] Reference Figure 8 The device 800 for estimating biological information may include an optical sensor 810, a processor 820, an output interface 830, a storage device 840, and a communication interface 850. The configurations of the optical sensor 810 and the processor 820 have already been described above, and therefore their detailed descriptions will not be repeated.

[0097] The output interface 830 can output the processing results of the processor 820 to the user. For example, the biometric estimation results can be provided to the user using a visual output module (such as a display), an audio output module (such as a speaker), or a haptic module that provides information through vibration or touch. In addition, the processor 820 can monitor the user's health status based on the biometric estimation results, and the output interface 820 can output warnings when a risk to the health status is anticipated.

[0098] The storage device 840 can store various reference information required for bioinformatics estimation or processing results from the processor 820. For example, the reference information may include information about the driving conditions of the light source, light source modulation, modulation of the internal reflective surface, bioinformatics estimation models, etc. Furthermore, the reference information may include user characteristic information (such as the user's age, gender, health status, etc.). However, the reference information is not limited to these.

[0099] Storage device 840 may include, but is not limited to, at least one type of storage medium selected from, but not limited to, flash memory, hard disk, micro multimedia card, card type memory (e.g., Secure Digital (SD) or Extreme Digital (XD) memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, magnetic disk, and optical disk.

[0100] The communication interface 850 can communicate with external devices to send and receive data related to bioinformatics estimation. In this case, the external device may include a user's portable device (such as a smartphone, tablet PC, desktop computer, laptop computer, etc.) and devices from professional medical institutions. The communication interface 850 can use Bluetooth communication, Bluetooth Low Energy (BLE) communication, near-field communication unit, wireless local area network (WLAN) communication, Zigbee communication, Infrared Data Association (IrDA) communication, Wi-Fi Direct (WFD) communication, ultra-wideband (UWB) communication, Ant+ communication, Wi-Fi communication, and 3G, 4G, and 5G communication technologies. However, the communication technologies used are not limited to these.

[0101] Figures 9 to 13 This is a flowchart illustrating a method for calibrating an optical sensor according to an embodiment. Figures 9 to 13 The method shown can be performed by the aforementioned device 100 or 800 for estimating biological information. Since biological information estimation has been described in detail above, a brief description will follow to avoid redundancy.

[0102] Reference Figure 9 An embodiment of the calibration method is described.

[0103] First, the device 100 or 800 for estimating biological information can acquire the first characteristics of the external light source when the internal light source of the optical sensor is turned off (910).

[0104] Then, the internal light source can be driven (920), and the second characteristics of the internal light source and the external light source can be acquired (930). At this time, the detector of the optical sensor can detect the light emitted by the internal light source and reflected by the internal reflective surface and the light entering from the outside, and acquire the second characteristic based on the detected light.

[0105] Then, the reference characteristic used in the calculation of absorbance can be obtained by subtracting the first characteristic from the second characteristic (940). In this case, the reference characteristic can be the characteristic of the light reflected by the internal reflective surface.

[0106] Reference Figure 10 Another embodiment of the calibration method is described.

[0107] First, the device 100 or 800 for estimating biological information can acquire the first characteristics of the external light source (1010) when the internal light source of the optical sensor is turned off.

[0108] Then, the phase or amplitude of the internal light source can be modulated (1020), and the second characteristics of the internal and external light sources can be acquired (1030).

[0109] Then, the reference characteristics used in the absorbance calculation can be obtained using a lock-on detection technique (1040).

[0110] Reference Figure 11 Another embodiment of the calibration method is described.

[0111] First, the device 100 or 800 for estimating biological information can drive an internal light source (1110) when the object comes into contact with the optical sensor, and modulate the reflectivity of the internal reflective surface (1120) by applying a voltage to the internal reflective surface.

[0112] Then, the light reflected by the object and the internal reflective surface can be detected (1130), and the reference characteristics used in the calculation of absorbance can be obtained using a lock detection technique (1140).

[0113] Reference Figure 12 and Figure 13 Another embodiment of the calibration method is described.

[0114] First, the initial characteristics of the internal light source of the optical sensor can be obtained by performing a first calibration (1210). At this time, the first calibration may be performed during the manufacturing of device 100 or 800 or when the user first uses device 100 or 800.

[0115] Figure 13 An embodiment of the operation 1210 for performing the first calibration is shown. (Refer to...) Figure 13 The device 100 or 800 for estimating biological information can drive an internal light source in a shielded environment (1310) and acquire initial characteristics of the internal light source by detecting light reflected from the internal reflective surface (1320). Light can then be emitted from the internal light source to the external reflective surface, and the optical characteristics of the external reflective surface can be acquired (1330). The spectral transmission constant can then be acquired based on the initial characteristics and the characteristics of the external reflective surface (1340).

[0116] Back Figure 12 The device 100 or 800 used to estimate biological information can perform a second calibration to acquire reference characteristics of the internal light source (1220). In this case, it has already been referenced Figures 3 to 7 The second calibration has been described, so its detailed description will be omitted below.

[0117] Then, the reference characteristic acquired in operation 1220 and the initial characteristic acquired in operation 1210 can be compared with each other (1230). When the comparison result is below or equal to the threshold, the acquired reference characteristic can be stored as a calibration result for bioinformatics estimation (1240), and when the comparison result exceeds the threshold, the user can be guided to remeasure (1250).

[0118] Figure 14 This is a diagram illustrating a wearable device according to one embodiment. The embodiments of the devices 100 and 800 described above for estimating biometric information can be installed in a smartwatch or smart band-type wearable device worn on the wrist. However, the device is not limited thereto.

[0119] Reference Figure 14 The wearable device 1400 may include a main body 1410 and a strap 1430.

[0120] The body 1410 can be formed in various shapes. The body 1410 may include various modules for performing functions related to biometric estimation, as well as various other functions such as monitoring and alarms. A battery may be embedded in the body 1410 or a strap to power the various modules of the wearable device 1400.

[0121] The band 1430 may be attached to the body 1410. The band 1430 may be flexible to bend around the user's wrist. The band 1430 may bend in a manner that allows it to separate from the user's wrist, or it may be formed as an inseparable band. Air may be injected into the band 1430 or an air bladder may be contained within the band 1430, such that the band 1430 is elastic in response to changes in pressure applied to the wrist, and that changes in wrist pressure may be transmitted to the body 1410.

[0122] The main body 1410 may include an optical sensor 1420. The optical sensor 1420 may be mounted on a surface of the main body 1410, and the main body 1410 is in contact with the user's wrist when the main body 1410 is worn on the user's wrist.

[0123] In addition, the processor can be installed within the main body 1410, and the processor can be electrically connected to various modules of the wearable device 1400 to control the modules.

[0124] The processor can perform calibration of the optical sensor 1420 and estimate biological information using the light signals detected from the object through the optical sensor 1420. Users can input various commands, including calibration of the optical sensor 1420 and estimation of biological information, via a display, a manipulator, and / or voice input using a microphone.

[0125] A display may be mounted on the front surface of the main body 1410. The display may be a touch panel including a touchscreen for touch input. The display may receive touch input from the user, send the received touch input to the processor, and output the processor's processing results. For example, the display may display bioinformatics estimation results, and may also display additional information (such as bioinformatics estimation history, changes in health status, warnings, etc.).

[0126] The main body 1410 may include storage devices for the processing results of the storage processor and various types of information. In this case, in addition to information related to the estimation of biological information, the various types of information may also include information related to other functions of the wearable device 1400.

[0127] In addition, the main body 1410 may include a manipulator 1440 that receives user commands and sends the received commands to the processor. The manipulator 1440 may include a power button for inputting commands to turn the wearable device 1400 on / off.

[0128] Furthermore, a communication interface for communicating with external devices can be installed in the main body 1410. The communication interface can output the estimation results of biological information to an external device (e.g., a portable terminal), or it can send the estimation results of biological information to an external device so that the estimation results can be stored in the storage module of the external device. In addition, the communication interface can receive information from the external device to support various other functions performed in the wearable device.

[0129] Figure 15 This is a diagram illustrating an embodiment of a smart device employing a device 100 or 800 for estimating biological information. In this case, the smart device may be a smartphone or a tablet PC, but is not limited thereto.

[0130] Reference Figure 15 The smart device 1500 may include an optical sensor 1530 mounted on a surface of the body 1510. For example, the optical sensor 1530 may include one or more light sources 1531 and detectors 1532. Figure 15 As shown, the optical sensor 1530 can be mounted on the rear surface of the body 1510, but is not limited thereto. The optical sensor 1530 can be combined with a fingerprint sensor or touch panel on the front surface to form sensor 1530.

[0131] A display can be mounted on the front surface of the main body 1510. The display can visually output estimation results of biological information, etc. The display may include a touch panel and can receive information input through the touch panel and send the received information to the processor.

[0132] An image sensor 1520 may be mounted in the main body 1510. When a user brings his / her finger close to the sensor 1530 to measure biosignals, the image sensor 1520 can capture an image of the finger and send the captured image to a processor. In this case, the processor can identify the relative position of the finger compared to the position of the optical sensor 1530 from the image of the finger, and provide the relative position information of the finger to the user via a display, thereby guiding the user to make precise contact between his / her finger and the optical sensor 1530.

[0133] The processor can be electrically connected to various modules, including the optical sensor 1530, and can control various functions, including the calibration of the optical sensor 1530 and the estimation of biological information. Furthermore, the processor can output processing results by controlling a display or similar device.

[0134] The current embodiments can be implemented as computer-readable code in a computer-readable recording medium. The code and code segments constituting a computer program can be readily deduced by a computer programmer in the art. Computer-readable recording media include all types of recording media that store computer-readable data. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage devices. Furthermore, the recording medium can be implemented in the form of a carrier wave (such as Internet transmission). Moreover, the computer-readable recording medium can be distributed across a networked computer system, wherein the computer-readable code can be stored and executed in a distributed manner.

[0135] Several examples have been described above. However, it will be understood that various modifications can be made. For example, suitable results may be achieved if the described techniques are performed in a different order, and / or if the components in the described system, architecture, apparatus, or circuit are combined in a different manner and / or replaced or supplemented by other components or their equivalents. Therefore, other embodiments are within the scope of the claims.

Claims

1. A method for calibrating an optical sensor, comprising: When the internal light source of the optical sensor is turned off, the first characteristics of the external light source are obtained through the detector of the optical sensor; Drive the internal light source; The second characteristics of the internal and external light sources are obtained through a detector; and Based on the first and second characteristics, reference characteristics of the internal light source are obtained for calculating the absorbance of the object. The steps for obtaining the reference characteristic include: obtaining the reference characteristic by subtracting the first characteristic from the second characteristic.

2. The method according to claim 1, wherein, The reference characteristics include at least one of the intensity and spectral characteristics of the light emitted from the internal light source and reflected on the internal reflective surface of the optical sensor.

3. The method according to claim 1, wherein, The step of driving the internal light source includes modulating at least one of the amplitude and phase of the internal light source, and the step of obtaining the reference characteristics includes using a lock-on detection technique to obtain the reference characteristics.

4. The method according to any one of claims 1 to 3, further comprising: The reference characteristics are compared with the initial characteristics, and a decision is made based on the comparison results as to whether to perform a remeasurement.

5. The method according to claim 4, further comprising: When it is determined that a remeasurement is needed, guide the user to perform the remeasurement.

6. The method according to claim 4, further comprising: Perform initial calibration to obtain initial characteristics.

7. The method according to claim 6, wherein, The steps for performing initial calibration include: driving the internal light source in a shaded environment and acquiring initial characteristics by detecting the light reflected from the internal reflective surface of the optical sensor via a detector.

8. The method according to claim 7, wherein, The steps for performing the initial calibration include: obtaining a third characteristic by detecting light reflected from the external reflective surface via a detector in a shielded environment, and obtaining a spectral transmission constant for calculating the absorbance of the object based on the initial characteristic and the third characteristic.

9. The method according to claim 8, wherein, The steps to obtain the spectral transmission constant include: normalizing the third characteristic and the initial characteristic, and obtaining the ratio of the normalized values ​​as the spectral transmission constant.

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