Head Tracking During Magneto-Encephalography (MEG) Data Recording via 'Flying Triangulation'

Summary of the results: In this wor, a prototype sensor based on the Flying Triangulation measurement principle and also compatible to MEG environment is developed and implemented in hardware. This sensor consist of two projection beam path and an observing pathes for 3 D data collection, mounted in 200 mm x 180 mm x 150 mm housing. To prevent any interposition between the MEG measurement and Flying Triangulation sensor acquisition, the housing is contructed with PVC. The triangulation angle for this sensor is Φ=6° and 3D data acquisition is 30 fps. For the light source two fiber-coupled laser diodes with 7 m multi-mide fiber length and output power 400 mW in wavelength λ=635 nm is used. For making the projection pattern, 25 lines DOE is implemented. For collimating the fiber output, f = 40 mm focal length collimator, which is not so perfect for our work, is used. This collimator can not focus the fiber output sharply, so we can not acquire thin lines and it increases our measurement uncertainty. The working distance of the sensor is dA = 1000 mm and measurement volume is 200 mm x 150 mm x 180 mm. By connecting the sensor to the 'Flytr-Reg' software, we can calibrate and acquire the data which object motion is completely detectable.