Ambiguity-free optical tracking system
US9561387B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 2013 |
| Grant date | Feb 7, 2017 |
| Priority date | — |
| Expiry date | Dec 17, 2033 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61N2005/1074
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An ambiguity-free optical tracking system (100) includes a position sensor unit (104), a control box (106), a computer (110) and software. The position sensor unit includes two cameras (121 and 122) that track a plurality of individual infra-red reflecting markers (160) affixed on a patient's skin. Coordinates of the cameras in a coordinate system of the cameras are determined as part of a system calibration process by intentionally creating ambiguous markers with two true markers. Using this information, an ambiguity elimination algorithm automatically identifies and eliminates ambiguous markers. A recursive backtracking algorithm builds a one-to-one correspondence between reference markers and markers optically observed during treatment. By utilizing a concept of null markers, the backtracking algorithm deals with missing, misplaced and occluded markers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.