Torque Sensor

• US 20050166685A1
• Filed: 01/27/2005
• Published: 08/04/2005
• Est. Priority Date: 01/29/2004
• Status: Active Grant

• Current Assignee: Ottobock SE & Co. KGaA
• Original Assignee: Otto Bock HealthCare GmbH (OTTO BOCK Holding GmbH & Company KG)
• Inventors: Boiten, Herman
• Granted Patent: US 7,500,407 B2
• Time in Patent Office: Days
• US Class Current: 73/862.191
• CPC Class Codes: A61F 2/64 Knee joints
• CPC Class Codes: A61F 2/68 Operating or control means
• CPC Class Codes: A61F 2/76 Means for assembling, fitting or testing prostheses, e.g. for measuring or balancing, e.g. alignment means
• CPC Class Codes: A61F 2002/6614 Feet
• CPC Class Codes: A61F 2002/7635 for measuring force, pressure or mechanical tension

Abstract

A torque sensor for measuring a torque at a predetermined location of a structural element, in particular of a prosthesis, can be arranged outside the measurement location by virtue of the fact that it is constructed as a sensor structure (13, 13′, 23) that forms a virtual pivot axis (16, 16′) outside the sensor. The sensor structure is provided with measurement transducers (29) which detect deformations of the sensor structure (13, 13′, 23) and are used to determine a torque about the virtual pivot axis (16, 16′). A preferred application for the torque sensor is its incorporation in a prosthesis for the purpose of controlling an artificial joint.

Claims

1. A torque sensor for measuring a torque at a predetermined location of a structural element, the torque sensor comprising:

a sensor structure formed with a virtual pivot axis outside the sensor, the sensor structure including measurement transducers which detect deformations of the sensor structure and are used to determine a torque about the virtual pivot axis.

2. The torque sensor as claimed in claim 1, wherein the sensor structure is designed as a multi-hinge structure with elastically deformable hinges.

3. The torque sensor as claimed in claim 2, wherein the sensor structure is designed as a four-hinge structure.

4. The torque sensor as claimed in claim 3, wherein the measurement transducers are strain gages.

5. The torque sensor as claimed in claim 1, wherein the sensor structure is designed with two planar leaf-spring arrangements whose planes intersect in the virtual pivot axis.

6. The torque sensor as claimed in claim 5, wherein the measurement transducers are strain gages.

7. The torque sensor as claimed in claim 1, wherein the measurement transducers are strain gages.

8. The torque sensor as claimed in claim 1, wherein the structural element comprises a prosthesis and the torque sensor is used to control an artificial joint of the prosthesis.

9. A prosthesis including an artificial joint, the prosthesis comprising:

a torque sensor adapted to control the artificial joint, the torque sensor configured to measure a torque at a predetermined location of a structural element, the torque sensor including a sensor structure formed with a virtual pivot axis outside the sensor and including measurement transducers which detect deformations of the sensor structure and are used to determine a torque about the virtual pivot axis.

10. The prosthesis as claimed in claim 9, wherein the torque sensor is designed as a multi-hinge structure with elastically deformable hinges.

11. The prosthesis as claimed in claim 10, wherein the torque sensor is designed as a four-hinge structure.

12. The prosthesis as claimed in claim 9, wherein the torque sensor is designed with two planar leaf-spring arrangements whose planes intersect in the virtual pivot axis.

13. The prosthesis as claimed in claim 9, wherein the measurement transducers are strain gages.

14. The prosthesis as claimed in claim 9, wherein the virtual pivot axis of the sensor structure lies in the below-knee area of the prosthesis, and the sensor structure is arranged in the knee area.

15. The prosthesis as claimed in claim 14, wherein the virtual pivot axis of the sensor structure lies in the ankle area of the prosthesis, and the sensor structure is arranged in the knee area.

16. A method of sensing torque for use in controlling an artificial joint of a prosthesis, the method comprising the steps of:

providing a torque sensor for measuring a torque at a predetermined location of the prosthesis, the torque sensor including a sensor structure formed with a virtual pivot axis outside the sensor;

detecting deformations of the sensor structure; and

determining a torque about the virtual pivot axis based on the detected deformations, wherein the torque may be used to control the artificial joint.

17. The method of claim 16, wherein the step of detecting deformations comprises the step of providing measurement transducers on the sensor structure.

18. The method of claim 17, wherein the measurement transducers comprise strain gages.

19. The method of claim 16, wherein the sensor structure comprises a multi-hinged structure with elastically deformable hinges.

20. The method of claim 16, wherein the sensor structure comprises two planar leaf-spring arrangements whose planes intersect in the virtual pivot axis.