PerCal: A Novel Permanent Calibration Method for Spinal Surgery Navigation. - Zhengyang Wu 002; Yucheng Shu; Jing Ling; Fayuan Zhou; Chen Zhao; Jia Li; Xin Ni; Xiaoji Luo; Wei Huang; Chao Zhang; Guifeng Xia; Weisheng Li 001; et al. (IEEE Trans. Instrum. Meas., 2024)