ProMIS Metrics

	Tracking instruments The ProMIS™ Surgical Simulator comprises a molded `Bodyform' linked to a laptop computer. Inside the Bodyform, a vision-tracking system enables tracking and measuring of real surgical instruments, objects (and hand movements). ProMIS analyses performance by tracking instruments and objects in 3-dimensional space. This patented technology is unique to ProMIS and enables real-time measurement of instruments in use. All Tasks use scientifically validated metrics, including time taken, path length, and economy of movement. See sample score sheet from Instrument Handling Task, below.

	User assessment and feedback Once a task is completed, the user is immediately presented with an analysis of their performance. Detailed metrics are given in summary, and for right and left hand as well as for each step of the Task. The user can also see a graphical playback that shows the exact track of their instruments during the Task. In physical Tasks, they may also view a video of their activity. The images opposite show how ProMIS detects errors: in the first image, ProMIS tracks not only the instruments, but also the 'pegs' and identifies whether they were dropped. The second image shows a Dissection task: using vision technology, ProMIS automatically measures the area dissected. Click here to read a SAGES paper on this >>>
	Learning Management System The metrics for a given Task can be reviewed in the ProMIS user application and in the Learning Management System (LMS). In the LMS, the Administrator/Tutor may view values for each Step of a Task as well as for the overall Task.

Recording Metrics

The same metrics are recorded for both physical tasks and virtual reality Tasks. Separate metrics are recorded for each instrument inserted in the Bodyform.

Recording begins when the instruments become visible to the vision system inside the Bodyform: this may be slightly different to the user view.

The user may view metrics for each instrument. In the Summary Analysis given directly on completion of a Task, the reported metrics show the combined metrics for left-hand and right-hand instruments:

Elapsed Time is the total time that one or both instruments were detected in the Bodyform;

The total Path Length metric represents the combined totals for each instrument;

The total Economy of Movement metric represents the combined and averaged totals for each instrument;

Hand Dominance is the percentage use of one instrument over the other, as measured by the level of movement of each instrument tip;

The Errors score is a `total' number based on Task-specific indicators (see above)

Metrics and Analysis

Immediately on completing a Task, the user is presented with a Summary Analysis of their performance.

This provides an indicator of current and previous performance in terms of the degree to which the user achieved the Expected Competency Level (ECL) for that Task. The ECL is marked as the mid-area, light-blue section of a bar, as shown in Figure 1. The grey section is below acceptable performance; the darker blue section represents `expert' performance level (or above ECL).

The arrow indicators (for Previous and Current attempts) show the user's performance value as a ratio of the lowest-to-best performance levels.