Purpose: The purpose of this study was to develop and verify an intraoperative module for supporting navigated biopsy procedures using optical see-through head-mounted display (HMD). Methods: Biopsy procedure including entry and endpoints of needle insertion was planned preoperatively having regard to the resection region segmentation and safety margin definition. Biopsy procedures were performed by two users using an intraoperative optical navigation module on a specially prepared brain phantom. Two visualization techniques were compared: an accurate augmented reality one, where a virtual plan is superimposed onto surgical field by using optical see-through HMD together with personalized calibration method and visualization on the external display. Results: Averaged errors from 24 trials using external display were 2.04 ± 0.83 mm for the first user and 2.69 ± 1.11 mm for the second one, while applying HMD 2.50 ± 0.93 mm (the first user) and 2.17 ± 0.82 mm (the second user), respectively. Conclusions: Proper usage of HMD visualization preceded by the personalized calibration allows the user to perform navigated biopsy procedure with comparable accuracy to its equivalent with the external display. Additionally, augmented reality visualization improves ergonomics and enables focusing on the surgical field without losing a direct line of sight with the field of view as it happens for external displays. However, ensuring high accuracy of augmented reality visualization still requires proper calibration and some user experience, which is challenging.
Calibration Method of Visual Parameters for See-Through Head-Mounted Display.
