Near-infrared beacons: tracking anatomy with biocompatible fluorescent dots for mixed reality surgical navigation

Mixed reality for surgical navigation is an emerging tool for precision surgery. Achieving reliable surgical guidance hinges on robust tracking of the mixed reality device relative to patient anatomy. Contemporary approaches either introduce bulky fiducials that need to be invasively attached to the anatomy or make strong assumptions about the patient remaining stationary.

We present an approach to anatomy tracking that relies on biocompatible near-infrared fluorescent (NIRF) dots. Dots are quickly placed on the anatomy intra-operatively and the pose is tracked reliably via PnP-type methods. We demonstrate the potential of our NIRF dots approach to track patient movements after image registration on a 3D printed model, simulating an image-guided navigation process with a tablet-based mixed reality scenario.

The dot-based pose tracking demonstrated an average accuracy of 1.13 mm in translation and 0.69 degrees in rotation under static conditions, and 1.39 mm/1.10 degrees, respectively, under dynamic conditions.

Our results are promising and encourage further research in the viability of integrating NIRF dots in mixed reality surgical navigation. These biocompatible dots may allow for reliable tracking of patient motion post-registration, providing a convenient alternative to invasive marker arrays. While our initial tests used a tablet, adaptation to head-mounted displays is plausible with suitable sensors.