Navigation Systems And Methods For Indicating And Reducing Line-Of-Sight Errors

Patent metadata

Field	Value
Publication number	US-2017119478-A1
Application number	US-201715407639-A
Country	US
Kind code	A1
Filing date	Jan 17, 2017
Priority date	Jan 16, 2013
Publication date	May 4, 2017
Grant date	—

Abstract

Navigation systems and methods used to track objects moving in space. One navigation system and method employs trackers having light emitters for indicating when line-of-sight between tracking elements on the trackers and sensors is obstructed or for other errors. Another navigation system and method instructs users on how to place a tracker with respect to an object to reduce line-of-sight issues during a surgical procedure.

First claim

What is claimed is:

1 . A navigation system comprising:
a tracking device including: a base attachable to an object; a tracking element; and a connector coupling said tracking element to said base to allow movement of said tracking element in at least one degree of freedom relative to said base to place said tracking element in a desired orientation; and a computing system configured to determine if said tracking element is in the desired orientation and instruct a user to move said tracking element relative to said base in said at least one degree of freedom if said tracking element is not in the desired orientation.

2 . A navigation system as set forth in claim 1 including an orientation sensor to determine if said tracking element is in the desired orientation.

3 . A navigation system as set forth in claim 2 wherein said orientation sensor is further defined as a gravity sensor configured to measure gravity components along three axes.

4 . A navigation system as set forth in claim 3 wherein said tracking element is capable of generating a line-of-sight tracking signal having a central signal axis and said computing system is configured to instruct the user to move said tracking element in said at least one degree of freedom in order to place the central signal axis in a position generally perpendicular to a direction of gravity.

5 . A navigation system as set forth in claim 4 including a camera unit having at least one sensor capable of receiving the line-of-sight tracking signal from said tracking element.

6 . A navigation system as set forth in claim 1 wherein said tracking device includes a tracking head supporting said tracking element, said tracking head being movable relative to said base to place said tracking element in said desired orientation

7 . A navigation system as set forth in claim 6 including second and third tracking elements supported by said tracking head.

8 . A navigation system as set forth in claim 7 wherein each of said tracking elements are light emitting diodes.

9 . A navigation system as set forth in claim 7 wherein each of said tracking elements are reflector balls.

10 . A navigation system as set forth in claim 7 wherein each of said tracking elements are line-of-sight tracking elements.

11 . A navigation system as set forth in claim 1 wherein said tracking device includes a gyroscope.

12 . A navigation system as set forth in claim 1 wherein said tracking element is one of an optical marker, radio frequency receiver, radio frequency transmitter, magnetic field sensor, magnetic field generator, ultrasonic sensor, or ultrasonic transmitter.

13 . A navigation system as set forth in claim 1 wherein said tracking device is attachable to bone.

14 . A navigation system as set forth in claim 1 wherein said connector is configured to allow movement of said tracking element in two degrees of freedom relative to said base to place said tracking element in said desired orientation.

15 . A method of setting up a navigation system to track an object wherein the navigation system comprises a computing system and a tracking device including a base, a tracking element, and a connector, said method comprising the steps of:
attaching the base to the object; determining if the tracking element is in a desired orientation; and instructing a user to move the tracking element relative to the base in at least one degree of freedom if the tracking element is not in the desired orientation.

16 . A method as set forth in claim 15 wherein determining if the tracking element is in the desired orientation includes determining an orientation of the tracking element with respect to gravity.

17 . A method as set forth in claim 16 wherein determining an orientation of the tracking element with respect to gravity includes measuring gravity components along x, y, and z axes.

18 . A method as set forth in claim 15 including the tracking element generating a line-of-sight tracking signal having a central signal axis and instructing the user to move the tracking element in at least one degree of freedom in order to place the central signal axis in a position generally perpendicular to a direction of gravity.

19 . A method as set forth in claim 15 including receiving the line-of-sight tracking signal with a camera unit of the navigation system.

20 . A method as set forth in claim 15 wherein determining if the tracking element is in the desired orientation includes determining if a rotational position of the tracking element is in a desired rotational position.

21 . A method as set forth in claim 15 wherein determining if the tracking element is in the desired orientation includes transmitting a signal from the tracking element and a plurality of additional tracking elements to a camera unit of the navigation system to determine a current orientation of the tracking elements.

22 . A method as set forth in claim 15 including instructing the user to move the tracking element relative to the base includes instructing the user to move the tracking element until the z-axis gravity component measurement is approximately zero.

23 . A method as set forth in claim 15 wherein instructing the user to move the tracking element relative to the base includes instructing the user to adjust a tilt position and rotational position of a tracking head of the tracking device relative to the base.

24 . A method as set forth in claim 23 wherein instructing the user to adjust the tilt position and the rotational position of the tracking head includes first instructing the user to adjust the tilt position and thereafter instructing the user to adjust the rotational position.

25 . A method as set forth in claim 15 wherein instructing the user to move the tracking element relative to the base in at least one degree of freedom includes instructing the user to move the tracking element in two degrees of freedom relative to the base to place the tracking element in the desired orientation.

26 . A method as set forth in claim 15 wherein instructing the user to move the tracking element relative to the base includes displaying instructions on a display of the navigation system.

27 . A method as set forth in claim 15 including graphically representing a current orientation of the tracking element on a display of the navigation system and dynamically adjusting the graphical representation as the user moves the tracking element.

28 . A method as set forth in claim 27 including graphically representing the desired orientation on the display so that the user can visually determine how close the current orientation is to the desired orientation.

29 . A method as set forth in claim 28 including indicating when the tracking element is in the desired orientation.

30 . A method as set forth in claim 29 wherein indicating when the tracking element is in the desired orientation includes visually indicating when the tracking element is in the desired orientation.

31 . A method as set forth in claim 15 including moving a tracking head of the tracking device relative to said base to place the tracking element in the desired orientation

32 . A method as set forth in claim 31 including actuating the connector to fix a current orientation of the trac

Assignees

• Stryker Corp

Inventors

• Malackowski Donald W
• Moctezuma De La Barrera José Luis

Classifications

• A61B17/8057

  the interlocking form comprising a thread · CPC title

• A61B17/808

  Instruments for holding or positioning bone plates, or for adjusting screw-to-plate locking mechanisms · CPC title

• A61B17/809

  with bone-penetrating elements, e.g. blades or prongs (bone staples A61B17/0642; intramedullary nails with a plate at an end A61B17/7233) · CPC title

• A61B2090/3991

  having specific anchoring means to fixate the marker to the tissue, e.g. hooks · CPC title

• A61B2090/3983

  Reference marker arrangements for use with image guided surgery · CPC title