加拿大 北方数字,Northern Digital ,  
加拿大北方数字公司(Northern Digital Inc)生产医疗以及工业行业所使用的光学及电磁测量系统，这些产品被用于计算机辅助的手术及治疗，以及影像导引的辐射治疗，此外还被用于光学跟踪和3D测量。

北方数字总部位于安大略省的滑铁卢，

NDI specializes in the design, manufacture and sale of advanced spatial measurement systems. Recognized as a global leader in the field, NDI provides solutions of the highest quality, accuracy and reliability. The technology makes possible some of the most advanced medical, industrial and life sciences applications in the world today. In fields as diverse as computer-assisted therapy, motion capture for sports, industrial reverse engineering and motion-measurement biomechanics research, NDI systems are internationally trusted as the technology of choice.
Specialties
motion capture for research, coordinate measurement machines, spatial measurement, reverse engineering, medical navigation, biomechanics, portable CMM, 3D laser scanning, metrology, sterile spheres for Image Guided Surgery (IGS), computer assited therapy