Neck Extender/Flexor for Fluoroscopy Examination Client: Victor Haughton, M.D. Advisor: Naomi Chesler, Ph.D. Alison Boumeester Vidhya Raju Susan Samreth Peter Strohm

Overview Problem Statement Background Information Product Design Specifications Design Alternatives Decision Matrix Future Work

Problem Statement Create neck positioner for use in fluoroscopy Accommodate comatose patient http://www.massgeneralimaging.org http://www.medi-fax.com

Background Information Cervical Spine Determine disk health through neck movement Fluoroscopy X-ray imaging in motion Metal not desirable in imaging areas Non-motorized device created Spring 2006 http://homepages.cae.wisc.edu/~bme402/neck_positioner_s06/

Product Design Specifications Must not induce neck injuries Motorized to prevent human error Simulate natural neck movement Extension/flexion to 45˚ from neutral Rate of rotation 1˚/sec Remote control operation Neck Extension www.rad.washington.edu Neck Flexion

Motor & Gear Design Bi-directional motor runs minor gear Minor gear rotates planetary gear guide Extension/ flexion centered about axis

Motor & Gear Design Cons Pros Gear must always support head board Limited potential for expanding rotation range Awkward shape Mechanically complex Pros Easy assembly No obstruction for lateral imaging Achieves desired range of rotation Realistic (anatomic) center of rotation Components beneath table

Gear Actuator Design Motorized worm gear controls shaft elevation Pins stabilize shaft, prevent rotation Head board supported by roller guide

Gear Actuator Design Cons Pros Frame limits lower rotation range Possible interference Mechanically complex Pros Easy assembly No obstruction for lateral imaging Achieves desired range of rotation Realistic (anatomic) center of rotation Components beneath table

Linear Actuator Design S-shaped board on table Movement from actuator Speed of rotation altered by adjusting voltage power supply AC to DC signal conversion

Linear Actuator Design Pros Easily constructed No obstruction of lateral imaging Achieves desired range of motion Easily powered Cons Moments will occur at base of actuator Base of actuator much lower than table Rotational rate will vary

Design Matrix 100 86 68 71 Criteria Weights Linear Actuator Worm Gear Gear and Motor Safety 30 25 27 22 Feasibility 40 39 20 Aesthetics 10 6 9 Mechanics 16 15 Totals 100 86 68 71

Future Work Research linear actuators/power supplies How to modify linear actuators Research materials that will not interfere with radiographic imaging How to machine these materials Prototype design

Acknowledgements Professor Block, Department of Biomedical Engineering Professor Fronczak, Department of Mechanical Engineering Professor Ranallo, Department of Radiology

Questions?