The impact of auditive feedback on neuronavigation

To improve the usefulness of the information offered by neuronavigation systems, we developed an auditive feedback system which can be used in addition to regular neuronavigation. Using a serial connection, instrument coordinates determined by a commercially available neuronavigation system were transferred to a laptop computer. Based on preoperative segmentation of the images, the software on the laptop computer produced an audible signal whenever the instrument moved into an area the surgeon wanted to avoid. Phantom experiments were conducted to evaluate the impact of this setup on volumetric resections. These consisted of the ‘resection’ of a preoperatively defined target-volume from eight blocks of floral foam using CT-based navigation, four with and four without the auditive feedback extension. The resemblance between the resection cavity, as demonstrated by a postoperative CT scan, and the target-volume was greater each time auditive feedback had been used. This corresponded with more complete removal of the target-volume in all cases and the removal of more nontarget ‘tissue’ in two out of four cases. Our results make the usefulness of auditive feedback plausible and, consequently, we recommend the relatively inexpensive incorporation of auditive feedback in commercially available neuronavigation systems.