Effect of reduced stereoscopic camera separation on ring placement with a surgical telerobot.

BACKGROUND: A custom, stereoscopic video camera was built to study the impact of decreased camera separation on a stereoscopically viewed, visual-manual task resembling some aspects of surgery. MATERIALS AND METHODS: Twelve naïve subjects and one of the experimenters were first trained in a ring placement task using the stereo-laparoscope and subsequently switched to the stereo-camera, which was used with differing camera separations ranging from 100% of the laparoscope's separation to a biocular view corresponding to no separation (2D). RESULTS: The results suggest firstly, that stereopsis (i.e., use of 3D laparoscopes) improves surgical performance over conventional 2D laparoscopes, and secondly that camera separation may be reduced 20-35% without appreciably degrading user performance. Even a 50% reduction in separation resulted in stereoscopically supported performance far superior compared to the 2D condition. CONCLUSIONS: The results suggest that existing 3D laparoscopes which use 5-mm camera separation may well be significantly miniaturized without causing substantial performance degradation.

3-D telestration: a teaching tool for robotic surgery.

BACKGROUND: Telestration is an important teaching tool in minimally invasive surgery (MIS). While robotic surgery offers the added benefit of three-dimensional (3-D) visualization, telestration technology does not currently exist for this modality. This project aimed to develop a video algorithm to accurately translate a mentor's two-dimensional (2-D) telestration into a 3-D telestration in the da Vinci visual field. MATERIALS AND METHODS: A prototype 3-D telestration system was constructed to translate 2-D telestration from a mentor station into 3-D graphics for the trainee at the robotic console. This system uses fast image correlation algorithms to allow 2-D images to be placed over the same anatomic location in the two separate video channels of the stereoscopic robotic visualization system. Three subjects of varying surgical backgrounds, blinded to the mode of telestration (2-D vs. 3-D), were tested in the laboratory, using a simulated robotic task. RESULTS: There were few technologic errors (2), only one of which resulted in a task error, in 99 total trials. Only the experienced MIS staff surgeon had a significantly faster task time in 2-D than in 3-D (P < 0.05). The MIS fellow recorded the fastest task times in 2-D and 3-D (P < 0.05). There were nine task errors, six of which were committed by the MIS fellow. The nonsurgeon trainee had the least number of errors but also had the slowest times. CONCLUSIONS: Robotic telestration in 3-D is feasible and does not negatively impact performance in laboratory tasks. We plan to refine the prototype and investigate its use in vivo.

Robot-assisted laparoscopic ultrasonography for hepatic surgery.

INTRODUCTION: This study describes and evaluates a novel, robot-assisted laparoscopic ultrasonographic device for hepatic surgery. Laparoscopic liver surgery is being performed with increasing frequency. One major drawback of this approach is the limited capability of intraoperative ultrasonography (IOUS) using standard laparoscopic devices. Robotic surgery systems offer the opportunity to develop new tools to improve techniques in minimally invasive surgery. This study evaluates a new integrated ultrasonography (US) device with the da Vinci Surgical System for laparoscopic visualization, comparing it with conventional handheld laparoscopic IOUS for performing key tasks in hepatic surgery. METHODS: A prototype laparoscopic IOUS instrument was developed for the da Vinci Surgical System and compared with a conventional laparoscopic US device in simulation tasks: (1) In vivo porcine hepatic visualization and probe manipulation, (2) lesion detection accuracy, and (3) biopsy precision. Usability was queried by poststudy questionnaire. RESULTS: The robotic US proved better than conventional laparoscopic US in liver surface exploration (85% success vs 73%; P = .030) and tool manipulation (79% vs 57%; P = .028), whereas no difference was detected in lesion identification (63 vs 58; P = .41) and needle biopsy tasks (57 vs 48; P = .11). Subjects found the robotic US to facilitate better probe positioning (80%), decrease fatigue (90%), and be more useful overall (90%) on the post-task questionnaire. CONCLUSION: We found this robot-assisted IOUS system to be practical and useful in the performance of important tasks required for hepatic surgery, outperforming free-hand laparoscopic IOUS for certain tasks, and was more subjectively usable to the surgeon. Systems such as this may expand the use of robotic surgery for complex operative procedures requiring IOUS.

Dynamic augmented reality for sensory substitution in robot-assisted surgical systems.

Teleoperated robot-assisted surgical systems provide surgeons with improved precision, dexterity, and visualization over traditional minimally invasive surgery. The addition of haptic (force and/or tactile) feedback has been proposed as a way to further enhance the performance of these systems. However, due to limitations in sensing and control technologies, implementing direct haptic feedback to the surgeon's hands remains impractical for clinical application. A new, intuitive augmented reality system for presentation of force information through sensory substitution has been developed and evaluated. The augmented reality system consists of force-sensing robotic instruments, a kinematic tool tracker, and a graphic display that overlays a visual representation of force levels on top of the moving instrument tips. The system is integrated with the da Vinci Surgical System (Intuitive Surgical, Inc.) and tested by several users in a phantom knot tying task. The augmented reality system decreases the number of broken sutures, decreases the number of loose knots, and results in more consistent application of forces.

Mentoring console improves collaboration and teaching in surgical robotics.

BACKGROUND: One of the most significant limitations of surgical robots has been their inability to allow multiple surgeons and surgeons-in-training to engage in collaborative control of robotic surgical instruments. We report the initial experience with a novel two-headed da Vinci surgical robot that has two collaborative modes: the "swap" mode allows two surgeons to simultaneously operate and actively swap control of the robot's four arms, and the "nudge" mode allows them to share control of two of the robot's arms. MATERIALS AND METHODS: The utility of the mentoring console operating in its two collaborative modes was evaluated through a combination of dry laboratory exercises and animal laboratory surgery. The results from surgeon-resident collaborative performance of complex three-handed surgical tasks were compared to results from single-surgeon and single-resident performance. Statistical significance was determined using Student's t-test. RESULTS: Collaborative surgeon-resident swap control reduced the time to completion of complex three-handed surgical tasks by 25% compared to single-surgeon operation of a four-armed da Vinci (P < 0.01) and by 34% compared to single-resident operation (P < 0.001). While swap mode was found to be most helpful during parts of surgical procedures that require multiple hands (such as isolation and division of vessels), nudge mode was particularly useful for guiding a resident's hands during crucially precise steps of an operation (such as proper placement of stitches). CONCLUSION: The da Vinci mentoring console greatly facilitates surgeon collaboration during robotic surgery and improves the performance of complex surgical tasks. The mentoring console has the potential to improve resident participation in surgical robotics cases, enhance resident education in surgical training programs engaged in surgical robotics, and improve patient safety during robotic surgery.