Apparatus and method for estimating biological information

Abstract

Provided are an apparatus and method for estimating biometric information. The apparatus for estimating biometric information includes a pulse wave sensor and a processor. The pulse wave sensor includes multiple channels, each of the multiple channels being configured to measure a first pulse wave signal having a first wavelength and a second pulse wave signal having a second wavelength different from the first wavelength. The processor is configured to, for each of the multiple channels, generate a first oscillogram based on the first pulse wave signal, generate a second oscillogram based on the second pulse wave signal, and convert the phase delay between the first oscillogram and the second oscillogram into an area. The processor is further configured to determine a channel among the multiple channels based on the area of ​​each channel and estimate biometric information based on the determined channel.

Description

[0001] This application claims priority from Korean Patent Application No. 10-2020-0127934 filed on October 5, 2020, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety for all purposes. Technical Field

[0002] Example embodiments of the present disclosure relate to an apparatus and method for estimating bio-information, and more particularly, to an apparatus and method for extracting cardiovascular characteristics without using a cuff and estimating bio-information based on the extracted cardiovascular characteristics. Background Art

[0003] Common techniques for extracting cardiovascular characteristics such as blood pressure without using a pressure cuff include a pulse wave analysis (PWA) method and a pulse wave velocity (PWV) method.

[0004] The PWA method extracts cardiovascular characteristics by analyzing the shape of photoplethysmography (PPG) signals or surface pressure signals obtained from peripheral body parts (e.g., fingertips, radial arteries, etc.). Blood ejected from the left ventricle causes reflections in large branching blood vessels (such as the renal and iliac arteries), and this reflection influences the shape of the pulse wave or body pressure wave measured at the peripheral body part. Therefore, by analyzing this shape, arterial stiffness, arterial age, aortic pressure waveform, and other factors can be inferred.

[0005] The PWV method is a method for extracting cardiovascular characteristics (such as arterial stiffness and blood pressure) by measuring the pulse wave transit time. In this method, an electrocardiogram (ECG) signal and a PPG signal are measured at a peripheral part of the body. The delay (pulse transit time (PTT)) between the R peak (left ventricular systolic interval) of the ECG obtained from a peripheral part of the body (e.g., a finger or radial artery) and the peak of the PPG signal is measured. The speed at which blood from the heart reaches the peripheral part of the body is calculated by dividing the approximate length of the arm by the PTT. Summary of the Invention

[0006] According to one aspect of an example embodiment, there is provided an apparatus for estimating biological information, the apparatus comprising: a pulse wave sensor comprising a plurality of channels, each of the plurality of channels being configured to measure a first pulse wave signal of a first wavelength and a second pulse wave signal of a second wavelength, the second wavelength being different from the first wavelength; and a processor configured to: for each of the plurality of channels, generate a first oscillogram based on the first pulse wave signal, generate a second oscillogram based on the second pulse wave signal, convert a phase delay between the first oscillogram and the second oscillogram into an area, determine a channel among the plurality of channels based on the area of ​​each channel, and estimate the biological information based on the determined channel.

[0007] The pulse wave sensor may include at least one light source configured to emit light of first and second wavelengths onto an object, and at least one light receiver configured to detect the light of first and second wavelengths scattered or reflected from the object.

[0008] The at least one light receiver may include at least one of a photodiode array or a complementary metal oxide semiconductor image sensor (CMOS).

[0009] The processor may be further configured to convert the phase delay between the first oscillogram and the second oscillogram into an area in a Lissajous waveform.

[0010] The processor may be further configured to determine the channel based on at least one of a size of an area, a slope of a Lissajous waveform, a shape of an area, or a ratio between a first area and a second area obtained by dividing an area of ​​each channel.

[0011] The processor may be further configured to exclude channels that do not satisfy a predetermined criterion from the determined channels based on the first oscillogram and the second oscillogram of each channel.

[0012] The processor may be further configured to generate, for each channel, a third oscillogram by subtracting the second oscillogram from the first oscillogram, and exclude channels from the determined channels based on at least one of the full width at half maximum (FWHM) in the third oscillogram, the full width at a point corresponding to a predetermined ratio between a reference point and a maximum point of the third oscillogram, or a statistical value of a residual between a pulse wave of the third oscillogram before curve fitting and a pulse wave of the third oscillogram after curve fitting.

[0013] The processor may be further configured to determine a difference coefficient based on the first wavelength and the second wavelength, and subtract the second oscillogram to which the difference coefficient is applied from the first oscillogram.

[0014] The apparatus may further include a force / pressure sensor configured to measure a contact force and / or a contact pressure applied between the object and the pulse wave sensor.

[0015] The processor may be further configured to estimate the bio-information by using the first oscillogram of the determined channel, the second oscillogram of the determined channel, or a third oscillogram generated by subtracting the second oscillogram of the determined channel from the first oscillogram of the determined channel.

[0016] The processor may be further configured to estimate the first bio-information by using the first oscillogram, estimate the second bio-information by using the second oscillogram, and obtain final bio-information based on at least one of the first bio-information or the second bio-information.

[0017] The processor may also be configured to determine two or more channels among the multiple channels based on the area of ​​each channel, estimate bio-information values ​​of the corresponding two or more channels, and obtain final bio-information by using at least one of the estimated bio-information values ​​of the corresponding two or more channels.

[0018] The biological information may include at least one of blood pressure, vascular age, arterial stiffness, aortic pressure waveform, vascular compliance, pressure index, fatigue level, skin age, or skin elasticity.

[0019] According to one aspect of an example embodiment, there is provided a method for estimating bio-information, the method comprising: measuring, for each of the plurality of channels, a first pulse wave signal of a first wavelength and a second pulse wave signal of a second wavelength, the second wavelength being different from the first wavelength, by using a pulse wave sensor having a plurality of channels; generating, for each channel, a first oscillogram based on the first pulse wave signal, and generating a second oscillogram based on the second pulse wave signal; converting, for each channel, a phase delay between the first oscillogram and the second oscillogram into an area; determining a channel among the plurality of channels based on the area of ​​each channel; and estimating the bio-information based on the determined channel.

[0020] The method may further include converting a phase delay between the first oscillogram and the second oscillogram into an area in a Lissajous waveform.

[0021] The determining may include determining the channel based on at least one of a size of an area, a slope of a Lissajous waveform, a shape of an area, or a ratio between a first area and a second area obtained by dividing an area of ​​each channel.

[0022] The method may further include excluding channels that do not satisfy a predetermined criterion from the determined channels based on the first oscillogram and the second oscillogram of each channel.

[0023] The method may further include generating, for each channel, a third oscillogram by subtracting the second oscillogram from the first oscillogram; and excluding channels from the determined channels based on at least one of the full width at half maximum (FWHM) in the third oscillogram, the full width at a point corresponding to a predetermined ratio between a reference point and a maximum point of the third oscillogram, or a statistical value of a residual between a pulse wave of the third oscillogram before curve fitting and a pulse wave of the third oscillogram after curve fitting.

[0024] The estimating may include estimating the bio-information by using the first oscillogram of the determined channel, the second oscillogram of the determined channel, or a third oscillogram generated by subtracting the second oscillogram of the determined channel from the first oscillogram of the determined channel.

[0025] The estimating may include estimating first bio-information by using a first oscillogram of the determined channel, estimating second bio-information by using a second oscillogram of the determined channel, and obtaining final bio-information based on at least one of the first bio-information or the second bio-information.

[0026] The estimating step may include: determining two or more channels among the plurality of channels based on the area of ​​each channel, estimating bio-information values ​​of the correspondingly determined two or more channels, and obtaining final bio-information by using at least one of the estimated bio-information values ​​of the correspondingly determined two or more channels.

[0027] According to one aspect of an example embodiment, there is provided an apparatus for estimating biological information, the apparatus comprising: a pulse wave sensor having a plurality of channels, each of the plurality of channels being configured to measure a first pulse wave signal of a first wavelength and a second pulse wave signal of a second wavelength, the second wavelength being different from the first wavelength; and a processor configured to: for each channel, obtain a first eigenvalue based on an alternating current (AC) component and a direct current (DC) component of the first pulse wave signal and an AC component and a DC component of the second pulse wave signal, determine a channel among the plurality of channels based on the obtained first eigenvalue of each channel, and estimate the biological information based on the determined channel.

[0028] The processor may be further configured to obtain a first characteristic value for each channel based on a ratio between an AC component and a DC component of the first pulse wave signal and a ratio between an AC component and a DC component of the second pulse wave signal.

[0029] The processor may also be configured to generate an oscillogram based on at least one of the first pulse wave signal or the second pulse wave signal of the determined channel, obtain a second eigenvalue by using the generated oscillogram, and estimate biological information based on at least one of the first eigenvalue or the second eigenvalue.

[0030] According to one aspect of an example embodiment, there is provided a method for estimating biological information, the method comprising: measuring, for each of the plurality of channels, a first pulse wave signal of a first wavelength and a second pulse wave signal of a second wavelength, the second wavelength being different from the first wavelength, by using a pulse wave sensor having a plurality of channels; obtaining, for each channel, a first eigenvalue based on an alternating current (AC) component and a direct current (DC) component of the first pulse wave signal and an AC component and a DC component of the second pulse wave signal; determining a channel among the plurality of channels based on the obtained first eigenvalue for each channel; and estimating the biological information based on the determined channel.

[0031] The obtaining may include obtaining a first characteristic value for each channel based on a ratio between an AC component and a DC component of the first pulse wave signal and a ratio between an AC component and a DC component of the second pulse wave signal.

[0032] The estimating step may include: generating an oscillogram based on at least one of the first pulse wave signal or the second pulse wave signal of the determined channel; obtaining a second eigenvalue by using the generated oscillogram; and estimating biological information based on at least one of the first eigenvalue or the second eigenvalue. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The above and other aspects will become more apparent by describing in detail example embodiments with reference to the accompanying drawings, in which:

[0034] Figure 1A and Figure 1B is a block diagram illustrating an apparatus for estimating bio-information according to an example embodiment;

[0035] Figure 2A and Figure 2B is a diagram illustrating an example of a configuration of a pulse wave sensor of an apparatus for estimating biological information according to an exemplary embodiment;

[0036] Figure 3 is a diagram illustrating a configuration of a processor included in an apparatus for estimating bio-information according to an example embodiment;

[0037] Figure 4A and Figure 4B is a diagram explaining an example of a general method for estimating biological information;

[0038] Figure 5A and Figure 5B is a diagram explaining an example of generating an oscillogram;

[0039] Figure 6A 、 Figure 6B and Figure 6C is a diagram explaining an example of selecting an optimal channel according to an example embodiment;

[0040] Figure 7 is a diagram illustrating a configuration of a processor included in an apparatus for estimating bio-information according to an example embodiment;

[0041] Figure 8 is a diagram explaining an example of selecting an optimal channel according to an example embodiment;

[0042] Figure 9 is a flowchart illustrating a method of estimating bio-information according to an example embodiment;

[0043] Figure 10 is a flowchart illustrating a method of estimating bio-information according to an example embodiment;

[0044] Figure 11 is a diagram illustrating a wearable device according to example embodiments; and

[0045] Figure 12 is a diagram illustrating a smart device according to an example embodiment. DETAILED DESCRIPTION

[0046] Details of example embodiments are included in the following detailed description and accompanying drawings. The advantages and features disclosed herein, as well as methods for implementing the disclosed embodiments, will be more clearly understood from the following detailed description of the embodiments with reference to the accompanying drawings. Throughout the drawings and detailed description, unless otherwise noted, like reference numerals will be understood to represent like elements, features, and structures.

[0047] It should be understood that although the terms first, second, etc. can be used to describe various elements herein, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. In addition, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. It will also be understood that, unless explicitly described to the contrary, when an element is referred to as "comprising" another element, the element is not intended to exclude one or more other elements, but rather to include one or more other elements. In the following description, terms such as "unit" and "module" indicate a unit for processing at least one function or operation, and they can be implemented using hardware, software, or a combination thereof.

[0048] Hereinafter, embodiments of an apparatus and method for estimating bio-information will be described in detail with reference to the accompanying drawings.

[0049] Figure 1A and Figure 1B is a block diagram illustrating an apparatus for estimating bio-information according to example embodiments. Figure 2A and Figure 2B is a diagram illustrating an example of a configuration of a pulse wave sensor of an apparatus for estimating biological information according to an example embodiment.

[0050] According to Figure 1A The apparatus 100a for estimating biological information according to the embodiment shown in FIG. Figure 1B The device 100b for estimating biometric information of the embodiment shown in the figure may be embedded in a terminal (such as a smart phone, a tablet PC, a desktop computer, a laptop computer, etc.), or may be manufactured as an independent hardware device. When the device 100a and the device 100b are manufactured as independent hardware devices, the hardware device may be implemented as a wearable device to be worn on the user's object OBJ, so that the user can easily measure the user's biometric information while carrying the wearable device. Examples of wearable devices may include watch-type wearable devices, bracelet-type wearable devices, wristband-type wearable devices, ring-type wearable devices, glasses-type wearable devices, headband-type wearable devices, etc., but the wearable device is not limited thereto and may be modified for various purposes (such as fixed devices used in medical institutions for measuring and analyzing biometric information, etc.).

[0051] Reference Figure 1A , an apparatus 100 a for estimating biological information includes a pulse wave sensor 110 and a processor 120 .

[0052] The pulse wave sensor 110 measures a photoplethysmography (PPG) signal (hereinafter referred to as a "pulse wave signal") from a subject. The subject may be a body region that can be brought into contact with the pulse wave sensor 110, and may be a body part where a pulse wave can be easily measured based on the PPG signal. For example, the subject may be a finger where blood vessels are densely located, but the subject is not limited thereto and may be any other body part (such as an area on the wrist adjacent to the radial artery, or a peripheral part of the body (such as the upper part of the wrist, toes, etc. where veins or capillaries are located)).

[0053] The pulse wave sensor 110 may include a plurality of light sources for emitting light onto an object, and one or more light receivers disposed at a predetermined distance from the light sources and detecting light scattered or reflected from the object. At least some of the plurality of light sources may emit light of different wavelengths. The plurality of light sources may include, but are not limited to, light-emitting diodes (LEDs), laser diodes (LDs), phosphors, and the like. Furthermore, the plurality of light receivers may include at least one of a photodiode, a photodiode array, a complementary metal oxide semiconductor (CMOS) image sensor, a charge coupled device (CCD) image sensor, and the like.

[0054] The pulse wave sensor 110 may have multiple channels for measuring multiple pulse wave signals at multiple points on a subject. The channels of the pulse wave sensor 110 may be arranged in a predetermined shape (such as a circle, an ellipse, a linear shape, etc.) to measure pulse wave signals at multiple points on a subject. Each channel of the pulse wave sensor 110 may include a light source and a light receiver that may be shared by two or more channels. In addition, each channel may detect pulse wave signals having multiple wavelengths.

[0055] Reference Figure 2A The pulse wave sensor 210 according to an embodiment may include a first channel 211 for measuring a pulse wave signal at a first point of the subject and a second channel 212 for measuring a pulse wave signal at a second point of the subject. The first light source 211a corresponding to the first channel 211 and the first light source 212a corresponding to the second channel 212, and the first light receiver 211b corresponding to the first channel 211 and the first light receiver 212b corresponding to the second channel 212 may have a size within a range of 3 mm to 10 mm, but their sizes are not limited thereto.

[0056] The first channel 211 may include a first light source 211a and a first light receiver 211b, and the second channel 212 may include a first light source 212a and a first light receiver 212b. The first light source 211a and the first light receiver 212a are configured to emit light of a first wavelength, and the first light receiver 211b and the first light receiver 212b are configured to detect light scattered or reflected from an object after the light is emitted by the first light source 211a and the first light receiver 212a. Furthermore, the first channel 211 may include a second light source 211c and a second light receiver 211d, and the second channel 212 may include a second light source 212c and a second light receiver 212d. The second light source 211c and the second light receiver 212c are configured to emit light of a second wavelength, and the second light receiver 211d and the second light receiver 212d are configured to detect light scattered or reflected from an object after the light is emitted by the second light source 211c and the second light receiver 212d. The first wavelength and the second wavelength may be different from each other and may include, for example, infrared wavelengths, green wavelengths, blue wavelengths, and / or red wavelengths.

[0057] For ease of explanation, Figure 2A Two channels 211 and 212 are shown, each of which includes a pair of two light sources and a pair of two light receivers. However, this is for ease of explanation only, and the channels are not limited thereto and may be provided in various numbers and configurations depending on the size and shape of the form factor, etc. For example, each of channels 211 and 212 may include multiple light sources and one light receiver for emitting light of multiple wavelengths, so that the multiple light sources can be driven sequentially and the pulse wave signals can be measured sequentially by one light receiver. In addition, each of channels 211 and 212 may include only one light source and one light receiver, in which case a color filter may be provided on the front surface of the light source or light receiver to pass or detect light of different wavelengths.

[0058] Reference Figure 2B According to another exemplary embodiment, a pulse wave sensor 220 may include a group 221 of light sources and a group 222 of light receivers. Specifically, the pulse wave sensor 220 may include a first light source 221a and a second light source 221b, as well as a first light receiver 222a, a second light receiver 222b, a third light receiver 222c, and a fourth light receiver 222d. The first light source 221a, the first light receiver 222a, and the second light receiver 222b may form a first channel 221 for measuring a pulse wave signal at a first point on the subject, and the second light source 221b, the third light receiver 222c, and the fourth light receiver 222d may form a second channel 222 for measuring a pulse wave signal at a second point on the subject. For ease of explanation, the pulse wave sensor 220 has two channels, but is not limited thereto.

[0059] Each of the first light source 221a and the second light source 221b may emit light of a different wavelength, for example, by using a color filter. For example, the first light source 221a and the second light source 221b may emit light of infrared wavelengths, green wavelengths, blue wavelengths, red wavelengths, etc. The first to fourth light receivers 222a to 222d may respectively detect light of different wavelengths scattered or reflected from an object after the light from the first light source 221a and the second light source 221b is emitted onto the object. Although Figure 2B , two light sources and four light receivers included in two channels are shown, but the number of light sources and light receivers is not specifically limited, and one channel may include, for example, two light sources configured to emit light of different wavelengths onto an object and one light receiver that can be shared by the two light sources and detects light scattered or reflected from the object.

[0060] Reference above Figure 2A and Figure 2B describe Figure 1A Various embodiments of the structure of the pulse wave sensor 110 are described. However, these are merely examples, and the structure is not particularly limited to the above examples. In order to detect pulse wave signals at multiple points of an object, various numbers and arrangements of channels, light sources, and light receivers may be provided depending on the position of the object, the size and shape of the form factor, and the like.

[0061] Return to reference Figure 1A , the processor 120 can control each channel sequentially or simultaneously in a time-division manner. In addition, when each channel includes multiple light sources emitting light of different wavelengths, the processor 120 can drive the light sources in order from short wavelength to long wavelength, or vice versa. In this case, the driving conditions of the light sources (e.g., the driving order and current intensity, pulse duration, etc. of the light sources) can be predefined.

[0062] Furthermore, processor 120 can estimate biometric information using pulse wave signals measured at multiple points on the subject by the various channels of pulse wave sensor 110. Once pulse wave signals are obtained from the various channels of pulse wave sensor 110, processor 120 can use the obtained pulse wave signals to select a channel for estimating biometric information and estimate biometric information based on the pulse wave signal of the selected channel. Hereinafter, for purposes of this description, the selected channel may be referred to as the optimal channel. In this case, biometric information may include, but is not limited to, blood pressure, vascular age, arterial stiffness, aortic pressure waveform, skin elasticity, skin age, stress index, fatigue level, and the like. For ease of explanation, the following description will use blood pressure as an example.

[0063] Reference Figure 1B, an apparatus 100 b for estimating bio-information according to another embodiment includes a pulse wave sensor 110 , a processor 120 , a force / pressure sensor 130 , an output interface 140 , a storage device 150 , and a communication interface 160 .

[0064] The pulse wave sensor 110 may have a plurality of channels for measuring a plurality of pulse wave signals at a plurality of points of the subject. As described above, each channel may be set in various ways to detect a pulse wave signal having two or more wavelengths.

[0065] The processor 120 may determine an optimal channel for estimating bio-information based on the pulse wave signals obtained by the respective channels, and may estimate the bio-information by using the pulse wave signal of the determined optimal channel.

[0066] When a user places an object on the pulse wave sensor 110 and increases or decreases the pressing force for a predetermined period of time to measure the pulse wave signal, the force / pressure sensor 130 can measure the contact force and / or contact pressure between the object and the pulse wave sensor 110. The force / pressure sensor 130 can be formed as a single force sensor, a force sensor array, one or more pressure sensors, or a combination of a force sensor and an area sensor. The force / pressure sensor 130 can include a strain gauge, etc., but is not limited thereto. The contact force and / or contact pressure measured by the force / pressure sensor 130 can be used together with the pulse wave signal obtained by each channel to generate an oscillogram and estimate biometric information.

[0067] Upon receiving a request from the user to estimate biometric information, processor 120 may guide the user to the contact status of pulse wave sensor 110. For example, upon receiving the request to estimate biometric information, processor 120 may obtain a reference pressure to be applied by the subject to pulse wave sensor 110 from storage device 150 and may guide the obtained reference pressure to the user (or notify the user of the obtained reference pressure) via output interface 140. Furthermore, processor 120 may guide the contact pressure to the user in real time based on the contact force and / or contact pressure measured in real time by force / pressure sensor 130 while the pulse wave signal is being measured.

[0068] The output interface 140 can output and provide the pulse wave signal measured by the pulse wave sensor 110 and / or the processing result of the processor 120 to the user. The output interface 140 can provide information through various visual / non-visual methods using a display module, a speaker, a tactile device, etc. installed in the device 100b.

[0069] For example, the output interface 140 can output the measured pulse wave signal in the form of a graph, an oscillogram of each channel, etc. In addition, the output interface 140 can visually display the estimated bio-information value based on whether the estimated blood pressure value falls within the normal range or outside the normal range by using various visual methods (such as, by changing the color, line thickness, font, etc.). Additionally or optionally, the output interface 140 can output the estimated bio-information value through voice and / or vibration, touch, etc. based on whether the estimated bio-information value is abnormal, so that the user can easily identify the abnormality in the user's health condition. Optionally, when comparing the estimated bio-information value with the previous estimation history, based on determining that the estimated bio-information value is abnormal, the output interface 140 can provide a warning message, an alarm signal, etc., as well as guidance information about the user's actions (such as information about food that the user should pay attention to, relevant hospital information, etc.).

[0070] Storage device 150 may store various information related to estimated biometric information, such as acquired pulse wave signals and oscillograms, estimated biometric values, and the like. Furthermore, storage device 150 may store light source driving conditions, contact pressure conversion models, blood pressure estimation models, conditions for excluding channels, conditions for determining optimal channels, and the like. Furthermore, storage device 150 may store user characteristic information (such as the user's age, gender, and health status). However, the information stored in storage device 150 is not limited thereto.

[0071] The storage device 150 may include at least one storage medium selected from the following: a flash memory, a hard disk memory, a multimedia card micro memory, a card-type memory (e.g., a secure digital (SD) memory, an extreme digital (XD) memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, etc., but is not limited thereto.

[0072] The communication interface 160 can communicate with an external device using a communication technology under the control of the processor 120, and can receive data for estimating bio-information from the external device and / or can transmit a processing result of the processor 120 to the external device. The external device may include a smartphone, a tablet PC, a wearable device, a cuff pressure gauge, etc.

[0073] In this case, examples of communication technology may include Bluetooth communication, Bluetooth Low Energy (BLE) communication, near field communication (NFC), WLAN communication, Zigbee communication, Infrared Data Association (IrDA) communication, Wi-Fi Direct (WFD) communication, Ultra-Wideband (UWB) communication, Ant+ communication, WIFI communication, Radio Frequency Identification (RFID) communication, 3G communication, 4G communication, 5G communication, etc. However, this is merely exemplary and is not intended to be limiting.

[0074] Figure 3 It shows Figure 1A The apparatus 100a for estimating biological information shown in FIG. Figure 1B 2 is a diagram illustrating an example of a configuration of the processor 120 of the apparatus 100 b for estimating bio-information. Figure 4A and Figure 4B is a diagram explaining an example of a general method of estimating biological information. Figure 5A and Figure 5B 2 is a diagram explaining an example of generating an oscillogram according to an example embodiment. Figures 6A to 6C is a diagram explaining an example of selecting an optimal channel according to example embodiments.

[0075] Reference Figure 4A Devices for measuring blood pressure without a cuff typically measure blood pressure using a photoplethysmography (PPG) signal. In this case, a pulse wave sensor is brought into contact with the body surface at various pressure levels, and blood pressure is estimated by measuring the pulse wave signal at each contact pressure level and obtaining the mean arterial pressure (MAP) of local blood vessels. In this case, the PPG signal measured from the body surface by the pulse wave sensor can be observed as a combination of an arterial pulse wave signal generated at a relatively large depth from the body surface and a capillary pulse wave signal generated at a relatively shallow depth from the body surface. Here, the capillary pulse wave signal can act as noise when estimating blood pressure using oscillometric methods.

[0076] Reference Figure 4B The pulse wave signal at the bottom of the graph represents arterial pulse wave signal S1; the pulse wave signal at the center of the graph represents capillary pulse wave signal S2; and the pulse wave signal at the top of the graph represents peripheral pulse wave signal S3 measured from the body surface. Since peripheral pulse wave signal S3 is represented by the combination of arterial pulse wave signal S1 and capillary pulse wave signal S2, it can be seen that the point of maximum amplitude associated with blood pressure shifts from the arrow point of arterial pulse wave signal S1 to the arrow point of peripheral pulse wave signal S3. This shows that when measuring blood pressure using the oscillometric method, accuracy may decrease. That is, the value measured from the body surface includes an error value added to the arterial blood pressure value, resulting in a difference from the accurate blood pressure value.

[0077] Therefore, in order to solve the above problem that the accuracy of estimation is reduced when the oscillometric method is performed at a peripheral body part using a pulse wave signal with a relatively short wavelength, example embodiments provide a method of improving the accuracy of estimating biological information by selecting a channel that measures a pulse wave signal from a blood vessel at a relatively deep depth among a plurality of pulse wave signals.

[0078] Reference Figure 3 , the processor 300 according to an embodiment includes an oscillogram generator 310 , an area converter 320 , an optimal channel determiner 330 , and an estimator 340 .

[0079] Once the first pulse wave signal and the second pulse wave signal having different wavelengths are obtained through each channel, the oscillogram generator 310 may generate the first oscillogram and the second oscillogram based on the first pulse wave signal and the second pulse wave signal. The oscillogram generator 310 may generate the oscillogram by using the correlation between the change in contact pressure applied by the object to the pulse wave sensor 110 and the change in the amplitude of the pulse wave signal of each channel. In this case, Figure 1B The contact force and / or contact pressure obtained by the force / pressure sensor 130 can be used to obtain the change of the contact pressure. Figure 1A In the case where the force / pressure sensor 130 is not included as shown in FIG, the contact pressure can be obtained from the amplitude of the pulse wave signal by using a contact pressure conversion equation that defines the relationship between the amplitude of the pulse wave signal and the contact pressure.

[0080] Figure 5A An example is shown of a change in the amplitude of a pulse wave signal measured when an object in contact with the pulse wave sensor 110 gradually increases the pressing force on the pulse wave sensor 110 . Figure 5B An oscillogram OW representing the correlation between changes in contact pressure applied by a subject to the pulse wave sensor 110 and the amplitude of the pulse wave signal is shown.

[0081] The oscillogram generator 310 can, for example, extract the peak-to-peak point of the pulse wave signal waveform by subtracting the negative (-) amplitude value in3 from the positive (+) amplitude value in2 of the waveform envelope in1 at each measurement time of the pulse wave signal, and can obtain the oscillogram OW by plotting the peak-to-peak amplitude at each measurement time against the contact pressure value at the corresponding time and by performing, for example, polynomial curve fitting.

[0082] Once the oscillogram generator 310 generates a first oscillogram at a first wavelength and a second oscillogram at a second wavelength for each channel, the area converter 320 may obtain an area based on the generated first and second oscillograms. In this case, the first and second wavelengths may be different wavelengths.

[0083] For example, the area converter 320 may convert the phase delay between the first and second oscillograms into an area in a Lissajous waveform (or an area represented by a Lissajous waveform). In this case, the area converter 320 may normalize the first and second oscillograms. For example, the area converter 320 may normalize the amplitude of the second oscillogram based on the amplitude of the first oscillogram, or may normalize the first and second oscillograms by applying an absorbance-based model according to the Beer-Lambert law.

[0084] Once the area is obtained for each channel, the optimal channel determiner 330 may determine the optimal channel based on the obtained area.

[0085] For example, Figure 6A The phase delay converted into area A1 between the first oscillogram OS1 and the second oscillogram OS2 of the first channel is shown. Figure 6B The phase delay between the first oscillogram OS1 and the second oscillogram OS2 of the second channel is converted into an area A2. The best channel determiner 330 may determine the best channel based on the converted area as described above. For example, because the area A1 of the first channel is larger than the area A2 of the second channel, the best channel determiner 330 may determine the channel with the largest area (i.e., the first channel) as the best channel. Alternatively, the best channel determiner 330 may determine a predetermined number of channels as the best channels, starting with the largest area and in descending order of corresponding area sizes.

[0086] In another example, the best channel determiner 330 may divide the area of ​​each channel into two or more regions according to one or more criteria, and may determine the best channel based on the area ratios between the divided regions. For example, the best channel determiner 330 may determine one or more channels as the best channels in descending order of the area ratios of each channel, starting with the highest area ratio. Figure 6CAn example of dividing the area of ​​each channel based on a straight line RL having a slope of 1 is shown, however, the slope is not necessarily limited to 1. In addition, the area does not necessarily need to be divided based on a straight line passing through the origin, and the area can be divided based on the center of gravity of each area or based on a straight line perpendicular to the X-axis or Y-axis and passing through any value on the X-axis or Y-axis. The method of dividing the area of ​​each channel is not limited. The optimal channel determiner 330 can obtain a first area ratio for the first channel by dividing the first area A11 having a smaller area by the second area A12 having a larger area; and can obtain a second area ratio for the second channel by dividing the first area A21 having a smaller area by the second area A22 having a larger area; and can determine the channel having the larger area ratio of the first area ratio and the second area ratio as the optimal channel.

[0087] In another example, the optimal channel determiner 330 may determine the optimal channel based on the shape of the Lissajous waveform, including the slope of the Lissajous waveform of each channel. For example, the optimal channel determiner 330 may calculate the slope of the Lissajous waveform of each channel and determine the channel whose calculated slope meets a predetermined standard as the optimal channel. Alternatively, the optimal channel determiner 330 may calculate the similarity between the area shape of the Lissajous waveform and a reference area shape and determine one or more channels as the optimal channel in descending order of the calculated similarity. However, the optimal channel is not limited to this and may be determined by analyzing the slope or area shape of the Lissajous waveform using a model obtained based on machine learning, artificial intelligence, neural networks, etc.

[0088] Furthermore, based on the first and second oscillograms for each channel, the optimal channel determiner 330 may exclude channels that do not meet predetermined criteria when determining the optimal channel. For example, the optimal channel determiner 330 may generate a third oscillogram using the first oscillogram at the first wavelength for each channel and the second oscillogram at the second wavelength for each channel, and may determine whether each channel meets the predetermined criteria based on the generated third oscillogram. For example, the optimal channel determiner 330 may determine a difference coefficient based on the first and second wavelengths, apply the determined difference coefficient to the second oscillogram, and generate the third oscillogram by subtracting the second oscillogram, to which the difference coefficient is applied, from the first oscillogram. In one example, the difference coefficient may be a value used to normalize the oscillograms. In one example, the difference coefficient may be predefined based on wavelength, etc. Alternatively, the difference coefficient may be the ratio of the AC / DC ratio (the ratio of the magnitude of the AC component to the magnitude of the DC component) at the first wavelength to the AC / DC ratio at the second wavelength. In one example, the optimal channel determiner 330 may apply the determined difference coefficient to the second oscillogram by multiplying the determined difference coefficient by the second oscillogram. However, the example is not limited thereto, and the optimal channel determiner 330 may apply the determined difference coefficient to the second oscillogram (e.g., each pulse wave amplitude of the second oscillogram) by adding the determined difference coefficient to the second oscillogram (e.g., each pulse wave amplitude of the second oscillogram) or subtracting the determined difference coefficient from the second oscillogram (e.g., each pulse wave amplitude of the second oscillogram).

[0089] For example, if the full width at half maximum (FWHM) between the contact pressure at the baseline point and the contact pressure at the half-maximum point of the third oscillogram is greater than or equal to a predetermined threshold, then optimal channel determiner 330 may exclude the corresponding channel. In this example, the baseline point may be the minimum point of the third oscillogram, but examples are not limited thereto and may be the starting point of the third oscillogram, etc. Alternatively, if the width at a point corresponding to a predetermined ratio between the baseline point and the maximum point of the third oscillogram is greater than or equal to a predetermined threshold, or if the statistical value (e.g., the sum, average, median, etc.) of the residual between the actual pulse wave amplitude at a point corresponding to a predetermined contact pressure value and the pulse wave amplitude of the third oscillogram after curve fitting (e.g., the residual between the pulse wave of the third oscillogram before curve fitting and the pulse wave of the third oscillogram after curve fitting) is greater than or equal to a predetermined threshold, then optimal channel determiner 330 may exclude the corresponding channel. However, channel exclusion is not limited to this. In one example, the optimal channel determiner 330 may exclude a channel based on at least one of the following items: the FWHM in the third oscillogram, the full width at a point corresponding to a predetermined ratio between a reference point and a maximum point of the third oscillogram, and a statistical value of a residual between the pulse wave of the third oscillogram before curve fitting and the pulse wave of the third oscillogram after curve fitting.

[0090] The estimator 340 may estimate the bio-information using the oscillogram of the optimal channel determined by the optimal channel determiner 330. For example, the estimator 340 may estimate the blood pressure using the first oscillogram or the second oscillogram of the optimal channel. For example, the first oscillogram or the second oscillogram may be an oscillogram at a relatively long wavelength. In one example, the estimator 340 may estimate the first bio-information using the first oscillogram of the optimal channel, estimate the second bio-information using the second oscillogram of the optimal channel, and obtain the final bio-information based on at least one of the first bio-information and the second bio-information. Alternatively, when a third oscillogram is generated by subtracting the second oscillogram from the first oscillogram of the optimal channel, the estimator 340 may estimate the blood pressure using the generated third oscillogram. In one example embodiment, multiple optimal channels may be determined, and the estimator 340 may estimate the blood pressure for each optimal channel. The estimated blood pressure values ​​may be combined to obtain an average, median, or other mean of the blood pressure values ​​for each optimal channel as the final blood pressure value. In one example, the estimator 340 may estimate bio-information values ​​of the respective optimal channels and obtain final bio-information by using at least one of the estimated bio-information values ​​of the respective optimal channels.

[0091] Reference Figure 5B, the estimator 340 may estimate the mean arterial pressure (MAP) based on the contact pressure value MP at the maximum point MA of the pulse wave in the third oscillogram. For example, the estimator 340 may determine the contact pressure value MP at the maximum point MA of the pulse wave itself as the MAP. Alternatively, the estimator 340 may estimate the MAP by applying the contact pressure value MP to a predefined MAP estimation equation. In this case, the MAP estimation equation may be expressed in the form of various linear or nonlinear combination functions (e.g., addition, subtraction, division, multiplication, logarithm, regression equation, etc., without particular limitation).

[0092] Furthermore, the estimator 340 may estimate the diastolic pressure (DBP) and the systolic pressure (SBP) based on the contact pressure values ​​DP and SP at points to the left and right of the amplitude value at the maximum point MA of the pulse wave and having a preset ratio (e.g., 0.5 to 0.7) of the amplitude value at the maximum point MA. Similarly, the estimator 340 may also determine the contact pressure values ​​DP and SP as the DBP and SBP, respectively, or alternatively may estimate the DBP and SBP by using predefined DBP and SBP estimation equations, respectively.

[0093] Figure 7 It shows that according to Figure 1A The apparatus 100a for estimating biometric information according to the embodiment of the present invention and Figure 1B FIG. 1 is a diagram illustrating another example of a configuration of the processor 120 of the apparatus 100 b for estimating bio-information according to an embodiment of the present invention. Figure 8 is a diagram explaining another example of determining the optimal channel.

[0094] Reference Figure 7 , the processor 700 according to an embodiment includes a first eigenvalue obtainer 710 , an optimal channel determiner 720 , a second eigenvalue obtainer 730 , and an estimator 740 .

[0095] like Figure 8 As shown in , the first feature value obtainer 710 may obtain, for each channel, (1) the magnitude AC1 of the alternating current (AC) component and the magnitude DC1 of the direct current (DC) component from a first pulse wave signal having a first wavelength, and (2) the magnitude AC2 of the alternating current (AC) component and the magnitude DC2 of the direct current (DC) component from a second pulse wave signal having a second wavelength. Furthermore, the first feature value obtainer 710 may obtain a first feature value based on the magnitude of the obtained AC component and the magnitude of the DC component.

[0096] For example, the first characteristic value obtainer 710 may divide the ratio (AC1 / DC1) between the magnitude AC1 of the AC component and the magnitude DC1 of the DC component of the first pulse wave signal having the first wavelength by the ratio (AC2 / DC2) between the magnitude AC2 of the AC component and the magnitude DC2 of the DC component of the second pulse wave signal having the second wavelength. In other words, the first characteristic value obtainer 710 may obtain a value obtained by ((AC1 / DC1)÷(AC2 / DC2)) as the first characteristic value. The first wavelength may be a wavelength relatively longer than the second wavelength.

[0097] When the first eigenvalue obtainer 710 obtains the first eigenvalue of each channel, the optimal channel determiner 720 may determine the optimal channel based on the magnitude of the first eigenvalue of each channel. For example, the optimal channel determiner 720 may determine the channel with the highest first eigenvalue or a predetermined number of channels starting from the highest first eigenvalue in descending order of magnitude of the first eigenvalue as the optimal channel.

[0098] The second characteristic value obtainer 730 can estimate the second characteristic value by using the pulse wave signal of the optimal channel determined by the optimal channel determiner 720. The second characteristic value obtainer 730 can generate an oscillogram using at least one of the first pulse wave signal and the second pulse wave signal of the determined optimal channel (e.g., a pulse wave signal having a relatively long wavelength). As described above, by using the generated oscillogram, the second characteristic value obtainer 730 can obtain the following items as the second characteristic value: the contact pressure value corresponding to the amplitude value at the maximum point MA of the pulse wave, and the contact pressure values ​​DP and SP at points on the left and right sides of the amplitude value at the maximum point MA of the pulse wave and having a preset ratio (e.g., 0.5 to 0.7) of the amplitude value at the maximum point MA. Alternatively, the second characteristic value obtainer 730 can generate a third oscillogram by generating the first and second oscillograms from the first and second pulse wave signals of the optimal channel, respectively, and can obtain the second characteristic value by using the generated third oscillogram.

[0099] Furthermore, the second characteristic value obtainer 730 may obtain the second characteristic value by analyzing the waveform of the pulse wave signal of the optimal channel. For example, the second characteristic value obtainer 730 may obtain at least one of the following items as the second characteristic value: heart rate, waveform shape, time and / or amplitude at the maximum point in the contraction phase of the pulse wave signal, time and / or amplitude at the minimum point of the pulse wave signal, total area or partial area of ​​the waveform of the pulse wave signal, duration of the pulse wave signal, amplitude and / or time of the waveform of the pulses constituting the pulse wave signal, etc.

[0100] The estimator 740 may estimate the bio-information based on the first eigenvalue obtained by the first eigenvalue obtainer 710 and / or the second eigenvalue obtained by the second eigenvalue obtainer 730. For example, as described above, the estimator 740 may estimate blood pressure using an oscillometric method. Alternatively, the estimator 740 may estimate the bio-information using a predefined bio-information estimation model. In this case, the bio-information estimation model may be expressed in the form of various linear or nonlinear combination functions (e.g., addition, subtraction, division, multiplication, logarithm, regression equation, etc., without particular limitation).

[0101] Figure 9 is a flowchart illustrating a method of estimating bio-information according to example embodiments.

[0102] Figure 9 The method is based on Figure 1A The apparatus 100a for estimating biometric information according to the embodiment of the present invention and Figure 1B An example of a method of estimating biometric information performed by any one of the apparatuses 100b for estimating biometric information of the embodiments of the present invention. Various embodiments thereof are described in detail above, and thus will be briefly described below.

[0103] First, the apparatuses 100a and 100b for estimating bio-information may measure a first pulse wave signal having a first wavelength in 911 and a second pulse wave signal having a second wavelength in 912 through each channel of the pulse wave sensor. In this case, the first wavelength and the second wavelength may be different wavelengths. The apparatuses 100a and 100b for estimating bio-information may control the pulse wave sensor upon receiving a request for estimating bio-information from a user or upon satisfying predetermined criteria. Various examples of multi-channel pulse wave sensors for measuring pulse wave signals at multiple points on a subject have been described in detail above.

[0104] The apparatuses 100 a and 100 b for estimating bio-information may generate a first oscillogram based on the first pulse wave signal in 921 , and may generate a second oscillogram based on the second pulse wave signal in 922 .

[0105] Subsequently, in 930, the apparatuses 100a and 100b for estimating biological information may exclude channels that do not meet predetermined criteria from the plurality of channels based on the first and second oscillograms generated for each channel. For example, if the full width at half maximum (FWHM) of the pulse wave signal is greater than or equal to a predetermined threshold, or if the statistical value of the residuals in the oscillogram (such as the sum of the residuals) is greater than or equal to a predetermined threshold, the apparatuses 100a and 100b for estimating biological information may exclude the corresponding channel. However, operation 930 may be omitted.

[0106] Next, in 940 , the apparatuses 100 a and 100 b for estimating bio-information may convert the phase delay between the first oscillogram and the second oscillogram generated for each channel into an area in a Lissajous waveform.

[0107] Then, the apparatuses 100a and 100b for estimating biological information may determine an optimal channel based on the converted area of ​​each channel in 950. For example, the apparatuses 100a and 100b for estimating biological information may determine the optimal channel based on at least one of an area size, a slope of a Lissajous waveform, an area shape, an area ratio between a first area and a second area divided from the converted area, and the like.

[0108] Subsequently, the apparatuses 100a and 100b for estimating biological information may estimate biological information by using the determined optimal channel in 960. For example, the apparatuses 100a and 100b for estimating biological information may select the first oscillogram or the second oscillogram, or may generate a third oscillogram by subtracting the second oscillogram from the first oscillogram, and may estimate blood pressure by using the selected oscillogram or the generated third oscillogram.

[0109] Figure 10 is a flowchart illustrating a method of estimating bio-information according to another embodiment.

[0110] Figure 10 The method is based on Figure 1A The apparatus 100a for estimating biometric information according to the embodiment of the present invention and Figure 1B Another example of a method of estimating bio-information performed by any one of the apparatuses 100b for estimating bio-information of the embodiments of the present invention is provided. Various embodiments thereof are described in detail above, and thus will be briefly described below.

[0111] First, the apparatuses 100 a and 100 b for estimating bio-information may measure a first pulse wave signal of a first wavelength in 1011 and a second pulse wave signal of a second wavelength in 1012 through each channel of the pulse wave sensor.

[0112] Then, the apparatuses 100 a and 100 b for estimating bio-information may extract an AC component and a DC component from the first pulse wave signal in 1021 , and may extract an AC component and a DC component from the second pulse wave signal in 1022 .

[0113] Subsequently, in 1030, the apparatuses 100a and 100b for estimating biological information may obtain a first characteristic value for each channel based on the magnitude of the AC component and the magnitude of the DC component of the first pulse wave signal and the magnitude of the AC component and the magnitude of the DC component of the second pulse wave signal. For example, the apparatuses 100a and 100b for estimating biological information may obtain a value ((AC1 / DC1)÷(AC2 / DC2)) for each channel as the first characteristic value, where the value ((AC1 / DC1)÷(AC2 / DC2)) is obtained by dividing the ratio (AC1 / DC1) between the magnitude AC1 of the AC component and the magnitude DC1 of the DC component of the first pulse wave signal by the ratio (AC2 / DC2) between the magnitude AC2 of the AC component and the magnitude DC2 of the DC component of the second pulse wave signal.

[0114] Next, the apparatuses 100a and 100b for estimating bio-information may determine an optimal channel based on the first eigenvalue of each channel in 1040. For example, the apparatuses 100a and 100b for estimating bio-information may determine one or a predetermined number of channels as the optimal channels, starting from the highest first eigenvalue and in descending order of magnitude of the first eigenvalue of each channel.

[0115] Then, in 1050, the bio-information estimating devices 100a and 100b may estimate the bio-information using the determined optimal channel. For example, the bio-information estimating devices 100a and 100b may estimate the bio-information using an oscillometric method based on the pulse wave signal of the optimal channel. Alternatively, the bio-information estimating devices 100a and 100b may obtain one or more second eigenvalues ​​by using an oscillogram of the optimal channel or by analyzing the waveform of the pulse wave signal. The bio-information estimating devices 100a and 100b may estimate the bio-information based on the obtained first eigenvalues ​​and / or second eigenvalues ​​using a predefined bio-information estimation model.

[0116] Figure 11 is a diagram illustrating a wearable device according to an example embodiment. The above-described embodiments of the apparatuses 100a and 100b for estimating bio-information may be installed in the wearable device.

[0117] Reference Figure 11 , the wearable device 1100 includes a main body 1110 and a band 1130 .

[0118] The straps 1130 connected to both ends of the body 1110 can be flexible so as to wrap around the user's wrist. The straps 1130 can include a first strap and a second strap that are separate from each other. One end of the first strap and the second strap are connected to the body 1110, and the other ends of the first strap and the second strap can be connected to each other via a connecting device. In this case, the connecting device can be formed in the form of a magnetic connection, a Velcro connection, a pin connection, etc., but is not limited to these. Furthermore, the straps 1130 are not limited to these and can be integrally formed as a non-detachable strap.

[0119] Air may be injected into the band 1130 , or the band 1130 may be provided with an air bag to have elasticity according to a change in pressure applied to the wrist, and the change in pressure of the wrist may be transmitted to the body 1110 .

[0120] A battery may be embedded in the body 1110 or the band 1130 to supply power to the wearable device 1100 .

[0121] The main body 1110 may include a sensor unit 1120 mounted thereon. The sensor unit 1120 may include a pulse wave sensor for measuring a pulse wave signal. The pulse wave sensor may include a light source that emits light onto the skin of an object (such as a wrist or finger) and a light receiver (such as a contact image sensor (CIS) optical sensor, a photodiode, etc.) that detects light scattered or reflected from the wrist or finger. The pulse wave sensor may have multiple channels for measuring pulse wave signals at multiple points on an object (such as a wrist or finger), and each channel may include a light source and a light receiver, or may include multiple light sources configured to emit light of different wavelengths onto the object and / or multiple light receivers configured to detect light scattered or reflected from the object. The number of light sources and light receivers included in each channel is not limited. In addition, the sensor unit 1120 may also include a force sensor configured to measure the contact force between the object (such as a wrist or finger) and the sensor unit 1120.

[0122] The processor may be installed in the body 1110. The processor may be electrically connected to the module installed in the wearable device 1100. As described above, when the sensor unit 1120 obtains the pulse wave signal of each channel, the processor may determine the optimal channel and estimate the bio-information by using the pulse wave signal of the determined optimal channel. A detailed description thereof will be omitted.

[0123] In addition, the body 1110 may include a storage device that stores reference information used to estimate blood pressure and perform various functions of the wearable device 1100 and information processed by various modules thereof.

[0124] In addition, the main body 1110 may include a manipulator 1140, which is provided on one side surface of the main body 1110 and receives a user's control command and sends the received control command to the processor. The manipulator 1140 may have a power button for inputting a command to turn on / off the wearable device 1100.

[0125] In addition, a display for outputting information to the user may be mounted on the front surface of the main body 1110. The display may have a touch screen for receiving touch input. The display may receive the user's touch input and send the touch input to the processor, and may display the processing result of the processor.

[0126] In addition, the main body 1110 may include a communication interface for communicating with an external device. The communication interface may transmit the blood pressure estimation result to the external device (eg, a user's smartphone).

[0127] Figure 12 1 is a diagram illustrating a smart device according to an exemplary embodiment. The smart device may include a smart phone, a tablet PC, etc. The smart device may include the functions of the aforementioned apparatuses 100a and 100b for estimating bio-information.

[0128] Reference Figure 12 , the smart device 1200 includes a main body 1210 and a pulse wave sensor 1230 mounted on one surface of the main body 1210. For example, the pulse wave sensor 1230 may include one or more light sources 1232 disposed at one or more predetermined locations thereof. The one or more light sources 1232 may emit light of different wavelengths. In addition, a plurality of light receivers 1231 may be disposed at locations spaced a predetermined distance from the light sources 1232. However, this is merely an example, and the pulse wave sensor 1230 may have various shapes and configurations. Furthermore, a force sensor for measuring the contact force of a finger may be mounted in the main body 1210 at the lower end of the pulse wave sensor 1230.

[0129] In addition, a display may be mounted on the front surface of the body 1210. The display may visually output blood pressure estimation results, health status assessment results, etc. The display may include a touch screen, and may receive information input through the touch screen and transmit the information to the processor.

[0130] The body 1210 may include Figure 12 The image sensor 1220 shown in FIG. The image sensor 1220 can capture various images and can obtain, for example, a fingerprint image of a finger in contact with the pulse wave sensor 1230. In addition, when an image sensor based on CIS technology is installed in the light receiver 1231 of the pulse wave sensor 1230, the image sensor 1220 can be omitted.

[0131] As described above, the processor may determine the optimal channel based on the pulse wave signal measured by the pulse wave sensor 1230 and may estimate the bio-information based on the determined optimal channel. A detailed description thereof will be omitted.

[0132] The disclosure can be implemented using computer-readable codes written on a computer-readable recording medium. The computer-readable recording medium may be any type of recording device that stores data in a computer-readable manner.

[0133] Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic disks, floppy disks, optical data storage devices, and carrier waves (e.g., data transmission via the Internet). Computer-readable recording media can be distributed across multiple networked computer systems so that computer-readable code is written therein and executed therefrom in a decentralized manner. Programmers with ordinary skill in the art to which the disclosure pertains can easily derive the functional programs, codes, and code segments required to implement the disclosure.

[0134] According to example embodiments, at least one of the components, elements, modules and units described herein can be implemented as various numbers of hardware, software and / or firmware structures that perform the above-mentioned various functions. For example, at least one of these components, elements and units can use a direct circuit structure (such as memory, processor, logic circuit, lookup table, etc.) that can be controlled by one or more microprocessors or other control devices to perform various functions. In addition, at least one of these components, elements and units can be specifically implemented by a part of a module, program or code and executed by one or more microprocessors or other control devices, wherein a part of a module, program or code contains one or more executable instructions for performing a specific logical function. In addition, at least one of these components, elements and units can also include a processor (such as a central processing unit (CPU), microprocessor, etc. that performs various functions) or is implemented by a processor. Two or more of these components, elements and units can be combined into a separate component, element or unit that performs all operations or functions of two or more of the combinations in the components, elements and units. In addition, at least one part of the function of at least one of these components, elements and units can be performed by another of these components, elements and units. In addition, although a bus is not shown in the above block diagram, the communication between the components, elements and units can be performed by a bus. The functional aspects of the above exemplary embodiments may be implemented in algorithms executed on one or more processors. In addition, the components, elements and units or processing operations represented by the blocks may adopt any number of related art technologies for electronic configuration, signal processing and / or control, data processing, etc.

[0135] The disclosure has been described herein with respect to example embodiments. However, it will be apparent to those skilled in the art that various modifications may be made without departing from the gist of the disclosure. Therefore, it should be understood that the scope of the disclosure is not limited to the above-described embodiments, but is intended to encompass various modifications and equivalents within the spirit and scope of the appended claims.

Claims

1. A device for estimating biological information, the device comprising: a pulse wave sensor comprising at least one light source configured to emit light of a first wavelength and light of a second wavelength onto an object and at least one light receiver configured to detect the light of the first wavelength and the second wavelength scattered or reflected from the object, wherein the pulse wave sensor comprises a plurality of channels, each of the plurality of channels being configured to measure a first pulse wave signal and a second pulse wave signal through the at least one light receiver, the second wavelength being different from the first wavelength; and The processor is configured to: For each of the plurality of channels, a first oscillogram is generated based on the first pulse wave signal, a second oscillogram is generated based on the second pulse wave signal, and a phase delay between the first oscillogram and the second oscillogram is converted into an area; and determining a channel among the plurality of channels based on the area of ​​each channel, and estimating bio-information based on the determined channel, wherein the first oscillogram is generated based on a correlation between changes in contact pressure applied by the subject to the pulse wave sensor and changes in the amplitude of the first pulse wave signal, The second oscillogram is generated based on a correlation between changes in contact pressure applied by the subject to the pulse wave sensor and changes in the amplitude of the second pulse wave signal.

2. The device according to claim 1, wherein The at least one light receiver includes at least one of a photodiode array and a complementary metal oxide semiconductor image sensor.

3. The device according to claim 1, wherein The processor is further configured to convert a phase delay between the first oscillogram and the second oscillogram into an area in a Lissajous waveform.

4. The device according to claim 3, wherein The processor is further configured to determine the channel based on at least one of a size of an area, a slope of a Lissajous waveform, a shape of an area, and an area ratio between a first region and a second region obtained by dividing an area of ​​each channel.

5. The device according to any one of claims 1 to 4, wherein The processor is further configured to exclude channels that do not meet a predetermined criterion based on the first oscillogram and the second oscillogram of each channel.

6. The device according to claim 5, wherein The processor is also configured to: for each channel of the plurality of channels, generating a third oscillogram by subtracting the second oscillogram from the first oscillogram, and The channels are excluded based on at least one of the following items: the full width at half maximum in the third oscillogram, the full width at a point corresponding to a predetermined ratio between a reference point and a maximum point of the third oscillogram, and a statistical value of a residual between the pulse wave of the third oscillogram before curve fitting and the pulse wave of the third oscillogram after curve fitting.

7. The apparatus according to claim 6, wherein The processor is further configured to determine a difference coefficient based on the first wavelength and the second wavelength, and subtract the second oscillogram to which the difference coefficient is applied from the first oscillogram to generate a third oscillogram.

8. The apparatus according to any one of claims 1 to 4, further comprising: The force sensor is configured to measure a contact force between the object and the pulse wave sensor.

9. The device according to any one of claims 1 to 4, wherein: The processor is further configured to estimate the bio-information by using the first oscillogram of the determined channel, the second oscillogram of the determined channel, or a third oscillogram generated by subtracting the second oscillogram of the determined channel from the first oscillogram of the determined channel.

10. The apparatus according to any one of claims 1 to 4, wherein: The processor is further configured to estimate first bio-information by using a first oscillogram of the determined channel, estimate second bio-information by using a second oscillogram of the determined channel, and obtain final bio-information based on at least one of the first bio-information and the second bio-information.

11. The apparatus according to any one of claims 1 to 4, wherein: The processor is further configured to: determine two or more channels among the multiple channels based on the area of ​​each channel among the multiple channels, estimate bio-information values ​​of the determined two or more channels, and obtain final bio-information by using at least one of the estimated bio-information values ​​of the determined two or more channels.

12. The apparatus according to any one of claims 1 to 4, wherein: The biological information includes at least one of blood pressure, vascular age, arterial stiffness, aortic pressure waveform, vascular compliance, pressure index, fatigue level, skin age, and skin elasticity.

13. A method for estimating biological information, the method comprising: measuring a first pulse wave signal and a second pulse wave signal for each of the plurality of channels by using at least one light receiver of a pulse wave sensor having a plurality of channels, wherein the pulse wave sensor includes at least one light source configured to emit light of a first wavelength and a second wavelength onto an object, and the at least one light receiver configured to detect light of the first wavelength and the second wavelength scattered or reflected from the object, the second wavelength being different from the first wavelength; generating, for each of the plurality of channels, a first oscillogram based on the first pulse wave signal and a second oscillogram based on the second pulse wave signal; for each channel of the plurality of channels, converting a phase delay between a first oscillogram and a second oscillogram into an area; determining a channel among the plurality of channels based on an area of ​​each channel; and Estimating biological information based on the determined channels, wherein the first oscillogram is generated based on a correlation between a change in contact pressure applied by the subject to the pulse wave sensor and a change in the amplitude of the first pulse wave signal, The second oscillogram is generated based on a correlation between changes in contact pressure applied by the subject to the pulse wave sensor and changes in the amplitude of the second pulse wave signal.

14. The method according to claim 13, wherein The converting step includes converting the phase delay between the first oscillogram and the second oscillogram into an area in a Lissajous waveform.

15. The method according to claim 14, wherein The determining step includes determining the channel based on at least one of a size of an area, a slope of a Lissajous waveform, a shape of an area, and an area ratio between a first region and a second region, the first region and the second region being obtained by dividing an area of ​​each channel.

16. The method according to any one of claims 13 to 15, further comprising: Channels that do not meet a predetermined criterion are excluded based on the first oscillogram and the second oscillogram of each channel.

17. The method according to claim 16, wherein The steps to troubleshoot include: for each channel of the plurality of channels, generating a third oscillogram by subtracting the second oscillogram from the first oscillogram; and The channels are excluded based on at least one of the following items: the full width at half maximum in the third oscillogram, the full width at a point corresponding to a predetermined ratio between a reference point and a maximum point of the third oscillogram, and a statistical value of a residual between the pulse wave of the third oscillogram before curve fitting and the pulse wave of the third oscillogram after curve fitting.

18. The method according to any one of claims 13 to 15, wherein: The estimating step includes estimating the bio-information by using the first oscillogram of the determined channel, the second oscillogram of the determined channel, or a third oscillogram generated by subtracting the second oscillogram of the determined channel from the first oscillogram of the determined channel.

19. The method according to any one of claims 13 to 15, wherein: The estimating step includes estimating first bio-information by using a first oscillogram of the determined channel, estimating second bio-information by using a second oscillogram of the determined channel, and obtaining final bio-information based on at least one of the first bio-information and the second bio-information.

20. The method according to any one of claims 13 to 15, wherein: The estimating step includes determining two or more channels among the plurality of channels based on an area of ​​each channel, estimating bio-information values ​​of the determined two or more channels, and obtaining final bio-information by using at least one of the estimated bio-information values ​​of the determined two or more channels.

21. A device for estimating biological information, the device comprising: A pulse wave sensor comprising at least one light source and at least one light receiver, the at least one light source being configured to sequentially emit light of a first wavelength and light of a second wavelength onto an object, the at least one light receiver being configured to sequentially detect the light of the first wavelength and the light of the second wavelength scattered or reflected from the object, wherein the pulse wave sensor comprises a plurality of channels, each of the plurality of channels being configured to sequentially measure a first pulse wave signal and a second pulse wave signal through the at least one light receiver, the second wavelength being different from the first wavelength; and The processor is configured to: For each of the plurality of channels, obtaining a first characteristic value based on the AC component and the DC component of the first pulse wave signal and the AC component and the DC component of the second pulse wave signal, determining a channel among the plurality of channels based on the obtained first eigenvalue of each channel, and Estimate biological information based on the determined channels, The processor is configured to obtain a first characteristic value by dividing the ratio between the magnitude of the AC component and the magnitude of the DC component of the first pulse wave signal by the ratio between the magnitude of the AC component and the magnitude of the DC component of the second pulse wave signal. wherein the first wavelength is a wavelength relatively longer than the second wavelength, The processor is configured to determine a channel having the highest first eigenvalue or a predetermined number of channels starting from the highest first eigenvalue and in descending order of magnitude of the first eigenvalue.

22. The apparatus according to claim 21, wherein The processor is further configured to generate an oscillogram based on at least one of the first pulse wave signal and the second pulse wave signal of the determined channel, obtain a second eigenvalue by using the generated oscillogram, and estimate bio-information based on at least one of the first eigenvalue and the second eigenvalue.

23. A method for estimating biological information, the method comprising: sequentially measuring a first pulse wave signal and a second pulse wave signal for each of the plurality of channels by using at least one light receiver of a pulse wave sensor having a plurality of channels, wherein the pulse wave sensor includes at least one light source configured to sequentially emit light of a first wavelength and light of a second wavelength onto an object, and the at least one light receiver configured to sequentially detect light of the first wavelength and light of the second wavelength scattered or reflected from the object, the second wavelength being different from the first wavelength; For each of the plurality of channels, obtaining a first characteristic value based on the AC component and the DC component of the first pulse wave signal and the AC component and the DC component of the second pulse wave signal; determining a channel among the plurality of channels based on the obtained first feature value of each channel; and Estimate biological information based on the determined channels, The step of obtaining the first characteristic value includes: obtaining the first characteristic value by dividing the ratio between the magnitude of the AC component and the magnitude of the DC component of the first pulse wave signal by the ratio between the magnitude of the AC component and the magnitude of the DC component of the second pulse wave signal; wherein the first wavelength is a wavelength relatively longer than the second wavelength, The step of determining the channel includes determining the channel having the highest first eigenvalue or a predetermined number of channels starting from the highest first eigenvalue and in descending order of magnitude of the first eigenvalue.

24. The method according to claim 23, wherein The steps of estimation include: generating an oscillogram based on at least one of the first pulse wave signal and the second pulse wave signal of the determined channel; obtaining a second eigenvalue by using the generated oscillogram; and The biological information is estimated based on at least one of the first eigenvalue and the second eigenvalue.

25. A computer-readable recording medium storing a computer program, which, when executed by a processor, causes the processor to perform the method according to any one of claims 13 to 20 and 23 to 24.

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