PURPOSE: Accurate, practical, and affordable joint encoding on legacy C-arm fluoroscopes is a major technical challenge. Conventional pose tracking methods, like optical cameras and radiographic fiducials, are hampered by significant shortcomings. METHODS: We propose to retrofit legacy C-arms with a tilt sensing accelerometer for rotation encoding. Our experimental setup consists of affixing an accelerometer to a full scale C-arm with a webcam as an alternative to X-ray imaging for this feasibility research. Ground-truth C-arm poses were obtained from the webcam that tracked a checkerboard plate. From these we constructed a series of angle and structural correction equations that can properly relate the accelerometer angle readings to C-arm pose during surgery and compensate for systematic structural C-arm deformations, such as sagging and bending. RESULTS: Real-time tracking of the primary and secondary angle rotations of the C-arm showed an accuracy and precision of less than 0.5 degrees in the entire range of interest.
PURPOSE: Accurate, practical, and affordable joint encoding on legacy C-arm fluoroscopes is a major technical challenge. Conventional pose tracking methods, like optical cameras and radiographic fiducials, are hampered by significant shortcomings. METHODS: We propose to retrofit legacy C-arms with a tilt sensing accelerometer for rotation encoding. Our experimental setup consists of affixing an accelerometer to a full scale C-arm with a webcam as an alternative to X-ray imaging for this feasibility research. Ground-truth C-arm poses were obtained from the webcam that tracked a checkerboard plate. From these we constructed a series of angle and structural correction equations that can properly relate the accelerometer angle readings to C-arm pose during surgery and compensate for systematic structural C-arm deformations, such as sagging and bending. RESULTS: Real-time tracking of the primary and secondary angle rotations of the C-arm showed an accuracy and precision of less than 0.5 degrees in the entire range of interest.
Authors: Ehsan Dehghan; Mehdi Moradi; Xu Wen; Danny French; Julio Lobo; W James Morris; Septimiu E Salcudean; Gabor Fichtinger Journal: Med Phys Date: 2011-10 Impact factor: 4.071
Authors: Christoph Wilkmann; Nobutake Ito; Tobias Penzkofer; Peter Isfort; Hong-Sik Na; Michael Hennes; Catherine Disselhorst-Klug; Andreas H Mahnken; Christiane K Kuhl; Philipp Bruners Journal: Int J Comput Assist Radiol Surg Date: 2014-06-28 Impact factor: 2.924