Device for referencing a system of coordinates

• US 6,224,613 B1
• Filed: 05/03/2000
• Issued: 05/01/2001
• Est. Priority Date: 11/04/1997
• Status: Expired due to Term

• Current Assignee: AO Technology AG
• Original Assignee: Synthes USA LLC (Johnson & Johnson)
• Inventors: Hofstetter, Robert
• Primary Examiner(s): Philogene, Pedro
• Application Number:
  US09/562,948
• Time in Patent Office: 363 Days
• Field of Search: 606/130, 600/424, 600/439, 600/414, 600/417, 600/409, 128/899, 128/903
• US Class Current: 606/130
• CPC Class Codes: G01C 11/02 Picture taking arrangements specially adapted for photogrammetry or photographic surveying, e.g. controlling overlapping of pictures
• CPC Class Codes: G01C 9/12 by using a single pendulum plumb lines G01C15/10

Abstract

The invention relates to a device for referencing a system of coordinates (1) in space (2). It comprises a body (4) that is suspended in space (2), and which is aligned in a local gravitational field (3). Further, the device has at least two first components (5) that emit electromagnetic or acoustic waves that are located at a distance, A, from each other. Second components (5) for detecting acoustic waves or a magnetic field may also be arranged on the body (4) at a distance, A, from each other, instead of the first components which emit the electromagnetic or acoustic waves. Advantageously, the device and first components are incorporated in a Computer Assisted Surgery (CAS) System which includes the second components. Thus, the second components may interact with the first components, while the CAS system includes a plotting unit for determining the spatial coordinates of the body.

Claims

1. A Computer Assisted Surgery (CAS) System that includes a device incorporated therein for referencing a system of coordinates in space, using a body suspended in space and aligned in a local gravitational field, wherein the body comprises a first set of at least two means that are optically, acoustically, or electromagnetically active and that have been placed at a distance, A, from each other beforehand;

and wherein the system further comprises;

a second set of at least two additional means that are optically, acoustically, or electromagnetically active and which interact with the first set of means; and

a plotting unit for determining the spatial coordinates of the body.

2. The system of claim 1, wherein the first set of means includes transmitters that emit electromagnetic or acoustic waves, and the second set of means includes optical or acoustical sensors.

3. The system of claim 1, wherein the first set of means includes acoustical receivers, and the second set of means includes acoustical transmitters.

4. The system of claim 1, wherein the body is suspended by a thread, a wire, or a chain.

5. The system of claim 1, wherein the body is suspended by gimbals.

6. The system of claim 1, wherein the body is suspended by a ball-and-socket-joint.

7. The system of claim 1, wherein the body is suspended by being embedded in an elastomer.

8. The system of claim 7, wherein the elastomer is a silicon rubber or a foamed silicon rubber.

9. The system of claim 1, wherein the alignment of the body in the gravitational field is mechanically or electromagnetically damped.

10. The system of claim 9, wherein the alignment of the body in the gravitational field is damped by a water bath that surrounds the body, by springs, or by pneumatic shock absorbers.

11. The system of claim 2, wherein at least one set of means used includes optical emitters, reflectors, or receivers;

Light Emitting Diodes (LEDs);

or Infrared LEDs.

12. The system of claim 2, wherein the first set of means includes Light Emitting Diodes (LEDs) or Infrared LEDs and the second set of means includes optical emitters, reflectors, or receivers.

13. The system of claim 2, wherein the second set of means comprises at least two cameras, optical sensors, or acoustic sensors.

14. The system of claim 13, wherein the second set of means comprises two cameras having a position that is determined by recording and analyzing a stable control point field.

15. The system of claim 13, wherein the first set of means comprises at least one transmitter of electromagnetic waves and the second set of means comprises two cameras for detecting the electromagnetic waves emitted or reflected by the at least one transmitter to aid in determining the position of space coordinates of the system of coordinates.

16. The system of claim 13, wherein the second set of means comprises two stabilized cameras for videographically determining the position of space coordinates of the system of coordinates.

17. The system of claim 16, wherein the cameras are stabilized digital cameras.

18. The system of claim 13, wherein the first set of means comprises sound wave emitters or reflectors and the second set of means comprises acoustical sensors that detect the sound waves emitted or reflected by the first set of means to aid in determining the position of space coordinates of the system of coordinates.

19. The system of claim 18, wherein the position of the space coordinates of the system of coordinates is determined through analysis of interference effects.

20. The system of claim 13, wherein the first set of means comprises light wave emitters or reflectors and the second set of means comprises optical sensors that detect the light waves emitted or reflected by the first set of means to aid in determining the position of space coordinates of the system of coordinates.

21. The system of claim 20, wherein the position of the space coordinates of the system of coordinates is determined through analysis of interference effects.

22. The system of claim 2, wherein the first set of means comprises at least one coil used to set up a magnetic field.

23. The system of claim 22, wherein the second set of means comprises at least two coils used to detect the magnetic field and that, together with the plotting unit, aid in determining the position of space coordinates of the system of coordinates through analysis of magnetic induction.

24. The system of claim 22, wherein the second set of means comprises at least two echo sensors used to detect the magnetic field and that, together with the plotting unit, aid in determining the position of space coordinates of the system of coordinates, through analysis of echo effects.

25. The system of claim 3, wherein the first set of means includes acoustical transmitters and the second set of means includes microphones.

26. The system of claim 3, wherein the first set of means comprises at least two acoustic transmitters or reflectors and the second set of means comprises microphones to detect the sound waves, such that the position of space coordinates of the system of coordinates is determined through analysis of interference effects.