KR102309974B1 - Optical sensor based blood pressure measuring device - Google Patents

Abstract

A blood pressure measuring apparatus according to an aspect of the present disclosure includes a signal processing module for calculating a blood pressure value based on a signal reflected by a light emitting element, a light receiving element, and a light receiving element. At this time, the signal processing module generates an optical arterial wave based on the signal reflected by the light receiving element through execution of the signal processing blood pressure measurement program, and calculates a blood pressure value based on the optical arterial wave. The signal processing module calculates a blood pressure difference between the first point and the second point based on a difference between the height of the portable blood pressure measuring device located at the first point and the height of the second point.

Description

Optical sensor-based blood pressure measurement device {OPTICAL SENSOR BASED BLOOD PRESSURE MEASURING DEVICE}

The present invention relates to a blood pressure measuring device based on an optical sensor.

Recently, interest in health care is increasing, and as the number of patients with high blood pressure and low blood pressure increases, research on wearable devices that can conveniently check their own blood pressure is being actively conducted.

In particular, in order to improve portability of the blood pressure device, a wearable device for measuring blood pressure using an optical sensor without using an air pump or the like has recently been developed. In a blood pressure measuring device using such an optical sensor, a laser is irradiated to a subject, a light receiving element detects a signal reflected from the subject, and a signal processing module calculates a blood pressure value.

However, since such a conventional blood pressure measuring apparatus does not take into account a change in blood pressure according to a measurement height, there is a limitation in that it cannot accurately measure a blood pressure value.

Laid-Open Patent 10-2016-0028303 (Title of the Invention: Apparatus and method for monitoring blood pressure, wearable device having blood pressure monitoring function)

The present invention is to solve the problems of the prior art described above, by calculating the difference in blood pressure at two points located at different heights and the difference in the amplitude of the optical arterial wave signal to set the blood pressure level per unit length, and the blood pressure level per unit length. An object of the present invention is to provide a more accurate blood pressure value by measuring the distance from the baseline position to the two points with respect to the optical arterial wave signal stored in advance in the portable blood pressure measuring device based on the .

However, the technical problems to be achieved by the present embodiment are not limited to the technical problems described above, and other technical problems may exist.

A blood pressure measuring apparatus according to a first aspect of the present application includes: a light emitting element irradiating an optical signal to a region of interest of a subject; a light receiving element for sensing a signal reflected from the region of interest; a signal processing module for calculating a blood pressure value based on the reflected signal, wherein the signal processing module includes a memory storing a blood pressure measurement program and a processor executing the blood pressure measurement program, wherein the program is executed by the processor Executed to generate an optical arterial wave based on the reflected signal, and calculate a blood pressure value based on the optical arterial wave, wherein the portable blood pressure measuring device is positioned at a first point and a second point. and calculating a difference in blood pressure at the first point and the second point based on the difference in .

A blood pressure measuring device according to a second aspect of the present invention includes a light emitting device for irradiating an optical signal to a region of interest of a subject, a light receiving device for sensing a signal reflected from the region of interest, and a blood pressure value based on the reflected signal. a signal processing module for calculating, wherein the signal processing module includes a memory storing a blood pressure measurement program and a processor executing the blood pressure measurement program, wherein the program is executed by the processor and based on the reflected signal A pulse wave is generated, and a blood pressure value is calculated based on the optical arterial wave, and the reference height difference indicating the height difference between the position of the heart of the user and the lowest point that the user can have while wearing the portable blood pressure measuring device is stored in the memory. , a process of calculating a measurement height difference representing the difference between the height of the portable blood pressure measurement device at the user's blood pressure measurement time and the height at the lowest point, Compensating blood pressure based on a value obtained by subtracting the measurement height difference from the reference height difference and calculating the blood pressure value at the heart position at the measurement time point by summing the blood pressure value at the measurement time point and the compensation blood pressure.

A blood pressure measuring method according to a third aspect of the present invention uses a portable blood pressure measuring device for measuring blood pressure based on light sensing, wherein the portable blood pressure measuring device is positioned at a height of a first point and a second point. and calculating a difference in blood pressure at the first point and the second point based on the difference in height of .

According to the above-described problem solving means of the present application, it is possible to calculate the blood pressure in consideration of the change in blood pressure according to the measurement height, so that it is possible to calculate the blood pressure more accurately than using the conventional measurement method.

1 is a block diagram showing the configuration of an optical sensor-based blood pressure measuring apparatus according to an embodiment of the present invention.
2 is a view for explaining a process of a blood pressure measuring apparatus according to an embodiment of the present invention.
3 is an optical arterial wave signal graph for explaining a blood pressure calculation method according to an embodiment of the present invention.
4 is a formula for calculating a blood pressure difference according to an embodiment of the present invention.
5 is a flowchart of a method for measuring blood pressure in consideration of a height difference according to an embodiment of the present invention.
6 is a view for explaining a height difference between the lowest point and the heart of the blood pressure measuring apparatus according to an embodiment of the present invention.
7 is a flowchart of a blood pressure measuring method in consideration of a height difference between the lowest point and the heart of the blood pressure measuring apparatus according to an embodiment of the present invention.

Hereinafter, embodiments of the present application will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art to which the present application pertains can easily implement them. However, the present application may be embodied in several different forms and is not limited to the embodiments described herein. And in order to clearly explain the present application in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout this specification, when a part is said to be "connected" with another part, it includes not only the case where it is "directly connected" but also the case where it is "electrically connected" with another element interposed therebetween. do.

Throughout this specification, when a member is said to be located “on” another member, this includes not only a case in which a member is in contact with another member but also a case in which another member is present between the two members.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing the configuration of an optical sensor-based blood pressure measuring apparatus according to an embodiment of the present invention.

As shown, the optical sensor-based blood pressure measuring device 10 includes a light emitting device 100, a light receiving device 110, and a signal processing module 120, wherein the signal processing module 120 includes a program for measuring blood pressure. It includes a stored memory 121 and a processor 122 for executing a program.

Such an optical sensor-based blood pressure measuring apparatus 10 is provided in the form of a wearable device worn on the user's wrist, etc., and may be configured in various forms such as a wrist watch, smart band, or bracelet to be worn on the wrist. A detailed description of the wearing device will be omitted.

The principle of operation of the present invention is that the light emitting device 100 irradiates an optical signal such as a laser to the region of interest of the subject, the light receiving element 110 detects a signal reflected from the region of interest, and based on the reflected signal to calculate the blood pressure value in the signal processing module 120, in detail, the blood pressure calculation program in the memory 121 included in the signal processing module 120 is executed by the processor 122, and the program is reflected A blood pressure value is calculated by generating an optical arterial wave based on the received signal.

Here, the light emitting device 100 may be an element such as a laser, and is arranged to be irradiated toward the radial artery of the wrist, but is not limited thereto, and may be arranged to be irradiated toward other blood vessels of the wrist.

The light receiving device 110 receives the light emitting device 100 signal reflected from the region of interest, and the light emitting device 100 signal received from the light receiving device 110 is transmitted to the signal processing module 120 . In this case, the light emitting device 100 and the light receiving device 110 adopt a conventionally known configuration, and a detailed description thereof will be omitted.

The signal processing module 120 generates an optical arterial wave based on the reflected signal of the light emitting device 100 received through the light receiving device 110 , and calculates a blood pressure value based thereon.

The memory 121 stores a program for measuring blood pressure and various data necessary for the execution of the program. The memory 121 collectively refers to a non-volatile storage device that continuously maintains stored information even when power is not supplied, and a volatile storage device that requires power to maintain the stored information.

The processor 122 executes a program for measuring blood pressure stored in the memory 121 to generate an optical arterial wave, calculate a blood pressure value, and the like. In particular, in the present invention, the blood pressure is calculated at different points, the blood pressure difference is calculated based on the difference in the respective measured heights, and the blood pressure level per unit length is calculated by dividing this by the difference in the signal level of the optical arterial wave. Perform accurate blood pressure calculation. In this case, as the processor 122 , various types of generally distributed micro-computing processors may be used.

5 is a flowchart of a method for measuring blood pressure in consideration of a height difference according to an embodiment of the present invention.

First, the reference optical artery wave generated in the calibration process, which is an initial setting process, is matched with a program in the memory 121, and the reference blood pressure value input through the external blood pressure monitor is matched to the reference optical artery wave to set the position of the baseline. (S1). Through this process, it is possible to specify a baseline indicating a value of 0 with respect to a value on the y-axis with respect to a future optical arterial wave signal.

On the other hand, since the specific method for generating the optical arterial wave signal corresponds to a conventionally known configuration as disclosed in Korean Patent Application Laid-Open No. 10-2016-0028303, a detailed description thereof will be omitted.

Thereafter, the optical arterial wave is sensed at points located at different heights (S2), and the subject generated when the blood pressure measuring device 10 is located at the first point h1 and at the second point h2. of the optical arterial wave is sensed.

2 is a view for explaining a process of a blood pressure measuring apparatus according to an embodiment of the present invention.

As shown in the drawing, in a state in which the blood pressure measuring device 10 is worn on the wrist, optical arterial waves are respectively generated at the first point h1 and the second point h2, and the height value of the measurement point is also sensed. In this case, the blood pressure measuring device 10 includes at least one of an acceleration sensor, a gyro sensor, an altitude sensor, and a differential pressure gauge, and a blood pressure based on a sensing value output from at least one of the acceleration sensor, the gyro sensor, the altitude sensor, and the differential pressure gauge. The height of the point where the measuring device 10 is located is calculated.

As described above, when the height of the first point h1 and the height of the second point h2 are respectively sensed, the difference in blood pressure at the first point h1 and the second point h2 is calculated through the equation of FIG. 4 . can be calculated.

In this case, the gravitational acceleration is a fixed value, and the blood density ρ may be a preset value stored in the blood pressure measuring device 10 or separately measured and stored for each user.

Referring back to FIG. 5 , the difference in signal amplitude between the first optical artery wave sensed at the first point h1 and the second optical artery wave sensed at the second point h2 is the difference in the blood pressure calculated in step S2 ( ΔP) to set the blood pressure level per unit length (S3). In this case, the blood pressure magnitude per unit length is a value for measuring blood pressure on the optical arterial wave signal graph thereafter, and represents, for example, the blood pressure magnitude compared to the distance on the y-axis of the optical arterial wave signal. Therefore, after the blood pressure level per unit length is set, if the distance on the y-axis of the optical artery wave signal is known, the blood pressure for the optical artery wave signal can be calculated.

Thereafter, the distance from the position of the baseline for the optical arterial wave signal previously stored in the portable blood pressure measuring device 10 to the first or second optical arterial wave is measured (S4).

Then, the blood pressure value is calculated by multiplying the measured distance by the blood pressure size per unit length (S5).

3 is an optical arterial wave signal graph for explaining a blood pressure calculation method according to an embodiment of the present invention.

Using the blood pressure magnitude per unit length calculated in the previous step (S3), blood pressure values are calculated for the first optical artery wave sensed at the first point h1 and the second optical artery wave sensed at the second point h2, respectively. can do.

Taking the first optical artery wave as an example, since the baseline has been determined in the previous step S1, the distance from the baseline of the first optical artery wave to the lowest point can be specified, and the blood pressure level per unit length can be specified at this distance. By multiplying by , the blood pressure at the lowest point of the first optical arterial wave can be calculated. Similarly, the distance from the baseline of the first optical arterial wave to the highest point can be specified, and by multiplying this distance by the blood pressure per unit time, the blood pressure at the highest point of the first optical arterial wave can be calculated.

7 is a flowchart illustrating a method of measuring a blood pressure in consideration of a height difference between a lowest point and a heart of the blood pressure measuring apparatus according to another embodiment of the present invention.

A blood pressure measuring method in consideration of the height difference between the lowest point of the blood pressure measuring device and the heart will be described with reference to FIG. 7 .

This measurement method is based on the measurement method using the blood pressure level per unit length in FIG. 5 described above, and the detailed description thereof is the same as above.

First, while the user wears the portable blood pressure measuring device 10 , the lowest point (hereinafter, the first point) at which the portable blood pressure measuring device 10 can be located is set ( S1 ′).

Referring to FIG. 6, the distance H0 from the set first point to the heart is measured (S2'). The height difference between the lowest point and the position of the heart may be measured using various sensors built into the portable blood pressure measuring device 10 . However, it is also possible to measure the height difference using a tape measure or the like according to the user's selection, and then store it in the form of being inputted to the portable blood pressure measuring device 10 by the user.

Next, the distance ΔH1 from the first point to the current blood pressure measurement position (hereinafter, the second point) is measured ( S3 ′). In this case, the current blood pressure measurement position means an arbitrary position between the user's heart position and the lowest point.

Thereafter, the distance (H0-ΔH1) from the second point to the heart is calculated by subtracting the distance (ΔH1) from the first point to the second point from the distance (H0) from the first point to the heart (S4') .

The blood pressure value calculated by dividing the calculated distance (H0-ΔH1) from the second point to the heart by the unit length and multiplying the blood pressure size per unit length calculated through the process described above with reference to FIG. 5 is obtained at the second point. By compensating for the value (S5'), the final blood pressure value is calculated (S6'). That is, the blood pressure value at the second point is calculated using the method of FIG. 5 described above, and the value obtained by multiplying the blood pressure value per unit length by the distance (H0-ΔH1) from the second point to the heart is added. Compensation processing is performed.

Through this process, the blood pressure measured at an arbitrary point may be converted into a blood pressure value at the heart location.

An embodiment of the present invention may also be implemented in the form of a recording medium including instructions executable by a computer, such as a program module executed by a computer. Computer-readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. Also, computer-readable media may include computer storage media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data.

Although the methods and systems of the present invention have been described with reference to specific embodiments, some or all of their components or operations may be implemented using a computer system having a general purpose hardware architecture.

The above description of the present application is for illustration, and those of ordinary skill in the art to which the present application pertains will understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present application. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may be implemented in a combined form.

The scope of the present application is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present application.

10: blood pressure measuring device
100: laser
110: light receiving element
120: signal processing module
121: memory
122: processor

Claims (12)

A portable blood pressure measuring device for measuring blood pressure based on an altitude difference, comprising:
A light emitting device that irradiates an optical signal to the region of interest of the subject;
a light receiving element for detecting a signal reflected from the region of interest;
a memory in which a blood pressure measurement program for calculating a blood pressure value based on the reflected light signal is stored;
A processor for executing the blood pressure measurement program,
The program is executed by the processor to generate an optical artery wave based on the reflected signal, and calculates a blood pressure value based on the optical artery wave,
The process of calculating the difference in blood pressure at the first point and the second point based on the difference between the height of the portable blood pressure measuring device located at the first point and the height of the second point, and sensing at the first point A process of determining a blood pressure level per unit length by dividing a signal level difference between a first optical artery wave and a second optical artery wave sensed at a second point by the calculated blood pressure difference, and calculating a blood pressure value based on the blood pressure level per unit length A portable blood pressure measuring device comprising the process of calculating. The method of claim 1,
The program calculates the distance of the first optical artery wave or the second optical artery wave from the position of the baseline with respect to the previously stored optical arterial wave signal, and calculates the blood pressure value for the first optical artery wave or the blood pressure value for the second optical artery wave. A portable blood pressure measuring device that performs the calculation process. 3. The method of claim 2,
The program matches the reference optical artery wave generated in the initial setting process, receives a reference blood pressure value input through external blood pressure measurement, and sets the position of the baseline by matching the reference blood pressure value to the reference optical artery wave. blood pressure measuring device. The method of claim 1,
The portable blood pressure measuring device includes at least one of an optical sensor, an acceleration sensor, a gyro sensor, an altitude sensor, and a differential pressure gauge,
wherein the program calculates the height of the portable blood pressure measuring device based on a sensing value output from at least one of the acceleration sensor, the gyro sensor, the altitude sensor, and the differential pressure gauge. 3. The method of claim 2,
wherein the program calculates a distance separated from the baseline to the lowest or highest point of the optical artery wave, and multiplies the separated distance by the size of the blood pressure per unit length to calculate the blood pressure value. A portable blood pressure measuring device for measuring blood pressure based on an altitude difference, comprising:
A light emitting device that irradiates an optical signal to the region of interest of the subject;
a light receiving element for detecting a signal reflected from the region of interest;
a memory in which a blood pressure measurement program for calculating a blood pressure value based on the reflected signal is stored;
A processor for executing the blood pressure measurement program,
The program is executed by the processor to generate an optical artery wave based on the reflected signal, and calculates a blood pressure value based on the optical artery wave,
The memory stores a reference height difference representing a height difference between the user's heart position and the lowest point that the user can have while wearing the portable blood pressure measuring device, and the height of the portable blood pressure measuring device at the user's blood pressure measurement time and the The process of calculating the measured height difference representing the height difference at the lowest point, the process of calculating the compensation blood pressure based on a value obtained by subtracting the measured height difference from the reference height difference, the blood pressure value at the measurement point and the compensation blood pressure Comprising the process of calculating the blood pressure value at the heart position at the measurement time point by summing,
The program matches the reference optical artery wave generated in the initial setting process, receives the reference blood pressure value input through external blood pressure measurement, and sets the position of the baseline by matching the reference blood pressure value to the reference optical artery wave;
The process of calculating the difference in blood pressure at the first point and the second point based on the difference between the height of the portable blood pressure measuring device located at the first point and the height of the second point, and sensing at the first point A process of determining the magnitude of blood pressure per unit length by dividing the difference in signal magnitude between the first optical artery wave and the second optical artery wave sensed at the second point by the calculated difference in blood pressure, from the baseline to the lowest point or the highest point of the optical artery wave The portable blood pressure measuring device is to calculate the separated distance, and multiply the separated distance by the blood pressure level per unit length to calculate the blood pressure value at the measurement time point. delete 7. The method of claim 6,
The portable blood pressure measuring device includes at least one of an optical sensor, an acceleration sensor, a gyro sensor, an altitude sensor, and a differential pressure gauge,
wherein the program calculates the height of the portable blood pressure measuring device based on a sensing value output from at least one of the acceleration sensor, the gyro sensor, the altitude sensor, and the differential pressure gauge. A blood pressure measurement method using a portable blood pressure measurement device for measuring blood pressure based on an altitude difference, the method comprising:
calculating a blood pressure difference at a first point and a second point based on a difference between the height of the portable blood pressure measuring device located at the first point and the height of the second point;
checking a blood pressure level per unit length by dividing a signal level difference between the first optical arterial wave sensed at the first point and the second optical arterial wave sensed at the second point by the calculated blood pressure difference;
setting a position of a baseline with respect to the optical artery wave signal by matching the reference blood pressure value input through measurement of an external blood pressure monitor to the reference optical arterial wave;
The distance of the first optical artery wave or the second optical artery wave is calculated from the position of the baseline based on the size of the blood pressure per unit length, and the blood pressure value for the first optical artery wave or the blood pressure value for the second optical artery wave is calculated. A blood pressure measurement method comprising the step of calculating. delete 10. The method of claim 9,
The calculating of the blood pressure value may include calculating a distance from the baseline to the lowest point or the highest point of the first or second optical artery wave, and multiplying the separated distance by the blood pressure value per unit length to obtain the blood pressure value. A blood pressure measurement method that calculates 10. The method of claim 9,
calculating a measurement height difference representing a difference between the height of the portable blood pressure measurement device at the first point or the second point and the height at the lowest point that a user can have while wearing the portable blood pressure measurement device;
calculating a compensation blood pressure based on a value obtained by subtracting the measured height difference from a reference height difference indicating a height difference between the user's heart position and the lowest point; and
calculating the blood pressure value for the heart position at the first point or the second point by adding the blood pressure value for the first optical arterial wave or the blood pressure value for the second optical arterial wave and the compensation blood pressure; How to measure.

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