KR20190143340A - Apparatus and method for measuring bio-information - Google Patents

Abstract

Disclosed is a bio-information measurement device which can accurately measure bio-information such as blood pressure without having a separate sensor for measuring contact pressure. According to an aspect of the present invention, the bio-information measurement device comprises: a pulse wave sensor radiating light of a multi-wavelength to a subject and detecting a pulse wave signal of the multi-wavelength emitted from the subject; and a processor obtaining a conversion signal showing contact pressure between the subject and the pulse wave sensor based on the detected multi-wavelength pulse wave signal, obtaining an oscillometric envelope based on the multi-wavelength pulse wave signal and the conversion signal, and measuring bio-information by using the oscillometric envelope.

Description

Apparatus and Method for Measuring Biological Information {APPARATUS AND METHOD FOR MEASURING BIO-INFORMATION}

Apparatus and method for measuring biometric information, and more particularly, to a technique for measuring biometric information using an oscillometric technique.

In general, there is a method of measuring blood pressure non-invasive without harming the human body, there is a method of measuring the blood pressure by measuring the cuff-based pressure itself and a method of estimating blood pressure through pulse wave measurement without cuff. .

The cuff-based blood pressure measurement method is a Korotkoff sound method in which a cuff is wound around the upper arm, the cuff pressure is increased, and then the pressure in the cuff is heard and the blood pressure is heard through a stethoscope to measure blood pressure. (Korotkoff-sound method) and an automated machine to wind the cuff over the upper arm, increase the cuff pressure, and gradually measure the pressure in the cuff while gradually decreasing the cuff pressure. There is an oscillometric method for measuring blood pressure.

Common methods of measuring blood pressure include a method of estimating blood pressure by calculating pulse transit time (PTT) and a pulse wave analysis (PWA) method of estimating blood pressure by analyzing pulse wave shapes.

An apparatus and method for measuring biometric information based on an oscillometric technique by extracting contact pressure from a multi-wavelength pulse wave signal without having to provide a separate sensor for measuring contact pressure are provided.

According to an aspect, an apparatus for measuring biometric data may include contacting a subject and a pulse wave sensor based on a pulse wave sensor for irradiating light of multiple wavelengths to the subject and detecting a pulse wave signal of multiple wavelengths emitted from the subject, and the detected pulse wave pulse signal. And a processor for acquiring a converted signal representing pressure, acquiring an oscillometric envelope based on the multi-wavelength pulse wave signal and the converted signal, and measuring biometric information using the oscillometric envelope.

The pulse wave sensor may include one or more light sources that irradiate the subject with light of multiple wavelengths and one or more detectors that detect scattered pulse wave signals from the subject.

In this case, one or more light sources may be disposed on different distances from the detector.

In this case, the one or more light sources may include at least one of a light emitting diode (LED), a laser diode, and a phosphor.

In this case, the multi-wavelength may include two or more of an infrared wavelength, a red wavelength, a green wavelength, and a blue wavelength.

The processor may calculate a difference signal between the detected pulse wave signals and obtain a converted signal based on the calculated difference signal.

The processor may obtain a converted signal corresponding to the calculated differential signal based on a correlation model representing a correlation between the differential signal strength at each time point and the actual contact pressure.

The processor may calculate a difference signal between the remaining pulse wave signals based on the pulse wave signal having a blue wavelength among the detected pulse wave signals.

The processor may obtain the converted signal based on a ratio between the first differential signal obtained by subtracting the blue wave pulse signal from the green pulse wave signal and the second differential signal obtained by subtracting the blue wave pulse signal from the red wavelength pulse signal.

The processor may select one or more pulse wave signals among the multi-wavelength pulse wave signals, and obtain an oscillometric envelope based on the selected one or more pulse wave signals and the converted signal.

The processor may select one or more pulse wave signals based on at least one of a maximum amplitude value, an average amplitude value, and a difference between the maximum amplitude value and the minimum amplitude value of each of the multi-wavelength pulse wave signals.

When the plurality of pulse wave signals are selected, the processor may differentiate the pulse wave signals having a short wavelength from the pulse wave signals having a relatively long wavelength, and acquire an oscillometric envelope based on the differential signal and the converted signal.

When a plurality of pulse wave signals are selected, the processor may acquire each oscillometric envelope by using each of the selected pulse wave signals and the converted signal, and acquire one oscillometric envelope by integrating the obtained oscillometric envelopes. .

The processor extracts a peak-to-peak point at each measurement time point of the selected pulse wave signal, and extracts the value of the converted signal at the time point corresponding to each measurement time point from the extracted peak-to-peak point. Plot to obtain an oscillometric envelope.

The processor extracts at least one of the maximum amplitude value, the contact pressure value of the maximum amplitude point in the oscillometric envelope, and the contact pressure value at a point corresponding to a predetermined ratio based on the contact pressure value, and based on the extracted feature. Biometric information can be measured with

The biometric information may include one or more of blood pressure, vascular age, arteriosclerosis, aortic pressure waveform, vascular elasticity, stress index, and fatigue degree.

The biometric information measuring apparatus may further include an output unit configured to output a processing result of the processor.

When the biometric information measurement request is received, the output unit may output guide information for guiding a reference contact pressure to be applied to the pulse wave sensor by the user.

When the conversion signal is acquired by the processor, the output unit may output guide information for guiding the contact pressure actually applied to the pulse wave sensor by using the obtained conversion signal.

According to one aspect, a method of measuring biometric information includes: irradiating light of a multi-wavelength to a subject, detecting a multi-wavelength pulse wave signal from the subject, and a subject and a pulse wave sensor based on the detected multi-wavelength pulse wave signal. Acquiring an converted signal representing a contact pressure between the liver, acquiring an oscillometric envelope based on the multi-wavelength pulse wave signal and the converted signal, and measuring biometric information using the oscillometric envelope. .

The acquiring of the converted signal may calculate a difference signal between the detected pulse wave signals and obtain the converted signal based on the calculated difference signal.

The obtaining of the converted signal may calculate a difference signal between the remaining pulse wave signals based on the pulse wave signal of the blue wavelength among the detected pulse wave signals.

The acquiring of the converted signal may include obtaining a first differential signal obtained by subtracting a blue wave pulse signal from a green pulse wave signal and a second differential signal obtained by subtracting a blue wave pulse signal from a red wave pulse signal and a first differential signal. And acquiring the converted signal based on a ratio between the signal and the second differential signal.

Acquiring the oscillometric envelope may select one or more pulse wave signals among the multi-wavelength pulse wave signals and obtain an oscillometric envelope based on the selected one or more pulse wave signals and the converted signal.

Acquiring the oscillometric envelope may select one or more pulse wave signals based on at least one of a maximum amplitude value, an average amplitude value, and a difference between the maximum amplitude value and the minimum amplitude value of each of the multi-wavelength pulse wave signals.

In the obtaining of the oscillometric envelope, when a plurality of pulse wave signals are selected, the pulse wave signals having a short wavelength may be differentiated from the pulse wave signals having a relatively long wavelength, and the oscillometric envelope may be obtained based on the differential signal and the converted signal.

The step of acquiring an oscillometric envelope includes obtaining each oscillometric envelope using each of the selected pulse wave signals and the transformed signal, and integrating each of the obtained oscillometric envelopes using a single pulse wave signal and a converted signal. A metric envelope can be obtained.

The measuring of the biometric information may include extracting at least one of a maximum amplitude value, a contact pressure value at the maximum amplitude value point, and a contact pressure value at a point corresponding to a predetermined left and right ratio based on the contact pressure value in the oscillometric envelope. It may include, and measure the biometric information based on the extracted feature.

It is possible to accurately measure biometric information such as blood pressure without having a separate sensor for measuring contact pressure.

1 is a block diagram of an apparatus for measuring biometric information according to an exemplary embodiment.
2 is a block diagram of an apparatus for measuring biometric information according to another exemplary embodiment.
3 is a block diagram of a processor configuration according to an embodiment.
4 is a view for explaining the correlation between the multi-wavelength pulse wave signal, the converted signal and the contact pressure.
5A and 5B are diagrams for explaining blood pressure measurement using an oscillometric technique.
6A to 6C are diagrams for explaining the correlation between the blood pressure measurement value and the actual blood pressure.
7 is a flowchart illustrating a method of measuring biometric information according to an exemplary embodiment.
8 is a flowchart of a method of measuring biometric information according to another exemplary embodiment.
9 illustrates a wearable device to which the biometric information measuring apparatus is applied.
10A and 10B illustrate a smart device to which a biometric information measuring device is applied.

Specific details of other embodiments are included in the detailed description and the drawings. Advantages and features of the described technology, and methods of achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the drawings. Like reference numerals refer to like elements throughout.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are only used to distinguish one component from another. Singular expressions include plural expressions unless the context clearly indicates otherwise. In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated. In addition, the terms “… unit”, “module”, etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented in hardware or software, or a combination of hardware and software.

Hereinafter, embodiments of the biometric information measuring apparatus and method will be described in detail with reference to the accompanying drawings.

1 is a block diagram of an apparatus for measuring biometric information according to an exemplary embodiment.

Referring to FIG. 1, the biometric information measuring apparatus 100 includes a pulse wave sensor 110 and a processor 120.

The pulse wave sensor 110 measures a photoplethysmography (PPG) signal (hereinafter referred to as a 'pulse wave signal') from a subject. According to the present embodiment, the pulse wave sensor 110 measures a pulse wave signal of multiple wavelengths from a subject. can do. In this case, the multi-wavelength may include an infrared wavelength, a red wavelength, a green wavelength, a blue wavelength, and the like.

The pulse wave sensor 110 detects light emitted from the light source 111 that irradiates the subject and light emitted by the light source 111 is scattered or reflected from a biological tissue such as a skin surface or blood vessel of the subject. The detector 112 may be included.

The light source 111 may include a light emitting diode (LED), a laser diode (LD) or a phosphor. One or more light sources 111 may be formed to irradiate the subject with light of multiple wavelengths in order to detect pulse waves of multiple wavelengths. For example, the pulse wave sensor 110 may be formed of a plurality of light sources 111 irradiating light having different wavelengths, respectively. In this case, the plurality of light sources 111 may be disposed on different distances from the detector 112. As another example, the pulse wave sensor 110 may be a single light source 111 for irradiating light of different wavelengths sequentially or a single band for irradiating a wide band of light including a multi-wavelength band to be detected under the control of the processor 120. It may be formed of a light source 111.

The detector 112 may be formed of one or more photo diodes, a photo transistor (PTr), an image sensor (eg, a CMOS image sensor), or the like. The detector 112 may be formed to correspond to each of the plurality of light sources 111 in order to detect light having multiple wavelengths. Alternatively, the detector 112 may be formed in plural to respond to light of different wavelengths in order to detect light of multiple wavelengths emitted by the single light source 111.

When the processor 120 receives the biometric information measurement request, the processor 120 may guide the strength of the reference contact pressure to be applied by the user with reference to the reference information. In addition, the processor 120 may drive the pulse wave sensor 100 in response to a biometric information measurement request. The processor 120 may sequentially drive the light source 111 to irradiate light having multiple wavelengths based on a preset light source driving condition. In this case, the light source driving condition may include light intensity and pulse duration of each light source 111.

When the processor 120 receives the pulse wave signal of the multi-wavelength detected at a specific time from the pulse wave sensor 110, the processor 120 analyzes the received pulse wave signal of the multi-wavelength and indicates a contact pressure between the subject and the pulse wave sensor 110. A signal can be obtained.

In addition, the processor 120 may measure biometric information based on the received multi-wavelength pulse wave signal and / or converted signal. At this time, the biometric information includes, but is not limited to, heart rate, systolic blood pressure, diastolic blood pressure, vascular age, arteriosclerosis, aortic pressure waveform, vascular elasticity, stress index, and fatigue. For example, the processor 120 may acquire an oscillometric envelope based on the multi-wavelength pulse wave signal and the converted signal, and measure biometric information using the obtained oscillometric envelope.

2 is a block diagram of an apparatus for measuring biometric information according to another exemplary embodiment.

2, the biometric information measuring apparatus 200 may include a pulse wave sensor 110, a processor 120, an output unit 210, a storage unit 220, and a communication unit 230. Since the pulse wave sensor 110 and the processor 120 have been described with reference to FIG. 1, the rest of the configuration will be described below.

The output unit 210 may output a multi-wavelength pulse wave signal detected by the pulse wave sensor 110 or a processing result of the processor 120, for example, a biometric information measurement result. In this case, the output unit 210 may visually provide various information to the user through a display. Alternatively, various types of information may be provided to the user through a speaker module or a haptic module in a non-visual manner such as voice, vibration, and touch. For example, if the measured blood pressure is out of the normal range, it may be displayed in red to warn, or the haptic module may provide additional warning information through vibration or touch.

In addition, when the biometric information measurement request is received, the output unit 210 may output guide information to be applied to the pulse wave sensor 110 under the control of the processor 120. In this case, the guide information may include information about the intensity of pressure that the subject should apply to the pulse wave sensor 110 and / or the actual contact pressure extracted by the processor 120 while the pulse wave sensor 110 detects the pulse wave signal. It may include.

For example, when the biometric information measurement request is received, the output unit 210 outputs a graph indicating a time versus contact pressure for a predetermined time period on the display under the control of the processor 120, and the user should apply it at each time point. An identification mark indicating the reference contact pressure value and / or the range of the reference contact pressure value can be output on the graph. For example, the identification mark may include a line connecting points corresponding to the reference contact pressure value at each time point, or a line connecting the highest values and the lowest values of the reference contact pressure ranges.

In addition, the output unit 210 obtains a converted signal indicating the contact pressure by the processor 120 using the multi-wavelength pulse wave signal, and outputs a contact pressure value corresponding to the actual contact pressure applied to the pulse wave sensor by the user at each measurement time point. If so, the contact pressure value of each measured time point may be output on the graph. The processor 120 may apply the contact pressure applied by the user by comparing the reference contact pressure with the contact pressure obtained through the conversion signal. The warning information may be generated so as to change the output, and the output unit 210 may visually display the generated warning information or output the same through voice or vibration.

The storage unit 220 may store various reference information or processing results of the pulse wave sensor 110 and / or the processor 120. In this case, the various reference information includes user information such as user's age, gender and health status, reference contact pressure value or range of reference contact pressure, reference information for calibration such as cuff pressure or cuff blood pressure, and the above-described measurement state. Information or information necessary for measuring biometric information, such as a measurement model of biometric information, and the like.

In this case, the storage unit 220 may include a flash memory type, a hard disk type, a multimedia card micro type, and a card type memory (eg, SD or XD memory). Etc.), Random Access Memory (RAM), Random Random Access Memory (SRAM), Read-Only Memory (ROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Programmable Read-Only Memory (PROM), Magnetic Storage media such as memory, magnetic disks, optical disks, and the like, but are not limited thereto.

Meanwhile, according to the present embodiment, the processor 120 may perform the calibration of the biometric information measurement model or the biometric information measurement value when the user's calibration request is received or when the preset calibration period is satisfied. Alternatively, when the biometric information is measured, it may be determined whether to calibrate based on the biometric information measurement result.

For example, the processor 120 may determine to calibrate when the measured biometric information is out of the normal range. Alternatively, when the measured value of the biological information is out of the normal range, it may be determined to calibrate if the total number of times out of the normal range for a predetermined time is greater than or equal to the threshold. Alternatively, when the measured value of the biometric information is out of the normal range, it may be determined that the calibration is performed if the number of times that the out of the normal range has been continuously exceeded the threshold is previously included. However, this is only an example, and the present disclosure is not limited thereto, and a criterion for setting the criterion may be set in consideration of various conditions such as whether the subject and / or the state of measurement are changed or whether the state of the user is changed.

When the processor 120 determines to calibrate, the processor 120 may obtain reference information for calibration from the storage unit 220 and calibrate the biometric information measurement value or the biometric information measurement model. In this case, the reference information for calibration may include an actual biometric information measurement value (for example, cuff blood pressure) and an offset value, but is not limited thereto.

The processor 120 may control the communication unit 230 according to a preset reference to receive the reference information for calibration from the external device 250. In this case, the preset criteria may include a specific period, a health state of the user, a state of the subject, and the above-described calibration determination criteria. For example, the processor 120 may control the communicator 230 when there is a change in the health state of the user and / or when a specific cycle occurs. Alternatively, when calibration is performed a predetermined number of times or more, it may be determined that a change has occurred in reference information such as reference blood pressure, and the communication unit 230 may be controlled to obtain new reference information.

The communicator 230 may perform wired or wireless communication with various external devices 250 under the control of the processor 120. The external device 250 may include an information processing device such as a smartphone, a tablet PC, a desktop PC, and the like. In addition, the external device 250 may include a device for measuring biometric information in a more accurate manner, such as a cuff blood pressure measurement device. However, it is not limited thereto.

The communication unit 230 includes Bluetooth communication, BLE (Bluetooth Low Energy) communication, Near Field Communication (Near Field Communication), WLAN communication, Zigbee communication, Infrared Data Association (IrDA) communication, WFD (Wi-Fi Direct) communication, ultra-wideband (UWB) communication, Ant + communication, WIFI communication, Radio Frequency Identification (RFID) communication, 3G communication, 4G communication and 5G communication can be used to communicate with external devices. However, this is only an example and is not limited thereto.

The communication unit 230 may receive reference information for calibrating the biometric information measurement value from the external device 250 under the control of the processor 120, and store the reference information in the storage unit 220.

3 is a block diagram of a processor configuration according to an embodiment. 4 is a view for explaining the correlation between the multi-wavelength pulse wave signal, the converted signal and the contact pressure. 5A and 5B are diagrams for explaining blood pressure measurement using an oscillometric technique. 6A to 6C are diagrams for explaining the correlation between the blood pressure measurement value and the actual blood pressure.

Referring to FIG. 3, the processor 120 includes a contact pressure guide unit 310, a pulse wave signal receiver 320, a conversion signal acquirer 330, an envelope acquirer 340, and a biometric information measurer 340. can do.

When the biometric information measurement request is received, the contact pressure guide unit 310 may provide the user with a reference contact pressure, which should be applied to the pulse wave sensor 110 during the measurement time, with reference to the reference information through the output unit 210. Can be. The reference contact pressure may be preset for each user in consideration of the gender, age, state of the test site, health state, and biometric information measurement history of the user.

For example, the contact pressure guide unit 310 may output a graph including an identification mark indicating the reference contact pressure through the output unit 210. In this case, the identification mark may indicate a reference contact pressure value to be applied while the user contacts the pulse wave sensor 110 at each measurement time point, or a range of the reference contact pressure value, for example, a minimum value, a maximum value, and / or an average value. have. For example, the output unit 210 may output a predetermined mark (eg, a circle, a rectangle, an arrow, etc.) at a point corresponding to the reference contact pressure value for each time point on the graph, or the reference contact pressure for each time point. In order to easily recognize the range of, the line connecting the lowest value, the highest value and the average value can be displayed. However, the present invention is not limited thereto and may be output in various forms of visual display or voice.

In addition, when the contact pressure guide unit 310 obtains a conversion signal indicating the contact pressure for each measurement time point by the conversion signal acquisition unit 330, the contact pressure obtained based on the conversion signal is output through the output unit 210. You can output to the display.

The pulse wave signal receiving unit 320 may receive the multi-wavelength pulse wave signal detected from the pulse wave sensor 110 and transmit the received multi-wavelength pulse wave signal to the conversion signal obtaining unit 330 and the envelope obtaining unit 340. In this case, the pulse wave signal receiver 320 may be electrically connected to the pulse wave sensor 110.

In addition, when the pulse wave signal receiving unit 310 receives the multi-wavelength pulse wave signal, the pulse wave signal receiving unit 310 filters the multi-wavelength pulse wave signal as necessary before removing the normalized pulse wave signal, and removes or normalizes the signal. Can be performed. In this case, the pulse wave signal receiver 310 may pass each pulse wave signal through a low pass filter to obtain a pulse wave DC signal of each wavelength.

When the multi-wavelength pulse wave signal at a specific point in time is received from the pulse wave sensor 110, the converted signal obtaining unit 330 may contact pressure between the subject and the pulse wave sensor 110 at the specific point in time based on the received multi-wave pulse wave signal. It is possible to obtain a converted signal indicating.

For example, the conversion signal acquisition unit 330 generates a differential signal by differentially performing pulse wave DC signals having the remaining wavelengths IR, R, and G based on the pulse wave DC signal having a blue wavelength B obtained at a specific time point. In addition, the generated differential signal may be combined to extract contact pressure at a specific point in time.

For example, the conversion signal acquisition unit 330 may be a first difference signal obtained by subtracting a blue wave pulse signal from a green wave pulse signal, and a pulse wave signal of blue wavelength from a red wave pulse signal as shown in Equation 1 below. The ratio between the differential signals can be calculated, and a converted signal representing the contact pressure at each time can be obtained based on the calculated ratio. Alternatively, the calculated ratio may be input to a predefined correlation model to obtain contact pressure. The contact pressure at each measurement point may be obtained using the obtained conversion signal. In this case, the correlation model may be defined in the form of a mathematical function algorithm or a matching table indicating a correlation between the ratio of the two differential signals and the contact pressure.

Here, Sg represents the pulse wave DC signal of the green wavelength G, Sb represents the pulse wave DC signal of the blue wavelength B, Sr represents the pulse wave DC signal of the red wavelength R, and Dr represents the ratio between the differential signals. . In addition, CP represents contact pressure and a and b represent arbitrary constants that define the correlation between the contact pressure and the ratio between the differential signals.

4 is a view for explaining the correlation between the pulse wave signal and the conversion signal of each wavelength and the contact pressure. FIG. 4 is a view illustrating a red wavelength and a green wavelength measured for a predetermined time from a subject through a device equipped with a contact pressure sensor for comparison between an actual contact pressure applied by a user and a converted signal obtained through the present embodiment. Pulse wave signals of (G) and blue wavelength (B), actual contact pressures measured by the contact pressure sensor, and contact pressures obtained by the above-described method using the multi-wavelength pulse wave signals (R, G, B). The converted signal is shown.

As shown in FIG. 4, it can be seen that there is a high correlation between the contact pressure of the converted signal acquired through the multi-wavelength pulse wave signal and the contact pressure measured by the actual contact pressure sensor. Therefore, according to the present embodiment, since the contact pressure similar to the contact pressure actually touched by the user can be obtained through the converted signal using the multi-wavelength pulse wave signal, the biometric information can be measured accurately. In addition, it is not necessary to mount a separate contact pressure sensor such as a force sensor or an area sensor, so that the device can be miniaturized.

The envelope obtaining unit 340 may acquire an oscillometric envelope using a multi-wavelength pulse wave signal and a converted signal. The envelope obtaining unit 340 may select one or more pulse wave signals among preset pulse wave signals based on a preset reference, and acquire an oscillometric envelope using the selected pulse wave signal and the converted signal. In this case, the preset reference may include at least one of a maximum amplitude value, an average amplitude value, and a difference between the maximum amplitude value and the minimum amplitude value of each of the multi-wavelength pulse wave signals. However, the present invention is not limited thereto, and it is also possible to select a pulse wave signal having a predetermined specific wavelength among multiple wavelengths.

As an example, the envelope obtaining unit 340 may select one pulse wave signal having a largest difference between the maximum amplitude value and the minimum amplitude value of the pulse wave signal. When any one pulse wave signal is selected, the envelope obtaining unit 340 extracts a peak-to-peak point at each measurement time point of the selected pulse wave signal, and extracts the extracted peak-to-peak point. It is possible to obtain an oscillometric envelope of the contact pressure vs. the pulse wave signal by plotting the value based on the value of the converted signal corresponding to each measurement time point, that is, the contact pressure value.

Referring to FIG. 5A, the peak-to-peak point is extracted by subtracting the amplitude value in3 of the minus point from the amplitude value in2 of the plus point of the waveform envelope in1 at each measurement time point. can do. Then, the envelope obtaining unit 340 obtains an oscillometric envelope OW by plotting the amplitude of the peak-to-peak point at each measurement point based on the contact pressure value of the converted signal as shown in FIG. 5B. can do.

As another example, the envelope obtaining unit 340 may select two or more pulse wave signals according to a preset criterion. For example, the envelope acquiring unit 340 selects a pulse wave signal having a relatively long wavelength (for example, an infrared wavelength) and a short wavelength (for example, a green wavelength), subtracts a pulse wave signal having a short wavelength from a pulse wave having a relatively long wavelength, and provides a differential signal. Can be used to obtain an oscillometric envelope. At this time, the differential signal can be obtained by secondly differenting each pulse wave signal and differentiating a short wavelength differential signal from a long wavelength differential signal.

As another example, the envelope obtaining unit 340 may acquire an oscillometric envelope using at least some or all of the pulse wave signals of the multi-wavelength pulse wave signal. For example, each oscillometric envelope is obtained using each pulse wave signal and a transformed signal, and each oscillometric envelope obtained by inputting each of the oscillometric envelopes into a predetermined linear functional formula or integrated model as shown in Equation 2 below is integrated into one oscillator. A metric envelope can be obtained. At this time, each oscillometric envelope can be obtained as described above.

Here, f ₁ , f _2, and f ₃ mean each oscillometric envelope, and c ₁ , c _2, and c ₃ mean coefficients for each oscillometric envelope. f _total means the integrated oscillometric envelope. On the other hand, the coefficients c ₁ , c _2, and c ₃ for each oscillometric envelope are preprocessed based on the type of device to be applied, the location of the test, the size of the device, the light intensity of each light emitting unit, the wavelength range, and the health of the user. Can be calculated in advance. However, the present invention is not limited thereto.

The biometric information measuring unit 350 may measure biometric information by using the oscillometric envelope obtained by the envelope obtaining unit 340. The biometric information measuring unit 350 may extract one or more features from the oscillometric envelope, and measure the biometric information using the extracted features.

Referring to FIG. 5B, the biometric information measuring unit 350 includes an amplitude value MA of the maximum peak point, a contact pressure value MP of the maximum peak point, and a contact pressure value of the maximum peak point in the oscillometric envelope OW. The contact pressure values SP and DP of the left and right points having a predetermined ratio (for example, 0.5 to 0.7) based on (MP) may be extracted. The biometric information measuring unit 350 may measure biometric information by using the extracted feature.

For example, when measuring blood pressure, the biometric information measuring unit 350 may calculate the contact pressure value MP of the maximum peak point extracted from the oscillometric envelope OW as the average blood pressure. In addition, the biometric information measuring unit 350 stores the systolic blood pressure SBP and the contact pressure at the left point of the contact pressure value SP at the right point within a predetermined ratio range based on the contact pressure value MP at the maximum peak point. The value DP can be calculated as the diastolic blood pressure DBP.

Alternatively, when one or more features are extracted from the oscillometric envelope, the biometric information measuring unit 350 may measure the biometric information using a predefined measurement model as shown in Equation 3 below.

Here, y denotes biometric information to be obtained, for example, diastolic blood pressure, systolic blood pressure, and average blood pressure, and x means extracted feature values. In addition, a and b are values calculated in advance through a preprocessing process, and may be defined differently according to types of bio information, for example, diastolic blood pressure, systolic blood pressure, and average blood pressure. The present invention is not limited thereto and may be pre-built in a table format in which blood pressure values are compared with feature values.

6A to 6C illustrate measurement values of systolic blood pressure (SBP), diastolic blood pressure (DBP), and average blood pressure (MBP) measured by the biometric information measuring unit 350 using an oscillometric envelope as described above. It is a graph which shows the correlation between the systolic blood pressure SBP, the diastolic blood pressure DBP, and the reference value ref of the average blood pressure MBP measured using the same blood pressure measuring apparatus. According to the disclosed embodiment, accurate biometric information can be measured without having a sensor for measuring the actual contact pressure.

7 is a flowchart illustrating a method of measuring biometric information according to an exemplary embodiment.

FIG. 7 is an embodiment of a biometric information measuring method performed by the biometric information measuring apparatuses 100 and 200 according to the embodiments of FIGS. 1 and 2, and will be briefly described in order to reduce duplication.

First, the biometric information measuring device may receive a biometric information measurement request (710). The biometric information measurement request may be input from the user. Or it may be received from an external device connected to the communication. However, the present invention is not limited thereto and may determine that a request for measuring biometric information is automatically received when a predetermined period is reached. Meanwhile, when the biometric information measurement request is received, the user may be provided with guide information for guiding contact pressure to be applied by the user.

Next, the pulse wave sensor may be controlled to detect a pulse wave signal having a multi wavelength from the subject (720). In this case, the multi-wavelength includes, but is not limited to, an infrared wavelength, a green wavelength, a red wavelength, a blue wavelength, and the like. One or more light sources of the pulse wave sensor may be formed to radiate light of multiple wavelengths. For example, the pulse wave sensor may be formed of one light source formed to irradiate light of a multi-wavelength band or a plurality of light sources such that each light source irradiates light of different wavelengths. In addition, the pulse wave sensor may be formed of one or more detectors.

Next, when a pulse wave signal of multiple wavelengths is detected (720), a converted signal may be obtained based on the detected pulse wave signal of multiple wavelengths (730). For example, two or more pulse wave signals in the detected pulse wave signals may be combined to obtain a converted signal representing a contact pressure between the pulse wave sensor and the subject. For example, a pulse wave DC signal of each wavelength may be generated by passing a multi-wavelength pulse wave signal through a low pass filter (LPF), and a converted signal may be obtained by combining two or more pulse wave DC signals of each wavelength. In this case, a differential signal may be generated by differentially pulsating the pulse wave DC signals of the remaining wavelengths based on the pulse wave DC signal having the blue wavelength, and the converted signal may be obtained based on the ratio of the generated differential signals.

Next, an oscillometric envelope may be obtained based on the multi-wavelength pulse wave signal and the obtained converted signal (740). For example, using the envelope of the differential signal waveform by second derivative of the pulse wave signal, the peak-to-peak of the waveform is subtracted by subtracting the negative value from the positive value of the differential signal waveform at each measurement point. To-peak points may be extracted and the peak-to-peak points may be plotted based on contact pressure values to obtain an oscillometric envelope.

Next, the biometric information may be measured based on the obtained oscillometric envelope (750). For example, one or more features may be extracted from an oscillometric envelope, and biometric information such as blood pressure may be measured using the extracted features. In the oscillometric envelope, the amplitude value of the maximum peak point, the contact pressure value of the maximum peak point, or the contact pressure value of the left and right points having a preset ratio (for example, 0.5 to 0.7) based on the contact pressure value of the maximum peak point, etc. By extracting the feature, the biometric information such as blood pressure may be measured using the extracted feature.

Next, the biometric information measurement result may be output (770). For example, a biometric information measurement result and extracted contact pressure information may be visually provided to the user through a display. Alternatively, the warning information may be provided to the user through a speaker module or a haptic module in a non-visual manner such as voice, vibration, and touch.

8 is a flowchart of a method of measuring biometric information according to another exemplary embodiment.

FIG. 8 may be an embodiment of a biometric information measuring method performed by the biometric information measuring apparatus 200 of FIG. 2.

First, when the biometric information measuring apparatus receives the biometric information measurement request (810), the biometric information measuring apparatus may detect a pulse wave signal having a multi-wavelength from the subject by controlling the pulse wave sensor (820). In this case, the multi-wavelength may include an infrared wavelength, a green wavelength, a red wavelength, a blue wavelength, and the like, and the pulse wave sensor may include one or more light sources to irradiate light of the multi-wavelength.

Next, when a pulse wave signal of multiple wavelengths is detected (820), a converted signal may be obtained based on the detected pulse wave signal of multiple wavelengths (830). For example, a pulse wave DC signal may be generated by filtering a multi-wavelength pulse wave signal, and a converted signal may be obtained using two or more generated pulse wave DC signals.

Thereafter, an oscillometric envelope may be obtained based on the multi-wavelength pulse wave signal and the obtained converted signal (840), and biometric information may be measured based on the obtained oscillometric envelope (850). For example, one or more features may be extracted from an oscillometric envelope, and biometric information such as blood pressure may be measured using the extracted features.

In operation 860, it may be determined whether the measured biometric information measurement value is calibrated. For example, a calibration preset with one or more of a normal range of biometric measurements, a number of consecutive out of normal ranges, a total number of out of normal ranges for a given time, a change in the subject's state, and a user's state of health The determination criteria may be used to determine whether to calibrate the biometric information measurement value.

Next, if it is determined that the calibration is performed (860), the biometric information may be calibrated using the calibration reference information (880). In this case, when the preset criterion is satisfied, the reference information for calibration may be received by connecting to an external device before calibration (870), and the measured biometric information may be calibrated using the received reference information (880).

If the determination result 860 does not require calibration, the measured biometric information measured value or the calibrated biometric information measured value may be output (890).

9 illustrates a wearable device to which the biometric information measuring apparatus is applied. As described above, various embodiments of the biometric information measuring apparatus may be mounted on a smart watch or a smart band type wearable device worn on a wrist. However, since this is only one example for convenience of description, the present embodiments are not limited to being applied only to a smart watch or a smart band type wearable device.

Referring to FIG. 9, the wearable device 900 includes a device body 910 and a strap 930.

The strap 930 may be flexible and be connected to both ends of the main body 910 to be bent in a form wrapped around the user's wrist or to be bent in a form separated from the user's wrist. Alternatively, the strap 930 may be configured in the form of a band that is not separated. In this case, the strap 930 may be formed to include air pockets or an air pocket to have elasticity according to a change in pressure applied to the wrist, and may transmit a pressure change of the wrist to the main body 910.

A battery for supplying power to the wearable device 900 may be built in the main body 910 or the strap 930.

In addition, the wearable device 900 uses the pulse wave sensor 920 for measuring the pulse wave signal and the contact pressure signal from the subject, and the biometric information of the user using the pulse wave signal and the contact pressure signal measured by the pulse wave sensor 920. A processor to measure is built in.

The pulse wave sensor 920 may be mounted to be exposed to a lower portion of the main body 910, that is, a portion that is in contact with a subject (for example, a user's wrist) to measure a pulse wave signal from the subject. The pulse wave sensor 920 may include one or more light sources that irradiate light onto the subject. In this case, each light source may emit light having a different wavelength. It may also include one or more detectors for detecting light emitted from the subject. In this case, one or more light sources may be disposed on different distances from the detector.

The processor may generate a control signal to control the pulse wave sensor 920 according to a user's biometric information measurement request, and obtain a converted signal indicating a contact pressure using the multi-wavelength pulse wave signal measured from the pulse wave sensor 920. .

The processor may acquire an oscillometric envelope using the multi-wavelength pulse wave signal and the converted signal, and measure biometric information such as blood pressure based on the obtained oscillometric envelope. Detailed description thereof will be omitted since it has been described above.

Meanwhile, when the biometric information measurement request is received from the user, the processor may guide the contact pressure to the user through the display unit so that the user may apply pressure to the main body 910 to change the contact pressure between the pulse wave sensor and the subject. .

In this case, the display unit may be mounted on the front surface of the main body 910, and may visually output the guide information and / or the biometric information measurement result of the contact pressure.

The processor may manage various types of information such as measurement blood pressure, blood pressure history information, pulse wave signals, contact pressure signals, and extracted features used to measure each blood pressure in the storage device. In addition, additional information necessary for the user's health care, such as alarm or warning information related to the measured biometric information and a change in health state, may be generated and managed in the storage device.

In addition, the wearable device 900 may include an operation unit 940 that receives a user's control command and transmits the same to a processor. The operation unit 940 may be mounted on the side of the main body 910 and may include a function for inputting a command to turn on / off the power of the wearable device 900.

In addition, the wearable device 900 may be equipped with a communication unit that transmits and receives various data with an external device and various modules for performing additional functions provided by the wearable device 900.

10A and 10B illustrate a smart device to which a biometric information measuring device is applied.

10A and 10B illustrate a smart device to which embodiments of the biometric information measuring apparatus are applied. In this case, the smart device may include a smartphone, a tablet PC, and the like.

10A and 10B, the smart device 1000 may be mounted in a form in which the pulse wave sensor 1030 is exposed to the outside on the rear surface of the main body 1010. In this case, the pulse wave sensor 1030 may include one or more light sources 1031 and one or more detectors 1032. Each light source 1031 may be formed of a light emitting diode (LED) or the like, and at least some of the light sources may be formed to emit light having different wavelengths. The detector 1032 may be formed of a photo diode, a photo transistor, or the like.

In addition, the display unit 1040 may be mounted on the front surface of the main body 1010. The display unit 1040 may output guide information regarding the contact pressure, or visually output a biometric information measurement result.

For example, when the user contacts the subject OBJ with the pulse wave sensor 1030 for measuring biometric information, the display unit 1040 displays the pulse wave sensor 1030 with the subject OBJ during the time when the pulse wave signal is measured. ), An identification mark SP for guiding the reference contact pressure to be applied to) can be output to the predetermined area GA.

In addition, when the processor acquires the converted signal representing the contact pressure using the multi-wavelength pulse wave signal, the display unit 1040 may output an identification mark AP representing the contact pressure at each time point. In this case, the display unit 1040 may display the reference contact pressure and the contact pressure obtained through the conversion signal by using different colors or the like so that the user can easily distinguish. In addition, when the processor determines that the contact state is not normal through comparison between the reference contact pressure and the contact pressure through the conversion signal at each time point, the display unit 1040 outputs an identification mark indicating a time point at which the contact state is not normal. For example, a warning message for changing the contact state can be output. However, it is not limited to this example.

Meanwhile, the image sensor 1020 may be mounted on the main body 1010. When the user approaches the subject (eg, a finger) to the pulse wave sensor 1030 to measure the pulse wave signal, the image sensor 1020 may photograph the finger and transmit the same to the processor. At this time, the processor detects the relative position of the finger relative to the actual position of the bio-signal measuring unit 1030 from the image of the finger, and provides the relative position information of the finger to the user through the display unit 1040 to make the pulse wave signal measurement more accurately. Can be guided to build.

Various modules for performing various embodiments of the above-described biometric information measuring apparatus may be mounted in the smart device 1000, and a detailed description thereof will be omitted.

In the meantime, the embodiments may be embodied as computer readable codes on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored.

Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disks, optical data storage devices, and the like, which may also be implemented in the form of carrier waves (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. And functional programs, codes and code segments for implementing the embodiments can be easily inferred by programmers in the art to which the present invention belongs.

Those skilled in the art will appreciate that the present disclosure may be embodied in other specific forms without changing the technical spirit or essential features disclosed. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

100, 200: biometric information measuring device 110: pulse wave sensor
111: light source 112: detector
120: processor 210: output unit
220: storage unit 230: communication unit
310: contact pressure guide portion 320: pulse wave signal receiving portion
330: conversion signal acquisition unit 340: envelope acquisition unit
350: biometric information measuring unit 900: wearable device
910: main body 920: pulse wave sensor
930: strap 940: control panel
1000: smart device 1010: main body
1020: image sensor 1030: pulse wave sensor
1031: light source 1032: detector
1040: display unit

Claims (28)

A pulse wave sensor for irradiating light of multiple wavelengths to a subject and detecting pulse wave signals of multiple wavelengths emitted from the subject; And
Acquire a conversion signal representing the contact pressure between the subject and the pulse wave sensor based on the detected multi-wavelength pulse wave signal, and obtain an oscillometric envelope based on the multi-wavelength pulse wave signal and the converted signal. And a processor for measuring biometric information using the metric envelope. The method of claim 1,
The pulse wave sensor is
One or more light sources for irradiating the subject with light of the multi-wavelength; And
And at least one detector for detecting a pulse wave signal scattered from the subject. The method of claim 2,
And at least one light source is disposed at different distances from the detector. The method of claim 2,
The at least one light source includes at least one of a light emitting diode (LED), a laser diode and a phosphor. The method of claim 1,
The multi-wavelength measuring apparatus comprises at least two of an infrared wavelength, a red wavelength, a green wavelength, and a blue wavelength. The method of claim 1,
The processor is
And calculating a difference signal between the detected pulse wave signals of multiple wavelengths and obtaining the converted signal based on the calculated difference signal. The method of claim 6,
The processor is
And a conversion signal corresponding to the calculated differential signal based on a correlation model representing a correlation between the differential signal strength at each time point and the actual contact pressure. The method of claim 6,
The processor is
And calculating a difference signal between the remaining pulse wave signals based on the pulse wave signal having a blue wavelength among the detected pulse wave signals. The method of claim 8,
The processor is
Measurement of biometric information for obtaining the converted signal based on a ratio between a first differential signal obtained by subtracting a blue wave pulse signal from a green wave pulse signal and a second differential signal obtained by subtracting the blue wave pulse signal from a red wave pulse signal Device. The method of claim 1,
The processor is
And at least one pulse wave signal is selected from among the multi-wavelength pulse wave signals, and an oscillometric envelope is obtained based on the at least one selected pulse wave signal and the converted signal. The method of claim 10,
The processor is
And at least one pulse wave signal is selected based on at least one of a maximum amplitude value, an average amplitude value, and a difference between the maximum amplitude value and the minimum amplitude value of each of the multiple wavelength pulse wave signals. The method of claim 10,
The processor is
And selecting a plurality of pulse wave signals, and dividing the pulse wave signal having a relatively short wavelength from the pulse wave signal having a relatively long wavelength, and obtaining an oscillometric envelope based on the difference signal and the converted signal. The method of claim 10,
The processor is
When a plurality of pulse wave signals are selected, each oscillometric envelope is obtained using each of the selected pulse wave signals and the converted signal, and biometric information is obtained by integrating the obtained oscillometric envelopes to obtain one oscillometric envelope. Device. The method of claim 10,
The processor is
Extracting a peak-to-peak point at each measurement time point of the selected pulse wave signal, and extracting the extracted peak-to-peak point of the converted signal at a time point corresponding to each measurement time point. A biometric information measuring device that obtains an oscillometric envelope by plotting a value. The method of claim 1,
The processor is
Extract at least one of a maximum amplitude value, a contact pressure value of the maximum amplitude value point, and a contact pressure value of a point corresponding to a predetermined left and right ratio based on the contact pressure value in the oscillometric envelope, and extract the extracted feature Biometric information measuring device for measuring biometric information on the basis. The method of claim 1,
The biometric information includes at least one of blood pressure, blood vessel age, arteriosclerosis, aortic pressure waveform, blood vessel elasticity, stress index, and fatigue degree. The method of claim 1,
And an output unit configured to output a processing result of the processor. The method of claim 17,
The output unit
When the biometric information measurement request is received, the biometric information measuring device for outputting the guide information for guiding the reference contact pressure that the user should apply to the pulse wave sensor through the subject. The method of claim 17,
The output unit
And a guide information for guiding the contact pressure actually applied to the pulse wave sensor by the subject through the converted signal obtained by the processor. Irradiating light of multiple wavelengths to the subject;
Detecting a multi-wavelength pulse wave signal from the subject; And
Acquiring a converted signal representing a contact pressure between the subject and the pulse wave sensor based on the detected multi-wavelength pulse wave signal;
Obtaining an oscillometric envelope based on the multi-wavelength pulse wave signal and the converted signal; And
And measuring biometric information using the oscillometric envelope. The method of claim 20,
Acquiring the converted signal
And calculating a difference signal between the detected pulse wave signals of multiple wavelengths and obtaining the converted signal based on the calculated difference signal. The method of claim 21,
Acquiring the converted signal
And calculating a differential signal between the remaining pulse wave signals based on the pulse wave signal having a blue wavelength among the detected pulse wave signals. The method of claim 22,
Acquiring the converted signal
Acquiring a first differential signal obtained by subtracting a blue wave pulse signal from a green wave pulse signal, and a second differential signal obtained by subtracting the blue wave pulse signal from a red wave pulse signal; And
And obtaining the converted signal based on a ratio between the first difference signal and the second difference signal. The method of claim 20,
Acquiring the oscillometric envelope
And selecting at least one pulse wave signal from a multi-wavelength pulse wave signal, and obtaining an oscillometric envelope based on the selected at least one pulse wave signal and the converted signal. The method of claim 24,
Acquiring the oscillometric envelope
And selecting at least one pulse wave signal based on at least one of a maximum amplitude value, an average amplitude value, and a difference between the maximum amplitude value and the minimum amplitude value of each of the multiple wavelength pulse wave signals. The method of claim 24,
Acquiring the oscillometric envelope
And selecting a plurality of pulse wave signals, and dividing a pulse wave signal having a short wavelength from a pulse wave having a relatively long wavelength, and obtaining an oscillometric envelope based on the difference signal and the converted signal. The method of claim 24,
Acquiring the oscillometric envelope
When selecting a plurality of pulse wave signals, obtaining respective oscillometric envelopes using the selected pulse wave signals and the converted signals; And
And obtaining one oscillometric envelope by integrating the obtained oscillometric envelopes. The method of claim 20,
Measuring the biometric information
And extracting at least one of a maximum amplitude value, a contact pressure value of the maximum amplitude value point, and a contact pressure value of a point corresponding to a predetermined left and right ratio based on the contact pressure value in the oscillometric envelope, Biometric information measuring method for measuring biometric information based on the extracted feature.

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