Abstract
Purpose :
Actuator derived intraocular grasping tools (ADIGT) like forceps and scissors are commonly used in vitreoretinal surgery. Actuation of ADIGT to grasp or cut targeted tissues is a multi-muscular activity that demands coordination. The pupose of this study is to to introduce a method to study the relationship between actuation and the accompanied unintentional movements of ADIGT tip.
Methods :
Optical reflective sensors (See attached Figure) were used to find the root mean square (RMS) of involuntary movements while monitoring the extent of the its actuation. The experiment was attempted 10 times by the same VR surgeon.
Results :
When ADIGT was held motionless (5 attempts) the mean RMSs were: 57.91µ (SD:33.48), 51.81µ (SD:39.36) and 64.31 (SD:26.55)µ at ranges of 185.00µ (SD:83.37), 133.33µ (SD:72.85) and 151.67µ (SD:48.75) and when the ADIGT was actuated (5 attempts) the mean RMS were: 330µ (SD:127.32), 89.52µ (SD:24.25) and 224.6µ (SD:133.66) at mean ranges of 635.00µ (SD:128.96), 398.33µ (SD:142.47) and 665.00µ (SD:271.57) for X, Y and Z axes respectively. Mean RMSs of movements with frequencies of < 5Hz (deflections) were similar to mean RMSs before applying frequency filters. RMSs of movements with frequencies between 8-12Hz (usually frequency of tremor) while the instrument was held motionless were: 1.64µ (SD:), 1.34µ (SD:) and 1.29µ (SD:) at mean ranges of 25.97µ (SD:22.55), 22.2µ (SD:18.40) and 26.74µ (SD:26.35) for X, Y and Z axes respectively. The correlation between the actuation and the involuntary movements were 5.6 times higher for deflections compared to tremors.
Conclusions :
Optical reflective sensors provide are reliable methods the quantification of intra-operative unintentional movement artefacts and can aid designing better hand pieces in training young vitreo-retinal surgeons
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.