Enhanced Functionality and Accuracy For a Wrist-Based Multi-Parameter Monitor

• US 20080306354A1
• Filed: 10/30/2006
• Published: 12/11/2008
• Est. Priority Date: 11/23/2005
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Mason, Martin K.
• Granted Patent: US 8,182,429 B2
• Time in Patent Office: Days
• US Class Current: 600/301
• CPC Class Codes: A61B 2560/0261 using hydrostatic pressure
• 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 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

A method for adjusting a blood pressure measurement to compensate for a pressure offset due to obtaining the blood pressure measurement at an elevation other than heart level is illustrated. The method includes measuring a blood pressure at a location above or below a heart level and adjusting the measured blood pressure in accordance with a pressure difference between the location at which the blood pressure is obtained and the heart level.

Claims

1. A method for adjusting a blood pressure measurement to compensate for a pressure offset due to obtaining the blood pressure measurement at an elevation other than heart level, comprising:

measuring a blood pressure at a location above or below a heart level;

adjusting the measured blood pressure in accordance with a pressure difference between the location at which the blood pressure is obtained and the heart level.

2. The method as set forth in claim 1, further including measuring the blood pressure and a pressure difference with respect to atmospheric pressure.

3. The method as set forth in claim 2, further including one of adding and subtracting the blood pressure and the pressure difference in one of an analog and a digital domain.

4. The method as set forth in claim 1, further including hydraulically combining the blood pressure and the pressure difference during the measuring step.

5. The method as set forth in claim 1, further including sensing the blood pressure and at least one other physiological parameter through a multi-parameter monitoring device.

6. The method as set forth in claim 5, wherein the multi-parameter monitoring device is a wrist-based physiological sensing device.

7. The method as set forth in claim 6, further including conveying the blood pressure, a pressure difference, and at least one other physiological signal together from the wrist-based physiological sensing device.

8. The method as set forth in claim 1 further including prior to the measuring step:

connecting a blood pressure monitor to a subject'"'"'s wrist;

running a fluid filled tube from the subject'"'"'s wrist, up the subject'"'"'s arm to a level of the heart.

9. A system for adjusting a blood pressure measurement to compensate for a pressure offset due to obtaining the blood pressure measurement at an elevation other than heart level, comprising:

a blood pressure sensor that measures a blood pressure at a location above or below a heart level;

a pressure compensation system that determines an offset pressure between the location at which the blood pressure measurement is obtained and the heart level.

10. The system as set forth in claim 9, the pressure compensation system including:

a fluid filled cavity extending from a level of the blood pressure sensor to the heart level; and

a pressure compensation component disposed at one end of the cavity, on which the pressure compensation component accommodates at least one of the atmospheric pressure changes, fluid temperature changes, and deformation to the fluid filled cavity.

11. The system as set forth in claim 9, the pressure compensation system further including:

a pressure sensor disposed in contact with the fluid in the cavity, which pressure sensor measures a pressure within the cavity relative to atmospheric pressure.

12. The system as set forth in claim 11, wherein the pressure sensor is disposed at an end of the cavity that is positioned at one of:

about the heart level, and

about blood pressure sensor level.

13. The system as set forth in claim 9, wherein the blood pressure sensor measures the blood pressure relative to atmospheric pressure and wherein the pressure compensation system further including:

a pressure sensor that senses pressure in a fluid filled cavity that extends from a level of the blood pressure sensor to the heart level relative to atmospheric pressure; and

a component for combining the blood pressure measured relative to atmospheric pressure and the cavity fluid pressure relative to atmosphere to generate a measure of blood pressure at the heart level.

14. The system as set forth in claim 13, wherein the pressure sensor includes one or more of a solid state transducer, an amplifier, and an analog-to-digital converter.

15. The system as set forth in claim 10, wherein the fluid filled cavity includes a flexible tube.

16. The system as set forth in claim 9, wherein the pressure compensation system includes:

a fluid filled cavity that extends from a level of the blood pressure sensor to the heart level and is operatively coupled to the blood pressure sensor, such that pressure in the fluid filled cavity is hydraulically combined with the blood pressure during the measuring by the blood pressure sensor.

17. The system as set forth in claim 9, further including:

a device for mounting the blood pressure sensor to a wrist.

18. The system as set forth in claim 17, further including:

a pressure sensor that senses pressure of a fluid filled conduit that extends from the wrist device to the heart level and wiring that carries the measured fluid pressure being routed through the wrist device.

19. A physiological measurement system, comprising:

a wrist-based physiological sensing device, including;

a blood pressure sensor;

a fluid filled tube that extends from the wrist based sensing device (to a level of the heart;

a pressure sensor that measures a pressure of fluid in the tube;

a monitoring component that combines the measured blood pressure and the fluid pressure to render a heart level blood pressure.

20. The system as set forth in claim 19 further including:

heart electrical activity sensors and leads to the heart activity sensors running from the wrist-based device along the fluid filled tube.

21. The system as set forth in claim 19, further including a transceiver that conveys the pressure of the fluid in the tube to the monitoring component, wherein the transceiver is housed in a separate body-worn pack.