Abstract
Abstract: :
Purpose: Advances in the complexity of vitreoretinal surgeries have resulted in a need for more versatile instrument handle designs. If prototype and existing designs are tested for specific performance factors by multiple surgeons, those factors which result in wider utility can be identified and incorporated into more versatile instruments. Methods: In a prospective laboratory study, we compared surgeons' subjective ergonomic assessment of multiple parameters of microsurgical handles with standard questionnaires and grading. Baseline data included surgeon hand size, years of experience, and preferred commercially available handle(s). The parameters that we scored included weight, range of closure, shape, compression force required to close the instrument, balance, activation surface finish and texture, and the ability to rotate the instrument during use. The scores from these ergonomic evaluations in microsurgical models mimicking vitreous surgery were analyzed to guide the evolution of several surgical handle designs, including 360–degree grasping designs. Results: Among surgeons, there was a significant preference for a handle that could be rotated while being activated. Surgical experience did not correlate with preferences. There were preferred ranges of motion (particularly maximal and minimal finger positions), a specific taper of the handle adjacent to the levers, a handle length adequate to rest between the index finger and thumb, and a moderately light, weight–balanced handle. These characteristics were incorporated into several prototypes and further tested. New handles based on these results have been commercially introduced including the Grieshaber RevolutionTM (Alcon Laboratories, Fort Worth, TX) and the SynapseTM (Synergetics Inc, Saint Charles, MO). Conclusions: : No single handle best meets all the possible requirements, especially when economic considerations are taken into account. Better ergonomics result in wider acceptance, and lessons learned in developing one design can be used to improve existing designs.
Keywords: vitreoretinal surgery • retina