Environmental mapping for robotic assisted surgery

Patent metadata

Field	Value
Publication number	US-11154369-B2
Application number	US-201916250341-A
Country	US
Kind code	B2
Filing date	Jan 17, 2019
Priority date	Jan 24, 2018
Publication date	Oct 26, 2021
Grant date	Oct 26, 2021

Abstract

A system and method of use thereof are provided for dynamically generating an environmental map for use in robotic assisted surgery. The generated environmental map is used to plan a recovery tool path that an end-effector tool can safely and efficiently follow to re-position the tool back to a cutting position following the displacement of the tool from the cutting position. Additionally, the environmental map is used to update a virtual representation of a bone to provide a user with visual feedback as to the progression of the end-effector tool as the tool removes material from the bone during a surgical procedure.

First claim

The invention claimed is:

1. A method to dynamically generate an environmental map in a robotic assisted surgery system, comprising:
removing material from a workpiece or a bone by manipulating an end-effector tool of the robotic surgical system along a tool path; and
dynamically generating the environmental map as material is being removed by labeling the removed material as free space in the environmental map and labeling the non-removed material as invalid space in the environmental map.

2. The method of claim 1 further comprising generating a three-dimensional virtual model of the bone and registering the virtual model of the bone to the bone.

3. The method of claim 1 wherein the labelling of the removed material as free space in the environmental map only occurs when an end-effector tool of the robotic assisted surgical system is in an ‘on’ operating state.

4. The method of claim 3 wherein the labelling of the removed material as free space in the environmental map only occurs when the end-effector tool crosses a boundary in a direction towards the bone.

5. The method of claim 1 wherein the environmental map is generated with reference to a robotic coordinate system or a tracking system coordinate system.

6. The method of claim 1 wherein the longitudinal axis of the bone is at least one of a mechanical axis of the bone or an anatomical axis of the bone.

7. The method of claim 1 further comprising planning a recovery tool path for an end-effector tool with the dynamically generated environmental map.

8. The method of claim 7 wherein the planning of the recovery tool path further comprises displacing the end-effector tool away from the tool path to a displaced position and planning the recovery tool path based on the labelled free space and the labelled invalid space.

9. The method of claim 8 wherein the planning of the recovery tool path further comprises minimizing a path length from the displaced position into proximity to the pre-displaced position on the tool path utilizing the labeled free space, and maximizing dexterity and distance away from obstacles utilizing the labeled invalid space.

10. The method of claim 9 wherein the minimizing of the path length and the maximizing of the dexterity and distance away from obstacles is accomplished with an algorithm including at least one of: optimization algorithms, probability roadmaps (PRM), rapidly-exploring random trees (RRT), or potential field methods.

11. The method of claim 10 wherein the tool path further includes one or more checkpoints positioned along the tool path wherein the planning of the recovery tool path from the displaced position back to, or near, the pre-displaced position utilizes one or more of the checkpoints.

12. The method of claim 11 further comprising determining which of the one or more checkpoints is in closest proximity to the pre-displaced position of the end-effector tool and planning the recovery tool path based on one or more of said checkpoints.

13. A surgical system comprising:
a surgical robot with an end effector tool; and
a computing system comprising a processor and software to generate the environmental map of claim 1 .

14. The system of claim 13 further comprising an environmental map generator software module for generating an environmental map.

15. The system of claim 14 wherein the environmental map generator software module further comprises a motion planner software module for dynamically planning a recovery path for the end-effector tool.

16. The system of claim of claim 13 further comprising at least one of a mechanical digitizer or a non-mechanical tracking system.

17. The method of claim 1 further comprising registering the bone relative to the robotic assisted surgical system.

18. The method of claim 1 further comprising defining a boundary in the environmental map based a plane non-parallel to a longitudinal axis of the bone.

19. The method of claim 18 further comprising:
labeling regions starting at the boundary and away from the bone as free space in the environmental map; and
labeling regions starting at the boundary and towards the bone as invalid space in the environmental map.

Assignees

• Think Surgical Inc

Inventors

• Roldan Jay
• Hanson Randall

Classifications

• A61B34/30 Primary

  Surgical robots · CPC title

• A61B2034/104

  Modelling the effect of the tool, e.g. the effect of an implanted prosthesis or for predicting the effect of ablation or burring · CPC title

• A61B2034/105

  Modelling of the patient, e.g. for ligaments or bones · CPC title

• A61B2034/2055

  Optical tracking systems · CPC title

• A61B2034/2068

  using pointers, e.g. pointers having reference marks for determining coordinates of body points · CPC title