In this work, an optical coherence tomography (OCT) guided lasercochleostomy system has been proposed and successfully realized for future surgical applications at the inner ear. After appropriate image quality enhancement of the intraoperatively acquired OCT scans, the position of the bone-endosteum-perilymph boundary can be detected several hundred micrometers before its exposure to the air. Position and duration of the succeeding ablation pulses are planned based on the residual bone

more »

... s above the critical structure. OCT itself is also used as a highly accurate optical tracking system for motion compensation between the target area and the laser optics. During ex vivo experimental evaluation on fresh porcine cochleae, the ablation process terminated automatically when the thickness of the residual tissue layer uniformly reached a predefined value. The shape of the resulting channel bottom converged to the natural curvature of the endosteal layer without injuring the critical structure. Preliminary measurements in OCT scans indicated that the mean absolute accuracy of the shape approximation was only around 20µm. A closed-loop control of the endosteum preserving laser-cochleostomy with the accuracy on tens of micrometer scale is thereby established. i 2.3. Endosteum Preserving Laser-Cochleostomy