Method and apparatus for cufflessly and non-invasively measuring wrist blood pressure in association with communication device

• US 20080228089A1
• Filed: 03/11/2008
• Published: 09/18/2008
• Est. Priority Date: 03/12/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jung, Sun-Tae, Cho, Jae-Geol, Im, Jae-Joong
• Granted Patent: US 8,086,301 B2
• Time in Patent Office: Days
• US Class Current: 600/485
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02125 of pulse wave propagation time
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle

Abstract

A method of cufflessly and non-invasively measuring blood pressure in a wrist region of a patient in association with a communication device that relays the information being measured includes: detecting a magnitude difference between a plurality of pulse wave signals detected from a wrist of a user; detecting feature points from an electrocardiogram (ECG) and pulse wave signals detected from the user; extracting variables needed to calculate the highest blood pressure and the lowest blood pressure using the detected feature points; and calculating the highest blood pressure and the lowest blood pressure of the user by deducing a scatter diagram using the extracted variables.

Claims

1. A method of cufflessly and non-invasively measuring wrist blood pressure in association with a communication device, the method comprising:

(a) detecting an electrocardiogram (ECG) and pulse wave signals from a wrist region of a user using an ECG sensor and a pressure sensor;

(b) detecting feature points from the ECG and pulse wave signals detected from the user;

(c) extracting variables for calculating a highest blood pressure and a lowest blood pressure by applying the feature points detected in step (b) to a blood pressure calculation algorithm; and

(d) calculating the highest blood pressure and the lowest blood pressure of the user by deducing a scatter diagram using the extracted variables.

2. The method of claim 1, wherein the detecting of the ECG and pulse wave signals in step (a) comprises:

(i) setting a criterion of pressure applied to the wrist using magnitude differences of the measured more than one pulse wave signals; and

(ii) compensating for a user environment, including at least one of a position and depth of an artery measured using an infrared sensor, and a criterion value change according to a sensor applied pressure difference.

3. The method of claim 1, wherein the detecting of the feature points from the ECG and pulse wave signals detected from the user in step (b) comprises:

(i) detecting an R-peak in a P-QRS-T waveform indicating one period of electric activity of a heart from the measured ECG signal; and

(ii) detecting a beginning point, the highest point, and a notch point.

4. The method of claim 1, wherein the variables for calculating the highest blood pressure and the lowest blood pressure comprises a time value from a detected R-peak of the ECG signal to a pulse wave beginning point, a time value from the R-peak to a pulse wave highest point, a time value from the pulse wave beginning point to a pulse wave highest point, a time value from the pulse wave highest point to a pulse wave notch point, and an area value from the pulse wave beginning point to the pulse wave notch point, and

the R-peak obtained from the ECG signal is used as a criterion value of time.

5. The method of claim 3, wherein the calculating of the highest blood pressure and the lowest blood pressure comprises:

deducing a linear regression expression by using the extracted variables as independent variables; and

calculating the highest blood pressure and the lowest blood pressure of the user from the deduced linear regression expression.

6. The method according to claim 1, wherein the ECG sensor and pressure sensor are integrated in a sensor unit for measuring blood pressure in a wrist region without a cuff.

7. The method according to claim 1, further comprising (e) transmitting the highest and lowest blood pressure values calculated are transmitted to an external device.

8. The method according to claim 5, further comprising (e) transmitting the highest and lowest blood pressure values calculated are transmitted to an external device.

9. The method according to claim 5, further comprising (e) storing the highest and lowest blood pressure values from step (d) in a memory.

10. The method according to claim 5, further comprising (e) display the highest and lowest blood pressure values calculated in step (d).

11. The method according to claim 8, wherein the highest and lowest blood pressure values are transmitted when the values exceed a predetermined threshold value.

12. An apparatus for cufflessly and non-invasively measuring wrist blood pressure in association with a communication device, the apparatus comprising:

a sensor unit for measuring electrocardiogram (ECG) signals and pulse wave signals from a user, wherein said sensor unit does not include a cuff;

a controller for controlling the ECG and pulse wave signals measured by the sensor unit; and

a display unit for displaying the controlled signals.

13. The apparatus of claim 12, wherein the sensor unit comprises:

an ECG sensor for measuring the ECG signals;

a pressure sensor for measuring the pulse wave signals; and

an infrared sensor for measuring an infrared signal providing at least one of a position and depth of an artery in a wrist region of the user, and

wherein said sensor unit further comprises gel filled inside a closed space of the sensor unit.

14. The apparatus of claim 12, wherein the controller comprises:

an Analog to Digital (A/D) converter for converting an analog signal measured by each sensor to a respective digital signal;

a Random Access Memory (RAM) for storing an ECG signal from among the digital signals;

a Read Only Memory (ROM) for storing the infrared signal and the pulse wave signal;

a digital signal processor for performing digital signal processing by adding signals continuously measured by a continuous blood pressure analysis program; and

a flash memory for storing a signal processed by the digital signal processor.

15. The apparatus of claim 12, wherein the display unit comprises:

an external input providing the controller with commands;

an external device for communicating with one or more communication devices using an interface terminal; and

a status display Light Emitting Diode (LED) for displaying measured values.

16. The apparatus of claim 15, wherein the interface device comprises an external communication terminal, and the controller communicating with the external device when the sensor unit senses values outside of a predetermined range.