ALIGNMENT ALGORITHM FOR THE VESTIBULAR

PROSTHESIS

By:

Brian Hensley

Mentors:

Dr. A. Shkel

Ilya Chepurko

Graduate Student Team:

Monty Rivers

Adam Schofield

Alexander Trusov

Vestibular Prosthesis Overview There are

currently various types of VP

The overall goal of the lab is to create a totally implantable vestibular prosthesis

http://www.jvl.meei.harvard.edu/jvdl/prosthesis.html

Motivation

During surgery the implementation of the orientation does not have to be as precise

The Vestibular Prosthesis could shift later depending what it is attached to

http://biomedcentral.inist.fr

Project Overview

Areas which I am involved: Rotational

axes algorithm 3D Modeling

http://anorganik.uni-tuebingen.de/klaus/nmr/conventions/euler/euler.html

Goal

http://www.stewart.cs.sdsu.edu/cs596-3dprog/lecs/index.html

The Vestibular Organs

http://www.neuroanatomy.wisc.edu/virtualbrain/BrainStem/13VNAN.html

How the Signal Travels

Natural System Vestibular Prosthesis

http://anatomy.iupui.edu/courses/histo_D502/D502f04/lecture.f04/Earf04/Ear.f04.htmlhttp://www.psconsulting.net.au/ttraining.html

Gyroscope

Transfer Function

RotationalAxis

Algorithm

Transfer Function

The flow rate of endolymph in the ear was characterized in the following equation, by Fernandez and Goldberg in 1971:

)1()1(

1

1)(

21 ss

s

s

sfsH

L

A

A

Graph of Model

Graphic by Ilya Chepurko

Rotational Algorithm-Scalar Projection

http://www.nixfiles.com/critters/proposal-slides.html

Tests

Electrical Simulation

Single Gyroscope on rate table Flat Inclined

Electrical Simulation

Wanted to see if the microchip accurately responded to input voltage by producing graph of transfer function

Results of Electrical Simulation

Graphic by Ilya Chepurko

Rate Table Test of a Single Gyro The Flat Tests

Results of Rotation without Incline

Incline Test

Did not have a tilt table to test, had to improvise

Used 4 different objects to prop gyro up against giving 4 angles: 8.45 28.38 50.31 59.32 1sin sin

Y Y

X X

Incline Tests

Vestibular Prosthesis

Unfolded Box Folded Box

3D Model Designed by Monty Rivers

Stress in Latches

2-D Silicon Beam Test

Width of Latch

Conclusion and Future Work

Either Rotational Algorithm would work Need to test to see which one would be

faster Apply Rotational Axis Algorithm to Three

axis system Strength of VP

Acknowledgements

NSF UCI

Dr. Shkel and Ilya Chepurko Microsystems Lab

Monty Rivers Adam Schofield Alex Trusov

IM-SURE Said Shokair IM-SURE Fellows

SAP