Compact and Lightweight End-Effectors to Drive Hand-Operated Surgical Instruments for Robot-Assisted Microsurgery

In this article, we develop two end-effectors for robot-assisted microsurgery with the aim of implementing compact and lightweight devices that can drive hand-operated commercial surgical instruments, such as forceps and scissors. To achieve this objective, we mainly consider the type of actuator and the driving mechanism that influence not only the working performance but also the structural features of devices. As a suitable actuator, we employ shape memory alloy actuators because of their operational benefits, such as high energy density and configurational simplicity. The two drivers are designed with the geometric models and then fabricated as functional prototypes for performance evaluation. Further, we investigate the practical applicability and usability of the devices based on the robot-assisted microsurgery on animal subjects. In the in vivo experiment, we perform the epineurium windowing microsurgery. In this surgery, which is performed as a prerequisite of the process for conducting the visualization of peripheral nerve fibers with a confocal laser endomicroscope, we can precisely peel off the outer membrane of the peripheral nerve (approximately 1 mm in diameter) by using a teleoperated surgical robot equipped with the proposed end-effectors. The result of the peripheral nerve fiber visualization demonstrates that the proposed devices can be suitably utilized for the epineurium windowing microsurgery.