Co-located haptic and 3D graphic interface for medical simulations.

We describe a system which provides high-fidelity haptic feedback in the same physical location as a 3D graphical display, in order to enable realistic physical interaction with virtual anatomical tissue during modelled procedures such as needle driving, palpation, and other interventions performed using handheld instruments. The haptic feedback is produced by the interaction between an array of coils located behind a thin flat LCD screen, and permanent magnets embedded in the instrument held by the user. The coil and magnet configuration permits arbitrary forces and torques to be generated on the instrument in real time according to the dynamics of the simulated tissue by activating the coils in combination. A rigid-body motion tracker provides position and orientation feedback of the handheld instrument to the computer simulation, and the 3D display is produced using LCD shutter glasses and a head-tracking system for the user.

Simultaneous Independent Translational and Rotational Feedback Motion Control System for a Cylindrical Magnet using Planar Arrays of Magnetic Sensors and Cylindrical Coils.

This letter describes an electromagnetic feedback control system for rigid-body motion control of a magnet. Its novel features are that sensing and actuation using magnetometer sensors and actuator coils operate simultaneously, and magnetic field models from the controlled magnet and each of the actuator coil currents are used together to calculate the 3D position and orientation of the magnet to control motion simultaneously and independently in multiple degrees of freedom including planar translation and two in rotation, leaving rotation about the cylindrical axis of magnetization uncontrolled. The system configuration and the localization and actuation methods are presented with experimental results of magnet localization with constant and varying coil currents, and during feedback control of trajectory following motion of the magnet in multiple directions on a planar surface and with controlled changes in orientation. The intended application of the system is for motion control of magnetic endoscope capsules and other miniature medical devices inside the human body.

A Compact Modular Teleoperated Robotic System for Laparoscopic Surgery.

Compared with traditional open surgery, minimally invasive surgical procedures reduce patient trauma and recovery time, but the dexterity of the surgeon in laparoscopic surgery is reduced owing to the small incisions, long instruments and limited indirect visibility of the operative site inside the patient. Robotic surgical systems, teleoperated by surgeons from a master control console with joystick-type manipulation interfaces, have been commercially developed yet their adoption into standard practice may be limited owing to their size, complexity, cost and time-consuming setup, maintenance and sterilization procedures. The goal of our research is to improve the effectiveness of robot-assisted surgery by developing much smaller, simpler, modular, teleoperated robotic manipulator systems for minimally invasive surgery.

Development of miniaturized light endoscope-holder robot for laparoscopic surgery.

PURPOSE: We have conducted experiments with an innovatively designed robot endoscope holder for laparoscopic surgery that is small and low cost. MATERIALS AND METHODS: A compact light endoscope robot (LER) that is placed on the patient's skin and can be used with the patient in the lateral or dorsal supine position was tested on cadavers and laboratory pigs in order to allow successive modifications. The current control system is based on voice recognition. The range of vision is 360 degrees with an angle of 160 degrees . Twenty-three procedures were performed. RESULTS: The tests made it possible to advance the prototype on a variety of aspects, including reliability, steadiness, ergonomics, and dimensions. The ease of installation of the robot, which takes only 5 minutes, and the easy handling made it possible for 21 of the 23 procedures to be performed without an assistant. CONCLUSION: The LER is a camera holder guided by the surgeon's voice that can eliminate the need for an assistant during laparoscopic surgery. The ease of installation and manufacture should make it an effective and inexpensive system for use on patients in the lateral and dorsal supine positions. Randomized clinical trials will soon validate a new version of this robot prior to marketing.

Torque Contribution to Haptic Rendering of Virtual Textures.

Despite the fact that conventional haptic interfaces and rendering algorithms commonly approximate interactions with force only, the dynamic effects of even simple tasks, e.g., writing on a paper, involve both forces and torques. To extend previous algorithms as well as to investigate the effects of torque feedback on human roughness perception, we deployed a novel haptic platform with two probes, fingertip and penhandle. Three torque conditions were examined: 1) Slope Torque, which orients the probe perpendicular to the surface, 2) No Torque, where no active torque is provided by the device, and 3) Stiff Torque, where torque feedback is provided to keep the probe upright. A conventional magnitude estimation experiment was performed. The results indicated that both the torque signals and grasp type mediate human perception of virtual textures. Slope Torque led to greater perceived roughness when the fingertip was used, and the fingertip led to higher roughness ratings than the penhandle with the Slope Torque condition. The Slope Torque algorithm appears to be advantageous for generating rougher surfaces compared to the force-based algorithms which are typically limited by the system stability and actuator saturation.

Compact teleoperated laparoendoscopic single-site robotic surgical system: Kinematics, control, and operation.

BACKGROUND: To date a variety of teleoperated surgical robotic systems have been developed to improve a surgeon's ability to perform demanding single-port procedures. However typical large systems are bulky, expensive, and afford limited angular motion, while smaller designs suffer complications arising from limited motion range, speed, and force generation. This work was to develop and validate a simple, compact, low cost single site teleoperated laparoendoscopic surgical robotic system, with demonstrated capability to carry out basic surgical procedures. METHODS: This system builds upon previous work done at the University of Hawaii at Manoa and includes instrument and endoscope manipulators as well as compact articulated instruments designed to overcome single incision geometry complications. A robotic endoscope holder was used for the base, with an added support frame for teleoperated manipulators and instruments fabricated mostly from 3D printed parts. Kinematics and control methods were formulated for the novel manipulator configuration. RESULTS: Trajectory following results from an optical motion tracker and sample task performance results are presented. CONCLUSIONS: Results indicate that the system has successfully met the goal of basic surgical functionality while minimizing physical size, complexity, and cost.

[Preclinical development of the TIMC LER (light endoscope robot)]. / Robot coelioscopique porte-endoscope miniaturisé LER (light endoscope robot) : développement pré-clinique.

INTRODUCTION: The authors participated in the development of an innovative endoscope robot in laparoscopic surgery designed by TIMC-GMCAO, providing a solution to the disadvantages of currently available systems, i.e. their cost and large dimensions. MATERIAL AND METHODS: A compact robot (LER) placed on the patient's skin that can be used in the lateral and dorsal supine position was tested on cadavres and laboratory pigs in order to allow successive modifications. The current control system is based on voice recognition. The amplitude of vision is 360 degrees with an angle of 160 degrees. Twenty three procedures were performed (2 radical prostatectomies, 4 pelvic lymph node dissections, 6 nephrectomies, 2 adrenalectomies, 3 cholecystectomies, 1 small bowel resection-anastomosis, 1 cystectomy, 1 splenectomy, and 3 appendicectomies). RESULTS: Among the various control systems tested, we adopted voice recognition on the basis of its intuitive nature and the fact that it leaves one hand free. In the light of these studies, several aspects of the prototype were modified: reliability, fixation, ergonomy and dimensions. The ease of installation, which takes only 5 minutes, and the easy handling of the robot allowed 21 out of 23 laparoscopic procedures to be performed without the need for an assistant. CONCLUSION: The LER robot is an endoscope robot guided by the surgeon's voice that can eliminate the need for an assistant to hold the camera during laparoscopic surgery in the lateral and dorsal supine positions. The ease of installation and manufacture should make this an effective and inexpensive system. The gain in operating time was not evaluated during these trials on cadavres and pigs, as various prototypes were tested and several problems of reliability were successively resolved. Ongoing randomized, prospective clinical trials should soon validate this robot prior to marketing.

Development and testing of a compact endoscope manipulator for minimally invasive surgery.

OBJECTIVE: This report describes the design, development, and testing of a novel compact surgical assistant robot to control the orientation and insertion depth of a laparoscopic endoscope during minimally invasive abdominal surgery. In contrast to typical endoscope manipulators, the described robot is particularly compact and lightweight, is simple to set up and use, occupies no floor or operating table space, and does not limit access to the patient in any way. MATERIALS AND METHODS: The sterilizable endoscope manipulator is sufficiently small and lightweight at 625 g and 110 mm in diameter that it can be placed directly on the abdomen of the patient without interfering with other handheld instruments during minimally invasive surgery. It consists of an annular base, a clamp to hold an endoscope trocar, and two joints which enable azimuth rotation and inclination of the endoscope about a pivot point at the incision. The endoscope insertion depth is controlled by a cable winding acting against a compression spring on the endoscope shaft. Voice recognition and miniature keypad user command interfaces are provided, and the manipulator motors are backdriveable for manual repositioning. RESULTS: Endoscope camera trajectory-following accuracy and response-time results were measured using an optical localizer. Experimental results are given comparing the current prototype with the previous cable-driven prototype. The endoscope manipulator and its user interface were tested and evaluated by several surgeons during a series of minimally invasive surgical training procedures on cadavers and animals. CONCLUSIONS: The endoscope manipulator described has been shown to be a viable, practical device with performance and functionality equivalent to those of commercially available models, yet with greatly reduced size, weight, and cost.

Robot-assisted stapedotomy: micropick fenestration of the stapes footplate.

OBJECTIVE: Micropick fenestration of the stapes footplate, a difficult step in stapedotomy, was selected for trials evaluating the potential for robotic assistance (RA) to improve clinical measures of surgical performance. STUDY DESIGN: In a surgical model of stapedotomy, we measured accuracy of fenestration to a desired point location and force applied to the stapes footplate. Performance variables were measured for 3 experienced and 3 less-experienced surgeons. RESULTS: RA significantly reduced the maximum force applied to the stapes footplate. For fenestration targeting, RA significantly improved accuracy for less-experienced surgeons and significantly worsened targeting for more-experienced surgeons. CONCLUSIONS: RA significantly improves performance for micropick fenestration in a surgical model of stapedotomy. For certain tasks, RA differentially affects performance for users of different experience levels. CLINICAL SIGNIFICANCE: These are the first results showing quantitative improvements in performance during simulated ear surgery using RA and differential effects of RA on performance for users of different experience levels.

Robotic-surgical instrument wrist pose estimation.

The Compact Lightweight Surgery Robot from the University of Hawaii includes two teleoperated instruments and one endoscope manipulator which act in accord to perform assisted interventional medicine. The relative positions and orientations of the robotic instruments and endoscope must be known to the teleoperation system so that the directions of the instrument motions can be controlled to correspond closely to the directions of the motions of the master manipulators, as seen by the the endoscope and displayed to the surgeon. If the manipulator bases are mounted in known locations and all manipulator joint variables are known, then the necessary coordinate transformations between the master and slave manipulators can be easily computed. The versatility and ease of use of the system can be increased, however, by allowing the endoscope or instrument manipulator bases to be moved to arbitrary positions and orientations without reinitializing each manipulator or remeasuring their relative positions. The aim of this work is to find the pose of the instrument end effectors using the video image from the endoscope camera. The P3P pose estimation algorithm is used with a Levenberg-Marquardt optimization to ensure convergence. The correct transformations between the master and slave coordinate frames can then be calculated and updated when the bases of the endoscope or instrument manipulators are moved to new, unknown, positions at any time before or during surgical procedures.