SLEEP POSITION DETECTION

• US 20100262026A1
• Filed: 12/09/2008
• Published: 10/14/2010
• Est. Priority Date: 12/12/2007
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Meftah, Mohammed, Brauers, Andreas
• Granted Patent: US 9,649,043 B2
• Time in Patent Office: Days
• US Class Current: 600/509
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/1114 Tracking parts of the body
• CPC Class Codes: A61B 5/1116 Determining posture transitions
• CPC Class Codes: A61B 5/282 Holders for multiple electrodes for introduction into the body A61B5/287
• CPC Class Codes: A61B 5/341 Vectorcardiography [VCG]
• CPC Class Codes: A61B 5/4806 Sleep evaluation A61B5/4821 takes precedence; devices for inducing sleep A61M21/02
• CPC Class Codes: A61B 5/6887 mounted on external non-worn devices, e.g. non-medical devices
• CPC Class Codes: A61B 5/6892 Mats

Abstract

A method of determining body position uses ECG sensors at fixed positions, not fixed to the patient. The ECG signals recorded from the sensors are used to detect body position, using the variation of ECG potential over the surface of the body. The results may be processed by measuring artefacts related to the angle between the sensors and the heart, in particular the polarity of the QRS complex. The sensors may be fixed on the upper surface of a bed and used to measure sleep position.

Claims

1. Apparatus for measuring body position, comprising

at least two biometric sensors (18) arranged in a fixed position with respect to a body support (12), for measuring at least one electrocardiogram signal from a body, wherein the at least one electrocardiogram signal changes with body position as a result of the variation of electrocardiogram potential over the surface of the body;

and

a processing means (30) arranged to capture at least one electrocardiogram signal from the sensors (18), and to determine the body position from the captured at least one electrocardiogram signal using the variation of electrocardiogram potential over the surface of the body.

2. Apparatus according to claim 1, wherein a plurality of the biometric sensors (18) are arranged in an array (16) distributed across the bed (10).

3. Apparatus according to claim 1, comprising:

a bed (10), wherein the bed (12) comprises the body support (12) and the biometric sensors (18) are arranged fixed in the bed (10).

4. Apparatus according to claim 3, wherein the biometric sensors (18) are arranged on an upper sleeping surface (14) of the bed (10).

5. Apparatus according to claim 1 wherein the processing means (30) is arranged to capture a plurality of electrocardiogram signals measured from a respective plurality of the biometric sensors and to determine the body position from the plurality of electrocardiogram signals.

6. Apparatus according to claim 1, wherein the processing means (30) is adapted to determine the polarity of the QRS complex of the electrocardiogram signal or signals to determine the orientation of the heart with respect to the respective pair of sensors.

7. Apparatus according to claim 1 wherein the processing means (30) is adapted to compare the QRS complex of the electrocardiogram signal or signals with a plurality of prerecorded electrocardiogram signals in respective body positions and to identify the closest match.

8. Apparatus according to claim 1 wherein the sensors (18) are capacitive electrodes.

9. Apparatus according to claim 1 wherein the electrocardiogram sensors are contact electrodes (40), the apparatus further comprising a conductive foot contact (42) and/or conductive pillow (44) on the upper surface (14) of the bed to serve as a return path for electrical current.

10. A method of measuring body position, comprising:

supporting the body on a body support (14) having electrocardiogram sensors (18) fixed with respect to the body support;

capturing at least one electrocardiogram signal from respective electrocardiogram sensors (18), the at least one electrocardiogram signal changing with body position as a result of the variation of electrocardiogram potential over the surface of the body; and

determining the body position from the at least one electrocardiogram signal using the variation of electrocardiogram potential over the surface of the body.

11. A method according to claim 10, wherein the step of determining the body position from the at least one electrocardiogram signal includes determining the polarity of the QRS complex of the at least one electrocardiogram signal.

12. A method according to claim 11 wherein the step of determining the body position from the at least one electrocardiogram signal includes determining the angle between the electrical axis of the heart and the orientation of the respective pair of biometric sensors from the polarity of the QRS complex.

13. A method according to claim 11, wherein the step of determining the body position from the at least one electrocardiogram signal compares the QRS complex of each electrocardiogram signal with a plurality of prerecorded electrocardiogram signals in respective body positions and identifies the closest match.

14. A method according to claim 10 wherein the sensors are arranged as an array over the surface of a bed and the step of measuring body position determines which sensors of the array can detect an electrocardiogram signal and measures the body position from the electrocardiogram signals from those sensors.