Online measurement and evaluation of the Er:YAG laser ablation process using an integrated OCT system

Abstract

Laser surgery has gained clinical importance due to numerous advantages including contact-free processing, arbitrary cutting geometries, and high precision. However, online process control remains a challenge for widespread clinical use. Therefore, we established a combined setup of a pulsed Er:YAG laser ( = 2940 nm) and an optical coherence tomography (OCT) ( = 930 nm) for in situ monitoring of hard tissue ablation. The optical setup facilitates an interactive control of the laser ablation depth and remaining tissue strength through the depth resolution of OCT. The 3D OCT data-set, which is acquired after ablation, provides contours and layer thicknesses.

Comparison of tablet-based strategies for incision planning in laser microsurgery

“…1a and comprises an Er:YAG laser (DPM-15, Pantec Engineering AG, Liechtenstein), a galvanometer based three-axis scanning unit with a resolution of 2 µm (VarioScan and HurryScan, SCANLAB AG, Germany) and focusing optics. 5 The laser spot can be positioned in a three-dimensional, cubic workspace of 10 mm in each direction. Stereo images are acquired with two miniature camera modules having an image definition of 640 × 480 pixels and a baseline of 5 mm.…”

Towards Intra-operative OCT Guidance for Automatic Head Surgery: First Experimental Results

“…This important feature enables an in situ imaging and control of the ablation process. We refer to [4] for further information and first results.…”

Remote photoacoustic sensing using speckle-analysis

“…Evaluation of tissue carbonization, thermal tissue damage and ablation crater can here be achieved. Furthermore, OCT was successfully tested as an automated feedback system for hard tissue surgery 17 . Ablation depth measurement and also classification of underlying tissue structures was achieved 18,19 .…”