Actuator 2 Provides rotation about the roll direction.

1
Automated Animal Board for Positioning in Ocular
Photography and Imaging
Dhaval Desai1, Nathan Kleinhans1, Holly Liske1,
Laura Piechura1, Kellen Sheedy1 Advisor
Professor Wally Block, PhD1,2 Client BAnn
Gabelt3 1 Department of Biomedical Engineering, 2
Department of Radiology, 3 Ophthalmology and
Visual Sciences
Abstract
Design Criteria
Prototype Testing
Glaucoma is the second leading cause of blindness
in the world. Currently, no cure exists for
glaucoma and the inability to diagnose this
disease in its early stages exacerbates the
problem. The incorporation of eye-imaging tools
such as OCT (Optical Coherence Tomography), HRT
(Heidelberg Retinal Tomography), and GDxVCC
(Confocal Laser Polarimetry) in conjunction with
chemotherapeutics and gene therapy offer
promising solutions to diagnose and cure
glaucoma. However, in order to make strides
towards a cure, fine adjustments in the
positioning of the eye of animal subjects are
necessary to obtain quality images of the retina
and nerve. The goal of this project is to
construct an automated positioning device that
provides accurate alignment of the animal for
successive scans in longitudinal research studies
that may one day unearth the cure for glaucoma.

• Device must be automated or require minimal
  manual labor
• Device must support weights up to 50 pounds
• Device should be able to rotate 15 to 30 from
  horizontal in pitch and roll directions
• Pitch and roll motion of the platform should
  allow a resolution of approximately 2

• Moveable weight
• Able to easily move 51 pounds without
  statistically significant decrease in speed
• Maximum pitch and roll of 19 from horizontal
• Reproducibility of board position

Final Design
The final design is named the Linear Actuator
model. It consists of two plates constructed
from High Density Polyethylene (HDPE) held
together by two linear actuators and a stainless
steel rod. Each actuator is controlled by a
momentary switch, which allows for extension and
contraction of the actuators.
Problem Statement
Actuator 1 Provides rotation about the pitch
direction

• Glaucoma
• Eye disorder characterized by high intraocular
  pressure
• Increased pressure causes damage of the nerve
  fibers and
• the optic disc
• Results in loss of peripheral vision
• No current cure exists
• Second leading cause of blindness in the world

Figure 6 Testing data regarding reproducibility
of specific angles in pitch and roll directions.
Vertical displacement from base of prototype was
recorded to gauge accuracy. Lines indicate
initial displacement, while data points indicate
position after each trial.
Roll
Pitch
Actuator 2 Provides rotation about the roll
direction.
Future Work
Figure 3 The actuators and the center support
are connected to a bearing that allows for the
necessary rotation.

• Incorporate digital inclinometer for digital
  readout
• Validate reproducibility with animal testing
• Replace bearings if greater rotation needed
• Devise a way to shorten overall height of
  prototype

Figure 4 The inclinometer magnetically attaches
to the metal piece on the top plate, providing
information on degree of rotation.
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
• Linear Motors and Electric Actuators.
  www.mcmastercarr.com
• Firgelli Automations. www.firgelliauto.com

Figure 1 Glaucoma is a high intraocular pressure
that may lead to blindness.

• Client Motivation
• Aim 1 Early diagnosis of glaucoma
• Measure nerve fiber layer thickness in normal vs.
  
• glaucoma eyes
• Aim 2 Explore treatment options
• Test different chemotherapeutics and gene therapy
• Monitor nerve fiber layer parameters at several
  time points
• Animal model Monkey
• Track the movements of chemotherapeutics and gene
  therapy vectors over time.

Acknowledgments
Figure 5 The switches, which are powered by a
power adapter, control each actuator
independently.
Thanks to our client, BAnn Gabelt and Carol
Rasmussen for their cooperation. We would also
like to thank Mike Tomkowiak for his input.
Lastly, we would like to acknowledge our advisor,
Wally Block, for his continued support and
encouragement.