Abstrakt Technologie Leden 2009

“Intraoperative Ultrasound: Application in Pediatric Pyeloplasty.”

Ginger (2009).

Urology 73(2): 377-379.


Objectives: To describe a simple method of using a readily available portable ultrasound device to confirm distal stent placement for antegrade placed stents. Antegrade placement of internal double-J ureteral stents during open or laparoscopic pyeloplasty has become an alternative to retrograde placement but might be less reliable owing to the lack of confirmation of the distal stent position. Methods: The SonoSite S-Nerve ultrasound system was used with a L38 × 10-5 MHz linear array transducer to evaluate the distal curl of the double-J stent within the bladder intraoperatively during da Vinci robotic-assisted pyeloplasty. The patient did not require repositioning or removal of the robotic arms. Results: Visualization of the stent was successful in all patients with an age range of 8 months to 17 years. Conclusions: We present the first published method of using ultrasonography to assess and confirm distal stent placement intraoperatively during antegrade stent placement. This simple method uses off-the-shelf equipment available within most operating rooms. In addition, intraoperative ultrasound confirmation of double-J stent placement allows for the ease of antegrade placement with the distal visual confirmation of the stent position without necessitating fluoroscopy or patient repositioning. © 2009 Elsevier Inc. All rights reserved.


“Toward Image Guided Robotic Surgery: System Validation.”

Herrell (2009).

Journal of Urology 181(2): 783-790.

Purpose: Navigation for current robotic assisted surgical techniques is primarily accomplished through a stereo pair of laparoscopic camera images. These images provide standard optical visualization of the surface but provide no subsurface information. Image guidance methods allow the visualization of subsurface information to determine the current position in relationship to that of tracked tools. Materials and Methods: A robotic image guided surgical system was designed and implemented based on our previous laboratory studies. A series of experiments using tissue mimicking phantoms with injected target lesions was performed. The surgeon was asked to resect “tumor” tissue with and without the augmentation of image guidance using the da Vinci® robotic surgical system. Resections were performed and compared to an ideal resection based on the radius of the tumor measured from preoperative computerized tomography. A quantity called the resection ratio, that is the ratio of resected tissue compared to the ideal resection, was calculated for each of 13 trials and compared. Results: The mean ± SD resection ratio of procedures augmented with image guidance was smaller than that of procedures without image guidance (3.26 ± 1.38 vs 9.01 ± 1.81, p <0.01). Additionally, procedures using image guidance were shorter (average 8 vs 13 minutes). Conclusions: It was demonstrated that there is a benefit from the augmentation of laparoscopic video with updated preoperative images. Incorporating our image guided system into the da Vinci robotic system improved overall tissue resection, as measured by our metric. Adding image guidance to the da Vinci robotic surgery system may result in the potential for improvements such as the decreased removal of benign tissue while maintaining an appropriate surgical margin. © 2009 American Urological Association.


“Electromyographic response is altered during robotic surgical training with augmented feedback.”

Judkins (2009).

J Biomech 42(1): 71-6.

There is a growing prevalence of robotic systems for surgical laparoscopy. We previously developed quantitative measures to assess robotic surgical proficiency, and used augmented feedback to enhance training to reduce applied grip force and increase speed. However, there is also a need to understand the physiological demands of the surgeon during robotic surgery, and if training can reduce these demands. Therefore, the goal of this study was to use clinical biomechanical techniques via electromyography (EMG) to investigate the effects of real-time augmented visual feedback during short-term training on muscular activation and fatigue. Twenty novices were trained in three inanimate surgical tasks with the da Vinci Surgical System. Subjects were divided into five feedback groups (speed, relative phase, grip force, video, and control). Time- and frequency-domain EMG measures were obtained before and after training. Surgical training decreased muscle work as found from mean EMG and EMG envelopes. Grip force feedback further reduced average and total muscle work, while speed feedback increased average muscle work and decreased total muscle work. Training also increased the median frequency response as a result of increased speed and/or reduced fatigue during each task. More diverse motor units were recruited as revealed by increases in the frequency bandwidth post-training. We demonstrated that clinical biomechanics using EMG analysis can help to better understand the effects of training for robotic surgery. Real-time augmented feedback during training can further reduce physiological demands. Future studies will investigate other means of feedback such as biofeedback of EMG during robotic surgery training.


“Validated robotic laparoscopic surgical training in a virtual-reality environment.”

Katsavelis (2009).

Surgical Endoscopy 23(1): 66-73.

Background: A robotic virtual-reality (VR) simulator has been developed to improve robot-assisted training for laparoscopic surgery and to enhance surgical performance in laparoscopic skills. The simulated VR training environment provides an effective approach to evaluate and improve surgical performance. This study presents our findings of the VR training environment for robotic laparoscopy. Methods: Eight volunteers performed two inanimate tasks in both the VR and the actual training environment. The tasks were bimanual carrying (BC) and needle passing (NP). For the BC task, the volunteers simultaneously transferred two plastic pieces in opposite directions five times consecutively. The same volunteers passed a surgical needle through six pairs of holes in the NP task. Both tasks require significant bimanual coordination that mimics actual laparoscopic skills. Data analysis included time to task completion, speed and distance traveled of the instrument tip, as well as range of motion of the subject’s wrist and elbow of the right arm. Electromyography of the right wrist flexor and extensor were also analyzed. Paired t-tests and Pearson’s r were used to explore the differences and correlations between the two environments. Results: There were no significant differences between the actual and the simulated VR environment with respect to the BC task, while there were significant differences in almost all dependent parameters for the NP task. Moderate to high correlations for most dependent parameters were revealed for both tasks. Conclusions: Our data shows that the VR environment adequately simulated the BC task. The significant differences found for the NP task may be attributed to an oversimplification in the VR environment. However, they do point to the need for improvements in the complexity of our VR simulation. Further research work is needed to develop effective and reliable VR environments for robotic laparoscopic training. © 2008 Springer Science+Business Media, LLC.


“Computer-based laparoscopic and robotic surgical simulators: Performance characteristics and perceptions of new users.”

Lin (2009).

Surgical Endoscopy 23(1): 209-214.

Background: This study aimed to define perceptions of the need and the value of new simulation devices for laparoscopic and robot-assisted surgery. The initial experience of surgeons using both robotic and nonrobotic laparoscopic simulators to perform an advanced laparoscopic skill was evaluated. Methods: At the 2006 Society of American Gastroesophageal Surgeons (SAGES) meeting, 63 Learning Center attendees used a new virtual reality robotic surgery simulator (SEP Robot) and either a computer-enhanced laparoscopic simulator (ProMIS) or a virtual reality simulator (SurgicalSIM). Demographic and training data were collected by an intake survey. Subjects then were assessed during one iteration of laparoscopic suturing and knot-tying on the SEP Robot and either the ProMIS or the SurgicalSIM. A posttask survey determined users’ impressions of task realism, interface quality, and educational value. Performance data were collected and comparisons made between user-defined groups, different simulation platforms, and posttask survey responses. Results: The task completion rate was significantly greater for experts than for nonexperts on the virtual reality platforms (SurgicalSIM: 100% vs 36%; SEP Robot: 93% vs 63%; p < 0.05). Prior robot use was predictive of task completion on the SEP Robot, and nonexperts were more likely to complete the virtual reality task on the SEP Robot than on the SurgicalSIM. Experts performed better than nonexperts for all performance measures on the ProMIS. All the survey scores pertaining to realism except image quality were higher for the ProMIS than for either virtual reality trainer. Conclusion: The task completion rate was the best discriminant of expert performance on both virtual reality platforms, whereas simulator metrics best discriminated expertise for the videoscopic platform. Similar comparisons for the virtual reality platforms were not feasible because of the low task completion rate for nonexperts. The added degrees of freedom associated with the robotic surgical simulator instruments facilitated completion of the task by nonexperts. All platforms were perceived as effective training tools. © 2008 Springer Science+Business Media, LLC.


“The value of haptic feedback in conventional and robot-assisted minimal invasive surgery and virtual reality training: a current review.”

Meijden, v. d. (2009).

Surg Endosc.

BACKGROUND: Virtual reality (VR) as surgical training tool has become a state-of-the-art technique in training and teaching skills for minimally invasive surgery (MIS). Although intuitively appealing, the true benefits of haptic (VR training) platforms are unknown. Many questions about haptic feedback in the different areas of surgical skills (training) need to be answered before adding costly haptic feedback in VR simulation for MIS training. This study was designed to review the current status and value of haptic feedback in conventional and robot-assisted MIS and training by using virtual reality simulation. METHODS: A systematic review of the literature was undertaken using PubMed and MEDLINE. The following search terms were used: Haptic feedback OR Haptics OR Force feedback AND/OR Minimal Invasive Surgery AND/OR Minimal Access Surgery AND/OR Robotics AND/OR Robotic Surgery AND/OR Endoscopic Surgery AND/OR Virtual Reality AND/OR Simulation OR Surgical Training/Education. RESULTS: The results were assessed according to level of evidence as reflected by the Oxford Centre of Evidence-based Medicine Levels of Evidence. CONCLUSIONS: In the current literature, no firm consensus exists on the importance of haptic feedback in performing minimally invasive surgery. Although the majority of the results show positive assessment of the benefits of force feedback, results are ambivalent and not unanimous on the subject. Benefits are least disputed when related to surgery using robotics, because there is no haptic feedback in currently used robotics. The addition of haptics is believed to reduce surgical errors resulting from a lack of it, especially in knot tying. Little research has been performed in the area of robot-assisted endoscopic surgical training, but results seem promising. Concerning VR training, results indicate that haptic feedback is important during the early phase of psychomotor skill acquisition.


“Urologic robots and future directions.”

Mozer (2009).

Current Opinion in Urology 19(1): 114-119.

Purpose of review: Robot-assisted laparoscopic surgery in urology has gained immense popularity with the daVinci system, but a lot of research teams are working on new robots. The purpose of this study is to review current urologic robots and present future development directions. Recent findings: Future systems are expected to advance in two directions: improvements of remote manipulation robots and developments of image-guided robots. Summary: The final goal of robots is to allow safer and more homogeneous outcomes with less variability of surgeon performance, as well as new tools to perform tasks on the basis of medical transcutaneous imaging, in a less invasive way, at lower costs. It is expected that improvements for a remote system could be augmented in reality, with haptic feedback, size reduction, and development of new tools for natural orifice translumenal endoscopic surgery. The paradigm of image-guided robots is close to clinical availability and the most advanced robots are presented with end-user technical assessments. It is also notable that the potential of robots lies much further ahead than the accomplishments of the daVinci system. The integration of imaging with robotics holds a substantial promise, because this can accomplish tasks otherwise impossible. Image-guided robots have the potential to offer a paradigm shift. © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins.


“Haptic feedback in robot-assisted minimally invasive surgery.”

Okamura (2009).

Current Opinion in Urology 19(1): 102-107.

Purpose of review: Robot-assisted minimally invasive surgery (RMIS) holds great promise for improving the accuracy and dexterity of a surgeon and minimizing trauma to the patient. However, widespread clinical success with RMIS has been marginal. It is hypothesized that the lack of haptic (force and tactile) feedback presented to the surgeon is a limiting factor. This review explains the technical challenges of creating haptic feedback for robot-assisted surgery and provides recent results that evaluate the effectiveness of haptic feedback in mock surgical tasks. Recent findings: Haptic feedback systems for RMIS are still under development and evaluation. Most provide only force feedback, with limited fidelity. The major challenge at this time is sensing forces applied to the patient. A few tactile feedback systems for RMIS have been created, but their practicality for clinical implementation needs to be shown. It is particularly difficult to sense and display spatially distributed tactile information. The cost-benefit ratio for haptic feedback in RMIS has not been established. Summary: The designs of existing commercial RMIS systems are not conducive for force feedback, and creative solutions are needed to create compelling tactile feedback systems. Surgeons, engineers, and neuroscientists should work together to develop effective solutions for haptic feedback in RMIS. © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins.


“Does 3-Dimensional (3-D) visualization improve the quality of assistance during robotic radical prostatectomy?”

Ramanathan (2009).

World J Urol 27(1): 95-9.

OBJECTIVE: 3-Dimensional (3-D) visualization by the surgeon is considered to be one of the major advantages of robotic prostatectomy. We undertook this study to see if passing on this technology to the surgical assistants would improve the efficiency of their assistance. MATERIALS AND METHODS: The study was conducted in consecutive patients undergoing robotic radical prostatectomy by the same team, in one month at our center. A 3-D head mounted device (HMD) was used by the left and/or right assistant. Video recording from these patients were studied by a blinded observer with prior training in laparoscopic surgery for the efficiency of laparoscopic moves by the two assistants. These moves were scored on a point scoring system from 0 to 100 with 100 signifying the best possible performance. RESULTS: After exclusions, 26 videos were available for review. Each patient had a right and left-sided assistant. The right-sided assistant had prior experience in Laparoscopic Urology, and the left-sided assistant had a relatively limited laparoscopic experience. The mean scores for the left assistant improved from 76.3 to 84.6 with the use of 3-D visualization (p < 0.002), while the improvement for the right assistant was from 84.1 to 86.9 (NS). CONCLUSIONS: The use of 3-D visualization possibly improves the efficiency of assistance during robotic radical prostatectomies, for the assistant with limited experience in laparoscopic surgery. Because of the high-quality 3-D vision provided, these HMDs have the potential to be used as teaching aids in the robotic lab.