MUSCULAR-SKELETAL TRACKING SYSTEM AND METHOD

• US 20140136143A1
• Filed: 11/09/2012
• Published: 05/15/2014
• Est. Priority Date: 11/09/2012
• Status: Active Grant

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: OrthoSensor, Inc (Stryker Corporation)
• Inventors: Stein, Marc, Vaughn, Glen
• Granted Patent: US 9,237,885 B2
• Time in Patent Office: Days
• US Class Current: 702/150
• CPC Class Codes: A61B 17/00 Surgical instruments, devices or methods, e.g. tourniquets A61B18/00 takes precedence; contraceptive devices, pessaries, or applicators therefor A61F6/00; eye surgery A61F9/007; ear surgery A61F11/00
• CPC Class Codes: A61B 2017/00473 Distal part, e.g. tip or head A61B2017/00464 takes precedence
• CPC Class Codes: A61B 2017/00725 Calibration or performance testing
• CPC Class Codes: A61B 2017/00734 battery operated
• CPC Class Codes: A61B 2034/2048 using an accelerometer or inertia sensor
• CPC Class Codes: A61B 2560/063 Devices specially adapted for delivering implantable medical measuring apparatus
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 34/25 User interfaces for surgical systems
• CPC Class Codes: A61B 5/061 Determining position of a probe within the body employing means separate from the probe, e.g. sensing internal probe position employing impedance electrodes on the surface of the body A61B1/00158 takes precedence
• CPC Class Codes: A61B 5/064 using markers A61B5/062 takes precedence
• CPC Class Codes: A61B 5/066 Superposing sensor position on an image of the patient, e.g. obtained by ultrasound or x-ray imaging
• CPC Class Codes: A61B 5/067 using accelerometers or gyroscopes
• CPC Class Codes: A61F 2/4611 of spinal prostheses

Abstract

At least one embodiment is directed to a tracking system for the muscular-skeletal system. The tracking system can identify position and orientation. The tracking system can be attached to a device or integrated into a device. In one embodiment, the tracking system couples to a handheld tool. The handheld tool with the tracking system and one or more sensors can be used to generate tracking data of the tool location and trajectory while measuring parameters of the muscular-skeletal system at an identified location. The tracking system can be used in conjunction with a second tool to guide the second tool to the identified location of the first tool. The tracking system can guide the second tool along the same trajectory as the first tool. For example, the second tool can be used to install a prosthetic component at a predetermined location and a predetermined orientation. The tracking system can track hand movements of a surgeon holding the handheld tool within 1 millimeter over a path less than 5 meters.

Claims

1. An orthopedic position tracking system comprising:

a first tri-axial accelerometer;

a multiplexer (MUX) coupled to the first accelerometer;

a converter coupled to the multiplexer;

an analog to digital converter (ADC) coupled to the converter;

a transceiver coupled to the analog to digital converter configured to send position data from the system; and

control logic coupled to the first accelerometer, multiplexer, converter, and transceiver configured to control position measurement where the position tracking system is configured to sample at greater than 40 times per second allowing tracking within 1 millimeter over a path length less of 5 meters or less.

2. The system of claim 1 further including a second tri-axial accelerometer coupled to the multiplexer and the control logic where the first and second tri-axial accelerometers are respectively located at first and second positions and where the system is configured to track orientation within 1 degree.

3. The system of claim 2 where the analog to digital converter has a resolution of greater than 16 bits and where the position tracking system is configured to sample at greater than 100 times per second.

4. The system of claim 3 where the analog to digital converter has a resolution of at least 20 bits.

5. The system of claim 3 where a low-pass anti-aliasing filter is configured to filter a signal from the first or second tri-axial accelerometer.

6. The system of claim 4 where the system is configured to apply dithering to the signal from the first or second tri-axial accelerometer.

7. The system of claim 5 further including:

a quantization noise filter coupled to the analog to digital converter where the analog to digital converter is an over-sampling analog to digital converter; and

a decimator coupled to the quantization noise filter.

8. The system of claim 7 where the first and second tri-axial accelerometers are piezo-resistive accelerometers.

9. The system of claim 7 where the first and second tri-axial accelerometers are capacitive accelerometers.

10. The system of claim 6 further including feedback circuitry configured to counteract displacement of moveable capacitor plates.

11. An orthopedic position tracking system comprising:

a first tri-axial capacitive accelerometer located in a first position;

a second tri-axial capacitive accelerometer located in a second position;

a multiplexer (MUX) coupled to the first and second accelerometers;

a converter coupled to the multiplexer;

an analog to digital converter (ADC) coupled to the converter;

a transceiver coupled to the analog to digital converter configured to send position data from the system; and

control logic coupled to the first accelerometer, the second accelerometer, the multiplexer, the converter, and the transceiver configured to control position measurement where the position tracking system samples at greater than 40 times per second.

12. The system of claim 11 where the analog to digital converter has a resolution of greater than 16 bits and where the position tracking system is configured to track within 1 millimeter over a path length less of 5 meters or less and where the position tracking system is configured to provide orientation within 1 degree.

13. The system of claim 12 further including feedback circuitry configured to counteract displacement of moveable capacitor plates.

14. The system of claim 13 where a low-pass anti-aliasing filter is configured to filter a signal from the first or second tri-axial accelerometer and where the system is configured to apply dithering to the signal from the first or second tri-axial accelerometer.

15. The system of claim 14 further including:

a quantization noise filter coupled to the analog to digital converter where the analog to digital converter is an over-sampling analog to digital converter; and

a decimator coupled to the quantization noise filter.

16. An orthopedic position tracking system comprising:

a first tri-axial piezo-resistive accelerometer located in a first position;

a second tri-axial piezo-resistive capacitive accelerometer located in a second position;

a multiplexer (MUX) coupled to the first and second accelerometers;

a converter coupled to the multiplexer;

an analog to digital converter (ADC) coupled to the converter;

a transceiver coupled to the analog to digital converter configured to send position data from the system; and

control logic coupled to the first accelerometer, the second accelerometer, the multiplexer, the converter, and the transceiver configured to control position measurement where the position tracking system is configured to sample at greater than 40 times per second, track within 1 millimeter over a path length less of 5 meters or less, and to provide orientation within 1 degree.

17. A method of tracking a surgical instrument comprising:

coupling a first tracking device to a first location where the tracking device includes at least one accelerometer;

coupling a second tracking device to a surgical instrument where the second tracking device includes at least one accelerometer;

activating the surgical tracking system;

moving the surgical tracking system to an initial position and orientation and sending a signal to the surgical tracking system to save data representative of the initial position and orientation;

replacing the surgical device with a second surgical device;

moving the second surgical device to the initial position within 1 mm positional accuracy; and

moving the second surgical device to the initial orientation within 1 degree accuracy.

18. The method according to claim 17, further including a step of moving the second surgical device to the initial position within 1 mm positional accuracy is in response to haptic feedback from the surgical tracking system.

19. The method according to claim 18, further including a step of moving the second surgical device to the initial orientation within 1 degree accuracy is in response to haptic feedback from the surgical tracking system.

20. The method according to further including a step of moving the second surgical device in response to visual feedback on a computer display.