The aim of this study was to examine the advantages and risks of the Automated Endoscopic System for Optical Positioning (AESOP) 3000 robot system during uncomplicated laparoscopic cholecystectomies or laparoscopic hernioplasty. In a randomized study, we examined two groups of 120 patients each with the diagnosis cholecystolithiasis respectively the unilateral inguinal hernia. We worked with the AESOP 3000, a robotic arm system that is voice-controlled by the surgeon. The subjective and objective comfort of the surgeon as well as the course and length of the operation were measured. The robot-assisted operations required significantly longer preparation and operation times. With regard to the necessary commands and manual camera corrections, the assistant group was favored. The same was true for the subjective evaluation of the surgical course by the surgeon. Our study showed that the use of AESOP during laparoscopic cholecystectomy and hernioplasty is possible in 94% of all cases. The surgeon must accept a definite loss of comfort as well as a certain loss of time against the advantage of saving on personnel.

The AESOP robot system in laparoscopic surgery: increased risk or advantage for surgeon and patient?

Laparoscopic camera navigation (LCN) is vital for the successful performance of laparoscopic operations, yet little time is spent on training. This study aimed to develop an inexpensive LCN simulator, to design a structured curriculum, and to determine the transferability of skills acquired. In this study, 0° and 30° LCN simulators were developed for use on a videotrainer platform. Transferability was tested by enrolling 20 medical students in an institutional review board-approved, randomized, controlled, blinded protocol. Subjects viewed a video tutorial and were pretested in LCN on a porcine Nissen model. Procedures were videotaped and the LCN performance was scored by a blinded rater according to the number of standardized verbal cues required and the percentage of time an optimal surgical view (%OSV) was obtained. Procedure time also was recorded. Subjects were stratified and randomized. The trained group practiced on the LCN simulator until competency was demonstrated. The control group received no training. Both groups were posttested on the porcine Nissen model. The constructed simulators required 35 man hours for development, cost $25 per board for materials, and proved to be durable. The trained group demonstrated significant improvement in verbal cues (p = 0.001), %OSV (p < 0.001), and procedure time (p = 0.001), whereas the control group showed improvement only in verbal cues (p < 0.02). At posttesting, the training group demonstrated significantly better scores for verbal cues (2.1 vs 8.0; p = 0.02) and %OSV (64% vs 45% p = 0.01) than the control group. These data suggest that the LCN simulator is cost effective and provides trainees with skills that translate to the operating room.

Development and transferability of a cost-effective laparoscopic camera navigation simulator

During minimally invasive procedures an assistant is controlling the laparoscope. Ideally, the surgeon should be able to manipulate all instruments including the camera him/herself, to avoid communication problems and disturbing camera movements. Camera holders return camera-control to the surgeon and stabilize the laparoscopic image. An additional holder can be used to stabilize an extra laparoscopic instrument for retracting. A literature survey has been carried out giving an overview of the existing "robotic" and passive camera and instrument holders and, if available, results of their clinical value. Benefits and limitations were identified. Most studies showed that camera holders, passive and active, provide the surgeon with a more stable image and enables them to control their own view direction. Only the passive holders were suitable for holding instruments. Comparisons between different systems are reviewed. Both active and passive camera and instrument holders are functional, and may be helpful to perform solo-surgery. The benefits of active holders are questionable in relation to the performance of the much simpler passive designs.

Camera and instrument holders and their clinical value in minimally invasive surgery.

The old paradigm of "see one, do one, teach one" has now changed to "see several, learn the skills and simulation, do one, teach one." Modern medicine over the past 30 years has undergone significant revolutions from earlier models made possible by significant technological advances. Scientific and technological progress has made these advances possible not only by increasing the complexity of procedures, but also by increasing the ability to have complex methods of training to perform these sophisticated procedures. Simulators in training labs have been much more embraced outside the operating room, with advanced cardiac life support using hands-on models (CPR "dummy") as well as a fusion with computer-based testing for examinations ranging from the United States medical licensure exam to the examinations administered by the American Board of Surgery and the American Board of Colon and Rectal Surgery. Thus, the development of training methods that test both technical skills and clinical acumen may be essential to help achieve both safety and financial goals.

Review of available methods of simulation training to facilitate surgical education

LER is a compact surgical assistant robot for positioning of an endoscope and camera during minimally invasive surgery. In contrast to typical endoscope manipulators, LER is particularly compact and lightweight at 625 g and 110 mm in diameter, so that it is simple to set up and use, occupies no floor space, and does not limit access to the patient in any way. Our current prototype is fully sterilizeable by autoclave and is ready for clinical trials. It features a full motion range of 360/spl deg/ in rotation and inclination to 10/spl deg/ from the horizontal plane and is backdriveable for manual positioning. Actuation forces are limited for safety. LER may be held in place on the abdomen by adhesive strips or sutures, or attached to the sides of the table with elastic straps or clamps. We have implemented a variety of different user command interfaces for LER, including a miniature keypad, automatic optical instrument motion tracking, and voice command recognition. Experimental trajectory following results and performance parameters are given.

LER: the light endoscope robot

Background: Instrument positioners can position and lock a laparoscopic instrument. This study uses time-action analysis to evaluate objectively whether IPs can substitute for a surgical assistant efficiently and safely. Methods: In four hospitals, 78 laparoscopic cholecystectomies were randomly assisted by a surgical assistant or an instrument positioner (AESOP and PASSIST) The efficiency and safety of laparoscopic cholecystectomies were analyzed with respect to time, number and type of actions, positioning accuracy, and peroperative complications. A questionnaire evaluated the difficulties for each operation and the comfort of instrument positioner use. Results: The PASSIST and AESOP were able to replace the surgical assistant during laparoscopic cholecystectomies without significantly changing either the efficiency or the safety of the operation. The questionnaire showed that the surgeons preferred to operate with an instrument positioner. Conclusion: This study assessed objectively that instrument positioners can substitute for a surgical assistant efficiently and safely in elective laparoscopic cholecystectomies.

Time-action analysis of instrument positioners in laparoscopic cholecystectomy.

Background and Purpose: During minimally invasive procedures, an assistant controls the camera and often a laparoscopic grasper. Ideally, the surgeon should be able to manipulate the instruments because the indirect way of control complicates the surgeon's observation and actions and disturbs eye-hand coordination. Reported replacements for the assistant are active positioners, "robots," such as the Aesop and the EndoAssist. Because positioning instruments is often a static task, the Academic Medical Center has developed a passive assistant for instrument positioning (PASSIST) to allow solo surgery. Methods: The PASSIST was designed to be simple, fully autoclavable, slender, and stiff. The joints have adjustable friction and spring compensation for stabilizing the instrument in a fixed position, enabling intuitive single-hand repositioning. Results: The PASSIST has been tested in three laparoscopic procedures: cholecystectomy, laparoscopically assisted vaginal hysterectomy, and spondylodesis. In all of these procedures, the assistant could be replaced satisfactorily, and the surgeon was able to manipulate all of the instruments on his own. Conclusion: Solo surgery using the PASSIST is feasible. The positioner enables the surgeon to manipulate the viewpoint, to have a stable image, and therefore to improve observation and manipulating actions.

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J. E. N. Jaspers

Papers

Time-action analysis of instrument positioners in laparoscopic cholecystectomy.

Design and feasibility of PASSIST, a passive instrument positioner.

Design and Evaluation of Endoscope Positioners