1 Magellan: Technical Description of a New System for Robot-Assisted Nerve Blocks Joshua Morse * , Mohamad Wehbe ‡ , Riccardo Taddei † , Shantale Cyr § , and Thomas M. Hemmerling §¶ * Department of Electrical and Computer Engineering, McGill University, Montreal, QC, Canada email: joshua.morse@mail.mcgill.ca ‡ Department of Experimental Surgery, McGill University, Montreal, QC, Canada † Department of Anesthesiology, University of Pisa, Pisa, Italy § Department of Anesthesia, McGill University, Montreal, QC, Canada ¶ Institute of Biomedical Engineering, University of Montreal, Montreal, QC, Canada email: thomas.hemmerling@mcgill.ca Abstract—Nerve blocks are common procedures used to remove sensation from a specific region of the body via injection of local anesthetic. Ultrasound-guided nerve blocks are common-place in anesthesia, but require specialized training and advanced bi-manual dexterity. This paper de- scribes a system designed to robotically assist in ultrasound- guided nerve blocks. Robot-assisted nerve blocks could allow for more precise needle placement, and therefore a higher efficacy of blocks. This system is the first step in developing a completely automated nerve block system, which would also require the incorporation of ultrasound image recognition of nerves and other physiological markers. Index Terms—Regional anesthesia, nerve blocks, robotic anesthesia. I. I NTRODUCTION N ERVE blocks are a procedure of regional anesthesia used to remove the sensitivity from an area of the body via the injection of an anesthetic drug into the nerve innervating the target area. Nerve blocks were first used in surgery in 1885 [1] and are now a common procedure performed routinely around the world. Performing regional nerve blocks requires special train- ing. Anesthesiologists performing regional nerve blocks only on an occasional basis have a significant failure rate, as high as 45% [2]. Most regional blocks are performed using ultrasound guidance; this necessitates careful bi- manual operation of the ultrasound probe and the nerve block needle. Precise movement of the needle is important for successful blocks. One centimeter movement in any direction can make the difference between a failed and a successful block. Mechanical robots have been used in surgery for more than 10 years, the da Vinci Surgical System (Intuitive Surgical, Inc., Sunnyvale, CA) being the latest. These mechanical robots are shown to increase precision of movements and improve outcome [3]. Recently, Tighe et al. have used the da Vinci Surgical System to perform successful nerve blocks in an ultrasound phantom [4]. We present the first robotic system, called Magellan, designed specifically to perform routine nerve blocks. II. MATERIALS AND METHODS The Magellan system is designed to perform robot- assisted, ultrasound-guided nerve blocks. The system has 4 primary components: a standard nerve block needle and syringe mounted via a custom clamp to a robotic arm (JACO robotic arm, Kinova, Montreal, QC, Canada), an ultrasound machine, a joystick (ThrustMaster T.Flight Hotas X, Guillemot Inc., New York, NY, USA), and a software control system. The system is designed to work with any ultrasound machine with a video output. The ul- trasound video signal is captured via a USB video capture device (Dazzle DVC100, Pinnacle Systems, Mountain View, CA, USA). The software system is designed on a client/server model so that nerve blocks can be performed remotely. Both the client and server programs were written in C# and communicate using UDP/IP. The client software inter- faces with the ultrasound machine, robotic arm, and a webcam (Lifecam HD, Microsoft Corporation, Redmond, WA, USA). The ultrasound and webcam video feeds are streamed from the client to the server, where they are displayed in a graphical user interface (GUI) created in LabView (National Instruments, Austin, TX, USA). The webcam is positioned in order to provide a direct view of the target nerve insertion area and the ultrasound probe. The server software interfaces with the joystick and transmits the joystick commands to the client over the IP network. The client and server, as well as their software subsystems, are detailed in Fig. 1. Further explanation of the individual subsystems of both applications are presented below. A. Software Control System 1) Server Application: The Controller Subsystem im- plements an interface that decouples the precise con- troller’s driver from the system, allowing for the controller to be easily changed. This subsystem reads the state of the controller and provides it to the Server Networking Subsystem. The Server Networking Subsystem is responsible for JOURNAL OF COMPUTERS, VOL. 8, NO. 6, JUNE 2013 1401 © 2013 ACADEMY PUBLISHER doi:10.4304/jcp.8.6.1401-1405