UBC Theses and Dissertations
Assessing performance and construct validity of laparoscopic surgical simulators Lim, Joanne
The objective of this work is to assess the construct and performance validity of two laparoscopic surgical simulators. Currently, the evaluation of surgeons is considered subjective and unreliable, and this is a reason why surgical educators have been studying surgical simulators as a method to quantitatively assess surgeons. But we must find out if these simulators are valid and reliable methods for training and assessing surgeons. We have designed an experimental surgical tool and data collection system to quantitatively measure surgeon motor behaviour in the operating room (OR). Our experimental system collects kinematics and force/torque data from sensors, and we have developed a sensor fusion algorithm to be able to extract high frequency and continuous kinematics data. We have collected data from surgical residents (PGY4), and compared it to expert surgeon data to investigate construct validity of both a physical simulator and virtual reality (VR) simulator. We also study the performance validity of both the simulators by comparing measurable quantities, such as force and kinematics, on the simulators with that collected in the OR. To examine differences in our contexts, we use the Kolmogorov-Smirnov statistic. According to our intrasubject intersetting (OR, VR , physical) comparisons, we see large differences between the OR and VR simulator, leading to the conclusion of poor performance validity. Conversely, we see smaller differences between the physical simulator and the OR, and therefore showing fair performance validity. In our interlevel (expert vs. resident) comparisons, we see that the VR simulator shows poor construct validity with little difference detected between skill levels, while the physical simulator seems to be able to detect differences in some performance measures and can be considered to show fair construct validity.
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