Magnetic laser scanner for endoscopic microsurgery

Abstract

Scanning lasers increase the quality of the laser microsurgery enabling fast tissue ablation with less thermal damage. However, the possibility to perform scanning laser microsurgery in confined workspaces is restricted by the large size of currently available actuators, which are typically located outside the patient and require direct line-of-sight to the microsurgical area. Here, a magnetic scanner tool is designed to allow endoscopic scanning laser microsurgery. The tool consists of two miniature electromagnetic coil pairs and permanent magnets attached to a flexible optical fiber. The actuation mechanism is based on the interaction between the electromagnetic field and the permanent magnets. Controlled and high-speed laser scanning is achieved by bending of the optical fiber with magnetic torque. Results demonstrate the achievement of a 3×3 mm2 scanning range within the laser spot is controlled with 35μm precision. The system is also capable of automatically executing high-speed laser scanning operations over customized trajectories with a root-mean-squared-error (RMSE) in the order of 75μm. Furthermore, it can be teleoperated in real-time using any appropriate user interface device. This new technology enables laser scanning in narrow and difficult to reach workspaces, promising to bring the benefits of scanning laser microsurgery to laparoscopic or even flexible endoscopic procedures. In addition, the same technology can be potentially used for optical fiber based imaging, enabling for example the creation of new family of scanning endoscopic OCT or hyperspectral probes.