APPARATUS AND METHOD FOR ESTIMATING BLOOD PRESSURE BY USING VARIABLE CHARACTERISTIC RATIO

• US 20100298721A1
• Filed: 03/15/2010
• Published: 11/25/2010
• Est. Priority Date: 05/22/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: KIM, Youn-ho, KIM, Seok Chan
• Granted Patent: US 9,585,573 B2
• Time in Patent Office: Days
• US Class Current: 600/486
• CPC Class Codes: A61B 5/02108 from analysis of pulse wave characteristics
• CPC Class Codes: A61B 5/022 by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers
• CPC Class Codes: A61B 5/02225 using the oscillometric method

Abstract

A method of estimating blood pressure includes obtaining a pressure wave detected at a measurement body part of a subject, calculating a characteristic ratio of the subject according to a shape of the detected pressure wave based on a correlation between the characteristic ratio used to determine blood pressure at a measurement body part and the shape of the pressure wave detected at the measurement body part, and estimating blood pressure at the measurement body part of the subject is estimated using the calculated characteristic ratio.

Claims

1. A method of estimating blood pressure, the method comprising:

obtaining a pressure wave detected at a measurement body part of a subject;

calculating a characteristic ratio of the subject according to a shape of the obtained pressure wave based on a correlation between the characteristic ratio used to determine blood pressure at a measurement body part and the shape of the pressure wave detected at the measurement body part; and

estimating blood pressure at the measurement body part of the subject using the calculated characteristic ratio.

2. The method of claim 1, wherein the shape of the pressure wave represents a rate of amplitude reduction with reference to a pressure value having a maximum amplitude as the pressure value one of increases and decreases.

3. The method of claim 1, wherein the characteristic ratio used to determine blood pressure at a measurement body part is determined using a reference blood pressure measured at the measurement body part.

4. The method of claim 3, wherein the reference blood pressure comprises at least one selected from the group consisting of a diastolic blood pressure and a systolic blood pressure, which are determined by applying the characteristic ratio used to determine the blood pressure, irrespective of the shape of the pressure wave, to a pressure wave detected while an upper arm of the measurement body part is pressed.

5. The method of claim 3, wherein the reference blood pressure is measured using an invasive method.

6. The method of claim 1, further comprising determining an index to be a difference between the blood pressure determined by applying the characteristic ratio used to determine the blood pressure, irrespective of the shape of the pressure wave, to the detected pressure wave, and a blood pressure having a maximum amplitude of the detected pressure wave, wherein the index represents the shape of the detected pressure wave,

wherein the calculating of the characteristic ratio of the subject according to the shape of the obtained pressure wave is performed using the determined index.

7. The method of claim 6, wherein the calculating of the characteristic ratio of the subject according to the shape of the obtained pressure wave includes applying the determined index to a relational equation derived using a plurality of data representing the correlation.

8. The method of claim 6, wherein the estimating of the blood pressure includes at least one blood pressure having an amplitude corresponding to the calculated characteristic ratio of the subject with respect to the maximum amplitude of the pressure wave detected while the measurement body part of the subject is pressed is estimated as the blood pressure of the subject.

9. The method of claim 6, further comprising determining a pseudo diastolic blood pressure by applying the characteristic ratio, irrespective of the shape of the pressure wave, to the pressure wave detected at the measurement body part of the subject,

wherein determining the index includes subtracting the determined pseudo diastolic blood pressure from the blood pressure having the maximum amplitude of the pressure wave detected at the measurement body part of the subject to determine a diastolic blood pressure index,

wherein the calculating of the characteristic ratio of the subject includes using the determined diastolic blood pressure index to calculate a characteristic ratio to determine a diastolic blood pressure of the subject, and

wherein the estimating of the blood pressure at the measurement body part of the subject includes estimating a blood pressure having an amplitude corresponding to the calculated characteristic ratio of the subject with respect to the maximum amplitude of the pressure wave to be the diastolic blood pressure of the subject.

10. The method of claim 6, further comprising determining a pseudo systolic blood pressure by applying the characteristic ratio, irrespective of the shape of the pressure wave, to the pressure wave detected at the measurement body part of the subject,

wherein determining the index includes subtracting the blood pressure having the maximum amplitude of the pressure wave detected at the measurement body part of the subject from the determined pseudo systolic blood pressure to determine a systolic blood pressure index,

wherein calculating the characteristic ratio of the subject includes calculating a characteristic ratio used to determine a systolic blood pressure of the subject using the determined systolic blood pressure index, and

wherein the estimating of the blood pressure at the measurement body part of the subject includes estimating a pressure having an amplitude corresponding to the calculated characteristic ratio of the subject with respect to the maximum amplitude of the pressure wave to be the systolic blood pressure of the subject.

11. A computer readable recording medium having embodied thereon a program for executing the method of claim 1.

12. A blood pressure estimating apparatus comprising:

a detection unit which detects a pressure wave at a measurement body part of a subject;

a characteristic ratio calculation unit which calculates a characteristic ratio of the subject according to a shape of the detected pressure wave based on a correlation between a characteristic ratio used to determine blood pressure at a measurement body part and the shape of the detected pressure wave at the measurement body part; and

a blood pressure estimating unit which estimates blood pressure at the measurement body part of the subject using the calculated characteristic ratio.

13. The apparatus of claim 12, wherein the shape of the pressure wave represents a rate of amplitude reduction with reference to a pressure value having a maximum amplitude as the pressure value one of increases and decreases.

14. The apparatus of claim 12, wherein the characteristic ratio used to determine blood pressure at a measurement body part is determined using a reference blood pressure measured at the measurement body part.

15. The apparatus of claim 14, wherein the reference blood pressure comprises at least one selected from the group consisting of a diastolic blood pressure and a systolic blood pressure, which are determined by applying the characteristic ratio used to determine the blood pressure, irrespective of the shape of the pressure wave, to a pressure wave detected while an upper arm of the measurement body part is pressed.

16. The apparatus of claim 14, wherein the reference blood pressure is measured using an invasive method.

17. The apparatus of claim 12, further comprising an index determination unit which determines a difference between the blood pressure determined by applying the characteristic ratio used to determine the blood pressure, irrespective of the shape of the pressure wave, to the detected pressure wave, and a blood pressure having a maximum amplitude of the detected pressure wave, to be an index which represents the shape of the detected pressure wave,

wherein the characteristic ratio calculation unit calculates the characteristic ratio of the subject using the determined index.

18. The apparatus of claim 17, wherein the characteristic ratio calculation unit calculates the characteristic ratio of the subject by applying the determined index to a relational equation derived using a plurality of data points representing the correlation.

19. The apparatus of claim 17, wherein the blood pressure estimation unit estimates at least one blood pressure having an amplitude corresponding to the calculated characteristic ratio of the subject with respect to the maximum amplitude of the pressure wave detected while the measurement body part of the subject is pressed, to be the blood pressure of the subject.

20. The apparatus of claim 17, further comprising:

a blood pressure determination unit which determines a pseudo systolic blood pressure by applying the characteristic ratio, irrespective of the shape of the pressure wave, to the pressure wave detected at the measurement body part of the subject,

wherein the index determination unit determines a result of subtracting the blood pressure having the maximum amplitude of the pressure wave detected at the measurement body part of the subject from the determined pseudo systolic blood pressure to be a systolic blood pressure index,

wherein the characteristic ratio calculation unit calculates a characteristic ratio used to determine a systolic blood pressure of the subject using the determined systolic blood pressure index, and

wherein the blood pressure estimation unit estimates a pressure having an amplitude corresponding to the calculated characteristic ratio of the subject with respect to the maximum amplitude of the pressure wave to be the systolic blood pressure of the subject.