Systems and methods for blood pressure measurement with psychological status validation

• US 10,105,089 B2
• Filed: 11/05/2015
• Issued: 10/23/2018
• Est. Priority Date: 06/18/2014
• Status: Active Grant

• Current Assignee: Hong Kong Applied Science And Technology Research Institute Co., Ltd.
• Original Assignee: Hong Kong Applied Science And Technology Research Institute Co., Ltd.
• Inventors: Leung, Lap Wai Lydia, Gu, Wenbo
• Primary Examiner(s): WESTON, TIFFANY C
• Application Number:
  US14/933,647
• Publication Number:
  US 20160100787A1
• Time in Patent Office: 1,083 Days
• CPC Class Codes: A61B 5/0064 Body surface scanning
• CPC Class Codes: A61B 5/0082 adapted for particular medical purposes
• CPC Class Codes: A61B 5/02116 of pulse wave amplitude A61B5/02225 takes precedence
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• CPC Class Codes: A61B 5/165 Evaluating the state of mind, e.g. depression, anxiety
• CPC Class Codes: A61B 5/489 Blood vessels
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• CPC Class Codes: A61B 5/7296 for compensation of signal variation due to stress unintentionally induced in the patient, e.g. due to the stress of the medical environment or examination deliberately inducing physiological or psychological stress A61B5/4884

Abstract

Techniques for effectively and accurately measuring psychological influencing factors, such as the white coat effect and mental stress, that may affect or otherwise influence biometric measurements, such as blood pressure measurements, are described. Embodiments of a measurement validation system herein may utilize a method for determining an artery location on a living subject'"'"'s skin and positioning a tonometry pressure sensor on the artery location for tonometric blood pressure measurement to obtain pressure pulse data for a subject. In operation according to embodiments, measurement logic of a measurement validation system may utilize the pressure pulse data to extract blood pressure data, heart rate data, blood pressure variability data, and heart rate variability data. The foregoing data may be utilized in identifying whether the blood pressure measurement properly and accurately reflects the situation of the subject.

Claims

1. A system for validating a psychological status with respect to a blood pressure measurement, the system comprising:

a pressure sensor platform adapted for measuring continual pressure pulse of a subject and providing pressure pulse data for the subject from the measured continual pressure pulse, wherein the pressure pulse data comprises data for a plurality of pressure waveforms associated with beat-to-beat blood pressure values of the subject;

data feature identification logic configured to identify peaks and troughs of the plurality of pressure waveforms;

measurement logic configured to derive a blood pressure measurement for the subject from the pressure pulse data and to derive heart rate variability data and blood pressure variability data from the pressure pulse data using the identified peaks and troughs of the plurality of pressure waveforms; and

analysis logic configured to analyze the heart rate variability data and blood pressure variability data and determine if one or more psychological influencing factors is present with respect to the subject, wherein the analysis logic provides information regarding validity of the blood pressure measurement based on the determination if one or more psychological influencing factors is present and outputs a signal indicating invalidity of the blood pressure measurement when the analysis logic determines that the one or more psychological influencing factors is present and indicating validity of the blood pressure measurement when the analysis logic determines that the one or more psychological influencing factors is not present; and

wherein the analysis logic is configured to trigger one or more additional measurements for deriving an additional blood pressure measurement for the subject in response to the signal indicating invalidity of the blood pressure measurement and to cause the blood pressure measurement to be recorded in response to the signal indicating validity of the blood pressure measurement.

2. The system of claim 1, wherein the pressure sensor platform comprises:

a tonometric pressure sensor, wherein the tonometric pressure sensor is applied to a surface of the subject with a pressure approximating a blood pressure for the continual pressure pulse measurement.

3. The system of claim 2, wherein the pressure sensor platform comprises:

an optical sensor, wherein the tonometric pressure sensor is applied to the surface of the subject in juxtaposition with a radial artery of the subject as determined using the optical sensor.

4. The system of claim 1, wherein the measurement logic derives the heart rate variability data and the blood pressure variability data from the pressure pulse data based on differences between data of the pressure pulse data for adjacent heart beats of the subject.

5. The system of claim 1, wherein the measurement logic further derives a heart rate for the subject from the pressure pulse data.

6. The system of claim 5, wherein the pressure pulse data is collected for a predetermined period of time, wherein the predetermined period of time is of at least 1 minute in duration.

7. The system of claim 1, further comprising:

a database of baseline heart rate variability data and blood pressure variability data for the subject, wherein the analysis logic operates to compare the derived heart rate variability data and blood pressure variability data for the subject with the baseline heart rate variability data and blood pressure variability data for the subject to determine if one or more psychological influencing factor is present with respect to the subject.

8. The system of claim 7, wherein the analysis logic operates to determine a mental stress is present with respect to the subject if the derived heart rate variability data is below the baseline heart rate variability data by a second heart rate variability variance metric (T_HRV2) and the derived blood pressure variability data is above the baseline blood pressure variability data by a blood pressure variability variance metric (T_BPV), wherein the mental stress is a psychological influencing factor of the one or more psychological influencing factors.

9. A method for validating a psychological status with respect to a blood pressure measurement, the method comprising:

providing pressure pulse data from a measured continual pressure pulse of a subject, wherein the pressure pulse data comprises data for a plurality of pressure waveforms associated with beat-to-beat blood pressure values of the subject;

identifying peaks and troughs of the plurality of pressure waveforms;

calculating a blood pressure measurement for the subject from the pressure pulse data;

calculating heart rate variability data from the pressure pulse data using the identified peaks and troughs;

calculating blood pressure variability data from the pressure pulse data using the identified peaks and troughs;

analyzing the calculated heart rate variability data and blood pressure variability data;

determining if one or more psychological influencing factors is present with respect to the subject based on the analyzing;

providing a signal regarding validity of the blood pressure measurement based on the determination if one or more psychological influencing factors is present, wherein the signal indicates invalidity of the blood pressure measurement when the one or more psychological influencing factors is determined to be present with respect to the subject and the signal indicates validity of the blood pressure measurement when the one or more psychological influencing factors is determined not to be present with respect to the subject; and

triggering one or more additional pressure pulse measurements for calculating an additional blood pressure measurement for the subject in response to the signal indicating invalidity of the blood pressure measurement and recording the blood pressure measurement in response to the signal indicating validity of the blood pressure measurement.

10. The method of claim 9, further comprising:

applying a tonometric pressure sensor to a surface of the subject with a pressure approximating a blood pressure, wherein the measured continual pressure pulse of the subject is measured using the tonometric pressure sensor applied to the surface of the subject with the pressure approximating the blood pressure.

11. The method of claim 10, further comprising:

locating a radial artery of the subject using an optical sensor, wherein the tonometric pressure sensor is applied to the surface of the subject in juxtaposition with the radial artery at a location determined using the optical sensor.

12. The method of claim 9, wherein the calculating heart rate variability data from the pressure pulse data is based on differences between data of the pressure pulse data for adjacent heart beats of the subject.

13. The method of claim 9, wherein the calculating blood pressure variability data from the pressure pulse data is based on differences between data of the pressure pulse data for adjacent heart beats of the subject.

14. The method of claim 9, further comprising:

calculating a heart rate for the subject from the pressure pulse data.

15. The method of claim 9, wherein the pressure pulse data is collected for a predetermined period of time, wherein the predetermined period of time is of at least 1 minute in duration.

16. The method of claim 9, further comprising:

comparing the calculated heart rate variability data and blood pressure variability data for the subject with baseline heart rate variability data and blood pressure variability data for the subject, wherein the determining if one or more psychological influencing factor is present with respect to the subject is based on the comparing.

17. The method of claim 16, wherein the determining if one or more psychological influencing factor is present with respect to the subject comprises:

determining a mental stress is present with respect to the subject if the calculated heart rate variability data is below the baseline heart rate variability data by a heart rate variability variance metric and the calculated blood pressure variability data is above the baseline blood pressure variability data by a blood pressure variability variance metric, wherein the mental stress is a psychological influencing factor of the one or more psychological influencing factors.

18. A system for validating a psychological status with respect to a blood pressure measurement, the system comprising:

a pressure sensor platform adapted for measuring continual pressure pulse of a subject and providing pressure pulse data for the subject from the measured continual pressure pulse, wherein the pressure pulse data comprises data for a plurality of pressure waveforms associated with beat-to-beat blood pressure values of the subject;

data feature identification logic configured to identify peaks and troughs of the plurality of pressure waveforms;

measurement logic configured to calculate heart rate variability data and blood pressure variability data from beat-to-beat differences in data of the pressure pulse data, wherein the blood pressure measurement is also calculated from the pressure pulse data using the identified peaks and troughs of the plurality of pressure waveforms; and

analysis logic configured to analyze the calculated heart rate variability data and blood pressure variability data and determine if one or more psychological influencing factors is present with respect to the subject, wherein the analysis logic provides a signal regarding validity of the blood pressure measurement based on the determination if one or more psychological influencing factors is present, wherein the signal indicates invalidity of the blood pressure measurement when the one or more psychological influencing factors is determined to be present with respect to the subject and the signal indicates validity of the blood pressure measurement when the one or more psychological influencing factors is determined not to be present with respect to the subject; and

wherein the analysis logic is configured to trigger one or more additional measurements for calculating an additional blood pressure measurement for the subject in response to the signal indicating invalidity of the blood pressure measurement and to cause the blood pressure measurement to be recorded in response to the signal indicating validity of the blood pressure measurement.

19. The system of claim 18, wherein the pressure sensor platform comprises:

a tonometric pressure sensor, wherein the tonometric pressure sensor is applied to a surface of the subject with a pressure approximating a blood pressure for the continual pressure pulse measurement, wherein the pressure sensor platform comprises;

an optical sensor, wherein the tonometric pressure sensor is applied to the surface of the subject in juxtaposition with a radial artery of the subject as determined using the optical sensor.

20. The system of claim 18, wherein the measurement logic further derives a heart rate for the subject from the pressure pulse data, wherein the blood pressure measurement is calculated from the pressure pulse data.

21. The system of claim 18, wherein the analysis logic operates to determine a mental stress is present with respect to the subject if the calculated heart rate variability data is below a baseline heart rate variability data by a heart rate variability variance metric and the calculated blood pressure variability data is above a baseline blood pressure variability data by a blood pressure variability variance metric, wherein the mental stress is a psychological influencing factor of the one or more psychological influencing factors.