BACKGROUND: Recently, robotic devices have been developed that have great potential to advance hand therapy. One application is having patients use a haptic “pen” to complete drawing and or writing tasks. This approach is advantageous as data can be electronically collected; many repetitions can be assessed quickly and easily. For this preliminary study, we tested hand precision by having patients attempt to trace circles. PURPOSE: Have patients use a haptic pen to complete a hand precision exam (drawing circles) and determine if there is a learning effect. METHODS: Thirteen healthy subjects participated in the study (24.23±4.37). Each participant completed ten trials. This was done by five consecutive repetitions, followed by a one-minute break, and then another five repetitions. Breaks were provisioned to eliminate adverse effect of fatigue. The forearm of dominated hand was harnessed using a 3D-printer fixture to isolate wrist movements; therefore, a participant could only move the wrist while completing tasks. A haptic pen (Touch, 3D Systems, USA) was utilized to trace predefined paths around four circles. For each trial, the participant traced a larger circle (D=6 cm) and three were smaller circles (d=2 cm). The perimeters of the three smaller circles (summated) was equal to the perimeter of the larger circle to equalize the amount of tracing. Each circle was analyzed in one-degree intervals. For each interval, a straight line was extended from the center of circle to intersect the participant’s traced circle. The error score was calculated at each interval (360 points). For each circle, the overall error score was determined by taking the mean of the 360 internal error scores. Finally, overall error score for the first five trials (error score 1) and the second five trials (error score 2). Dependent t-tests were used (𝛂;;;=0.05) to determine if there were significant differences between error score 1 and error score 2. RESULTS: Participant error scores ranged from 9mm-39mm. There was a significant reduction (p=0.03) in error scores from score 1 (22.1mm) to score 2 (17.1mm). Eleven of the 13 participants had error scores reduce (for error score 2). The other two participants were top performers with very low error scores (9-15mm) and minimal increase (approximately 1mm). CONCLUSION: There appeared to be a slight learning effect; participants reduced their error score by approximately 4 mm from round 1 to round 2. Future studies should assess more repetitions to determine when the learning effect plateaus.

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