Design and Coordination Kinematics of an Insertable Robotic Effectors Platform for Single-Port Access Surgery.

Single port access surgery (SPAS) presents surgeons with added challenges that require new surgical tools and surgical assistance systems with unique capabilities. To address these challenges, we designed and constructed a new insertable robotic end-effectors platform (IREP) for SPAS. The IREP can be inserted through a Ø15 mm trocar into the abdomen and it uses 21 actuated joints for controlling two dexterous arms and a stereo-vision module. Each dexterous arm has a hybrid mechanical architecture comprised of a two-segment continuum robot, a parallelogram mechanism for improved dual-arm triangulation, and a distal wrist for improved dexterity during suturing. The IREP is unique because of the combination of continuum arms with active and passive segments with rigid parallel kinematics mechanisms. This paper presents the clinical motivation, design considerations, kinematics, statics, and mechanical design of the IREP. The kinematics of coordination between the parallelogram mechanisms and the continuum arms is presented using the pseudo-rigid-body model of the beam representing the passive segment of each snake arm. Kinematic and static simulations and preliminary experiment results are presented in support of our design choices.

Feature classification for tracking articulated surgical tools.

Tool tracking is an accepted capability for computer-aided surgical intervention which has numerous applications, both in robotic and manual minimally-invasive procedures. In this paper, we describe a tracking system which learns visual feature descriptors as class-specific landmarks on an articulated tool. The features are localized in 3D using stereo vision and are fused with the robot kinematics to track all of the joints of the dexterous manipulator. Experiments are performed using previously-collected porcine data from a surgical robot.

Initial trial of a stereoscopic, insertable, remotely controlled camera for minimal access surgery.

BACKGROUND: Although video-laparoscopy has enabled successful minimal access surgery, the nature of the technology causes many troublesome limitations: (1) the fulcrum effect of the insertion site through the abdominal wall limits the angle of view, (2) the camera operator must use counterintuitive movements, (3) the laparoscope occupies an incision which otherwise could be used for an instrument, and (4) the laparoscope provides a two-dimensional image. METHODS: A stereoscopic, insertable, remotely controlled camera was developed to overcome the limitations imposed by traditional video-laparoscopy. Additional functionality included digital zoom, picture-in-picture (PIP), and tracking capability for autonomous function of the camera. Four surgical tasks were performed twice in a porcine model, once using the insertable camera and once using a standard video-laparoscope setup for visualization. Running the bowel, simulated laparoscopic appendectomy, laparoscopic nephrectomy, and laparoscopic suturing and tying were measured for time, blood loss, and complications. Digital zoom, PIP, and the ability of the computer to move the camera to track a marked instrument were subjectively evaluated. RESULTS: The tasks were aborted in one animal because a new three-dimensional (3D) display could not be synchronized with the camera and in another animal because a motor in the camera failed. The tasks were all completed twice in two animals. The mean time was less for all procedures using the insertable camera. There was no significant blood loss and there were no complications. Digital zoom and PIP displaying both a close-up and a panoramic view were subjectively felt to improve visualization by all observers. The computer could reliably move the camera to track a marked instrument to keep it in the center of the field of view. CONCLUSIONS: This preliminary proof-of-concept study suggests that a stereoscopic, insertable, remotely controlled camera may provide better visualization during minimal access surgery by overcoming many of the limitations of video-laparoscopy.

Comparison of monoscopic insertable, remotely controlled imaging device with a standard laparoscope in a porcine model.

Laparoscopic imaging has remained relatively unchanged since the introduction of the rod-lens system. The intent here is to improve imaging by designing and building sensors and effectors placed directly into the body and controlled remotely. An 11-mm monoscopic insertable pan/tilt endoscopic imaging device with an integrated light source was studied. In vivo testing included simulated appendectomy, nephrectomy, suturing, and running the bowel in a porcine model (n = 6). Subjective impression and time for each procedure were compared using each imaging modality. The insertable imaging device seemed easier and more intuitive to use than a standard laparoscope. Time to perform procedures was better than or equivalent to a standard laparoscope. The insertable camera was subjectively preferred, and times for completion of complex tasks were shorter using the insertable camera. The insertable imaging device has the potential to be an integral part of surgical system platforms.

In vivo pan/tilt endoscope with integrated light source, zoom and auto-focusing.

We describe a surgical imaging device with pan, tilt, zoom and integrated LED light source. It can be fully inserted into the abdomen, leaving the insertion port free for tooling. Using a porcine model we have tested the device and performed surgical procedures including cholecystectomy, appendectomy, running (measuring) the bowel, suturing, and nephrectomy. The tests show that the new device is: * Easier and more intuitive to use than a standard laparoscope. * Joystick operation requires no specialized operator training. * Field of view and access to relevant regions of the body were superior to a standard laparoscope using a single port. * Time to perform procedures was better or equivalent to a standard laparoscope. We believe these insertable platforms will be an integral part of future surgical systems.