Grzeda Victor, Fichtinger Gabor
Queen's University, Kingston, ON, Canada
Med Image Comput Comput Assist Interv. 2010;13(Pt 3):424-31. doi: 10.1007/978-3-642-15711-0_53.
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.
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.
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.
在传统C型臂荧光透视机上实现准确、实用且经济实惠的关节编码是一项重大技术挑战。传统的位姿跟踪方法，如光学相机和放射学基准标记，存在显著缺陷。
我们提议为传统C型臂配备倾斜感应加速度计以进行旋转编码。我们的实验装置包括将一个加速度计固定在一台全尺寸C型臂上，并使用网络摄像头替代X射线成像进行这项可行性研究。通过跟踪棋盘格板的网络摄像头获取C型臂位姿的真实值。基于这些数据，我们构建了一系列角度和结构校正方程，这些方程能够在手术过程中正确地将加速度计角度读数与C型臂位姿相关联，并补偿C型臂的系统性结构变形，如下垂和弯曲。
C型臂一次和二次角度旋转的实时跟踪在整个感兴趣的范围内显示出小于0.5度的精度和准确性。
