Real-time monitoring of incision profile during laser surgery using shock wave detection

Lack of sensory feedback during laser surgery prevents surgeons from discerning the exact location of the incision, which increases duration and complexity of the treatment. In this study we demonstrate a new method for monitoring of laser ablation procedures. Real-time tracking of the exact three dimensional (3D) lesion profile is accomplished by detection of shock waves emanating from the ablation spot and subsequent reconstruction of the incision location using time-of-flight data obtained from multiple acoustic detectors. Here, incisions of up to 9 mm in depth, created by pulsed laser ablation of fresh bovine tissue samples, were successfully monitored in real time. It was further observed that, by utilizing as little as 12 detection elements, the incision profile can be characterized with accuracy below 0.5 mm in all three dimensions and in good agreement with histological examinations. The proposed method holds therefore promise for delivering high precision real-time feedback during laser surgeries.