Head-Mounted Projector for Manual Precision Tasks: Performance Assessment.

The growing interest in augmented reality applications has led to an in-depth look at the performance of head-mounted displays and their testing in numerous domains. Other devices for augmenting the real world with virtual information are presented less frequently and usually focus on the description of the device rather than on its performance analysis. This is the case of projected augmented reality, which, compared to head-worn AR displays, offers the advantages of being simultaneously accessible by multiple users whilst preserving user awareness of the environment and feeling of immersion. This work provides a general evaluation of a custom-made head-mounted projector for the aid of precision manual tasks through an experimental protocol designed for investigating spatial and temporal registration and their combination. The results of the tests show that the accuracy (0.6±0.1 mm of spatial registration error) and motion-to-photon latency (113±12 ms) make the proposed solution suitable for guiding precision tasks.

Low-Computational Cost Stitching Method in a Three-Eyed Endoscope.

Aortic valve replacement is the only definitive treatment for aortic stenosis, a highly prevalent condition in elderly population. Minimally invasive surgery brought numerous benefits to this intervention, and robotics recently provided additional improvements in terms of telemanipulation, motion scaling, and smaller incisions. Difficulties in obtaining a clear and wide field of vision is a major challenge in minimally invasive aortic valve surgery: surgeon orientates with difficulty because of lack of direct view and limited spaces. This work focuses on the development of a computer vision methodology, for a three-eyed endoscopic vision system, to ease minimally invasive instrument guidance during aortic valve surgery. Specifically, it presents an efficient image stitching method to improve spatial awareness and overcome the orientation problems which arise when cameras are decentralized with respect to the main axis of the aorta and are nonparallel oriented. The proposed approach was tested for the navigation of an innovative robotic system for minimally invasive valve surgery. Based on the specific geometry of the setup and the intrinsic parameters of the three cameras, we estimate the proper plane-induced homographic transformation that merges the views of the operatory site plane into a single stitched image. To evaluate the deviation from the image correct alignment, we performed quantitative tests by stitching a chessboard pattern. The tests showed a minimum error with respect to the image size of 0.46 ± 0.15% measured at the homography distance of 40 mm and a maximum error of 6.09 ± 0.23% at the maximum offset of 10 mm. Three experienced surgeons in aortic valve replacement by mini-sternotomy and mini-thoracotomy performed experimental tests based on the comparison of navigation and orientation capabilities in a silicone aorta with and without stitched image. The tests showed that the stitched image allows for good orientation and navigation within the aorta, and furthermore, it provides more safety while releasing the valve than driving from the three separate views. The average processing time for the stitching of three views into one image is 12.6 ms, proving that the method is not computationally expensive, thus leaving space for further real-time processing.

Comparative health technology assessment of robotic-assisted, direct manual laparoscopic and open surgery: a prospective study.

BACKGROUND: Despite many publications reporting on the increased hospital cost of robotic-assisted surgery (RAS) compared to direct manual laparoscopic surgery (DMLS) and open surgery (OS), the reported health economic studies lack details on clinical outcome, precluding valid health technology assessment (HTA). METHODS: The present prospective study reports total cost analysis on 699 patients undergoing general surgical, gynecological and thoracic operations between 2011 and 2014 in the Italian Public Health Service, during which period eight major teaching hospitals treated the patients. The study compared total healthcare costs of RAS, DMLS and OS based on prospectively collected data on patient outcome in addition to healthcare costs incurred by the three approaches. RESULTS: The cost of RAS operations was significantly higher than that of OS and DMLS for both gynecological and thoracic operations (p < 0.001). The study showed no significant difference in total costs between OS and DMLS. Total costs of general surgery RAS were significantly higher than those of OS (p < 0.001), but not against DMLS general surgery. Indirect costs were significantly lower in RAS compared to both DMLS general surgery and OS gynecological surgery due to the shorter length of hospital stay of RAS approach (p < 0.001). Additionally, in all specialties compared to OS, patients treated by RAS experienced a quicker recovery and significantly less pain during the hospitalization and after discharge. CONCLUSIONS: The present HTA while confirming higher total healthcare costs for RAS operations identified significant clinical benefits which may justify the increased expenditure incurred by this approach.

Robot-assisted versus laparoscopic rectal resection for cancer in a single surgeon's experience: a cost analysis covering the initial 50 robotic cases with the da Vinci Si.

PURPOSE: The aim of this study is to compare surgical parameters and the costs of robotic surgery with those of laparoscopic approach in rectal cancer based on a single surgeon's early robotic experience. METHODS: Data from 25 laparoscopic (LapTME) and the first 50 robotic (RobTME) rectal resections performed at our institution by an experienced laparoscopic surgeon (>100 procedures) between 2009 and 2014 were retrospectively analyzed and compared. Patient demographic, procedure, and outcome data were gathered. Costs of the two procedures were collected, differentiated into fixed and variable costs, and analyzed against the robotic learning curve according to the cumulative sum (CUSUM) method. RESULTS: Based on CUSUM analysis, RobTME group was divided into three phases (Rob1: 1-19; Rob2: 20-40; Rob3: 41-50). Overall median operative time (OT) was significantly lower in LapTME than in RobTME (270 vs 312.5 min, p = 0.006). A statistically significant change in OT by phase of robotic experience was detected in the RobTME group (p = 0.010). Overall mean costs associated with LapTME procedures were significantly lower than with RobTME (p < 0.001). Statistically significant reductions in variable and overall costs were found between robotic phases (p < 0.009 for both). With fixed costs excluded, the difference between laparoscopic and Rob3 was no longer statistically significant. CONCLUSIONS: Our results suggest a significant optimization of robotic rectal surgery's costs with experience. Efforts to reduce the dominant fixed cost are recommended to maintain the sustainability of the system and benefit from the technical advantages offered by the robot.

Assessment of DICOM Viewers Capable of Loading Patient-specific 3D Models Obtained by Different Segmentation Platforms in the Operating Room.

Patient-specific 3D models obtained by the segmentation of volumetric diagnostic images play an increasingly important role in surgical planning. Surgeons use the virtual models reconstructed through segmentation to plan challenging surgeries. Many solutions exist for the different anatomical districts and surgical interventions. The possibility to bring the 3D virtual reconstructions with native radiological images in the operating room is essential for fostering the use of intraoperative planning. To the best of our knowledge, current DICOM viewers are not able to simultaneously connect to the picture archiving and communication system (PACS) and import 3D models generated by external platforms to allow a straight integration in the operating room. A total of 26 DICOM viewers were evaluated: 22 open source and four commercial. Two DICOM viewers can connect to PACS and import segmentations achieved by other applications: Synapse 3D® by Fujifilm and OsiriX by University of Geneva. We developed a software network that converts diffuse visual tool kit (VTK) format 3D model segmentations, obtained by any software platform, to a DICOM format that can be displayed using OsiriX or Synapse 3D. Both OsiriX and Synapse 3D were suitable for our purposes and had comparable performance. Although Synapse 3D loads native images and segmentations faster, the main benefits of OsiriX are its user-friendly loading of elaborated images and it being both free of charge and open source.