Device for estimating biological information

Abstract

A device for estimating bio-information is provided. The device for estimating bio-information may include: a pulse wave sensor configured to measure a pulse wave signal from a subject; a force sensor configured to measure a first force applied between the subject and the pulse wave sensor; and a processor configured to convert the first force into a second force based on structural information of the subject; and estimate the bio-information based on the pulse wave signal and the second force.

Description

[0001] This application is based upon and claims the benefit of Korean Patent Application No. 10-2020-0087568, filed on July 15, 2020, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. Technical Field

[0002] The following description relates to an apparatus and method for estimating biological information, and a technique for cuffless blood pressure estimation. Background Art

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

[0004] The pulse transit time (PTT) method extracts cardiovascular characteristics by analyzing the shape of photoplethysmography (PPG) signals or body surface pressure signals obtained from peripheral body sites (e.g., fingertips, radial arteries, etc.). Blood ejected from the left ventricle causes reflections in large branched regions (such as the renal and iliac arteries), and these reflections influence the shape of the pulse wave or body pressure wave measured at the peripheral site. Therefore, by analyzing this shape, it is possible to infer arterial stiffness, arterial age, aortic pressure waveform, and other parameters.

[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, the electrocardiogram (ECG) and PPG signals are measured at a peripheral part of the body, and 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 pulse transit time (PTT). The delay (PTT) between the R peak (left ventricular contraction interval) of the ECG and the peak of the PPG signal of the finger or radial artery is measured. Summary of the Invention

[0006] Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.

[0007] According to one aspect of an example embodiment, an apparatus for estimating bio-information may include: a pulse wave sensor configured to measure a pulse wave signal from an object; a force sensor configured to measure a first force applied between the object and the pulse wave sensor; and a processor configured to convert the first force into a second force based on structural information of the object; and estimate the bio-information based on the pulse wave signal and the second force.

[0008] The structural information of the object includes at least one of a blood vessel position, a blood vessel depth, and a bone depth.

[0009] The processor is further configured to obtain structural information of the object based on at least one of an optical image, an ultrasound image, a magnetic resonance imaging (MRI) image, and a photoacoustic image of the object and a user input.

[0010] The processor is further configured to convert the first force into a second force based on at least one of a ratio between the vessel depth and the bone depth and a difference between the vessel depth and the bone depth.

[0011] The processor is further configured to obtain sensor position information of the pulse wave sensor relative to the object based on the object in contact with the pulse wave sensor.

[0012] The processor is further configured to obtain sensor position information by analyzing a relative position between the object and the pulse wave sensor based on the image of the object in contact with the pulse wave sensor.

[0013] The device further includes a fingerprint sensor, wherein the processor is further configured to obtain sensor position information based on a fingerprint image obtained by the fingerprint sensor.

[0014] The processor is further configured to convert the first force into a third force based on the sensor position information, and convert the third force into a second force reflecting the structure of the object.

[0015] The processor is further configured to convert the first force into a third force based on a distance between a predetermined reference point of the object and the sensor location.

[0016] By using a predefined function, the processor is further configured to: obtain a first correction value based on a distance between a reference point and a sensor position; obtain a second correction value based on a distance between the reference point and a reference position; and convert the first force into a third force based on the first correction value and the second correction value.

[0017] The pulse wave sensor has multiple channels for measuring pulse wave signals at multiple points of the object, wherein the processor is further configured to: select at least one channel from the multiple channels based on a blood vessel position and a sensor position of the object; and convert the first force into a third force based on a distance between a predetermined reference point of the object and the selected channel.

[0018] The processor is further configured to select a channel located closest to a blood vessel of the subject based on the sensor position information.

[0019] The apparatus further includes an area sensor configured to measure a contact area between the object and the pulse wave sensor based on the object coming into contact with the pulse wave sensor and changing a force applied to the pulse wave sensor.

[0020] The processor is further configured to: obtain a contact pressure based on the second force and the measured contact area; and estimate bio-information based on the contact pressure and the pulse wave signal.

[0021] The biological information includes one or more of the following: blood pressure, vascular age, arterial stiffness, aortic pressure waveform, vascular compliance, stress index, fatigue level, skin age, and skin elasticity.

[0022] According to one aspect of an example embodiment, a method of estimating bio-information may include: measuring a pulse wave signal from an object; measuring a first force applied between the object and a pulse wave sensor; converting the first force into a second force based on structural information of the object; and estimating the bio-information based on the pulse wave signal and the second force.

[0023] The structural information of the object includes at least one of a blood vessel position, a blood vessel depth, and a bone depth.

[0024] In response to receiving a request for estimating biometric information from a user, the method includes determining whether structural information of an object of the user exists; and in response to determining that the structural information of the object does not exist, obtaining the structural information of the object.

[0025] The step of converting the first force includes converting the first force based on at least one of a ratio between the blood vessel depth and the bone depth and a difference between the blood vessel depth and the bone depth.

[0026] The method further includes obtaining sensor position information of the pulse wave sensor relative to the object when the object is in contact with the pulse wave sensor.

[0027] The step of converting the first force into the second force includes: converting the first force into a third force based on the sensor position information; and converting the third force into the second force based on the structural information of the object.

[0028] Converting the first force into a third force includes converting the first force into the third force based on a distance between a predetermined reference point of the object and the sensor location.

[0029] The step of converting the first force into the third force includes: obtaining a first correction value based on the distance between the reference point and the sensor position by using a predefined function; obtaining a second correction value based on the distance between the reference point and the reference position; and converting the first force into the third force based on the first correction value and the second correction value.

[0030] The step of converting the first force into the third force includes: in response to the pulse wave sensor having a plurality of channels for measuring the pulse wave signal at a plurality of points of the subject, selecting at least one channel among the plurality of channels based on blood vessel position information and sensor position information of the subject; and converting the first force into the third force based on a distance between a predetermined reference point of the subject and the at least one channel among the plurality of channels.

[0031] The method further includes measuring a contact area based on the object contacting the pulse wave sensor and changing a force applied to the pulse wave sensor.

[0032] The step of estimating the biological information includes: obtaining a contact pressure based on the second force and the contact area; and estimating the biological information based on the contact pressure and the pulse wave signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

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

[0035] Figure 2 It shows Figure 1A and Figure 1B A diagram illustrating an example of a configuration of a processor;

[0036] Figure 3A and Figure 3B It is a diagram that explains the relationship between the anatomy of an object and forces;

[0037] Figure 4A and Figure 4B is a diagram explaining an example of estimating blood pressure using the oscillometric method;

[0038] Figure 5 is a block diagram illustrating an apparatus for estimating bio-information according to another embodiment of the present disclosure;

[0039] Figures 6A to 6C is a diagram explaining an example of obtaining structural information of an object;

[0040] Figure 7 is a block diagram illustrating an apparatus for estimating bio-information according to yet another embodiment of the present disclosure;

[0041] Figure 8 It shows Figure 7 A diagram illustrating an example of a configuration of a processor;

[0042] Figures 9A to 9Cis a diagram explaining an example of estimating blood pressure by using sensor position information of a subject;

[0043] Figure 10 is a flowchart illustrating a method of estimating biological information according to an embodiment of the present disclosure;

[0044] Figure 11 is a flowchart illustrating a method of estimating biological information according to another embodiment of the present disclosure;

[0045] Figure 12 is a diagram illustrating an example of a wearable device; and

[0046] Figure 13 is a diagram illustrating an example of a smart device. DETAILED DESCRIPTION

[0047] Details of example embodiments are included in the following detailed description and accompanying drawings. The advantages and features of the present disclosure and methods for implementing the present disclosure 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 indicated, the same reference numerals will be understood to represent the same elements, features, and structures.

[0048] It will be understood that although the terms "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. In addition, unless otherwise clearly indicated, the singular form of the term is also intended to include the plural form of the term. 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 further include one or more other elements. In the following description, terms such as "unit" or "module" indicate a unit for processing at least one function or operation and that can be implemented using hardware, software, or a combination thereof.

[0049] Hereinafter, embodiments of an apparatus and method for estimating bio-information will be described in detail with reference to the accompanying drawings.

[0050] Figure 1A and Figure 1B is a block diagram illustrating an apparatus for estimating bio-information according to an embodiment of the present disclosure.

[0051] The apparatuses 100a and 100b for estimating biometric information according to an embodiment of the present disclosure may be installed in a terminal such as a smartphone, a tablet personal computer (PC), a desktop computer, a laptop computer, a wearable device, etc. In this case, examples of the wearable device may include a wristwatch-type wearable device, a bracelet-type wearable device, a wristband-type wearable device, a ring-type wearable device, a glasses-type wearable device, a headband-type wearable device, etc., but the wearable device is not limited thereto.

[0052] Reference Figure 1A , the apparatus 100a for estimating bio-information according to the embodiment includes a pulse wave sensor 110, a force sensor 120, and a processor 130. In addition, referring to Figure 1B , the apparatus 100 b for estimating bio-information according to another embodiment further includes an area sensor 140 in addition to the pulse wave sensor 110 , the force sensor 120 , and the processor 130 .

[0053] The pulse wave sensor 110 measures a photoplethysmography (PPG) signal (hereinafter referred to as a "pulse wave signal") from a subject. In this case, 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 using PPG. For example, the subject may be a finger where blood vessels are densely located, but the subject is not limited thereto and may be an area on the wrist adjacent to the radial artery, or a peripheral part of the body where veins or capillaries are located (such as the upper part of the wrist, toes, etc.).

[0054] The pulse wave sensor 110 may include one or more 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. The light sources may emit light of different wavelengths. For example, the light sources may emit light of infrared wavelengths, green wavelengths, blue wavelengths, red wavelengths, white wavelengths, and the like. The light sources may include, but are not limited to, light emitting diodes (LEDs), laser diodes (LDs), phosphors, and the like. Furthermore, the light receivers may include photodiodes, photodiode arrays, complementary metal oxide semiconductor (CMOS) image sensors, charge coupled device (CCD) image sensors, and the like.

[0055] The pulse wave sensor 110 may have a single channel including a light source and a light receiver to measure a pulse wave signal at a specific point on the subject. Alternatively, the pulse wave sensor 110 may have multiple channels to measure multiple pulse wave signals at multiple points on the subject. Each channel of the pulse wave sensor 110 may be formed in a predefined shape (such as a circle, an ellipse, a sector, etc.) so that the pulse wave signal can be measured at multiple points on the subject. Each channel of the pulse wave sensor 110 may include one or more light sources and one or more light receivers. In addition, each channel may include two or more light sources to emit light of multiple wavelengths. Alternatively, the pulse wave sensor 110 may be configured to measure multiple pulse wave signals in a predetermined area of ​​the subject. For example, the pulse wave sensor 110 may include one or more light sources and a light receiver formed as a CMOS image sensor and disposed at a predetermined distance from the one or more light sources.

[0056] When a user places an object on the pulse wave sensor 110 and increases or decreases pressing force to cause a change in pulse wave amplitude, the force sensor 120 may measure the contact force applied between the pulse wave sensor 110 and the object. The force sensor 120 may include a strain gauge or the like.

[0057] When the object contacts the pulse wave sensor 110 and changes pressure, the area sensor 140 may obtain the contact area. The area sensor 140 may be provided at an upper end or a lower end of the pulse wave sensor 110.

[0058] However, the apparatuses 100 a and 100 b for estimating bio-information are not limited thereto and may include a pressure sensor for measuring pressure between the subject and the pulse wave sensor 110 , etc., instead of including the force sensor 120 and the area sensor 140 .

[0059] The processor 130 may estimate bio-information based on the pulse wave signal obtained by the pulse wave sensor 110, the contact force obtained by the force sensor 120, and / or the contact area obtained by the area sensor 140. In this case, the bio-information may include, but is not limited to, blood pressure, vascular age, arterial stiffness, aortic pressure waveform, vascular compliance, skin elasticity, skin age, stress index, fatigue level, and the like.

[0060] For example, to improve the accuracy of estimating biometric information, the processor 130 may estimate the biometric information by considering structural information (e.g., anatomical structure information) of the object. For example, the processor 130 may convert the contact force measured by the force sensor 120 into a force reflecting the structural information, and may estimate the biometric information based on the pulse wave signal, the converted force, and / or the contact area.

[0061] Figure 2 It shows Figure 1A and Figure 1B FIG. 1 is a diagram illustrating an example of a configuration of the processor 130 . Figure 3A and Figure 3B A diagram that explains the relationship between an object's anatomy and forces. Figure 4A and Figure 4B is a diagram explaining an example of estimating blood pressure using the oscillometric method.

[0062] Reference Figure 2 , the processor 200 includes a force converter 210 and an estimator 220 .

[0063] Typically, when pressure is applied at a location far from a finger artery, the force actually applied to the artery may be lost due to the soft tissue of the finger. This can lead to a discrepancy between the force measured by the force sensor and the actual force applied to the artery, causing errors in the estimated finger contact pressure and reducing the accuracy of the estimated blood pressure.

[0064] Force transducer 210 may convert the measured contact force or contact pressure into a contact force or contact pressure reflecting the subject's anatomical structure information. In this case, the subject's anatomical structure information may include, but is not limited to, at least one of the following: blood vessel location, blood vessel depth, and bone depth. Force transducer 210 may convert the contact force into contact pressure using a predefined conversion model, the contact area obtained by area sensor 140, the area of ​​pulse wave sensor 110, and the like.

[0065] For ease of explanation, the following description will give an example of converting the contact force, but the example may also include converting the contact force into the contact pressure and then converting the contact pressure.

[0066] Figure 3A 3 is a diagram explaining an example of force conversion based on the anatomical structure of the object 30. For example, assuming that bones 32a and 32b are located at the same depth, (1) shows a case where blood vessel 31a is located relatively far from bone 32a in the object 30 (i.e., blood vessel 31a is located at a shallow depth from the surface of the object 30); compared to the case of (1), (2) shows a case where blood vessel 31b is located close to bone 32b (i.e., blood vessel 31b is located at a relatively deep depth from the surface of the object 30). In the case of (2), blood vessel 31b is located relatively close to bone 32b compared to the case of (1), so that the actual force applied to blood vessel 31b is smaller than the external force applied to the object 30. Therefore, assuming that in the case of (1), when force F is applied, mean arterial pressure (MAP) is applied to blood vessel 31a, in the case of (2), a force αF relatively larger than force F needs to be applied to apply an equal MAP to blood vessel 31b.

[0067] The force converter 210 may convert the force measured by the force sensor 120 into a force reflecting structural information of the object by using a conversion equation, such as the following Equation 1 defined based on the above relationship.

[0068] [Equation 1]

[0069]

[0070] Here, F represents the contact force measured by the force sensor 120 , F′ represents the force converted by reflecting the structural information of the object, d1 represents the depth of the blood vessel from the surface of the object, and d2 represents the depth of the bone from the surface of the object.

[0071] The conversion equation (such as Equation 1 above) shows an example of conversion by applying the ratio between the depth of the blood vessel and the depth of the bone, but is not limited thereto and may be defined as a conversion equation for various combinations such as the difference between the depth of the bone and the depth of the blood vessel (e.g., d2-d1), etc. In this case, a weight may be applied to each of the depth of the blood vessel and / or the depth of the bone according to individual characteristics (such as user characteristics or object characteristics), and the weighted depths of the blood vessel and / or the weighted depths of the bone may be combined.

[0072] Once the force transducer 210 converts the measured force into a force reflecting the anatomical characteristics of the object, the estimator 220 may estimate bio-information based on an oscillometric method using the converted force and a pulse wave signal.

[0073] exist Figure 3B In (1), the blood vessels are located as shown in Figure 3A In the case of a relatively shallow depth as shown in (1), the change from the waveform 33a of the force F before the conversion to the waveform 33b of the force F' after the conversion is shown; (2) shows that when the blood vessel is located at a relatively shallow depth as shown in (1), the change from the waveform 33a of the force F before the conversion to the waveform 33b of the force F' after the conversion is shown; Figure 3A FIG2 shows a change from waveform graph 34a of force F before conversion to waveform graph 34b of force F' after conversion in the case of a relatively deep depth shown in FIG3 . In the case of (2) where the blood vessel is located at a relatively deep depth, the shift width of the waveform graph is relatively larger when compared to the case of (1) where the blood vessel is located at a shallow depth.

[0074] Figure 4A and Figure 4B is a diagram explaining an example of estimating blood pressure using the oscillometric method.

[0075] Reference Figure 4A and Figure 4BThe estimator 220 may extract, for example, a peak-to-peak point of the pulse wave signal waveform by subtracting a negative (-) amplitude value in3 from a positive (+) amplitude value in2 of the waveform envelope in1 at each measurement time of the pulse wave signal, and may obtain an oscillogram (OW) by plotting the peak-to-peak amplitude at each measurement time versus the contact pressure value at the corresponding time (i.e., with the peak-to-peak amplitude at each measurement time as the ordinate and the contact pressure value at the corresponding time as the abscissa) and by performing, for example, polynomial curve fitting.

[0076] Furthermore, the estimator 220 may extract characteristic points for estimating blood pressure from the generated waveform graph OW and estimate blood pressure using the extracted characteristic points. For example, the estimator 220 may extract, from the waveform graph OW, the contact pressure value MP at the maximum point of the pulse wave, the contact pressure values ​​DP and SP at points corresponding to amplitude values ​​having a preset ratio (e.g., 0.5 to 0.7) to the maximum amplitude value MA, and the like as characteristic points. For example, the estimator 220 may determine the contact pressure value MP itself as the MAP, the contact pressure value DP as the diastolic blood pressure (DBP), and the contact pressure value SP as the systolic blood pressure (SBP). Alternatively, the estimator 220 may independently estimate the MAP, DBP, and SBP by applying each of the extracted contact pressure values ​​MP, DP, and SP to a predefined blood pressure estimation model. In this case, the blood pressure estimation model may be represented in the form of various linear or nonlinear combination functions (such as addition, subtraction, division, multiplication, logarithmic values, regression equations, etc.), without particular limitation.

[0077] Figure 5 is a block diagram illustrating an apparatus for estimating bio-information according to another embodiment of the present disclosure. Figures 6A to 6C is a diagram explaining an example of obtaining structural information of an object.

[0078] Reference Figure 5 The device 500 for estimating biological information includes a pulse wave sensor 510, a force sensor 520, a processor 530, a structural information input device 550, an output interface 560, and a storage device 570. Figures 1A to 2 The pulse wave sensor 510, the force sensor 520, and the processor 530 are described in detail. Figure 5 In an embodiment of the present invention, the apparatus 500 for estimating biometric information may further include: Figure 1B area sensor.

[0079] Structural information input device 550 can obtain structural information of the subject at the time of user registration. Furthermore, in response to a user's request to estimate biometric information, structural information input device 550 can check whether the user's subject's structural information exists in storage device 570 or whether it is time to calibrate the information. If the subject's structural information does not exist or it is time to calibrate the information, structural information input device 550 can obtain the subject's structural information from the user. At least some functions of structural information input device 550 can be integrated with processor 530.

[0080] The structural information input device 550 may directly receive input of the structural information of the object from the user, and / or may obtain the structural information of the object by using at least one of an optical image of the object, an ultrasound image, a magnetic resonance imaging (MRI) image, a photoacoustic image, etc. The following examples of obtaining the structural information of the object are merely exemplary, and the present disclosure is not limited thereto.

[0081] For example, Figure 6A The figure shows a smart device 60 to which the apparatus 500 for estimating biological information according to the embodiment is applied, wherein the structure information input device 550 can output an interface 62 on a display 61 through an output interface 560, so that a user can directly input the structure information of an object through the interface 62. Figure 6A As shown in , the interface 62 can display graphic objects for the user to input the blood vessel depth and the bone depth. In addition, a graphic object in the form of a button can be displayed for the user to directly specify the blood vessel position.

[0082] When the user Figure 6A When clicking the button to directly specify the blood vessel position, such as Figure 6B As shown in FIG6 , the structural information input device 550 may display a finger image 65 on the display 61. The user may directly designate a blood vessel position 66 on the finger image 65 using an input device (e.g., a finger, a touch pen, etc.); once the user designates the blood vessel position 66, the structural information input device 550 may display a mark indicating the blood vessel position of the object on the finger image 65.

[0083] In another example, Figure 6A As shown in FIG, the structure information input device 550 may display a graphic object 63 in the form of a button on the display 61 to receive an object image captured by an external image capturing device. In this case, the object image may be an optical image, an ultrasound image, a magnetic resonance imaging (MRI) image, a photoacoustic image, etc. captured by the external image capturing device, but the image is not limited thereto.

[0084] Once the user clicks the graphic object 63, the structure information input device 550 checks whether there is an image of the structure of the object pre-stored in the storage device 570. If the image does not exist, the structure information input device 550 may receive an image from an external image capture device via a communication module installed in the smartphone 60, and may store the received image in the storage device 570. In this case, the communication module may communicate with the external device using various wireless or wired communication technologies (such as Bluetooth communication, Bluetooth Low Energy (BLE) communication, Near Field Communication (NFC), Wireless Local Area Network (WLAN) communication, Zigbee communication, Infrared Data Association (IrDA) communication, Wireless Fidelity (Wi-Fi) Direct (WFD) communication, Ultra-Wideband (UWB) communication, Ant+ communication, Wi-Fi communication, Radio Frequency Identification (RFID) communication, mobile communication, etc.). However, this is merely exemplary and not intended to be limiting.

[0085] The structure information input device 550 can analyze the image of the object structure taken, store the analysis result in the storage device 570, and can be used as Figure 6C The analysis results are visually displayed on the display 610 as shown in FIG. Figure 6C As shown, the structural information input device 550 may display a finger image 67 and may display marks 68 and 69 indicating the positions of blood vessels and bones on the finger image 67. In addition, the structural information input device 550 may visually display the depth d1 of the blood vessels and the depth d2 of the bones.

[0086] In another example, Figure 6A As shown in , the structure information input device 550 can display a graphical object 64 in the form of a button on the display 61, allowing the user to directly capture an image of their finger. If the smartphone 60 has, for example, an ultrasonic sensor, the structure information input device 550 can control the ultrasonic sensor to capture an ultrasonic image of the user's finger. Alternatively, if the smartphone 60 does not have a device for capturing a finger image, the structure information input device 550 can be connected to an external image capture device via a communication module. Once the external image capture device captures the finger image, the structure information input device 550 can receive the captured image from the external device. The structure information input device 550 can obtain finger structure information by analyzing the received image and can store the obtained finger structure information in the storage device 570.

[0087] The output interface 560 can output the pulse wave signal measured by the pulse wave sensor 510, the contact force measured by the force sensor 520, the contact area obtained by the area sensor, the contact pressure, and / or the processing results of the processor 530. The output interface 560 can provide information to the user through various visual / non-visual methods using a display, a speaker, a tactile device, etc. For example, the output interface 560 can output the measured pulse wave signal in the form of a graph. In addition, the output interface 560 can visually display the user's estimated biometric information value using various visual methods (such as by changing the color, line thickness, font, etc. based on whether the estimated blood pressure value falls within or outside the normal range). Optionally, when comparing the estimated biometric information value with previous estimation history, if the estimated biometric information value is determined to be abnormal, the output interface 560 can provide a warning message, etc., as well as guidance information regarding the user's actions (such as information about foods that the user should be cautious of, relevant hospital information, etc.).

[0088] Storage device 570 can store various types of information used to estimate biometric information. For example, storage device 570 can store pulse wave signals measured by pulse wave sensor 510, contact forces measured by force sensor 520, contact areas obtained by area sensors, object processing results, biometric information estimation models, and captured images of object structures. Furthermore, storage device 570 can store characteristic information for each user (such as the user's age, gender, health status, object structure information, etc.). However, this information is not limited to this.

[0089] The storage device 570 may include at least one storage medium selected from the group consisting of a flash memory, a hard disk memory, a multimedia card micro memory, a card-type memory (for example, 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, and an optical disk, but is not limited thereto.

[0090] Figure 7 is a block diagram illustrating an apparatus for estimating biological information according to still another embodiment of the present disclosure. Figure 8 It shows Figure 7 A diagram of an example of a configuration of a processor. Figures 9A to 9C is a diagram explaining an example of estimating blood pressure by using sensor position information of a subject.

[0091] Reference Figure 7The apparatus 700 for estimating biological information according to the embodiment includes a pulse wave sensor 710, a force sensor 720, a processor 730, a structural information input device 750, an output interface 760, a storage device 770, and a sensor position sensor 780. Figures 1A to 6C The pulse wave sensor 710, the force sensor 720, the processor 730, the structural information input device 750, the output interface 760 and the storage device 770 are described in detail. In this embodiment, the apparatus 700 for estimating biological information may further include Figure 1B area sensor.

[0092] When the object contacts the pulse wave sensor 710 , the sensor position sensor 780 may obtain sensor position information of the pulse wave sensor 710 on the object when the object contacts the pulse wave sensor 710 . At least some functions of the sensor position sensor 780 may be integrated with the processor 730 .

[0093] For example, the sensor position sensor 780 may obtain sensor position information based on an image of an object captured by an external image capturing device. The external image capturing device may be a camera module installed at a fixed location or a camera module installed in a mobile device (such as a smartphone). For example, once the external image capturing device captures an image of a finger in contact with the pulse wave sensor 710, the sensor position sensor 780 may receive the image of the finger through a communication module installed in the apparatus 700 for estimating biometric information.

[0094] By analyzing the relative position between the pulse wave sensor 710 and the finger based on the image of the finger, the sensor position sensor 780 can obtain the position of the finger in contact with the pulse wave sensor 710 as the sensor position. In addition, if an external image capturing device having a function of obtaining a sensor position obtains sensor position information by capturing an image of the finger, the sensor position sensor 780 can receive the sensor position information from the external image capturing device through the communication module.

[0095] In another example, the sensor position sensor 780 may include a fingerprint sensor for obtaining a fingerprint image of the object in contact with the pulse wave sensor 710. The fingerprint sensor may be provided at the upper or lower end of the pulse wave sensor 710. The sensor position sensor 780 may estimate the sensor position by analyzing changes in the fingerprint pattern based on the fingerprint image of the object. For example, when a finger applies pressure to the pulse wave sensor 710, the contact position between the finger and the pulse wave sensor 710 is pressed more than other positions of the finger, resulting in a greater distance between ridges or valleys of the fingerprint at the contact position between the finger and the pulse wave sensor 710 than at other positions. If the distance between ridges or valleys of the fingerprint at a predetermined position of the finger is greater than or equal to a predetermined threshold value when compared to other positions, the sensor position sensor 780 may determine that position as the sensor position.

[0096] Once the sensor position sensor 780 obtains the sensor position, the processor 730 may estimate bio-information based on the sensor position and the blood vessel position.

[0097] Reference Figure 8 , the processor 800 according to the embodiment includes a channel selector 810 , a first force converter 820 , a second force converter 830 , and an estimator 840 .

[0098] The channel selector 810 may select a channel of the pulse wave sensor 710 for estimating blood pressure based on the blood vessel position and sensor position information included in the structural information of the object.

[0099] For example, if the pulse wave sensor 710 has a single channel including a light source and a light receiver, the channel selector 810 may guide the user on a contact position of the object based on a blood vessel position and sensor position information included in the structural information of the object.

[0100] Figure 9A 8 is a diagram explaining an example of a pulse wave sensor 710 having a single channel 92. The channel selector 810 can display an image of the finger 90 through the output interface 760 and can display the blood vessel position 91 of the finger superimposed on the position of the channel 92 of the pulse wave sensor 710 so that the user can place the blood vessel position of the finger on the channel 92.

[0101] In another example, if the pulse wave sensor 710 has a plurality of channels for measuring a plurality of pulse wave signals at a plurality of points of the subject, the channel selector 810 may determine an appropriate channel based on the blood vessel position and the sensor position of the subject.

[0102] Figure 9Bis a diagram explaining an example of a pulse wave sensor 710 having multiple channels 93 for measuring multiple pulse wave signals at multiple points on a finger 90. Each of channels Ch1, Ch2, and Ch3 may include a light source and a light receiver. For example, upon receiving a request for blood pressure estimation, the channel selector 810 may select at least one of the multiple channels 93 using the blood vessel location 91 of the finger 90 and sensor location information, and may drive the selected channel. For example, the channel selector 810 may drive channel Ch3, which is located closest to the blood vessel location 91 among channels Ch1, Ch2, and Ch3 of the pulse wave sensor 710. Alternatively, the channel selector 810 may obtain a pulse wave signal from each of channels Ch1, Ch2, and Ch3 by driving the multiple channels 93 of the pulse wave sensor 710 simultaneously or sequentially, and may select channel Ch3, which is located closest to the blood vessel location 91, as the channel for blood pressure estimation.

[0103] Figure 9C is a diagram explaining an example of a pulse wave sensor 710 having multiple channels 95 for simultaneously measuring multiple pulse wave signals in a predetermined area of ​​a finger 90. For example, multiple channels 95 may include a light source and multiple detector arrays or CMOS image sensors spaced a predetermined distance from the light source. Channel selector 810 may determine channel ch, located closest to blood vessel location 91, as the channel used for estimating blood pressure among multiple channels 95.

[0104] The first force converter 820 may convert the force measured by the force sensor 720 into a first force at a predefined reference position based on the position of the channel of the pulse wave sensor 710 selected by the channel selector 810 and the reference point of the subject. In this case, the reference point of the subject may be, for example, Figures 9A to 9C The top of the nail shown in BP.

[0105] For example, the first force converter 820 may convert the measured force into a force reflecting the sensor position (eg, the position of the channel of the pulse wave sensor 710 ) by applying a relational equation such as Equations 2 and 3 below as examples.

[0106] [Equation 2]

[0107]

[0108] Here, f represents an estimated oscillometric blood pressure value (e.g., estimated MAP) obtained based on the pulse wave signal at the sensor location, BP represents a reference blood pressure (e.g., actual MAP), a1 and a2 represent coefficients defined by preprocessing, and d represents Figures 9A to 9C, fr(d) represents a distance between a reference point of the finger 90 shown in FIG. 8 and the sensor position, and fr(d) represents a value for correcting the force measured by the force sensor 720 by reflecting the sensor position of the object.

[0109] [Equation 3]

[0110]

[0111] f′=f×fr(d des ) / fr(d mes )

[0112] The above equation 3 represents a relationship equation assuming that the blood pressure BP at the user's measurement position (ie, sensor position) is equal to the blood pressure BP at the desired reference position. Here, d mes represents the distance between the reference point of the user's finger and the sensor location, f represents the contact force measured at the sensor location, and fr(d mes ) represents a first correction value for correcting the force at the sensor position based on the distance between the predetermined reference point of the object and the sensor position using Equation 2 above, d des represents the distance between the reference point of the user's finger and the reference position, fr(d des ) denotes a second correction value for correcting the force at the reference position based on the distance between the predetermined reference point of the object and the reference position using Equation 2 above, and f' denotes a first force to be obtained at the reference position.

[0113] Once the first force converter 820 obtains the first force reflecting the sensor position, the second force converter 830 can convert the first force into a second force reflecting the anatomical structure of the object. As described above, the second force converter 830 can convert the first force into a second force reflecting the structure of the object by using Equation 1 above.

[0114] The estimator 840 can estimate the blood pressure by using the force converted by the second force converter 830. Figure 4A and Figure 4B As described above, the estimator 840 may estimate the blood pressure using an oscillometric method.

[0115] Figure 10 is a flowchart illustrating a method of estimating biological information according to an embodiment of the present disclosure. Figure 10 The method is an example of a method of estimating bio-information performed by the aforementioned apparatuses for estimating bio-information 100a, 100b, and 500. Various embodiments of estimating bio-information are described above in detail, and thus, will be briefly described below.

[0116] When a request for estimating bio-information is received from a user in operation 1010 , the apparatus for estimating bio-information may check whether structural information of an object exists in operation 1020 .

[0117] Then, at the time of the examination, if the structural information of the object does not exist in the storage device (operation 1020—No), the apparatus for estimating biological information may obtain the structural information of the object in operation 1030. For example, as described above, the apparatus for estimating biological information may directly receive an input of the structural information of the object from a user, or may obtain the structural information of the object by analyzing an ultrasound image, an MRI image, or the like acquired by an external device.

[0118] Subsequently, at the time of inspection, if there is structural information of the object (operation 1020-yes), in operation 1040, the apparatus for estimating bio-information may obtain a pulse wave signal of the object through the pulse wave sensor, and in operation 1050, the apparatus for estimating bio-information may obtain the force / pressure applied by the object to the pulse wave sensor.

[0119] Next, in operation 1060, the apparatus for estimating bio-information may convert the force / pressure obtained in operation 1050 based on the structural information of the object. For example, the apparatus for estimating bio-information may combine structural information of the object (such as the ratio or difference between the depth of a blood vessel and the depth of a bone), and may convert the force by applying the combined result to the measured force.

[0120] Then, in operation 1070 , the apparatus for estimating bio-information may estimate bio-information based on the pulse wave signal obtained in operation 1040 and the force converted in operation 1060 .

[0121] Subsequently, the apparatus for estimating bio-information may output a bio-information estimation result in operation 1080. For example, the apparatus for estimating bio-information may provide information (such as estimated bio-information values, warnings, measurements, bio-information estimation history, etc.) to the user in various ways by appropriately using a display, a speaker, a tactile device, etc.

[0122] Figure 11 is a flowchart illustrating a method of estimating biological information according to another embodiment of the present disclosure. Figure 11 The method is an example of a method of estimating bio-information performed by the aforementioned apparatus 700 for estimating bio-information, which is described in detail above and thus will be briefly described below.

[0123] When a request for estimating biometric information is received from the user in operation 1111, the apparatus for estimating biometric information may obtain sensor position information when the subject is in contact with the pulse wave sensor in operation 1112. In this case, the sensor position information may be obtained based on an image of the subject captured by an external image capturing device or a fingerprint image captured by a fingerprint sensor.

[0124] Then, in operation 1113, the apparatus for estimating bio-information may obtain a pulse wave signal of the subject through the pulse wave sensor, and in operation 1114, the apparatus for estimating bio-information may obtain force / pressure applied by the subject to the pulse wave sensor. In this case, if the pulse wave sensor has a single channel including one light source and one light receiver, the apparatus for estimating bio-information may guide the user to place the position of the subject's blood vessel at the position of the channel of the pulse wave sensor.

[0125] Subsequently, in operation 1115, the apparatus for estimating bio-information may select a channel of the pulse wave sensor based on the sensor position information and the position of the subject's blood vessels. If the pulse wave sensor has multiple channels for obtaining pulse wave signals at multiple points on the subject, the apparatus for estimating bio-information may select a channel located closest to the position of the subject's blood vessels.

[0126] Next, the apparatus for estimating bio-information may convert the force based on the position of the selected channel and the reference position of the object in operation 1116. For example, the apparatus for estimating bio-information may convert the force into a force reflecting the sensor position based on the distance between the reference position of the object and the position of the selected channel by using a predefined conversion equation.

[0127] Then, in operation 1117, the apparatus for estimating bio-information may convert the force reflecting the sensor position into a force reflecting the structural characteristics of the object by using the structural information of the object. As described above, the apparatus for estimating bio-information may convert the force by applying, for example, a ratio or difference between the depth of a blood vessel or the depth of a bone.

[0128] Subsequently, in operation 1118 , the apparatus for estimating bio-information may estimate bio-information based on the pulse wave signal obtained in operation 1113 and the force converted in operation 1117 .

[0129] Next, in operation 1119 , the apparatus for estimating bio-information may output a bio-information estimation result.

[0130] Figure 12 is a diagram illustrating an example of a wearable device. The various embodiments of the aforementioned apparatuses for estimating bio-information 100a, 100b, 500, and 700 may be installed in a wearable device.

[0131] Reference Figure 12 , the wearable device 1200 includes a main body 1210 and a band 1230 .

[0132] The straps 1230 connected to both ends of the body 1210 can be flexible so as to bend around the user's wrist. The straps 1230 can be composed of a first strap and a second strap that are separate from each other. One end of each of the first strap and the second strap is connected to the body 1210, and the other ends of each 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. Moreover, the strap 630 is not limited to this and can be formed as a single, non-detachable strap.

[0133] In this case, air may be injected into the band 1230 , or the band 1230 may be provided with an air bag to have elasticity according to a change in pressure applied to the wrist and may transmit the change in pressure of the wrist to the body 1210 .

[0134] A battery may be embedded in the body 1210 or the band 1230 to supply power to the wearable device 1200 .

[0135] The main body 1210 may include a sensor unit 1220 mounted on one side of the main body 1210. The sensor unit 1220 may include a pulse wave sensor for measuring a pulse wave signal. The pulse wave sensor may include a light source for emitting light onto the skin of a wrist or finger, and a light receiver (such as a contact image sensor (CIS) optical sensor, a photodiode, etc.) for detecting 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 the wrist, finger, etc., and each channel may include a light source and a light receiver, or may include multiple light sources for emitting light of different wavelengths. In addition, the sensor unit 1220 may also include a force / pressure sensor for measuring the force / pressure between the wrist or finger and the sensor unit 1220. In addition, the sensor unit 1220 may also include a fingerprint sensor, an ultrasonic sensor, etc. that can be stacked on top of each other.

[0136] The processor may be installed in the body 1210. The processor may be electrically connected to a module installed in the wearable device 1200. The processor may generate a waveform graph based on the pulse wave signal and contact force / pressure measured by the sensor unit 1220, and may estimate blood pressure based on the obtained waveform graph. In this case, the processor may convert force / pressure using information about the finger's anatomical structure, sensor position information, etc., and estimate blood pressure using the converted force, thereby improving the accuracy of the estimated blood pressure.

[0137] In addition, the main body 1210 may include a memory that stores reference information for estimating blood pressure and performing various functions of the wearable device 1200 and information processed by various modules of the main body 1210.

[0138] In addition, the main body 1210 may include a manipulator 1240, which is provided on one side surface of the main body 1210 and receives a user's control command and sends the received control command to the processor. The manipulator 1240 may have a power button for inputting a command to turn on / off the wearable device 1200.

[0139] In addition, a display for outputting information to the user may be mounted on the front surface of the main body 1210. 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.

[0140] In addition, the main body 1210 may include a communicator for communicating with an external device. The communicator may transmit the blood pressure estimation result to the external device (eg, a user's smartphone).

[0141] Figure 13 is a diagram illustrating an example of a smart device. In this case, the smart device may include a smart phone, a tablet PC, etc. The smart device may include the functions of the aforementioned apparatuses 100a, 100b, 500, and 700 for estimating biometric information.

[0142] Reference Figure 13 , smart device 1300 includes a main body 1310 and a pulse wave sensor 1330 mounted on one surface of main body 1310. For example, pulse wave sensor 1330 may include one or more light sources 1332 disposed at predetermined locations on pulse wave sensor 1330. One or more light sources 1332 may emit light of different wavelengths. Furthermore, to measure pulse wave signals at multiple points on a subject, multiple light receivers 1331 may be disposed at locations spaced a predetermined distance from light source 1332. However, this is merely an example, and pulse wave sensor 1330 may have various shapes as described above. Furthermore, a force / pressure sensor for measuring contact force / pressure of a finger may be mounted in main body 1310 at the lower end of pulse wave sensor 1330.

[0143] In addition, a display may be mounted on the front surface of the body 1310. 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.

[0144] like Figure 13As shown in FIG, the main body 1310 may include an image sensor 1320. The image sensor 1320 may capture various images and may acquire, for example, an image of a finger in contact with the pulse wave sensor 1330. In addition, when an image sensor based on CIS technology is installed in the light receiver 1331 of the pulse wave sensor 1330, the image sensor 1320 may be omitted.

[0145] As described above, the processor may convert the force measured by the force sensor based on the object's structural information and / or sensor position information obtained when the object is in contact with the pulse wave sensor, and may estimate blood pressure based on the converted force using an oscillometric method.

[0146] The present disclosure can be implemented as computer-readable codes written on a non-transitory computer-readable recording medium. The non-transitory computer-readable recording medium may be any type of recording device that stores data in a computer-readable manner.

[0147] Examples of non-transitory computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, and carrier wave (e.g., data transmission via the Internet). Non-transitory computer-readable recording media can be distributed on multiple computer systems connected to a network so that computer-readable code is written to and executed from the non-transitory computer-readable recording media in a decentralized manner. A programmer of ordinary skill in the art can easily derive the functional programs, codes, and code segments required to implement the present disclosure.

[0148] The present disclosure has been described herein with respect to example embodiments. However, it will be apparent to those skilled in the art that various changes and modifications may be made without changing the technical concepts and essential features of the present disclosure. Therefore, it is clear that the above-described embodiments are illustrative in all respects and are not intended to limit the present disclosure.

Claims

1. A device for estimating biological information, the device comprising: a pulse wave sensor configured to: measure a pulse wave signal from a subject; a force sensor configured to: measure a first force applied between the object and the pulse wave sensor; as well as The processor is configured to: converting the first force into a second force based on structural information of the object; and estimating biological information based on the pulse wave signal and the second force, The structural information of the object includes at least one of the following: blood vessel position, blood vessel depth, and bone depth. The processor is further configured to convert the first force into the second force based on at least one of a ratio between the blood vessel depth and the bone depth and a difference between the blood vessel depth and the bone depth.

2. The device according to claim 1, wherein The processor is further configured to obtain structural information of the object based on at least one of the optical image, the ultrasound image, the magnetic resonance imaging image, and the photoacoustic image of the object and a user input.

3. The device according to claim 1 or 2, wherein: The processor is further configured to obtain sensor position information of the pulse wave sensor relative to the object based on the object in contact with the pulse wave sensor.

4. The device according to claim 3, wherein The processor is further configured to obtain sensor position information by analyzing a relative position between the object and the pulse wave sensor based on the image of the object in contact with the pulse wave sensor.

5. The apparatus according to claim 3, wherein The device further includes a fingerprint sensor, wherein the processor is further configured to obtain sensor position information based on a fingerprint image obtained by the fingerprint sensor.

6. The apparatus according to claim 3, wherein The processor is further configured to convert the first force into a third force based on the sensor position information, and convert the third force into a second force reflecting structural information of the object.

7. The apparatus according to claim 6, wherein The processor is further configured to convert the first force into a third force based on a distance between a predetermined reference point of the object and the sensor position included in the sensor position information.

8. The apparatus according to claim 7, wherein The processor is further configured to: by using a predefined function, obtaining a first correction value based on a distance between a predetermined reference point of the object and the sensor location; obtaining a second correction value based on a distance between a predetermined reference point of the object and the reference position; as well as The first force is converted into a third force based on the first correction value and the second correction value.

9. The apparatus according to claim 3, wherein The pulse wave sensor has a plurality of channels for measuring pulse wave signals at a plurality of points of the subject, and The processor is further configured to: selecting at least one channel among the plurality of channels based on the blood vessel position of the subject and the sensor position information; and The first force is converted to a third force based on a distance between a predetermined reference point of the object and the selected channel.

10. The apparatus according to claim 9, wherein The processor is further configured to select a channel located closest to a blood vessel of the subject based on the sensor position information.

11. The apparatus according to claim 1, wherein The apparatus further includes an area sensor configured to measure a contact area between the object and the pulse wave sensor based on the object coming into contact with the pulse wave sensor and changing a force applied to the pulse wave sensor.

12. The apparatus according to claim 11, wherein The processor is also configured to: obtaining a contact pressure based on the second force and the measured contact area; and Estimating biometric information based on contact pressure and pulse wave signals.

13. The apparatus according to claim 1, wherein The biological information includes one or more of the following: blood pressure, vascular age, arterial stiffness, aortic pressure waveform, vascular compliance, stress index, fatigue level, skin age, and skin elasticity.

14. A computer-readable storage medium storing a program, wherein: When the program is executed by a processor, the processor executes a method for estimating biological information, the method comprising: measuring a pulse wave signal from the subject; measuring a first force applied between the subject and the pulse wave sensor; converting the first force into a second force based on structural information of the object; and estimating biological information based on the pulse wave signal and the second force, The structural information of the object includes at least one of the following: blood vessel position, blood vessel depth, and bone depth. The step of converting the first force includes converting the first force based on at least one of a ratio between the blood vessel depth and the bone depth and a difference between the blood vessel depth and the bone depth.

15. The computer-readable storage medium of claim 14, wherein: The method further comprises: In response to receiving a request for estimating biometric information from a user, determining whether structural information of an object of the user exists; and In response to determining that structural information of the object does not exist, structural information of the object is obtained.

16. The computer-readable storage medium according to claim 14 or 15, wherein: The method further includes obtaining sensor position information of the pulse wave sensor relative to the object when the object is in contact with the pulse wave sensor.

17. The computer-readable storage medium of claim 16, wherein: The steps of converting the first force into the second force include: converting the first force into a third force based on the sensor position information; and The third force is converted into the second force based on structural information of the object.

18. The computer-readable storage medium of claim 17, wherein: The converting of the first force into the third force includes converting the first force into the third force based on a distance between a predetermined reference point of the object and the sensor position included in the sensor position information.

19. The computer-readable storage medium of claim 18, wherein: The steps of converting the first force into the third force include: obtaining a first correction value based on a distance between a predetermined reference point of the object and the sensor location by using a predefined function; obtaining a second correction value based on a distance between a predetermined reference point of the object and the reference position; and The first force is converted into a third force based on the first correction value and the second correction value.

20. The computer-readable storage medium of claim 17, wherein: The steps of converting the first force into the third force include: In response to the pulse wave sensor having a plurality of channels for measuring pulse wave signals at a plurality of points of the subject, selecting at least one channel of the plurality of channels based on blood vessel position information and sensor position information of the subject; and The first force is converted to a third force based on a distance between a predetermined reference point of the object and the selected channel.

21. The computer-readable storage medium of claim 14, wherein: The method further comprises: The contact area is measured based on the object coming into contact with the pulse wave sensor and changing the force applied to the pulse wave sensor.

22. The computer-readable storage medium of claim 21, wherein: The steps to estimate biological information include: obtaining a contact pressure based on the second force and the contact area; and Estimating biometric information based on contact pressure and pulse wave signals.

Images