The goal of this research was to establish a methodology for quantifying performance of surgeons and distinguishing skill levels during live surgeries. We integrated three physical measures (kinematics, time and movement transitions) into a modeling technique for quantifying performance of surgical trainees. We first defined a new hierarchical representation called Motor and Cognitive Modeling Diagram for laparoscopic procedures, which: (1) decomposes ‘tasks’ into ‘subtasks’ and at the very detailed level into individual movements ‘actions’; and (2) includes an explicit cognitive/motor diagrammatic representation that enables to take account of the operative variability as most intraoperative assessments are conducted at the ‘whole procedure’ level and do not distinguish between performance of trivial and complicated aspects of the procedure. Then, at each level of surgical complexity, we implemented specific mathematical techniques for providing a quantitative sense of how far a performance is located from a reference level: (1) The Kolgomorov-Smirnov statistic to describe the similarity between two empirical cumulative distribution functions (e.g., speed profiles) (2) The symmetric normalized Jensen-Shannon Divergence to compare transition probability matrices (3) The Principal Component Analysis to identify the directions of greatest variability in a multidimensional space and to reduce the dimensionality of the data using a weight space. Two experimental studies were completed in order to show feasibility of our proposed assessment methodology by monitoring movements of surgical tools while: (1) dissecting mandarin oranges, and (2) performing laparoscopic cholecystectomy procedures at the operating room to compare residents and expert surgeons when executing two surgical tasks: exposing Calot’s Triangle and dissecting the cystic duct and artery. Results demonstrated the ability of our methodology to represent selected tasks using the Motor and Cognitive Modeling Diagram and to differentiate skill levels. We aim to use our approach in future studies to establish correspondences between specific surgical tasks and the corresponding simulations of these tasks, which may ultimately enable us to do validated assessments in a simulated setting, and to test its reliability in differentiating skill levels at the operating room as the number of subjects and procedures increase.

The goal of this research was to establish a methodology for quantifying performance of surgeons and distinguishing skill levels during live surgeries. We integrated three physical measures (kinematics, time and movement transitions) into a modeling technique for quantifying performance of surgical trainees. We first defined a new hierarchical representation called Motor and Cognitive Modeling Diagram for laparoscopic procedures, which: (1) decomposes ‘tasks’ into ‘subtasks’ and at the very detailed level into individual movements ‘actions’; and (2) includes an explicit cognitive/motor diagrammatic representation that enables to take account of the operative variability as most intraoperative assessments are conducted at the ‘whole procedure’ level and do not distinguish between performance of trivial and complicated aspects of the procedure. Then, at each level of surgical complexity, we implemented specific mathematical techniques for providing a quantitative sense of how far a performance is located from a reference level: (1) The Kolgomorov-Smirnov statistic to describe the similarity between two empirical cumulative distribution functions (e.g., speed profiles) (2) The symmetric normalized Jensen-Shannon Divergence to compare transition probability matrices (3) The Principal Component Analysis to identify the directions of greatest variability in a multidimensional space and to reduce the dimensionality of the data using a weight space. Two experimental studies were completed in order to show feasibility of our proposed assessment methodology by monitoring movements of surgical tools while: (1) dissecting mandarin oranges, and (2) performing laparoscopic cholecystectomy procedures at the operating room to compare residents and expert surgeons when executing two surgical tasks: exposing Calot’s Triangle and dissecting the cystic duct and artery. Results demonstrated the ability of our methodology to represent selected tasks using the Motor and Cognitive Modeling Diagram and to differentiate skill levels. We aim to use our approach in future studies to establish correspondences between specific surgical tasks and the corresponding simulations of these tasks, which may ultimately enable us to do validated assessments in a simulated setting, and to test its reliability in differentiating skill levels at the operating room as the number of subjects and procedures increase.

The goal of this research was to establish a methodology for quantifying performance of surgeons and distinguishing skill levels during live surgeries. We integrated three physical measures (kinematics, time and movement transitions) into a modeling technique for quantifying performance of surgical trainees. We first defined a new hierarchical representation called Motor and Cognitive Modeling Diagram for laparoscopic procedures, which: (1) decomposes ‘tasks’ into ‘subtasks’ and at the very detailed level into individual movements ‘actions’; and (2) includes an explicit cognitive/motor diagrammatic representation that enables to take account of the operative variability as most intraoperative assessments are conducted at the ‘whole procedure’ level and do not distinguish between performance of trivial and complicated aspects of the procedure. Then, at each level of surgical complexity, we implemented specific mathematical techniques for providing a quantitative sense of how far a performance is located from a reference level: (1) The Kolgomorov-Smirnov statistic to describe the similarity between two empirical cumulative distribution functions (e.g., speed profiles) (2) The symmetric normalized Jensen-Shannon Divergence to compare transition probability matrices (3) The Principal Component Analysis to identify the directions of greatest variability in a multidimensional space and to reduce the dimensionality of the data using a weight space. Two experimental studies were completed in order to show feasibility of our proposed assessment methodology by monitoring movements of surgical tools while: (1) dissecting mandarin oranges, and (2) performing laparoscopic cholecystectomy procedures at the operating room to compare residents and expert surgeons when executing two surgical tasks: exposing Calot’s Triangle and dissecting the cystic duct and artery. Results demonstrated the ability of our methodology to represent selected tasks using the Motor and Cognitive Modeling Diagram and to differentiate skill levels. We aim to use our approach in future studies to establish correspondences between specific surgical tasks and the corresponding simulations of these tasks, which may ultimately enable us to do validated assessments in a simulated setting, and to test its reliability in differentiating skill levels at the operating room as the number of subjects and procedures increase. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

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Thesis (M.S.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2031-01-01

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfillment of the requirements for the degree of Master of Medicine in Orthopaedic Surgery Johannesburg, 2017 / Background: The anterolateral approach to the spine for the surgical management of the Tuberculosis of the spine has been described. The surgical technique has evolved since the gold standard published by Hodgson et al. in 1956. The use of a Titanium Mesh Cage and the anterior instrumentation to construct the anterior column after adequate debridement defined the evolution. The aim of the study is to review the results of the patients that underwent this procedure between January 2012 and December 2015. Methods: The study was a retrospective study where 60 patients treated with this technique from 2012 – 2015 were reviewed. Sixty-one percent (61%) of the tested patients were HIV positive and 70.4% of the patients were female in the age group of 31-45 years. The surgical procedure was standardised for all the patients irrespective of their HIV status. The clinical and radiological outcomes measured consisted of the patients’ disability using the Oswestry Disability Index (ODI), the Frankel Neurological grading to measure neurological deficits and the Cobb angle to measure Kyphosis. The diagnosis of Tuberculosis of the Spine was confirmed in all the patients. Results: At a mean follow up period of 21.25 months, the ODI improved from a mean of 95.42% ± 6.57% before surgery to a mean of 8.00% ± 12.15% at the last follow up. There were 58 patients who were unable to walk independently before the surgery (Frankel A or B) but at the last follow up, 52 of the patients had achieved independent ambulation (Frankel D or E). The mean kyphosis was 33.90 ± 12.44 degrees before surgery, and in the immediate post-operative period, the mean kyphosis was 23.69 ± 10.31 degrees, and a mean of 26.27 ± 10.91 degrees was measured at the last follow up. There was a 30.12% correction achieved in the immediate post-operative period and an overall correction of 22.51% at the last follow up reflecting a loss of 7.61% in the kyphosis correction in the period between the immediate post-operative period and the last follow up. Complications were documented in six patients including two deaths unrelated to the procedure. Discussion: The ODI score showed an improvement as the mean value decreased by 87.42%. This is statistically and clinically significant (p=0.001). According to the work of Solberg et al. (2013) in degenerative spine, the threshold for a success is a mean change of 20% in the ODI scoring after lumbar disc surgery. Using this value as a proxy, an improvement of 87.42% is an excellent outcome. Before surgery, fifty-eight patients (96.7%) were non-ambulatory using the Frankel Neurological score. At the last follow up, 53 patients (91.4%) achieved a Frankel score of D or E and independent ambulation. This outcome compares favourably with ones published in the literature. The overall post-operative kyphosis correction achieved was 26.27 degrees (which translated to 22.51% correction) at the last follow up. This reflects a kyphosis correction loss of 7.61% that was not associated with any neurological deterioration and is therefore of no clinical significance. There were six cases of complications including two deaths unrelated to the procedure but the general debilitation of military Tuberculosis and Nosocomial infection. Conclusion: The anterior column reconstruction using the Titanium Mesh Cage and Anterior Instrumentation is safe and effective for the surgical management of the Tuberculosis of the Spine. There were good clinical outcomes as measured by the ODI score and the Frankel Neurological Grading system, and even though there was a loss of Kyphosis correction at the last follow up, this was not associated with a negative neurological outcome. Despite its limitation as a retrospective study, this study demonstrates that the procedure is safe and effective when used as an adjunct to the medical treatment of the Tuberculosis of the Spine. / MT2017

Thesis (M.S.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2031-01-01