2014 Summer Project Week:Open source electromagnetic trackers usingOpenIGTLink
Stylized image of three orthogonal coils used in 6-DOF electromagnetic tracker sensor
Handmade assembly of three commercial solenoidal coils; each solenoid is 11 millimeters long
Key Investigators
- Retired: Peter Traneus Anderson
- BWH: Tina Kapur, Sonia Pujol
Objectives
- This open-source electromagnetic tracker project aims to teach and develop open-source electromagnetic trackers, to enable extending performance in directions that existing proprietary trackers do not address.
- This project aims, in part, to develop methods of accurately characterizing transmitter and receiver coils without the use of costly precision robots.
Approach, Plan
- Over the past year, Peter has developed and tested a simple and fast buffer design between the steady-streaming ADC data and the bursty USB interface. This fast interface replaces two-years-ago's very-slow USB interface in Pete's prototype three-transmitter-coil three-receiver-coil 6DOF (degree-of-freedon) hardware.
- With the electronics now understood, Peter's attention is returning to the problem of accurately characterizing coils. Understanding of how the electromagnetics behaves, permits design of simpler and better characterization protocols than naive protocols that just try to optimize position and orientation accuracy.
- For three-transmitter-coil three-receiver-coil 6DOF trackers, we note the following:
1. The three transmitter coils are approximately-colocated, approximately-orthogonal approximately-dipoles.
2. The three receiver coils are approximately-colocated, approximately-orthogonal approximately-dipoles.
3. The position-and-orientation tracking problem naturally divides into one distance and five angles, as shown in Raab, Blood, Steiner, Jones, "Magnetic Position and Orientation Tracking System", IEEE Transactions on Aerospace and Electronic Systems, Vol. AES-15, No. 5, September 1979, pages 709 to 718.
Progress
References
Pete's published work to date is on Open Source Electromagnetic Trackers and on [http://home.comcast.net/~traneus].
