Automated Animal Board for Positioning in Ocular Photography and Imaging Dhaval Desai Nathan Kleinhans Holly Liske Laura Piechura Kellen Sheedy Client: B’Ann Gabelt Department of Ophthalmology Advisor: Wally Block, PhD Department of Biomedical Engineering

Glaucoma High intraocular pressure Damage of the nerve fibers and the optic disc Result: Vision loss Current cure: None Second leading cause of blindness in the world

Normal Vision National Eye Institute

Vision with Glaucoma National Eye Institute

Motivation Aim 1: Early diagnosis of glaucoma Nerve fiber layer thickness Normal vs. glaucoma Aim 2: Explore treatment options Chemotherapeutics and gene therapy Animal model: Monkey Monitor nerve fiber layer parameters at several time points

Problem Statement Fine adjustments in the positioning of the eye are necessary to obtain quality images of the retina and nerve for glaucoma research. The goal of this project is to construct an automated positioning device that provides accurate alignment of the animal for successive scans.

Design Specification Automated or require minimal manual labor Support weights up to 50 lbs Rotate 30 degrees from horizontal in pitch and roll directions

Rotary Actuator Model Independent rotary actuators Automated rotation Control pitch and roll Automated rotation Inclinometer to measure angular displacement

Rotary Actuator Model Pros: Cons: No center support of plate required Low center of gravity Direct correlation to handheld control Cons: Precision Torque on actuators Actuator cost

Ticker-Tape Model Mechanical approach Tape runs through platform in both directions Relies on system of internal pulleys Small motor retrieves tape (normalizes)

Ticker-Tape Model Cons: Pros: Manual Simple design Normalizing may decrease life in service Pros: Simple design Easy to record displacement Inexpensive design

Linear Actuator Model Employs two electric linear actuators Ball and socket heads are mounted to actuators Central ball and socket column Inclinometer to measure angular displacement

Linear Actuator Model Pros: Cons: Automated design Complicated design Continuous motion and fine adjustment capabilities Cons: Complicated design Actuators and inclinometers are expensive

Design Matrix Criteria Rotator Ticker Tape Linear Actuator Total 25 27 Accuracy 4 7 Maximum loads 6 9 Cost 2 8 5 Ease of Manufacturing Prototype Life Total 25 27 35

Future Work Final Design modifications Choose and order materials Build prototype Test

References Glaucoma Research Foundation. www.glaucoma.org National Glaucoma Research. American Health Assistance Foundation. www.ahaf.org Glaucoma Resource Guide. National Eye Institute. www.nei.nih.gov/health

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