AUTOMATIC ORIENTATION CALIBRATION FOR A BODY-MOUNTED DEVICE

• US 20130116602A1
• Filed: 07/12/2011
• Published: 05/09/2013
• Est. Priority Date: 07/27/2010
• Status: Abandoned Application

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Duric, Haris, Van Den Heuvel, Teun
• Application Number:
  US13/810,913
• Publication Number:
  US 20130116602A1
• Time in Patent Office: Days
• US Class Current: 600/595
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/1116 Determining posture transitions
• CPC Class Codes: A61B 5/1126 using a particular sensing technique
• CPC Class Codes: A61B 5/6801 specially adapted to be attached to or worn on the body surface
• CPC Class Codes: A61B 5/6823 Trunk, e.g., chest, back, abdomen, hip
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61N 1/36542 controlled by body motion, e.g. acceleration
• CPC Class Codes: A61N 1/37 Monitoring; Protecting

Abstract

In order to eliminate the need of tiresome and complex calibration procedures for posture-detecting devices, means are provided for determining an orientation of a body-mounted or implanted device (1) relative to the body (2), the device (1) having an orientation detection unit, wherein an uncontrolled output of the orientation detection unit over a period of time together with one or more reference conditions defined in a body reference system (x_b, y_b, z_b) are used for determining the relative orientation of the device and hence for calibration.

Claims

1. A device implantable or mountable to a body for determining its orientation relative to the body, comprising:

a three-dimensional orientation detection unit adapted to measure orientation data in a reference system of the orientation detection unit; and

a control unit adapted to determine the relative orientation of the device with respect to the body by determining a transformation relation between the body reference system and the reference system of the orientation detection unit by means of at least one predetermined reference condition defined in a body reference system and the measured orientation data.

2. The device of claim 1, wherein the orientation detection unit comprises a three-dimensional accelerometer

3. The device of claim 1, wherein the reference condition comprises a reference posture and/or a reference posture range defined in the body reference system having at least one predetermined characteristic.

4. The device of claim 3, wherein the at least one predetermined characteristic of the reference posture or reference posture range relates to a high or low prevalence level and/or a high or low activity level with respect to other postures.

5. The device of claim 3, wherein the control unit is further adapted to identify the reference posture and/or reference posture range in the measured orientation data by means of the predetermined characteristic in the reference system of the orientation detection unit.

6. The device according to claim 1, wherein at least one or more constraints and/or assumptions are definable for determining the orientation.

7. The device according to claim 1, wherein the control unit is adapted to filter rapidly changing postures by setting a maximal spatial distance between subsequent data points,

8. The device according to claim 1, wherein the control unit is further adapted to calculate at least one statistical parameter of the measured orientation data.

9. The device according to claim 1, wherein the control unit is further adapted to perform cluster analysis on the measured orientation data and/or to process the measured orientation data separately for each axis of the reference system of the orientation detection unit resulting in three-dimensional values.

10. The device according to claim 1, wherein the control unit is adapted to repeat the determination of the device orientation relative to the body in predetermined time intervals and/or when triggered by a signal, and/or wherein the three-dimensional orientation detection unit is adapted to measure the orientation data continuously.

11. The device according to claim 1, wherein the device is applicable for determining a posture of the body by transforming the measured orientation data into the body reference system using the determined transformation relation.

12. (canceled)

13. A system for determining an orientation of a device relative to a body, comprising:

a device being implantable or mountable to the body and having a three-dimensional orientation detection unit capable of measuring orientation data in a reference system of the orientation detection unit; and

a control unit capable of determinine an orientation of the device relative to the body by determining a transformation relation between the body reference system and the reference system of the orientation detection unit by means of a predetermined reference condition defined in a body reference system and the measured orientation data;

wherein the control unit and the device are in wired or wireless communication for unidirectional or bidirectional data transmission.

14. A method for determining an orientation of a body mounted or implanted device relative to the body, the device aving a three-dimensional orientation detection unit, the method comprising:

obtaining orientation data measured by the orientation detection unit in a reference system of the orientation detection unit;

defining at least one reference condition in a body reference system; and

determining the orientation of the device relative to the body 03-by determining a transformation relation between the body reference system and the reference system of the orientation detection unit by means of the reference condition and the measured orientation data

15. A computer-readable medium useable with a computer and a device that is implantable or mountable to a body and comprises a threedimensional orientation detection unit, the medium having a computer program stored, which when being executed by a processor, is adapted to carry out the method according to claim 14.