This paper describes a novel mechatronic tool for arthroscopy, which is at the same time a smart tool for traditional arthroscopy and the main component of a system for computer-assisted arthroscopy. The mechatronic arthroscope has a cable-actuated servomotor-driven multi-joint mechanical structure, is equipped with a position sensor measuring the orientation of the tip and with a force sensor detecting possible contact with delicate tissues in the knee, and incorporates an embedded microcontroller for sensor signal processing, motor driving and interfacing with the surgeon and/or the system control unit. When used manually, the mechatronic arthroscope enhances the surgeon's capabilities by enabling him/her to easily control tip motion and to prevent undesired contacts. When the tool is integrated in a complete system for computer-assisted arthroscopy, the trajectory of the arthroscope is reconstructed in real time by an optical tracking system using infrared emitters located in the handle, providing advantages in terms of improved intervention accuracy. The computer-assisted arthroscopy system comprises an image processing module for segmentation and three-dimensional reconstruction of preoperative computer tomography or magnetic resonance images, a registration module for measuring the position of the knee joint, tracking the trajectory of the operating tools, and matching preoperative and intra-operative images, and a human-machine interface that displays the enhanced reality scenario and data from the mechatronic arthroscope in a friendly and intuitive manner. By integrating preoperative and intra-operative images and information provided by the mechatronic arthroscope, the system allows virtual navigation in the knee joint during the planning phase and computer guidance by augmented reality during the intervention. This paper describes in detail the characteristics of the mechatronic arthroscope and of the system for computer-assisted arthroscopy and discusses experimental results obtained with a preliminary version of the tool and of the system.

Colonoscopy is an important procedure for the diagnosis of various pathologies, in particular cancer of the colon and of the rectum, the second most malignant tumor in industrialized countries. At present however, colonoscopy is a procedure often painful for the patient and complex for the doctor. This is mainly due to the characteristics of current colonoscopes, which are quite rigid and require the doctor to perform difficult maneuvers for insertion. In this paper we present the concept and describe the design and fabrication of a new system for colonoscopy based on a microrobot capable of being propelled semi-autonomously along the colon. The microrobot system comprises a mothership incorporating devices for clamping the colon wall and tools for diagnosis and intervention. The actuation system is based on purposely developed shape memory alloy (SMA) pneumatic microvalves. A human/machine interface allows the doctor to teleoperate or supervise the functioning of the microrobot and to receive visual and other information during endoscopy. Particular attention has been paid to investigating a reliable and safe method of locomotion and to develop an efficient clamping system for the microrobot. The resulting configuration of the microrobot is very simple and potentially suitable for real clinical application. A prototype microrobot system has been tested in vitro with promising results.