Real-Time 3D Tracking of Laparoscopy Training Instruments for Assessment and Feedback

Assessment of minimally invasive surgical skills is a non-trivial task, usually requiring the presence and time of expert observers, including subjectivity and requiring special and expensive equipment and software. Although there are virtual simulators that provide self-assessment features, they are limited as the trainee loses the immediate feedback from realistic physical interaction. The physical training boxes, on the other hand, preserve the immediate physical feedback, but lack the automated self-assessment facilities. This study develops an algorithm for real-time tracking of laparoscopy instruments in the video cues of a standard physical laparoscopy training box with a single fisheye camera. The developed visual tracking algorithm recovers the 3D positions of the laparoscopic instrument tips, to which simple colored tapes (markers) are attached. With such system, the extracted instrument trajectories can be digitally processed, and automated self-assessment feedback can be provided. In this way, both the physical interaction feedback would be preserved and the need for the observance of an expert would be overcome. Real-time instrument tracking with a suitable assessment criterion would constitute a significant step towards provision of real-time (immediate) feedback to correct trainee actions and show them how the action should be performed. This study is a step towards achieving this with a low cost, automated, and widely applicable laparoscopy training and assessment system using a standard physical training box equipped with a fisheye camera.

Addressing Surgical Instrument Oversupply: A Focused Literature Review and Case-Study in Orthopedic Hand Surgery

Background Instrument oversupply drives cost in the operating room (OR). We review previously reported methodologies for surgical instrument reduction and report a pilot methodology for optimizing instrument supply via ethnographic instrument tracking of thumb carpometacarpal (CMC) arthroplasties. Additionally, we report a cost analysis of instrument oversupply and potential savings of tray optimization methods. Methods Instrument utilization was tracked over 8 CMC arthroplasties conducted by 2 surgeons at an ambulatory surgery center of a large academic hospital. An optimized supply methodology was designed. A cost analysis was conducted using health-system-specific data and previously published research. Results After tracking instrument use in 8 CMC arthroplasties, a cumulative total of 59 out of the 120 instruments in the Hand & Foot (H&F) tray were used in at least 1 case. Two instruments were used in all cases, and another 20 instruments were used in at least 50% of the cases. Using a reduced tray with 59 instruments, potential cost savings for tray reduction in 60 cases were estimated to be $2086 without peel-packing and $2356 with peel-packing. The estimated cost savings were lower than those reported in literature due to a reduced scope and exclusion of OR time cost in the analysis. Conclusions Instrument oversupply drives cost at our institution’s ambulatory surgery center. Ethnography is a cost-effective method to track instrument utilization and determine optimal tray composition for small services but is not scalable to large health systems. The time and cost required to observe sufficient surgeries to enable supply reduction to motivate the need for more efficient methods to determine instrument utility.

525 Automated Continuous Instrument Tracking in Laparoscopic Box Trainers Predicts Performance at Assessment: A Prospective Cohort Study in Core Surgical Trainees

Introduction Box-trainers enable deliberate practice of laparoscopic skills and can be equipped with instrument tracking metrics to provide feedback. However, the relationship between metrics, assessment outcomes and practice are unclear. Method Core surgical trainees were provided take-home box trainers with SurgTrac™ instrument tracking metrics for practice (eoSurgical Ltd., Scotland, UK). Practice was incentivised by certification and video assessment of a basic task, peg capping. Assessment was by consultant general surgeons, using objective structured assessment of technical skills (OSATS). The following metrics were analysed: task duration, distance moved by instruments, average instrument speed, average instrument acceleration, left- or right-handedness and instrument smoothness. Metrics were correlated to OSATS scores using regression analysis. Threshold for significance was p = 0.05. Results During the study period, there were 1639 peg capping performances by 85 trainees; 103 video recordings were submitted for assessment. All metrics were significantly associated with OSATS score, except instrument acceleration. The multiple linear regression model was highly correlated with actual scores (Pearson correlation 0.658; p < 0.001). Practice was positively correlated with regression model predicted OSATS score (regression analysis; ANOVA p < 0.001). Conclusions Instrument tracking metrics reliably predict OSATS performance and practice improves predicted score. Trainees can use metrics in unsupervised practice and gauge whether they are improving as expected.

Mixed reality as a novel tool for diagnostic and surgical navigation in orthopaedics

Purpose This study presents a novel surgical navigation tool developed in mixed reality environment for orthopaedic surgery. Joint and skeletal deformities affect all age groups and greatly reduce the range of motion of the joints. These deformities are notoriously difficult to diagnose and to correct through surgery. Method We have developed a surgical tool which integrates surgical instrument tracking and augmented reality through a head mounted display. This allows the surgeon to visualise bones with the illusion of possessing “X-ray” vision. The studies presented below aim to assess the accuracy of the surgical navigation tool in tracking a location at the tip of the surgical instrument in holographic space. Results Results show that the average accuracy provided by the navigation tool is around 8 mm, and qualitative assessment by the orthopaedic surgeons provided positive feedback in terms of the capabilities for diagnostic use. Conclusions More improvements are necessary for the navigation tool to be accurate enough for surgical applications, however, this new tool has the potential to improve diagnostic accuracy and allow for safer and more precise surgeries, as well as provide for better learning conditions for orthopaedic surgeons in training.