2 DoF surgical training eye phantom for cataract surgery in a low-cost setting

Abstract

The human eye is a very delicate yet highly intricate organ, and treatments such as cataract surgery call for meticulous precision. Ophthalmologists hone their skills over years of practice, which they initially acquired during their studies in medical schools. Basic skills such as globe fixation and capsulorhexis training have a very steep learning curve as they are fundamental, albeit very challenging from the get-go. There is a lack of training simulators that can combine both surgical techniques as effectively and economically as animal eye setups. In this respect, the present research work aims at designing a cataract surgery eye phantom for capsulorhexis and globe fixation, which can replicate the movement of the eyeball in the orbit coupled with the inherent passive stiffness. The project culminates in the design of a 2-degree-of-freedom anterior human eye phantom with anatomically similar features of the human eye needed for training the aforementioned surgical steps. A significant part of the prototype structure is 3D printed using Draft resin V2 on the Formlabs Form 3+ printer to create minute yet almost anatomically impeccable components. Mechanical analyses were performed to tune the passive stiffness of the compliant mechanisms, and materials such as PlatSil Gel-00, hydrogel, and eggshell membrane were chosen and utilized to replicate the interactions between the tools and various tissues in the human eye. Clinical evaluations were conducted by a surgeon performing capsulorhexis on the prototype in a wet lab environment and several validation tests by an academic trainer for the suitability and practicality of the prototype. In that context, the present research serves as the first step toward creating innovative designs for training phantoms in the field of eye surgery.