Abstrakt Technologie Duben 2009

“The challenges of clinical validation of emerging technologies: Computer-assisted devices for surgery.”

Janda, M. and B. Buch (2009).

Journal of Bone and Joint Surgery – Series A 91(SUPPL. 1): 17-21.


Over the last decade, the use of computers and robotics in medicine has increased commensurate with emergent advances in technology. This article largely focuses on the challenges that the U.S. Food and Drug Administration faces when evaluating new technologies for entry into the market. How different categories of devices are categorized and what types of data have been used for regulatory approval or clearance are described. These are compared with expectations that the clinical community may have for these devices. A brief discussion of current regulatory thinking about these types of devices is also included. Copyright © 2009 by The Journal of Bone and Joint Surgery, Incorporated.


“Face, Content, and Construct Validity of dV-Trainer, a Novel Virtual Reality Simulator for Robotic Surgery.”

Kenney, P. A., M. F. Wszolek, et al. (2009).


Objectives: To assess the face, content, and construct validity of the dV-Trainer. The dV-Trainer is a virtual reality simulator for the da Vinci Surgical System that is in beta development. Methods: Medical students, residents, and attending surgeons were enrolled in a prospective, institutional review board-approved study. The subjects were prospectively categorized as novice or experienced. Each subject completed 2 EndoWrist modules and 2 needle-driving modules. The performance was recorded using a built-in scoring algorithm. Each subject completed a questionnaire after finishing the modules. Results: The novice group (n = 19) consisted of 3 students (16%), 11 residents (58%), and 5 attending surgeons (26%). The novices had operated an average of 1.3 ± 2.2 hours at the da Vinci console before using the simulator. The experienced subjects (n = 7) had performed an average of 140 robotic cases (range 30-320). Experienced robotic surgeons outperformed novices in nearly all variables, including total score, total task time, total instrument motion, and number of instrument collisions (P < .01). All experienced surgeons ranked the simulator as useful for training and agreed with incorporating the simulator into a residency curriculum. The virtual reality and instrumentation achieved acceptability. The needle-driving modules did not exceed the acceptability threshold. Conclusions: The results of the present study have shown that the dV-Trainer has face, content, and construct validity as a virtual reality simulator for the da Vinci Surgical System. The needle-driving modules need to be refined. Studies are underway to assess the concurrent and predictive criterion validity. The dV-Trainer could become a beneficial training simulator for robotic surgery. © 2009 Elsevier Inc. All rights reserved.


“Towards image guided robotic surgery: multi-arm tracking through hybrid localization.”

Kwartowitz, D. M., M. I. Miga, et al. (2009).

International Journal of Computer Assisted Radiology and Surgery: 1-6.

Objective: Use of the robotic assisted surgery has been increasing in recent years, due both the continuous increase in the number of applications and the clinical benefits that surgical robots can provide. Currently robotic assisted surgery relies on endoscopic video for navigation, providing only surface visualization, thus limiting subsurface vision. To be able to visualize and identify subsurface information, techniques in image-guidance can be used. As part of designing an image guidance system, all arms of the robot need to be co-localized in a common coordinate system. Methods: In order to track multiple arms in a common coordinate space, intrinsic and extrinsic tracking methods can be used. First, the intrinsic tracking of the daVinci, specifically of the setup joints is analyzed. Because of the inadequacy of the setup joints for co-localization a hybrid tracking method is designed and implemented to mitigate the inaccuracy of the setup joints. Different both optical and magnetic tracking methods are examined for setup joint localization. Results: The hybrid localization method improved the localization accuracy of the setup joints. The inter-arm accuracy in hybrid localization was improved to 3.02 mm. This inter-arm error value was shown to be further reduced when the arms are co-registered, thus reducing common error. © 2009 CARS.


“Collision detection and untangling for surgical robotic manipulators.”

Morvan, T., M. Martinsen, et al. (2009).

The international journal of medical robotics + computer assisted surgery : MRCAS.

BACKGROUND: Robotic-assisted minimally invasive surgery provides several advantages over traditional surgery; however, it also has several drawbacks, such as possible collisions between the robotic arms and a limited field of view. METHODS: A generic method for tracking the configuration of a surgical manipulator in real time is presented. It is coupled with a collision detection and dynamic simulation algorithm, allowing the operator to detect collisions between robotic arms before they happen and presenting the best possible untangling direction to get out of collisions. RESULTS: Our algorithm successfully tracks the configuration of the Zeus((R)) surgical system and accurately detects possible collisions in real time. A pilot study on our system proved its efficiency in reducing the duration and severity of collisions, at the price of longer completion times. CONCLUSION: Our system helps alleviate the collision problem by reducing the time in collision. Copyright (c) 2009 John Wiley & Sons, Ltd.


“An evaluation of knot integrity when tied robotically and conventionally.”

Muffly, T., T. C. McCormick, et al. (2009).

Am J Obstet Gynecol 200(5): e18-20.

OBJECTIVE: The purpose of this study was to evaluate the knot integrity of 3 commonly used sutures in sacrocolpopexy that were tied conventionally (by hand) and robotically. STUDY DESIGN: Knots were tied with polyglactin 910, polypropylene, and polyester, with 5-6 knots tied, depending on the suture used. We compared the knots that were subjected to tensile force until the suture broke or untied. RESULTS: The mean force that was required for the suture to untie was 47.7 +/- 18.8 (SD) Newtons and was seen only among the robotically tied polyglactin 910 knots. Robotically tied polyglactin 910 knots were significantly weaker than all other robotic and conventional knots that were tested (P < .05). The tying modality and material interaction was significant (P < .001), which suggests that the effect of suture material varied, depending on the tying modality. CONCLUSION: Knot failure rates for conventional or robotically tied suture varied based on the suture material that was used.


“A Highly Articulated Robotic Surgical System for Minimally Invasive Surgery.”

Ota, T., A. Degani, et al. (2009).

Annals of Thoracic Surgery 87(4): 1253-1256.

Purpose: We developed a novel, highly articulated robotic surgical system (CardioARM) to enable minimally invasive intrapericardial therapeutic delivery through a subxiphoid approach. We performed preliminary proof of concept studies in a porcine preparation by performing epicardial ablation. Description: CardioARM is a robotic surgical system having an articulated design to provide unlimited but controllable flexibility. The CardioARM consists of serially connected, rigid cyclindrical links housing flexible working ports through which catheter-based tools for therapy and imaging can be advanced. The CardioARM is controlled by a computer-driven, user interface, which is operated outside the operative field. Evaluation: In six experimental subjects, the CardioARM was introduced percutaneously through a subxiphoid access. A commercial 5-French radiofrequency ablation catheter was introduced through the working port, which was then used to guide deployment. In all subjects, regional (“linear”) left atrial ablation was successfully achieved without complications. Conclusions: Based on these preliminary studies, we believe that the CardioARM promises to enable deployment of a number of epicardium-based therapies. Improvements in imaging techniques will likely facilitate increasingly complex procedures. © 2009 The Society of Thoracic Surgeons.


“Comparing the Quality of the Suture Anastomosis and the Learning Curves Associated with Performing Open, Freehand, and Robotic-Assisted Laparoscopic Pyeloplasty in a Swine Animal Model.”

Passerotti, C. C., A. M. A. M. S. Passerotti, et al. (2009).

Journal of the American College of Surgeons 208(4): 576-586.

Background: It is believed that robotic assistance allows for improved suture reapproximation of tissue and decreases the lengthy learning time that is needed to master laparoscopic suturing. But there have been no studies directly comparing the efficiency of robotic-assisted laparoscopic surgery (RALS) to freehand laparoscopy (LS) and open surgery (OS). The purpose of this study was to compare the quality of the suture anastomosis of the ureteropelvic junction (UPJ) using the three techniques and to evaluate their associated learning curves. Study Design: The operative time for dismembered pyeloplasties performed in 57 pigs by 3 inexperienced and 1 experienced surgeon using each of the techniques was measured. The anastomosis was evaluated for water tightness and patency using antegrade and retrograde urodynamic measurements immediately after surgery and 2 weeks postoperatively. The histology of the operated UPJ was also evaluated at 15 days postoperatively. Results: RALS had a shorter procedural time and less steep learning curve compared with LS. Urodynamic measurements for patency and water tightness of the UPJ were comparable to those in the OS group. But with experience, both the RALS and LS procedural times and the urodynamic measurements for water tightness and patency of the UPJ approached those of the OS group. Histologic evaluation demonstrated that there was less collagen III deposition around the operated UPJ in pigs that underwent RALS compared with LS and OS. Conclusions: Among inexperienced surgeons, the efficiency of performing suturing using RALS is operator independent, requires less time to learn, and is better than those done by LS technique. © 2009 American College of Surgeons.


“Robotic Laparoendoscopic Single-Site Surgery Using GelPort as the Access Platform.” Stein, R. J., W. M. White, et al. (2009).

European Urology.

Background: Laparoendoscopic single-site surgery (LESS) allows for the performance of major urologic procedures with a single small incision and minimal scarring. The da Vinci Surgical System provides advantages of easy articulation and improved ergonomics; however, an ideal platform for these procedures has not been identified. Objective: To evaluate the GelPort laparoscopic system as an access platform for robotic LESS (R-LESS) procedures. Design, setting, and participants: Since April 2008, 11 R-LESS procedures have been completed successfully in a single institutional referral center. For the last four consecutive cases, the GelPort has been used as an access platform through a 2.5-5-cm umbilical incision. Intervention: R-LESS cases performed with the GelPort included pyeloplasty (n = 2), radical nephrectomy (n = 1), and partial nephrectomy (n = 1). Measurements: Perioperative data were obtained for all patients including demographic data, operative indications, operative records, length of stay, complications, and pathologic analysis. Results and limitations: For both pyeloplasty cases, average operative time (OR time) was 235 min and estimated blood loss (EBL) was 38 cm3. For the patient undergoing radical nephrectomy for a 5.1-cm renal tumor, OR time was 200 min and EBL was 250 cm3. The final patient underwent partial nephrectomy without renal hilar clamping for an 11-cm angiomyolipoma with OR time of 180 min and EBL of 600 cm3. All R-LESS procedures attempted with the GelPort were completed successfully and without complication. Average length of hospital stay was 1.75 d (range: 1-2). The partial nephrectomy patient required transfusion of 1 U of packed red blood cells. Conclusions: Use of the GelPort as an access platform for R-LESS procedures provides adequate spacing and flexibility of port placement and acceptable access to the surgical field for the assistant, especially during procedures that require a specimen extraction incision. Additional platform and instrumentation development will likely simplify R-LESS procedures further as experience grows. © 2009.