GESTURE CONTROL FOR MONITORING VITAL BODY SIGNS

• US 20130261771A1
• Filed: 12/14/2011
• Published: 10/03/2013
• Est. Priority Date: 12/17/2010
• Status: Active Grant

• Current Assignee: Lifeline Systems Company (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Ten Kate, Warner
• Granted Patent: US 9,898,182 B2
• Time in Patent Office: Days
• US Class Current: 700/63
• CPC Class Codes: A61B 2560/0266 for monitoring or limiting apparatus function
• CPC Class Codes: A61B 5/6801 specially adapted to be attached to or worn on the body surface
• CPC Class Codes: A61B 5/7475 User input or interface means, e.g. keyboard, pointing device, joystick
• CPC Class Codes: G06F 3/0346 with detection of the device orientation or free movement in a 3D space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors
• CPC Class Codes: G06F 3/0487 using specific features provided by the input device, e.g. functions controlled by the rotation of a mouse with dual sensing arrangements, or of the nature of the input device, e.g. tap gestures based on pressure sensed by a digitiser

Abstract

The present invention reuses an accelerometer, or, more precise, sensed accelerations of a body sensor for user control of the body sensor. This is achieved by detecting predefined patterns in the acceleration signals that are unrelated to other movements of the patient. These include tapping on/with the sensor, shaking, and turning the sensor. New procedures are described that make it possible to re-use the acceleration sensing for reliable gesture detection without introducing many false positives due to non-gesture movements like respiration, heart beat, walking, etc.

Claims

1. An apparatus for controlling a sensor device which uses a movement sensor (10), said apparatus comprising:

a gesture detector (40) for evaluating an acceleration output of said movement sensor (10) to detect at least one predetermined gesture; and

a device controller (50) for controlling a functional operation of said sensor device in response to a detection output of said gesture detector (40), wherein said gesture detector (40) is adapted to perform at least one of

observing each of three acceleration components of a three-dimensional acceleration output of said movement sensor (10), comparing said acceleration components with predetermined positive and negative thresholds, and determining a shake detection event if for at least one of said acceleration components the acceleration crosses said positive threshold and said negative threshold a minimum number of times in alternating order and within a maximum duration,

obtaining at least one one-dimensional signal component from said acceleration output, estimating a background level and detecting a candidate tap if said one-dimensional signal component surpasses a first threshold and said background level is below a second threshold, and

analyzing acceleration samples of said acceleration output on a frame by frame basis, determining a reference vector within a frame, and detecting a turn gesture if an angle between said reference vector and a series of acceleration samples is within a range from a first threshold for at least a first predetermined number of samples and thereafter below a second threshold for at least a second predetermined number of samples and thereafter within a third threshold for a third predetermined number of samples, which happens before a total duration of a fourth predetermined number of samples.

3. The apparatus according to claim 1, wherein said gesture detector (40) is adapted to detect a tap gesture and to pre-filter said acceleration output to obtain said one-dimensional signal component, and to determine a tap detection event if said candidate tap appears in a predetermined sequence.

4. The apparatus according to claim 3, wherein said gesture detector (40) is adapted to detect a tap gesture and to pre-filter said acceleration output by using a complementary median filter.

5. The apparatus according to claim 1, wherein said gesture detector (40) is adapted to a tap gesture and to estimate said background level by using an adaptive median filter.

6. The apparatus according to claim 1, wherein said gesture detector (40) is adapted to detect a tap gesture and to detect said candidate tap by testing the maximum of said background level to be above a third threshold.

9. A body sensor device comprising:

an inertial sensor (10) for sensing acceleration of said body sensor device; and

an apparatus according to claim 1.

2. (canceled)

7. (canceled)

8. (canceled)

10. A method of controlling a sensor device which uses a movement sensor (10), said method comprising:

evaluating an acceleration output of said movement sensor (10) to detect at least one predetermined gesture; and

controlling a functional operation of said sensor device in response to a detection of said at least one predetermined gesture;

wherein said evaluating comprises at least one of

observing each of three acceleration components of a three-dimensional acceleration output of said movement sensor (10), comparing said acceleration components with predetermined positive and negative thresholds, and determining a shake detection event if for at least one of said acceleration components the acceleration crosses said positive threshold and said negative threshold a minimum number of times in alternating order and within a maximum duration,

obtaining at least one one-dimensional signal component from said acceleration output, estimating a background level and detecting a candidate tap if said one-dimensional signal component surpasses a first threshold and said background level is below a second threshold, and

analyzing acceleration samples of said acceleration output on a frame by frame basis, determining a reference vector within a frame, and detecting a turn gesture if an angle between said reference vector and a series of acceleration samples is within a range from a first threshold for at least a first predetermined number of samples and thereafter below a second threshold for at least a second predetermined number of samples and thereafter within a third threshold for a third predetermined number of samples, which happens before a total duration of a fourth predetermined number of samples.

12. The method according to claim 10, wherein said evaluating comprises detecting a candidate tape and further comprises pre-filtering said acceleration output to obtain said one-dimensional signal component, and determining a tap detection event if said candidate tap appears in a predetermined sequence.

15. A computer program product comprising code means for producing the steps of method claim 10 when run on a computing device.

11. (canceled)

13. (canceled)

14. (canceled)