Device and method for estimating biological information

Abstract

Devices and methods for estimating biological information are provided. The device includes: a pulse wave sensor including a plurality of channels arranged in an isotropic shape; a force sensor configured to measure the force applied by an object to the pulse wave sensor; and a processor configured to: detect a center of gravity based on the pressure applied by the object in the space formed by the plurality of channels, based on the pulse wave signals measured by each of the plurality of channels included in the pulse wave sensor, provide guidance information for the contact between the object and the pulse wave sensor to the user based on the detected center of gravity, and estimate biological information based on the pulse wave signals and the force measured according to the guidance information.

Description

[0001] This application claims priority to Korean Patent Application No. 10-2021-0083382, filed with the Korean Intellectual Property Office on June 25, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0002] Example embodiments of the present disclosure relate to devices and methods for non-invasively estimating biological information. Background Art

[0003] Generally, methods for non-invasively measuring blood pressure without damaging the human body include a method of measuring blood pressure by measuring cuff-based pressure and a method of estimating blood pressure by measuring a pulse wave without using a cuff.

[0004] The Korotkoff sound method is one of the cuff-based blood pressure measurement methods, in which the pressure in the cuff wrapped around the upper arm is increased, and the blood pressure is measured by listening to the sounds generated in the blood vessels through a stethoscope while decreasing the pressure. Another cuff-based blood pressure measurement method is the oscillometric method using an automated machine, in which the cuff is wrapped around the upper arm, the pressure in the cuff is increased, the pressure in the cuff is continuously measured while the cuff pressure gradually decreases, and the blood pressure is measured based on the points where the change in the pressure signal is large.

[0005] Cuffless blood pressure measurement methods generally include a method of estimating blood pressure by calculating the pulse transit time (PTT) and a pulse wave analysis (PWA) method of estimating blood pressure by analyzing the pulse waveform. Summary of the Invention

[0006] One or more example embodiments provide devices and methods for non-invasively estimating biological information.

[0007] According to an aspect of an example embodiment, there is provided a device configured to estimate biological information, the device including: a pulse wave sensor including a plurality of channels arranged in an isotropic shape; a force sensor configured to measure a force applied by an object to the pulse wave sensor; and a processor configured to: detect a center of gravity based on a pressure applied by the object in a space formed by the plurality of channels, based on pulse wave signals measured by each of the plurality of channels included in the pulse wave sensor, provide guidance information regarding contact between the object and the pulse wave sensor to the user based on the detected center of gravity, and estimate biological information based on the pulse wave signals and the force measured according to the guidance information.

[0008] Each of the plurality of channels included in the pulse wave sensor may include at least one of a light source configured to emit light onto the object and a detector configured to detect light scattered or reflected from the object.

[0009] The processor may also be configured to: extract a direct current (DC) value from the pulse wave signals measured by each of the plurality of channels; generate an intensity map by mapping the DC values of each of the plurality of channels that are extracted to a circular boundary; and detect a center of gravity based on the generated intensity map.

[0010] Based on the DC values of each of the plurality of channels, the processor may also be configured to: obtain the DC values of a plurality of virtual channels to be set on the circular boundary; and generate an intensity map by mapping the DC values of each of the plurality of channels and the DC values of the plurality of virtual channels to the circular boundary.

[0011] The device may further include: an output interface configured to display a graphical object having a predetermined shape on a screen to guide a user to place the object on the space.

[0012] Based on the detected center of gravity, the output interface may also be configured to: highlight the position of the force exerted by the object on the graphical object; and move the highlighted position based on a change in the center of gravity.

[0013] The output interface may be configured to: display a center of gravity trajectory during an entire measurement time by superimposing the center of gravity trajectory on the graphical object.

[0014] The output interface may also be configured to: display a graph showing a change in a separation distance between the center of the space and the center of gravity.

[0015] The processor may also be configured to: calculate a score regarding the center of gravity trajectory based on the separation distance, and the output interface may also be configured to: display the calculated score on the screen.

[0016] The output interface may also be configured to display at least one of the following graphical objects: a graphical object configured to guide a change in a reference force to be exerted by an object on a pulse wave sensor during measurement of the pulse wave signal and a graphical object representing a change in an actual force measured by a force sensor.

[0017] The processor may also be configured to: determine whether to re-measure the pulse wave signal based on a separation distance between the center of gravity and the center of the space at each time point.

[0018] Based on at least one of the number of times the separation distance deviates from a reference value being greater than or equal to a threshold number of times, a time period during which the separation distance continuously deviates from the reference value being greater than or equal to a threshold time period, and a score of the center of gravity trajectory being less than or equal to a threshold, the processor may also be configured to determine whether to re-measure the pulse wave signal.

[0019] The processor may also be configured to: generate an oscillometric waveform envelope based on the pulse wave signal and the force; and estimate biological information based on the generated oscillometric waveform envelope.

[0020] The biological information may include one or more of blood pressure, vascular age, arterial stiffness, aortic pressure waveform, vascular compliance, pressure index, and fatigue level.

[0021] According to another aspect of an example embodiment, a method for estimating biological information is provided. The method includes: measuring a pulse wave signal from an object through a pulse wave sensor, the pulse wave sensor including a plurality of channels arranged in an isotropic shape; measuring a force applied by the object to the pulse wave sensor through a force sensor; detecting a center of gravity based on the pressure applied by the object in a space formed by the plurality of channels, based on the pulse wave signal measured by each of the plurality of channels included in the pulse wave sensor; providing guidance information regarding the contact between the object and the pulse wave sensor during the measurement of the pulse wave signal to the user based on the detected center of gravity; and estimating biological information based on the pulse wave signal and the force measured according to the guidance information.

[0022] The step of detecting the center of gravity may further include: extracting a direct current (DC) value from the pulse wave signal measured by each of the plurality of channels; generating an intensity map by mapping the DC values of each of the plurality of extracted channels to a circular boundary; and detecting the center of gravity based on the generated intensity map.

[0023] The step of generating the intensity map may include: obtaining the DC values of a plurality of virtual channels to be set on the circular boundary based on the DC value of the corresponding channel; and generating an intensity map by mapping the DC values of each of the plurality of channels and the DC values of the plurality of virtual channels to the circular boundary.

[0024] The method may further include: determining whether to re-measure the pulse wave signal based on a separation distance between the center of gravity and the center of the space at each time point.

[0025] The step of estimating biological information may further include: generating an oscillometric waveform envelope based on the pulse wave signal and the force; and estimating biological information based on the generated oscillometric waveform envelope.

[0026] According to another aspect of an exemplary embodiment, there is provided an electronic device including: a body; a pulse wave sensor including a plurality of channels arranged in an isotropic shape on a surface of the body that contacts an object; a force sensor disposed at an upper or lower end of the pulse wave sensor and configured to measure a force applied by the object to the pulse wave sensor; and a processor configured to: detect a center of gravity based on a pressure applied by the object in a space formed by the plurality of channels, based on pulse wave signals measured by each of the plurality of channels included in the pulse wave sensor, provide guidance information regarding contact between the object and the pulse wave sensor to a user based on the detected center of gravity, and estimate blood pressure based on the pulse wave signals and the force measured according to the guidance information.

[0027] According to another aspect of an exemplary embodiment, there is provided a device configured to estimate biological information, the device including: a pulse wave sensor including a plurality of channels arranged in an isotropic shape; a force sensor configured to measure a force applied by an object to the pulse wave sensor; and a processor configured to: detect a center of gravity based on a pressure applied by the object in a space formed by the plurality of channels, based on a direct current (DC) value extracted from pulse wave signals measured by each of the plurality of channels included in the pulse wave sensor, provide guidance information regarding contact between the object and the pulse wave sensor to a user based on the detected center of gravity being spaced apart from a center of the space, and estimate biological information based on the pulse wave signals and the force measured according to the guidance information. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or other aspects, features, and advantages of the disclosed exemplary embodiments will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0029] Figure 1 is a block diagram showing a device configured to estimate biological information according to an exemplary embodiment;

[0030] Figure 2 is a block diagram showing a device configured to estimate biological information according to another exemplary embodiment;

[0031] Figure 3A 、 Figure 3B 、 Figure 3C 、 Figure 3D and Figure 3E show an arrangement structure of a pulse wave sensor and a change in a center of gravity according to a pressure applied by an object;

[0032] Figure 4A 、 Figure 4B 、 Figure 4C 、 Figure 4D and Figure 4E show an example of detecting a change in a center of gravity according to a pressure applied by an object according to an exemplary embodiment;

[0033] Figure 5A 、 Figure 5B 、 Figure 5C 、 Figure 5D and Figure 5E illustrate examples of contacts of a guided object according to an exemplary embodiment;

[0034] Figure 6A and Figure 6B illustrate examples of oscillometric blood pressure estimation according to an exemplary embodiment;

[0035] Figure 7 is a flowchart illustrating a method of estimating biological information according to an exemplary embodiment; and

[0036] Figure 8 、 Figure 9 、 Figure 10 illustrate examples of an electronic device including a device configured to estimate biological information according to an exemplary embodiment. DETAILED DESCRIPTION

[0037] Details of the exemplary embodiments are included in the following detailed description and the accompanying drawings. The advantages and features of the present disclosure and the method of implementing the present disclosure will be more clearly understood from the exemplary embodiments described in detail below with reference to the accompanying drawings. Throughout the drawings and the detailed description, unless otherwise described, the same reference numerals will be understood to refer to the same elements, features, and structures.

[0038] 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 only used to distinguish one element from another. In addition, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. It will also be understood that unless explicitly stated to the contrary, when an element is referred to as "including" another element, the element is not intended to exclude one or more other elements, but also includes 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 may be implemented by using hardware, software, or a combination thereof.

[0039] An expression such as "at least one of..." modifies the entire list of elements when it is placed before a list of elements, rather than modifying a single element in the list. For example, the expression "at least one of a, b, and c" should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0040] Figure 1 is a block diagram illustrating a device configured to estimate biological information according to an exemplary embodiment.

[0041] Reference Figure 1 As shown in Figure 1 , the device 100 configured to estimate biological information includes a pulse wave sensor 110, a force sensor 120, and a processor 130.

[0042] The pulse wave sensor 110 can measure a pulse wave signal including a photoplethysmogram (PPG) signal from an object. The pulse wave sensor 110 can be composed of a plurality of channels formed in an isotropic shape. Each channel can include a light source and a detector. The light source is configured to emit light onto the object, and the detector is configured to detect the light that returns after being scattered or reflected from the skin surface or blood vessels of the object, or transmitted through the skin surface or blood vessels of the object, after the light is emitted by the light source. The pulse wave sensor 110 can include a plurality of light sources and detectors, and the plurality of light sources can emit light of green wavelength, blue wavelength, red wavelength, infrared wavelength, etc. The light source can include a light-emitting diode (LED), a laser diode (LD), a phosphor, etc., but is not limited thereto. In addition, the detector can include a photodiode, a phototransistor (PTr), an image sensor (e.g., a complementary metal oxide semiconductor (CMOS) image sensor), etc., but is not limited thereto.

[0043] When the user places the object on the pulse wave sensor 110 and gradually increases the pressing force, or when the user applies a force greater than or equal to a threshold value and then gradually decreases the force, the force sensor 120 can measure the force applied to the pulse wave sensor 110. The force sensor 120 can be provided at the upper end or the lower end of the pulse wave sensor 110. The force sensor 120 can include a strain gauge, etc., or can be formed as a single force sensor or a force sensor array. In this case, the force sensor 120 can be modified into a pressure sensor combined with a force sensor and an area sensor, or an airbag-type pressure sensor, etc.

[0044] The processor 130 can be electrically connected to the pulse wave sensor 110 and / or the force sensor 120, and can control the pulse wave sensor 110 and the force sensor 120 in response to a request configured to estimate biological information.

[0045] When receiving a request configured to estimate biological information from the user, the processor 130 can guide the contact position so that the user can correctly place the object on the space formed by the plurality of channels formed in an isotropic shape, and can guide the reference force so that an appropriate force can be applied during the measurement of the pulse wave signal.

[0046] In addition, when measuring the pulse wave signal, the processor 130 can guide changes in the contact position of the object, changes in the contact force, and / or the pressing position or direction of the object, etc., so that the user can apply a uniform force to each channel when the user places the object in the correct position. In addition, when the measurement of the pulse wave signal is completed, the processor 130 can determine whether to re-measure the pulse wave signal, and if re-measurement is required, the processor 130 can guide the user to re-measure the pulse wave signal. For example, by using the direct current (DC) component of the pulse wave signal of each channel, the processor 130 can detect the center of gravity according to the pressure applied by the object, and based on the detected center of gravity, the processor 130 can guide the contact position, pressing position, and / or pressing direction of the object, etc. In addition, the processor 130 can determine whether to re-measure the pulse wave signal.

[0047] The processor 130 can estimate biological information based on the last measured pulse wave signal and force. In this case, the biological information can include, for example, one or more of heart rate, blood pressure, vascular age, arterial stiffness, aortic pressure waveform, vascular compliance, stress index, fatigue level, skin elasticity, skin age, etc., but is not limited thereto. For the sake of easy explanation, blood pressure will be used as an example for the following description.

[0048] Referring to Figure 2 , in addition to the pulse wave sensor 110, the force sensor 120, and the processor 130, the device 200 configured to estimate biological information according to another exemplary embodiment may further include an output interface 210, a storage device 220, and a communication interface 230. The pulse wave sensor 110, the force sensor 120, and the processor 130 have been described above with reference to Figure 1 , so their descriptions will be omitted hereinafter.

[0049] The output interface 210 can output the pulse wave signal acquired by the pulse wave sensor 110, the contact force acquired by the force sensor 120, and / or various processing results of the processor 130 under the control of the processor 130.

[0050] For example, the output interface 210 can visually output the guiding information for the contact of the object generated by the processor 130 through, for example, a display module, or can non-visually output information through voice, vibration, touch, etc. using a speaker module, a tactile module, etc. According to the exemplary embodiment, the display area can be divided into two or more areas, where the output interface 210 can output guiding information for the contact force of the object in the first area, and can output guiding information for the contact position of the object, the center of gravity according to the pressure of the object, etc. in the second area.

[0051] In addition, the output interface 210 may visually output the estimated biometric information value generated by the processor 130 through a display module, or may non-visually output the value through voice, vibration, touch, etc. using a speaker module, a haptic module, etc. The display area may be divided into two or more areas, where the output interface 210 may output in the first area details (such as a pulse wave signal, contact force, etc.) configured to estimate biometric information in the form of various graphs. Together with the information, the output interface 210 may output the estimated biometric information value in the second area. In this case, when the estimated biometric information value falls outside the normal range, the output interface 210 may output a warning message in various ways (such as highlighting the abnormal value in red, etc., displaying the abnormal value together with the normal range, outputting a voice warning message, adjusting the vibration intensity, etc.).

[0052] The storage device 220 may store, under the control of the processor 130, the pulse wave signal acquired by the pulse wave sensor 110, the contact force acquired by the force sensor 120, and / or various processing results of the processor 130. In addition, the storage device 220 may store various reference information configured to estimate biometric information. For example, the reference information may include user characteristic information (such as the user's age, gender, health condition, etc.), a biometric information estimation model, etc., but is not limited thereto.

[0053] In this case, the storage device 220 may include at least one storage medium such as a flash memory type, a hard disk type, a multimedia card micro memory, a card type memory (e.g., SD memory, 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, and an optical disk, etc., but is not limited thereto.

[0054] The communication interface 230 may communicate with an external device by using wired or wireless communication technology under the control of the processor 130, and may send various data to the external device and receive various data from the external device. For example, while the measurement of the pulse wave signal is being performed, the communication interface 230 may send the guidance information for the contact of the object generated by the processor 130 to the external device so that the guidance information may be displayed on the display of the external device.

[0055] In addition, the communication interface 230 may send the biometric information estimation result to the external device, and may receive various reference information configured to estimate biometric information from the external device. In this case, the external device may include a cuff-type blood pressure measurement device and an information processing device (such as a smart phone, a tablet personal computer (PC), a desktop computer, a laptop computer, etc.).

[0056] In this case, examples of communication technologies 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, the embodiments are not limited thereto.

[0057] When both the output interface 210 and the communication interface 230 are provided, the processor 130 may selectively control the output interface 210 and the communication interface 230 so that the required information can be output to any one of an electronic device (e.g., a smartwatch) including the device 200 configured to estimate biometric information and an external device (e.g., a smartphone). In this case, the processor 130 may determine the device for outputting information in response to a user's request or by using various sensors installed in the electronic device including the device 200 configured to estimate biometric information. For example, by using an acceleration sensor and / or a camera module installed in the electronic device, etc., the processor 130 may automatically detect the direction of the display installed in the electronic device, and when the detected direction of the display is a direction not within the user's line of sight (e.g., a downward direction), the processor 130 may control the communication interface 230 to output the information required by the external device. According to another exemplary embodiment, the processor 130 may control both the output interface 210 and the communication interface 230 so that the information can be output in a complementary manner.

[0058] Various examples of guiding contact with the object will be described below with reference to Figures 3A to 5E Describe various examples of guiding contact with the object.

[0059] Figures 3A to 3E Show the arrangement structure of the pulse wave sensor and the change in the center of gravity according to the pressure applied by the object.

[0060] Figure 3A Show the arrangement structure of the pulse wave sensor according to an exemplary embodiment. Refer to Figure 3A , the pulse wave sensor 110 includes a plurality of channels ch1, ch2, ch3, and ch4 formed in an isotropic shape from the center AC of the pulse wave sensor, and when the plurality of channels ch1, ch2, ch3, and ch4 are formed in an isotropic shape, a virtual space AR is formed in a predetermined shape (e.g., a circle). In Figure 3A , four channels are shown as an example, but the number of channels is not limited thereto. As Figure 3AAs shown, channels ch1, ch2, ch3, and ch4 may respectively include light sources 11, 21, 31, and 41 and detectors 12, 22, 32, and 42. The number of light sources and detectors included in each of the channels ch1, ch2, ch3, and ch4 does not have to be limited to one, and may be formed into multiple arrays. In this case, the multiple light sources may emit light of different wavelengths (e.g., green, blue, red, and infrared wavelengths, etc.).

[0061] Referring to Figure 3B , in the structure of the pulse wave sensor formed in an isotropic shape as shown in Figure 3A , an object OBJ is placed on a virtual space AR, and when the pressing force of the object OBJ gradually increases or decreases, each of the channels ch1, ch2, ch3, and ch4 of the pulse wave sensor 110 may measure a pulse wave signal from the object. The processor 130 may sequentially drive the multiple channels ch1, ch2, ch3, and ch4 in a predetermined pattern (e.g., clockwise direction, counterclockwise direction, diagonal direction, etc.), or may simultaneously drive two or more of the multiple channels ch1, ch2, ch3, and ch4. In this case, when driving the light source 11 of, for example, channel 1ch1, the processor 130 may simultaneously drive the detector 32 of channel 3ch3 located on the diagonal of the light source 11, thereby allowing the detector 32 of channel 3ch3 to detect the light that reacts after being scattered or reflected from the object, or transmitted through the object, after the light is emitted by the light source 11 of channel 1ch1.

[0062] Figure 3C Shows the layout structure of a pulse wave sensor according to another exemplary embodiment. Referring to Figure 3C , one or more light sources L are provided at the center of the pulse wave sensor 110, and the channels ch1, ch2, ch3, and ch4 are formed in an isotropic shape from the center of the pulse wave sensor 110. Each of the channels ch1, ch2, ch3, and ch4 may include one or more detectors 12, 22, 32, and 42, and the one or more detectors 12, 22, 32, and 42 may detect the light emitted from the light source L at the center and reacting with the object when the object is placed on the virtual space AR as shown in Figure 3B . In this case, the light source L at the center is turned on in a time-division manner, and the channels ch1, ch2, ch3, and ch4 formed in an isotropic shape are driven in a time-division manner or simultaneously driven to detect the light.

[0063] Figure 3D Shows the layout structure of a pulse wave sensor according to yet another exemplary embodiment. Referring to Figure 3D, one or more detectors D are disposed at the center of the pulse wave sensor 110, and channels ch1, ch2, ch3, and ch4 are formed in an isotropic shape from the center of the pulse wave sensor 110. Each of the channels ch1, ch2, ch3, and ch4 may include one or more light sources 11, 21, 31, and 41, and when an object is placed on the virtual space AR as shown in Figure 3B , the light sources 11, 21, 31, and 41 of each of the channels ch1, ch2, ch3, and ch4 may be turned on in a time-division manner in a predetermined order (e.g., clockwise, counterclockwise, diagonal direction, etc.), and the detector D disposed at the center may detect the light that reacts with the object.

[0064] Figure 3E shows the change in the center of gravity and the intensity map according to the direction or position of the pressure applied by the finger when the finger is placed on the virtual space AR such that the feature point (e.g., the center of the fingerprint) is located at the center AC of the virtual space AR. In Figure 3E , the middle diagram shows an example in which the feature point of the finger is vertically pressed onto the center AC of the virtual space AR so that a uniform force can be applied to each channel. In this case, the center of gravity GC2 according to the pressure is located at the center of the intensity map 32, and the right and left diagrams show examples in which the position of the feature point of the finger is not vertically pressed onto the center AC of the virtual space AR and the force is applied to the lower and upper positions. As shown here, the centers of gravity GC1 and GC3 are located at the lower and upper sides of the intensity maps 31 and 33, respectively. Therefore, when the object does not vertically and uniformly apply a force to the center of the pulse wave sensor 110 and the direction or position of the force changes, noise may be included in the measured pulse wave signal, thereby reducing the accuracy of estimating biological information.

[0065] Figures 4A to 4E shows an example of detecting the change in the center of gravity according to the pressure applied by an object according to an exemplary embodiment.

[0066] By using each pulse wave signal measured by the multiple channels of the pulse wave sensor 110, the processor 130 may detect the center of gravity according to the pressure applied by the object at each time point. For example, Figure 4A shows the DC component signals of the pulse wave signals measured by the four channels ch1, ch2, ch3, and ch4 shown in Figure 3A . When each channel measures a pulse wave signal, the processor 130 may extract and normalize the DC component by filtering the pulse wave signal.

[0067] The processor 130 may generate an intensity map IM for each time point by mapping the DC value of each time point of each of the channels ch1, ch2, ch3, and ch4 to a corresponding position on a circular boundary centered at (0, 0) and having a radius of 1, for example. The processor 130 may detect the center of gravity GC for each time point based on the generated intensity map IM for each time point, as Figure 4B shown.

[0068] In this case, the processor 130 may also set a plurality of virtual channels on the circular boundary and may obtain the DC values of the plurality of virtual channels by performing circular interpolation on the obtained DC values of the actual channels ch1, ch2, ch3, and ch4. Figure 4C shows the DC component signals of all channels (e.g., 120 channels) including the DC components of the obtained plurality of virtual channels. By mapping the DC value of each time point of all the obtained channels to a corresponding position on the circular boundary, the processor 130 may generate an intensity map IM for each time point and may detect the center of gravity for each time point based on the intensity map IM.

[0069] Figure 4D shows the trajectory CT of the center of gravity during the entire measurement time. Figure 4E shows the change in the separation distance between the center of the space formed by the plurality of channels and the center of gravity. When the measurement of the pulse wave signal is completed, the processor 130 may generate the trajectory of the center of gravity and / or data on the change in the separation distance as shown herein by using the center of gravity for each time point detected based on the intensity map for each time point.

[0070] In addition, the processor 130 may calculate a score of the center of gravity trajectory based on the center of gravity for each time point and / or the data on the change in the separation distance. For example, the processor 130 may calculate the score of the center of gravity trajectory based on the number of times the separation distance deviates from a reference value during the entire measurement time and / or the time period when the separation distance continuously deviates from the reference value, etc. In another example, the processor 130 may convert Figure 4E the average area of the areas under the curve of each time in the separation distance curve graph shown in into a score of the center of gravity trajectory.

[0071] In addition, the processor 130 may determine whether to re-measure the pulse wave signal based on the separation distance and / or the score of the center of gravity trajectory, etc. For example, if a predetermined condition is satisfied (including at least one of the following cases: the number of times the separation distance deviates from the reference value during the entire measurement time is greater than or equal to a threshold number of times, the time period when the separation distance continuously deviates from the reference value is greater than or equal to a threshold time period, and the score of the center of gravity trajectory is less than or equal to a threshold, etc.), the processor 130 may determine to re-measure the pulse wave signal.

[0072] Figures 5A to 5E An example of guiding the contact of an object according to an exemplary embodiment is shown.

[0073] The output interface 210 and / or the communication interface 230 may be connected to the processor 130 to display information for guiding the contact of an object on the display screen 50 of the electronic device in which the device 200 configured to estimate biological information is installed and / or on an external device. For ease of explanation, the following description will be based on an example in which the output interface 210 outputs information on the display screen 50 of the electronic device in which the device 200 configured to estimate biological information is installed.

[0074] Referring to Figure 5A , when a request configured to estimate biological information is received, the output interface 210 may display, for example, a circular graphic object 51 representing a space formed by a plurality of channels, so that the user can correctly place the object on the pulse wave sensor 110. In this case, the output interface 210 may output text (such as, "Please place your index finger on the space shown below and then press it") at the upper end of the display screen 50. In addition, the output interface 210 may display a marker 52 having a predetermined shape (such as a cross shape, a circular shape, etc.) superimposed on the center of the graphic object 51 for guiding the feature point of the finger to be located at the center of the circle and pressed vertically onto the center.

[0075] Referring to Figure 5B , when the user's finger is placed on the pulse wave sensor 110, the processor 130 may detect the contact position and / or direction of the finger, and based on the information about the detected contact position and / or direction, the output interface 210 may display a graphic object 53 having a finger shape superimposed on the corresponding position of the graphic object 51.

[0076] Referring to Figure 5C , when a request configured to estimate biological information is received, the output interface 210 may divide the display screen 50 into two regions 50a and 50b, and may display, for example, a circular graphic object 51 in the lower region 50b as shown herein, so that the user can correctly place the object on the space of the pulse wave sensor 110, and may display a graphic object representing the change in the reference force applied by the object to the pulse wave sensor 110 during the measurement time (such as the upper limit 54a and the lower limit 54b of the reference force).

[0077] Referring to Figure 5D, when the processor 130 generates an intensity map for each time point while the pulse wave signal is being measured and detects the center of gravity, in response, the output interface 210 can display a circular graphic object 51 and / or a marker 52 representing the center on the display screen 50, and based on the detected center of gravity, the output interface 210 can output a graphic object 55 having a predetermined shape (e.g., circular) superimposed on the graphic object 51, so that the position of the force applied by the object can be highlighted.

[0078] In this case, based on the intensity map generated for each time point, the output interface 130 can change, for example, the type and concentration of color, the type and width of lines, etc. according to the position and each time point of the space / boundary of the first graphic object 51. For example, as the intensity of the DC value of each channel increases, the output interface 210 can increase the concentration of the color at the corresponding position on the circular boundary of the first graphic object 51. On the contrary, as the intensity of the DC value of each channel decreases, the output interface 210 can decrease the concentration of the color at the corresponding position. In addition, the output interface 210 can, for example, continuously move the graphic object 55 in the first direction, second direction, third direction, and fourth direction as shown here to highlight the position of the applied force, so that the change of the center of gravity over time can be visually displayed.

[0079] Referring to Figure 5E , when the processor 130 generates an intensity map for each time point while the pulse wave signal is being measured and detects the center of gravity, the output interface 210 can divide the display screen 50 into two regions 50a and 50b, and can output different types of information in the corresponding regions 50a and 50b.

[0080] For example, the output interface 210 can display in the upper region 50a a graphic object representing the upper limit 54a and lower limit 54b of the reference force applied by the object to the pulse wave sensor 110 during the measurement time and a graphic object 56 representing the intensity of the actual force measured by the force sensor 120 (or, display either of the two graphic objects). In this case, the shape of the graphic object 56 is not specifically limited, and the position of the graphic object 56 can, for example, continuously move along the first direction, second direction, and third direction shown, so that the change of the actual force over time can be visually recognized.

[0081] In addition, as referred to above Figure 5DAs described, the output interface 210 can display a circular graphic object 51 and / or a marker 52 representing the center in the lower region 50b, and based on the detected center of gravity, the output interface 210 can output a graphic object 55 superimposed on the graphic object 51 to highlight the position of the force exerted by the object. In this way, the user can more easily identify whether the object is placed at the correct position of the pulse wave sensor during the entire measurement time, or whether the object vertically and evenly applies force to the center of the pulse wave sensor.

[0082] In addition, when the measurement of the pulse wave signal is completed, the output interface 210 can output the change in the center of gravity trajectory or the separation distance between the center of gravity and the center of the display screen as shown in Figure 4D and Figure 4E , or can output in real time during the measurement of the pulse wave signal the change in the center of gravity trajectory or the separation distance up to the current time point. In addition, the score of the center of gravity trajectory calculated by the processor 130 etc. can be displayed on the display screen, and when the processor 130 determines to re-measure the pulse wave signal, the output interface 210 can display again on the screen Figures 5A to 5C and other information, so that the user can place the object on the pulse wave sensor 110 again.

[0083] Figure 6A and Figure 6B show an example of estimating blood pressure based on oscillometry according to an exemplary embodiment.

[0084] Figure 6A shows the change in the amplitude of the pulse wave signal when the object in contact with the pulse wave sensor 110 gradually increases the pressing force. Figure 6B shows an oscillometric waveform envelope OW representing the relationship between the change in contact pressure and the amplitude of the pulse wave signal. In this case, the contact pressure can be the measured force value measured by the force sensor 120, or a value obtained by converting the force value to a pressure value using a predefined conversion equation. According to another exemplary embodiment, in the case where a pressure sensor is installed instead of the force sensor 120, the contact pressure can be the pressure value measured by the pressure sensor.

[0085] The processor 130 can select at least some of the multiple channels, and can generate an oscillometric waveform envelope by using the pulse wave signals of the selected channels. For example, the processor 130 can select channels in the order of the intensity of the DC component values, in the order closer to the center of gravity, etc. In this case, if multiple channels are selected, the processor 130 can combine the pulse wave signals to generate a single pulse wave signal.

[0086] The processor 130 may extract the peak-to-peak points of the pulse wave signal waveform, for example, by subtracting the negative (-) amplitude value in3 from the positive (+) amplitude value in2 of the waveform envelope in1 at each measurement time point of the pulse wave signal. In addition, the processor 130 may obtain an oscillometric waveform envelope (OW) by plotting the peak-to-peak amplitude at each measurement time point against the contact pressure value at the corresponding time point and by performing, for example, polynomial curve fitting.

[0087] The processor 130 may estimate, for example, blood pressure by using the generated oscillometric waveform envelope OW. The processor 130 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 oscillometric waveform envelope OW. For example, the processor 130 may determine the contact pressure value MP itself at the maximum point MA of the pulse wave as the MAP, or may obtain the MAP from the contact pressure value MP by using a predefined MAP estimation equation. In this case, the MAP estimation equation may be represented in the form of various linear combination functions or non-linear combination functions (such as addition, subtraction, division, multiplication, logarithmic values, regression equations, etc., without particular limitation).

[0088] In addition, the processor 130 may estimate the diastolic blood pressure and the systolic blood pressure by using the contact pressure values DP and SP, respectively, where the contact pressure values DP and SP are located at the left point and the right point corresponding to the amplitude values having a preset ratio (for example, 0.5 to 0.7) to the amplitude value at the maximum point MA of the pulse wave. The processor 130 may determine the contact pressure value DP as the diastolic blood pressure and the contact pressure value SP as the systolic blood pressure, or may estimate the diastolic blood pressure and the systolic blood pressure from the corresponding contact pressure values DP and SP by using predefined diastolic blood pressure estimation equations and systolic blood pressure estimation equations.

[0089] Figure 7 is a flowchart showing a method of estimating biological information according to an exemplary embodiment.

[0090] Figure 7 The method may be performed by devices 100 and 200 configured to estimate biological information according to the embodiments described in detail above Figure 1 and Figure 2 and will be briefly described below.

[0091] First, in operation 710, when an object contacts a pulse wave sensor and changes the pressing force, the device configured to estimate biological information may measure a pulse wave signal from the object by using the pulse wave sensor. In this case, the pulse wave sensor may include a plurality of channels formed in an isotropic shape. In this case, when a request for estimating biological information is received, the device configured to estimate biological information may output information for guiding the contact position or contact force of the object on the display screen.

[0092] In operation 720, when a pulse wave sensor measures a pulse wave signal from an object, a device configured to estimate biological information can measure the force applied between the object and the pulse wave sensor by using a force sensor.

[0093] Then, in operation 730, based on the pulse wave signals acquired by multiple channels in operation 710, a device configured to estimate biological information can detect the center of gravity according to the pressure applied by the object. For example, a device configured to estimate biological information can extract the DC component from the pulse wave signals of the corresponding channels, and can generate an intensity map at each time point by using the extracted DC component values at each time point. In addition, a device configured to estimate biological information can detect the center of gravity at each time point by using the generated intensity map.

[0094] Subsequently, in operation 740, a device configured to estimate biological information can guide the contact of the object based on the detected center of gravity. For example, as described above with reference to Figures 5A to 5E As described, a device configured to estimate biological information can display a graphical object representing a circular space formed by multiple channels, and can display a graphical object superimposed thereon within the circular space to highlight the position of the force applied by the object.

[0095] Next, in operation 750, when the measurement of the pulse wave signal is completed according to the guidance information, a device configured to estimate biological information can determine whether to re-measure the pulse wave signal. For example, as described above, a device configured to estimate biological information can determine whether to re-measure the pulse wave signal based on the separation distance between the detected center of gravity and the center of the pulse wave sensor. When it is determined that re-measurement is required, a device configured to estimate biological information proceeds to operation 710 to re-measure the pulse wave signal.

[0096] Then, if the measurement of the pulse wave signal is completed such that re-measurement is not required, in operation 760, a device configured to estimate biological information can estimate biological information based on the measured pulse wave signal and force. For example, a device configured to estimate biological information can generate an oscillogram envelope based on the pulse wave signal and force, and can estimate blood pressure by using the generated oscillogram envelope.

[0097] Subsequently, in operation 770, a device configured to estimate biological information can output the biological information estimation result. The estimated biological information value can be visually displayed through a display, and other relevant information can be output through a sound output module, a tactile module, etc.

[0098] Figures 8 to 10 is a diagram showing an example embodiment of an electronic device including a device configured to estimate biological information.

[0099] AsFigure 8 and Figure 9 As shown in Figure 9 , the electronic device may include a smartwatch-type wearable device 800 and a mobile device 900 (such as a smartphone). However, the wearable device is not limited thereto, and may include a smart band, smart glasses, a smart ring, a smart patch, a smart necklace, a tablet PC, etc. The electronic device includes devices 100 and 200 configured to estimate biological information, and all components of devices 100 and 200 configured to estimate biological information may be integrally installed in a single device or may be distributed in two or more devices.

[0100] Referring to Figure 8 , the electronic device may be implemented as a wristwatch wearable device 800 and may include a main body and a wristband. A display is provided on the front surface of the main body, and may display a general application screen and / or an application screen configured to estimate biological information. The general application screen includes time information, received message information, etc., and the application screen configured to estimate biological information displays guidance information about an object's contact, a blood pressure estimation result, etc. A sensor device 810 including a pulse wave sensor and a force sensor may be provided on the rear surface of the main body to measure a pulse wave signal and a force / pressure configured to estimate biological information. In addition, the main body may include a processor, an output interface, a communication interface, etc. The processor is used to guide an object's contact or estimate blood pressure by using the received data. The output interface is used to output data generated by the processor on the display, and the communication interface is used to send and receive information through communication with other electronic devices.

[0101] Referring to Figure 9 , the electronic device may be implemented as a mobile device 900 (such as a smartphone).

[0102] The mobile device 900 may include a housing and a display panel. The housing may form the exterior of the mobile device 900. The housing has a first surface, and the display panel and the cover glass may be sequentially provided on the first surface, and the display panel may be exposed to the outside through the cover glass. A sensor module 910, a camera module, and / or an infrared sensor, etc. may be provided on the second surface of the housing. When a user sends a request configured to estimate biological information by executing an application installed in the mobile device 900, etc., the mobile device 900 may measure a pulse wave signal and a force from an object by using the sensor module 910. The main body may include a processor, an output interface, a communication interface, etc. The processor is configured to guide an object's contact or estimate blood pressure by using the received data. The output interface is configured to output data generated by the processor on the display, and the communication interface is configured to send and receive information through communication with other electronic devices.

[0103] Figure 10An example of estimating blood pressure through the interconnection between the wrist-worn device 800 and the mobile device 900 is shown. As shown herein, when the user estimates blood pressure by using the wearable device 800, relevant information can be displayed on the display screen of the mobile device 900. In response to a user's request or when an object comes into contact with the sensor module 810, the wearable device 800 can detect the direction of the display orientation by using various sensors, and when the detected direction is toward a direction where the user may not be able to view the display (e.g., the bottom direction), the wearable device 800 can automatically interconnect with the mobile device 900. As shown herein, the wearable device 800 can send the guidance information about the contact of the object generated by the processor to the mobile device 900, so that the information can be output on the screen of the display 920 of the mobile device.

[0104] The present disclosure can be implemented as a computer-readable storage medium storing a program, which, when executed by a processor, causes the processor to execute the method for estimating biological information described above.

[0105] The present disclosure can be implemented as computer-readable code written on a computer-readable recording medium. The computer-readable recording medium can be any type of recording device that stores data in a computer-readable manner.

[0106] Examples of the computer-readable recording medium include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, and carrier wave (e.g., data transmission through the Internet). The computer-readable recording medium can be distributed among multiple computer systems connected to a network, such that the computer-readable code is written therein and executed therefrom in a distributed manner. A programmer of ordinary skill in the art of the invention can easily derive the functional programs, codes, and code segments required to implement the present invention.

[0107] It should be understood that the example embodiments described herein should be considered only for descriptive purposes and not for purposes of limitation. The description of features or aspects within each example embodiment should generally be considered applicable to other similar features or aspects in other embodiments. Although the example embodiments have been described with reference to the accompanying drawings, those of ordinary skill in the art will understand that various changes in form and detail can be made therein without departing from the spirit and scope defined by the appended claims and their equivalents.

Claims

1. A device configured to estimate biological information, the device comprising: a pulse wave sensor including a plurality of channels arranged in an isotropic shape; a force sensor configured to measure the force applied by an object to the pulse wave sensor; and a processor configured to: detect a center of gravity based on the pressure applied by the object in the space formed by the plurality of channels, based on the pulse wave signals measured by each of the plurality of channels included in the pulse wave sensor; provide guidance information for the contact between the object and the pulse wave sensor to the user based on the detected center of gravity; determine whether to re-measure the pulse wave signal based on the separation distance between the center of gravity and the center of the space according to the pressure applied by the object at each time point; and estimate biological information based on the pulse wave signal and the force measured according to the guidance information.

2. The device according to claim 1, wherein each of the plurality of channels included in the pulse wave sensor includes at least one of a light source configured to emit light onto the object and a detector configured to detect light scattered or reflected from the object.

3. The device according to claim 1, wherein the processor is further configured to: extract a DC value from the pulse wave signal measured by each of the plurality of channels; generate an intensity map by mapping the DC values of each of the plurality of channels extracted to a circular boundary; and detect the center of gravity based on the generated intensity map.

4. The device according to claim 3, wherein based on the DC values of each of the plurality of channels, the processor is further configured to: obtain the DC values of a plurality of virtual channels to be set on the circular boundary; and generate an intensity map by mapping the DC values of each of the plurality of channels and the DC values of the plurality of virtual channels to the circular boundary.

5. The device according to claim 1, further comprising: an output interface configured to display a graphical object having a predetermined shape on a screen to guide the user to place the object on the space.

6. The device according to claim 5, wherein based on the detected center of gravity, the output interface is further configured to: highlight the position of the force applied by the object on the graphical object; and move the highlighted position based on the change of the center of gravity.

7. The device according to claim 5, wherein the output interface is configured to: display the trajectory of the center of gravity during the entire measurement time by superimposing the trajectory of the center of gravity on the graphical object.

8. The device according to claim 7, wherein the output interface is further configured to: display a graph showing the change of the separation distance between the center of the space and the center of gravity.

9. The device according to claim 8, wherein the processor is further configured to: calculate a score regarding the trajectory of the center of gravity based on the separation distance, wherein the output interface is further configured to: display the calculated score on the screen.

10. The device according to claim 6, wherein The output interface is also configured to display at least one of the following graphical objects: a graphical object configured to guide a change in a reference force to be applied to the pulse wave sensor by an object during measurement of a pulse wave signal, and a graphical object representing a change in an actual force measured by a force sensor.

11. The apparatus according to claim 1, wherein based on at least one of a number of times the separation distance deviates from a reference value being greater than or equal to a threshold number of times, a period of time during which the separation distance continuously deviates from the reference value being greater than or equal to a threshold period of time, and a fraction of a center-of-gravity locus being less than or equal to a threshold, the processor is further configured to determine to re-measure the pulse wave signal.

12. The apparatus according to claim 1, wherein the processor is further configured to: generate an oscillometric waveform envelope based on the pulse wave signal and the force; and estimate biometric information based on the generated oscillometric waveform envelope.

13. The apparatus according to any one of claims 1 to 12, wherein the biometric information includes one or more of blood pressure, vascular age, arterial stiffness, aortic pressure waveform, vascular compliance, pressure index, and fatigue level.

14. A method for estimating biometric information, the method comprising: measuring a pulse wave signal from an object by a pulse wave sensor, the pulse wave sensor including a plurality of channels arranged in an isotropic shape; measuring a force applied by the object to the pulse wave sensor by a force sensor; detecting a center of gravity based on the pulse wave signal measured by each of the plurality of channels included in the pulse wave sensor according to a pressure applied by the object in a space formed by the plurality of channels; providing guidance information to the user regarding contact between the object and the pulse wave sensor during measurement of the pulse wave signal based on the detected center of gravity; determining whether to re-measure the pulse wave signal based on a separation distance between the center of gravity and the center of the space according to the pressure applied by the object at each time point; and estimating biometric information based on the pulse wave signal and the force measured according to the guidance information.

15. The method according to claim 14, wherein the step of detecting the center of gravity further includes: extracting a DC value from the pulse wave signal measured by each of the plurality of channels; generating an intensity map by mapping the extracted DC value of each of the plurality of channels to a circular boundary; and detecting the center of gravity based on the generated intensity map.

16. The method according to claim 15, wherein the step of generating the intensity map includes: obtaining DC values of a plurality of virtual channels to be set on the circular boundary based on the DC value of the corresponding channel; and generating an intensity map by mapping the DC value of each of the plurality of channels and the DC values of the plurality of virtual channels to the circular boundary.

17. The method according to any one of claims 14 to 16, wherein the step of estimating biometric information further includes: generating an oscillometric waveform envelope based on the pulse wave signal and the force; and estimating biometric information based on the generated oscillometric waveform envelope.

18. An electronic device, comprising: a main body; a pulse wave sensor including a plurality of channels arranged in an isotropic shape on a surface of the main body that contacts the object; A force sensor, disposed at an upper end or a lower end of the pulse wave sensor and configured to measure a force applied by an object to the pulse wave sensor; and a processor, configured to: Based on the pulse wave signals measured by each of the plurality of channels included in the pulse wave sensor, detect a center of gravity based on the pressure applied by the object in the space formed by the plurality of channels, Provide guidance information for the contact between the object and the pulse wave sensor to the user based on the detected center of gravity, Determine whether to re-measure the pulse wave signal based on the separation distance between the center of gravity and the center of the space according to the pressure applied by the object at each time point, and Estimate blood pressure based on the pulse wave signal and the force measured according to the guidance information.

19. A device configured to estimate biological information, the device comprising: A pulse wave sensor, including a plurality of channels arranged in an isotropic shape; A force sensor, configured to measure a force applied by an object to the pulse wave sensor; and a processor, configured to: Based on the DC value extracted from the pulse wave signals measured by each of the plurality of channels included in the pulse wave sensor, detect a center of gravity based on the pressure applied by the object in the space formed by the plurality of channels, Provide guidance information for the contact between the object and the pulse wave sensor to the user based on the detected center of gravity being spaced apart from the center of the space, Determine whether to re-measure the pulse wave signal based on the separation distance between the center of gravity and the center of the space according to the pressure applied by the object at each time point, and Estimate biological information based on the pulse wave signal and the force measured according to the guidance information.

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