The application of augmented reality–based navigation for accurate target acquisition of deep brain sites: advances in neurosurgical guidance

Abstract

OBJECTIVE The objective of this study is to quantify the navigational accuracy of an advanced augmented reality (AR)–based guidance system for neurological surgery, biopsy, and/or other minimally invasive neurological surgical procedures. METHODS Five burr holes were drilled through a plastic cranium, and 5 optical fiducials (AprilTags) printed with CT-visible ink were placed on the frontal, temporal, and parietal bones of a human skull model. Three 0.5-mm-diameter targets were mounted in the interior of the skull on nylon posts near the level of the tentorium cerebelli and the pituitary fossa. The skull was filled with ballistic gelatin to simulate brain tissue. A CT scan was taken and virtual needle tracts were annotated on the preoperative 3D workstation for the combination of 3 targets and 5 access holes (15 target tracts). The resulting annotated study was uploaded to and launched by VisAR software operating on the HoloLens 2 holographic visor by viewing an encrypted, printed QR code assigned to the study by the preoperative workstation. The DICOM images were converted to 3D holograms and registered to the skull by alignment of the holographic fiducials with the AprilTags attached to the skull. Five volunteers, familiar with the VisAR, used the software/visor combination to navigate an 18-gauge needle/trocar through the series of burr holes to the target, resulting in 70 data points (15 for 4 users and 10 for 1 user). After each attempt the needle was left in the skull, supported by the ballistic gelatin, and a high-resolution CT was taken. Radial error and angle of error were determined using vector coordinates. Summary statistics were calculated individually and collectively. RESULTS The combined angle of error of was 2.30° ± 1.28°. The mean radial error for users was 3.62 ± 1.71 mm. The mean target depth was 85.41 mm. CONCLUSIONS The mean radial error and angle of error with the associated variance measures demonstrates that VisAR navigation may have utility for guiding a small needle to neural lesions, or targets within an accuracy of 3.62 mm. These values are sufficiently accurate for the navigation of many neurological procedures such as ventriculostomy.

Use of Mixed Reality in Neuro-Oncology: A Single Centre Experience

“…However, there are several disadvantages that are associated with currently available systems [ 8 , 13 , 14 , 15 , 16 ]. Firstly, there is only the 2D projection of images on the screen requiring the surgeon to translate into a mental 3D image during planning.…”

Augmented Reality in Stereotactic Neurosurgery: Current Status and Issues

“…The first research direction is the evaluation of the feasibility of ARN-guided frameless stereotaxy. [4][5][6] ARN-guided stereotaxy for cranial phantoms showed that this procedure has the advantage of allowing the surgeon to advance the needle in a natural posture. The second research direction is the application of ARN in improving the safety of frame-based stereotaxy.…”

“…Gibby et al 4 ) and Majak et al 5 ) performed an HMD-based, ARN-guided, freehand brain biopsy on a cranial phantom to evaluate the feasibility of ARN. In these studies, HMDs were used to display the preplanned trajectory toward the target.…”

“…Recent progress in the accuracy and reliability of AR systems has led to the increased use of AR in stereotactic neurosurgery over the past several years. [4][5][6][7] In this report, we review the feasibility of AR as a surgical support modality or as a distinct approach to stereotactic neurosurgery. Our previous study included in this report was approved by the Jichi Medical University Hospital clinical research ethics committee as a study on the "development and clinical application of AR neuronavigation" (ID B15-116 and 20-143).…”

A systematic comparison of the accuracy of monocular RGB tracking and LiDAR for neuronavigation

“…Many techniques have been proposed to register and track patient anatomy and surgical tools in AR-assisted neurosurgery. The most predominant approaches leverage 2D cameras to detect and track planar fiducial markers [32,34,[37][38][39][40]. These approaches rely on the geometric characteristics and dimensions of the fiducials to be known.…”