Mixed Reality Needle Guidance Application on Smartglasses Without Pre-procedural CT Image Import with Manually Matching Coordinate Systems.

Abstract

To develop and assess the accuracy of a mixed reality (MR) needle guidance application on smartglasses. An MR needle guidance application on HoloLens2, without pre-procedural CT image reconstruction or import by manually matching the spatial and MR coordinate systems, was developed. First, the accuracy of the target locations in the image overlay at 63 points arranged on a 45 × 35 × 21cm box and needle angles from 0° to 80°, placed using the MR application, was verified. The needle placement errors from 12 different entry points in a phantom by seven operators (four physicians and three non-physicians) were compared using a linear mixed model between the MR guidance and conventional methods using protractors. The average errors of the target locations and needle angles placed using the MR application were 5.9 ± 2.6mm and 2.3 ± 1.7°, respectively. The average needle insertion error using the MR guidance was slightly smaller compared to that using the conventional method (8.4 ± 4.0mm vs. 9.6 ± 5.1mm, p = 0.091), particularly in the out-of-plane approach (9.6 ± 3.5mm vs. 12.3 ± 4.6mm, p = 0.003). The procedural time was longer with MR guidance than with the conventional method (412 ± 134s vs. 219 ± 66s, p < 0.001). MR needle guidance without pre-procedural CT image import is feasible when matching coordinate systems, and the accuracy of needle insertion is slightly better than that of the conventional method.