KR20220035747A - Blood Pressure Measurement System Using Dual Photo Plethysmo Graph - Google Patents

Abstract

The present invention includes a pressure sensor and a microphone, and can accurately calculate diastolic and systolic blood pressure by analyzing a plurality of pulse wave information measured in pressured and unapplied parts based on a blood pressure monitor worn on the subject's body. This relates to a blood pressure measurement system using multiple pulse wave information.

Description

Blood Pressure Measurement System Using Dual Photo Plethysmo Graph}

The present invention relates to a blood pressure measurement system, which includes a pressure sensor and a microphone in detail, and analyzes a plurality of pulse wave information measured in pressure-applied and non-pressurized parts based on a blood pressure monitor worn on the subject's body to determine diastolic stage. This relates to a blood pressure measurement system using multiple pulse wave information that can accurately calculate systolic blood pressure.

Blood, which supplies nutrients and oxygen to each part of the body, circulates through the heart, which acts as a pump. The human heart contracts with the left ventricle for each heartbeat, supplying blood to the aorta, arteries, arterioles, and capillaries of the human body. At this time, the highest pressure value in the artery due to contraction of the left ventricle is called systolic blood pressure (SBP), and the lowest pressure value in the artery due to expansion of the left ventricle for the next beat is called diastolic blood pressure (DBP). It is called.

The most accurate method for measuring blood pressure is the Direct Method, which involves inserting a catheter inside an artery, filling it with liquid, and transmitting the pressure of the blood vessel to an external pressure sensor, or making a hole in the skin or blood vessel. Due to the patient's pain caused by piercing and inserting the catheter, and cost issues, it is used only during surgery or for patients in critical condition.

Accordingly, various indirect methods are commonly used, and the traditionally used auscultation method (Korotokof Sound method) is a representative example of using corticophone sounds to determine the magnitude of systolic pressure and diastolic pressure.

That is, with a mercury manometer and a stethoscope, the pressure at the time of the corticoscopic sound generated by resistance to blood flow as air is injected and released into the air bag wrapped around the subject's arm is checked, and the air bag can be filled or discharged with gas. Not only does it have the disadvantage of making it difficult to check the exact value due to the short time interval between the two and that it must be performed by skilled medical personnel, but with the Minamata Convention coming into effect in 2020, blood pressure monitors using mercury have become unusable.

Therefore, in recent years, automatic blood pressure monitors using the oscillometric method have appeared, but there is a lot of controversy over measurement accuracy.

Republic of Korea Patent Publication No. 10-2007-0101696 (2007.10.17_

The present invention was created to solve the above problems, and the purpose of the present invention is to measure diastolic and systolic blood pressure using a plurality of pulse wave information measured respectively in the pressured and unapplied parts of the blood pressure monitor. The goal is to provide a blood pressure measurement system using multiple pulse wave information that can be accurately calculated and greatly improve the accuracy of digital measurement methods.

For the above purpose, the present invention is provided with a wearing band that is worn around a user's body part, and includes a pressure control unit that adjusts the pressure applied to the body part by controlling the amount of fluid flowing into the pocket, and the pressure control unit. A wearing unit including a pressure measuring unit that measures pressure applied through the unit; a first pulse wave measuring unit that is worn at a first position on the user's body that is not affected by the pressure applied through the wearing unit and collects first pulse wave information in a state where no pressure is applied; a second pulse wave measuring unit that is worn at a second location on the user's body that is affected by pressure applied through the wearing unit and collects second pulse wave information; The driving unit that controls the pressure regulator through a set program and the waveform information according to the first pulse wave information and the second pulse wave information are compared in chronological order, and the systolic and diastolic time points and the first occurrence time after the extinction of the second pulse wave information are compared. A control unit including a calculation unit that calculates pressure; It is characterized by including.

At this time, the calculation unit calculates the period and height of the pulse waveform from the first pulse wave information, and calculates the time of generation of the second pulse wave information according to pressure release from the time of disappearance of the second pulse wave information according to the pressure of the pressure regulator to the second systole. It is desirable to calculate the respective pressures by determining the point in time when the pulse wave information becomes equal to the waveform height of the first pulse wave information as diastole.

In addition, the wearing unit further includes an acoustic measuring unit that measures sounds including corticoscopic sounds generated in blood vessels, and the control unit includes pressure and sound measured through the pressure measuring unit and the acoustic measuring information, respectively, and first pulse wave information. And it may further include a storage unit that stores the second pulse wave information, and an analysis unit that analyzes the measured pressure and sound to calculate systolic and diastolic timing and pressure and compares and analyzes them with the measurement results of the calculation unit.

The present invention can accurately measure blood pressure in the conventional manner through multiple pulse wave information, and can produce a blood pressure measuring device with greatly improved simplicity and portability through a structure such as a finger cuff.

1 is a conceptual diagram of the present invention;
Figure 2 is a conceptual diagram showing a blood pressure waveform depending on whether pressure is applied or not;
Figure 3 is a block diagram showing the configuration and connection relationship according to an embodiment of the present invention;
Figure 4 is a graph comparing the measurement accuracy of the present invention compared to the prior art.

Hereinafter, the configuration of the blood pressure measurement system using multiple pulse wave information according to the present invention will be described in detail with reference to the attached drawings.

1 is a conceptual diagram of the present invention, FIG. 2 is a conceptual diagram showing a blood pressure waveform depending on whether pressure is applied, and FIG. 3 is a block diagram showing the configuration and connection relationship according to an embodiment of the present invention. The present invention relates to diastolic and systolic blood pressure. However, the accuracy is improved compared to the conventional method of measuring corticoscopic sounds through multiple pulse wave information.

Looking at the conventional method, the air bag of the blood pressure monitor is placed around the forearm or wrist of the human body, and pressure is applied by blowing gas into the air bag until the blood movement in the artery of the forearm or wrist completely stops, and the arteries within the range of the air bag are applied. After the heartbeat stops completely, the gas is slowly released.

At this time, the pulse rate within the blood vessel is continuously measured, and before the pressure within the air sac approaches the systolic pressure, the pulsation of the air sac is measured by the pressure meter, and the value that appears on the blood pressure monitor when the first sound source of Corti is measured. This is Systolic Pressure (SP).

Afterwards, the gas in the air sac is released to enlarge the blood vessels, and when the pressure in the air sac decreases to a certain level, the blood vessels are restored. After the spraying effect of blood flow due to pressure completely disappears, the corticoscopic sound source slows down and is the last. The value displayed on the blood pressure monitor when measuring a sound source is diastolic pressure (DP).

Likewise, in order to measure systolic and diastolic blood pressure, the present invention is equipped with a wear band and is worn around the user's arm, and the pressure applied to the arm is adjusted by controlling the amount of fluid flowing into the pocket. A wearable unit 110 is provided with an adjusting unit 111 and a pressure measuring unit 112 that measures the pressure applied through the pressure adjusting unit 111. Preferably, the injected fluid is air, and the pressure regulator 111 is configured as an air bladder capable of expanding and contracting, and is worn around the arm.

In addition, in the present invention, pulse waves are measured at at least two points on the user's body, respectively, a first location that is not affected by the pressure applied through the wearing unit 110, and a first location that is not affected by the pressure applied through the wearing unit 110. Pulse wave information is collected by measuring the pulse wave at a second location that is affected by the pressure.

In other words, the pressure generated by the heartbeat causes blood flow within the blood vessels, and each time a heartbeat occurs, the pressure acts on the capillaries at the end of the body, and even on the blood vessels at the tips of the fingers. Arterial blood from these fingertip capillaries supplies blood to cellular tissue, enters the veins, and returns to the heart.

Synchronized with the heartbeat, the arterial blood volume in the fingertip blood vessels increases and decreases repeatedly.

In the present invention, this blood volume is detected optically.

In other words, when light is irradiated from a light source to a body part such as a finger, light is absorbed in the blood, bones, and tissues, and some of it penetrates the body and reaches the light receiver. At this time, the degree to which light is absorbed is proportional to the amount of skin, tissue, and blood in the path of light, and since it is a component that does not change except for changes in blood flow due to heartbeat, it is proportional to the change in the amount of light absorbed.

Since the transmitted light detected in the light receiver is received after subtracting the amount of light absorbed by the finger, the change in the amount of light in the transmitted light also reflects the change in blood flow, so it is possible to detect changes in blood volume synchronized with the heartbeat by measuring the amount of light in the light receiver, which is usually measured as PPG (PPG). It is called Photo PlethysmoGraph (pulse wave).

In an embodiment of the present invention, pulse waves are measured at two points, and for this purpose, the device is basically worn at a first position on the user's body that is not affected by the pressure applied through the wearing unit 110 in a state where no pressure is applied. A first pulse wave measuring unit 120 that collects first pulse wave information, and a second pulse wave information collected by being worn at a second location on the user's body that is affected by the pressure applied through the wearing unit 110. Two pulse wave measurement units 130 are provided.

For example, if the wearing unit 110 is worn on one arm, the other arm is set as the first position, and the lower part of the wearing unit 110 on the arm on which the wearing unit 110 is installed is set as the second position. It can be. As mentioned above, the first pulse wave measuring unit 120 and the second pulse wave measuring unit 130 are optically equipped with a light source and a light receiving unit to measure pulse waves, and are manufactured in the form of a finger cuff, etc. to be worn separately. It can be worn and measured simply without any tools.

This wearable unit 110 and a control unit 140 for controlling the operation of the first pulse wave measuring unit 120 and the second pulse wave measuring unit 130 and calculating blood pressure are provided, which basically consists of a driving unit 141 and a calculating unit ( 142).

The driving unit 141 is configured to control the pressure regulating unit 111 through a set program. As the pressure regulating unit 111 is composed of an air bag, an air pump and discharge valve are provided to inject air into the pressure regulating unit 111. Includes. As in the normal blood pressure measurement process, the pressure regulator 111 is expanded to a level that can block the flow of blood while wearing the wearable part 110, and then the pressure regulator (111) is adjusted to a level where normal blood flow is achieved. 111) Reduce the pressure slowly.

The calculation unit 142 compares the waveform information according to the first pulse wave information and the second pulse wave information in chronological order and calculates the systolic and diastolic time points and pressure through the disappearance of the second pulse wave information and the first occurrence time after disappearance.

Specifically, the period and height of the pulse waveform are calculated from the first pulse wave information, and the time of occurrence of the second pulse wave information according to pressure release is calculated from the point of disappearance of the second pulse wave information according to the pressure of the pressure regulator to the systolic phase. The point at which the waveform height of the first pulse wave information becomes equal to the diastolic stage is determined to be the diastolic stage, and the respective pressures are calculated.

In the attached FIG. 2, the orange waveform is the signal of the part where pressure was not applied measured through the first pulse wave measuring unit 120, and the blue waveform is the signal of the part where pressure was applied measured through the second pulse wave measuring unit 130. represents each.

When the pressure regulator 111 expands and pressure is applied, the blood flow decreases and the waveform measured through the second pulse wave measuring unit 130 disappears and returns to a normal signal as the pressure is released. The time at which the first waveform occurs coincides with the time at which the corticoscopic sound occurs, indicating systole. Afterwards, the time when the pressure is completely released and the waveforms of the first pulse wave information and the waveform of the second pulse wave information become the same coincides with the time when the corticophone sound disappears, which means the diastolic period. Therefore, the pressure value obtained through the pressure measuring unit 112 at each time point is Blood pressure can be calculated through

To check accuracy, the wearing unit 110 may further include an acoustic measurement unit 113 that measures sounds including corticoscopic sounds generated from blood vessels. That is, sounds generated in blood vessels can be collected together through a microphone sensor, and in response, the control unit provides pressure and sound and first pulse wave information measured through the pressure measurement unit 112 and the sound measurement unit 113, respectively. and a storage unit 143 that stores the second pulse wave information, and an analysis unit 144 that analyzes the measured pressure and sound to calculate systolic and diastolic timing and pressure and compares them with the measurement results of the calculation unit 142. By further including this, accuracy can be improved through mutual verification of the pulse wave method and the acoustic method.

Figure 4 is a graph comparing the measurement accuracy of the present invention compared to the prior art, and Table 1 shows the error rate measurement results. It can be seen that the error rate of the method according to the present invention is smaller than that of the conventional method.

Blood pressure was measured in a total of 10 normal people using KBP (standard blood pressure measurement value from a mercury sphygmomanometer), OBP (blood pressure measurement value from an automatic sphygmomanometer), and PPG (blood pressure measurement value using two plethysmographs), and based on KBP, the existing automatic The performance of the blood pressure monitor (OBP) and the proposed method (PPG) were compared.

systole diastole Automatic blood pressure machine error rate 4.43% 7.23% PPG method error rate 3.01% 5.91%

The rights of the present invention are not limited to the embodiments described above but are defined by the claims, and those skilled in the art can make various changes and modifications within the scope of the claims. This is self-evident.

110: wearing part 111: pressure adjusting part
112: pressure measurement unit 113: acoustic measurement unit
120: first pulse wave measuring unit 130: second pulse wave measuring unit
140: control unit 141: driving unit
142: calculation unit 143: storage unit
144: Analysis department

Claims (3)

It is equipped with a wearing band and is worn around a part of the user's body, and includes a pressure control unit 111 that adjusts the pressure applied to the body part by controlling the amount of fluid flowing into the pocket, and the pressure control unit 111. A wearing unit 110 having a pressure measuring unit 112 that measures applied pressure;
a first pulse wave measuring unit 120 that is worn at a first position on the user's body that is not affected by the pressure applied through the wearing unit 110 and collects first pulse wave information in a state in which no pressure is applied;
a second pulse wave measuring unit 130 that is worn at a second location on the user's body affected by pressure applied through the wearing unit 110 and collects second pulse wave information;
The driving unit 141, which controls the pressure regulator 111 through a set program, and the waveform information according to the first pulse wave information and the second pulse wave information are compared in chronological order, and the first occurrence point after the disappearance and disappearance of the second pulse wave information A control unit 140 including a calculation unit 142 that calculates systolic and diastolic timing and pressure through; A blood pressure measurement system using multiple pulse wave information, comprising:
According to paragraph 1,
The calculation unit 142,
The period and height of the pulse waveform are calculated from the first pulse wave information, and the time of generation of the second pulse wave information according to pressure release is calculated from the time of disappearance of the second pulse wave information according to the pressure of the pressure regulator 111 to the systolic period. A blood pressure measurement system using multiple pulse wave information, characterized in that the point at which the waveform height of the first pulse wave information becomes equal to the diastolic stage is determined to calculate the respective pressures.
According to paragraph 1,
The wearing unit 110 further includes an acoustic measurement unit 113 that measures sounds including corticoscopic sounds generated in blood vessels,
The control unit 140 includes a storage unit 143 that stores the pressure and sound, first pulse wave information, and second pulse wave information measured through the pressure measurement unit and the acoustic measurement information, respectively, and analyzes the measured pressure and sound. A blood pressure measurement system using multiple pulse wave information, further comprising an analysis unit 144 that calculates the systolic and diastolic timing and pressure and compares and analyzes them with the measurement results of the calculation unit 142.