Robotic systems and methods for controlling a tool removing material from a workpiece

Patent metadata

Field	Value
Publication number	US-10117713-B2
Application number	US-201615195039-A
Country	US
Kind code	B2
Filing date	Jun 28, 2016
Priority date	Jul 1, 2015
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

Robotic systems and methods for controlling a tool to remove material from a workpiece. Workpieces such as bones are often non-homogenous and have varying density distributions throughout their volumes. In some embodiments, the systems and methods control the feed rate of the tool, the tool path of the tool, and the rotational speed of the tool based on the density distribution in order to provide a desired outcome for a surgical procedure.

First claim

What is claimed is:

1. A method for controlling a manipulator and a tool coupled to the manipulator to remove material from a workpiece during a procedure with a robotic system including a navigation computer and a manipulator controller coupled to the manipulator, said method comprising the steps of:
determining a density distribution of the workpiece;
generating with the navigation computer a tool path for the tool based on the determined density distribution of the workpiece with the tool path including a cutting depth;
determining with the navigation computer the cutting depth for the tool path based on the determined density distribution of the workpiece;
tracking with the navigation computer a position of the tool relative to the workpiece as the tool moves relative to the workpiece during the procedure; and
controlling with the manipulator controller a plurality of parameters associated with the tool including a feed rate of the tool, a rotational speed of the tool, and the tool path of the tool, wherein controlling the plurality of parameters of the tool includes: setting the feed rate of the tool based on the density distribution, controlling the rotational speed of the tool based on the feed rate of the tool, and controlling the cutting depth of the tool based on the density distribution of the workpiece and the position of the tool relative to the workpiece such that control of the tool takes into account the density distribution of the workpiece.

2. The method as set forth in claim 1 , further comprising generating with the navigation computer a three-dimensional model of the workpiece with the density distribution associated with the three-dimensional model.

3. The method as set forth in claim 1 , wherein the density distribution is a bone mineral density distribution.

4. The method as set forth in claim 3 , wherein controlling the plurality of parameters of the tool includes adjusting the feed rate of the tool based on the bone mineral density distribution as the tool moves relative to the workpiece.

5. The method as set forth in claim 3 , wherein adjusting the feed rate of the tool includes increasing or decreasing the feed rate based on the bone mineral density distribution.

6. The method as set forth in claim 5 , further comprising adjusting with the manipulator controller the feed rate of the tool based on a temperature of the workpiece.

7. The method as set forth in claim 5 , further comprising adjusting with the manipulator controller the feed rate of the tool based on a user setting.

8. The method as set forth in claim 3 , wherein controlling the plurality of parameters of the tool includes generating the tool path of the tool based on the bone mineral density distribution as the tool moves relative to the workpiece.

9. The method as set forth in claim 8 , wherein generating the tool path of the tool based on the bone mineral density distribution includes increasing or decreasing the cutting depth of the workpiece based on the bone mineral density distribution.

10. The method as set forth in claim 8 , wherein generating the tool path of the tool based on the bone mineral density distribution includes generating tool path segments based on the bone mineral density distribution.

11. The method as set forth in claim 8 , wherein generating the tool path of the tool based on the bone mineral density distribution includes classifying bone such that adjacent sections of the tool path have a common classification.

12. The method as set forth in claim 11 , wherein classifying the bone includes classifying the bone into a high density classification and a low density classification with respect to a bone mineral density threshold.

13. The method as set forth in claim 3 , wherein controlling the plurality of parameters of the tool includes adjusting the rotational speed of the tool based on the bone mineral density distribution as the tool moves relative to the workpiece.

14. The method as set forth in claim 13 , wherein adjusting the rotational speed of the tool based on the bone mineral density distribution includes increasing or decreasing the rotational speed based on the bone mineral density distribution.

15. The method as set forth in claim 1 , further comprising controlling with the manipulator controller the manipulator to move the tool along the tool path relative to the workpiece.

16. The method as set forth in claim 1 , further comprising generating with the navigation computer tool path segments based on the density distribution with the density distribution comprising a respective density distribution for each of the tool path segments.

17. The method as set forth in claim 16 , further comprising increasing or decreasing with the manipulator controller the cutting depth for one of the tool path segments based on the respective density distribution.

18. The method as set forth in claim 17 , further comprising determining with the navigation computer the feed rate for each of the tool path segments with the feed rate comprising the velocity of a distal end of the tool; and adjusting the feed rate between the tool path segments.

19. A method for controlling a manipulator and a tool coupled to the manipulator to remove material from a workpiece during a procedure with a robotic system including a navigation computer and a manipulator controller coupled to the manipulator and with the workpiece comprising denser material and less dense material, said method comprising the steps of:
determining a density distribution of the workpiece;
tracking with the navigation computer a position of the tool relative to the workpiece as the tool moves relative to the workpiece during the procedure;
generating with the navigation computer a tool path of the tool based on the density distribution; and
controlling with the manipulator controller a plurality of parameters associated with the tool including a feed rate of the tool, a rotational speed of the tool, and the tool path of the tool, wherein controlling the plurality of parameters of the tool includes: setting the feed rate of the tool based on the density distribution, controlling the rotational speed of the tool based on the feed rate of the tool, and controlling movement of the tool based on the generated tool path to remove the denser material in a layer having a first thickness, and remove the less dense material in a layer having a second thickness greater than the first thickness.

20. The method as set forth in claim 19 , further comprising:
providing a predetermined density threshold; and
controlling with the manipulator controller movement of the tool based on the generated tool path to remove an entirety of the less dense material below the predetermined density threshold prior to removing the denser material above the predetermined density threshold.

21. A method for controlling a manipulator and a tool coupled to the manipulator to remove material from a workpiece during a procedure with a robotic system including a navigation computer and a manipulator controller coupled to the manipulator, said method comprising the steps of:
determining a density distribution of the workpiece with the density distribution including a first density distribution and a second density distribution different than the first density distribution;
tracking with the navigation computer a position of the tool relative to the workpiece as the tool moves relative to the workpiece during the procedure;
generating with the navigation computer a tool pat

Assignees

• Mako Surgical Corp

Inventors

• Moctezuma De La Barrera José Luis
• Bowling David Gene
• Malackowski Donald W
• Roessler Patrick
• Beer Joel N

Classifications

• B25J9/1664

  characterised by motion, path, trajectory planning · CPC title

• B25J9/1671

  characterised by simulation, either to verify existing program or to create and verify new program, CAD/CAM oriented, graphic oriented programming systems · CPC title

• A61B2034/2063

  Acoustic tracking systems, e.g. using ultrasound · CPC title

• A61B2090/3945

  Active visible markers, e.g. light emitting diodes · CPC title

• A61B34/20

  Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis · CPC title