Optimal Spectral Bands for Instrument Detection in Microscope-Assisted Surgery

Optic image-guidance systems enable minimally invasive (MIS) approaches in surgery. However, available MIS-techniques limits both ergonomics and field of view (FoV), which can be detrimental for anatomical awareness and safe manipulation with tissues. Contemporary navigation techniques (i.e. neuronavigation) support spatial awareness during surgery. However, these techniques require time-consuming instrumentation and lack real-time precision needed in soft-tissue surgery. In this work, we utilize operative microscopes FoV as an unobtrusive source to support MIS-navigation with micro-instrument tracking. The FoV instrument tracking has been investigated in laparoscopy, however, high magnification, selection of instruments and bimanually variant characteristics of microneurosurgery make the current computational approaches challenging to adopt. In this work, we investigate potentials of spectral imaging for micro-instrument tracking. We present a spectral-imaging system suitable for the use at the operation rooms. Using a hyperspectral camera mounted to the side ocular of operation microscope and Xenon white light illumination, we collected samples of standard microsurgical instruments (reflective and non-reflective) that were positioned in a biological tissue (placenta). In the analysis of contrasts, we compared spectral images to traditional RGB. We observed 8-13% contrast enhancement with the optimal wavelength bands and 20.4% improvement in instrument-tracking time. Our results encourage application of wavelength-tuned cameras to improve efficiency of optic tracking in MIS-systems.