Sensor device, in particular for a prosthesis, and prosthesis having such a sensor device

• US 20030029247A1
• Filed: 08/06/2002
• Published: 02/13/2003
• Est. Priority Date: 08/10/2001
• Status: Active Grant

• Current Assignee: Otto Bock Healthcare Products GmbH (Albatros Son Holding BV)
• Original Assignee: Biedermann Motech GmbH
• Inventors: Matthis, Wilfried, Biedermann, Lutz
• Granted Patent: US 6,918,308 B2
• Time in Patent Office: Days
• US Class Current: 73/768
• CPC Class Codes: A61F 2/64 Knee joints
• 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 2002/607 Lower legs
• CPC Class Codes: A61F 2002/608 Upper legs
• CPC Class Codes: A61F 2002/6614 Feet
• CPC Class Codes: A61F 2002/7635 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2002/7695 Means for testing non-implantable prostheses for testing implantable prostheses A61F2240/008; for implanting artificial joints A61F2/468

Abstract

A sensor device (15) for a prosthesis, in particular for a leg prosthesis, is provided for measuring forces acting on the prosthesis, having a ring-shaped outer member (16) of closed construction and an inner member (21, 22) connecting two opposite inner sides (17a, 17b) of the outer member having a sensor element (31) for measuring the force acting in the direction of the connecting axis. The outer member deforms under the action of a bending moment while the inner member (21) feels only the axial force acting in the direction of its connecting axis. By this means measurement of the axial force unaffected by bending moments is possible. Furthermore, the sensor device is able to transmit loads.

Claims

1. Sensor device at the connecting point between two parts (4, 5), in particular in a prosthesis, having

a ring-shaped outer member (16) of closed construction for connecting the two parts (4, 5) and

an inner member (21, 22, 22′

) connecting two opposite inner sides (17a, 17b) of the outer member having a sensor element (31) for measuring the force acting in the direction of the connecting axis between the two parts (4, 5).

2. Sensor device according to claim 1, characterised in that an inner diameter of the outer member (16) at the position of the inner member (21) is smaller than in a direction perpendicular thereto.

3. Sensor device according to claim 1 or 2, characterised in that on opposite sides in a direction perpendicular to the direction of the connecting axis the outer member possesses at least one sensor element (30) for measuring a force acting on the outer member (16) outside the connecting axis of the inner member.

4. Sensor device according to one of claims 1 to 3, characterised in that the inner member (21) possesses an additional device (23) for flexural relief of the part (22) of the inner member (21) bearing the sensor element (31).

5. Sensor device according to one of claims 1 to 3, characterised in that the outer member (16) forms an oval ring and the inner member (22′

) is of web-shaped construction and connects the longitudinal sides of the oval ring to one another.

6. Sensor device according to one of claims 1 to 5, characterised in that the inner member (21) is constructed substantially in the form of a rectangular ring (23) having a central web, wherein the sensor element is provided on the central web (22).

7. Sensor device according to one of claims 1 to 6, characterised in that the cross-section of the inner member (21) is smaller at the point of the sensor element (31) than the cross-section of the outer member at the point of action of force in the direction of the connecting axis.

8. Sensor device according to one of claims 1 to 7, characterised in that on the outer member (16) symmetrically with respect to both sides of the inner member sensor elements (30) are provided for determining the bending moment acting on the outer member.

9. Sensor device according to one of claims 1 to 8, characterised in that the outer member and the inner member are fixedly connected to one another.

10. Sensor device according to one of claims 1 to 9, characterised in that the outer member and the inner member are formed from the same material.

11. Sensor device according to one of claims 1 to 10, characterised in that the sensor device (15) is provided on the lower leg part (2) of a leg prosthesis.

12. Sensor device according to one of claims 1 to 10, characterised in that the sensor device is a sensor device for a prosthesis, preferably a leg prosthesis.

13. Leg prosthesis having an upper leg part (1), a lower leg part (2) and an artificial knee joint (3), characterised in that a sensor device according to one of claims 1 to 10 is provided.

14. Leg prosthesis according to claim 13, characterised in that adjoining the artificial knee joint the lower leg part has a shin-bone section (4) and the sensor device (15) is integrated into the shin-bone section.

18. Sensor device according to one of claims 15 to 17, characterised in that the sensor section (22) is constructed as an inner member and the flexural relief section as an outer member according to one of claims 1 to 12.

15. Sensor device for measuring mechanical forces having a sensor section (22) containing a force sensor (31) for measuring a force (F_ax) acting on the sensor section (22) in a first direction and a flexural relief section (16, 23) connected to the sensor section (22) which is constructed in such a way that under the action of a force acting in a second direction it is deformed in such a way that the sensor section (22) remains substantially unaffected.

16. Sensor device according to claim 15, characterised in that the flexural relief section (16, 23) is constructed in such a way that it absorbs a bending moment (B) acting additionally to the force (F_ax) acting in the first direction, wherein the sensor section (22) remains substantially unaffected.

17. Sensor device according to claim 15 or 16, characterised in that the flexural relief section (16, 21) possesses at least one sensor (30) for measuring the bending moment (B).