Team Members:Team Leader- Jeremy GlynnCommunicator- Jeremy SchaeferBSAC- Mike ConrardyBWIG- Adam Goon

Client- Ian Rowland, Ph.D., Department Of RadiologyAdvisor- Professor Bill Murphy

Background Information Problem Statement Motivation Client Requirements Existing Technology Design Alternatives Design Matrix Future Work Questions?

Basics of MRI (Magnetic Resonance Imaging)◦ Generates very strong (4.7 T) magnetic field◦ Causes atoms to emit radiowaves

Uses of MRI:◦ MR images provides information such as:

Size of tumors Functions of organs Chemical concentrations

◦ Client’s focus – Brain imaging

http://en.wikipedia.org/wiki/Magnetic_resonance_imaging

MRI Coil for imaging ratsCaptured 2/5/08, UW Hospital

Design a stereotactic device that will:◦ Minimize head movement of rats/mice

while positioned in MRI◦ Incorporate a heating device to

prevent hypothermia◦ Fit within the MRI coil◦ Allow for provided anesthetic

Imaging quality and efficiency◦ Allow for imaging over a longer time period

Animals metabolic rates decrease with anesthesia Can lead to hypothermia or death

◦ Anesthetic can be connected quickly and easily◦ Animal can be positioned with ease

Animal safety◦ Current heating methods are inadequate

Can’t interfere with MRI images Animals brain must be centrally aligned in MRI Heating device to warm animal

◦ Within 5o of 37oC Fit inside MRI coils

◦ Rat- 63 mm diameter◦ Mouse-36 mm diameter

Anesthetic mask must cover animals mouth Minimal movement of animal

◦ Restraint without harm Withstand 4.7 Tesla magnetic field

David KOPF Instruments◦ Model 324 MRI Head Holder for Rat◦ Model 325 MRI Head Holderfor Mouse◦ Model 923M MRI Mouse Gas Anesthesia Adaptor Enzyme Research Facility

http://www.kopfinstruments.com/Stereotaxic/StereotaxicPrintables/324-325-P.pdf

Enzyme Research Facility (Beth Rauch)

Tooth restraint does not obscure anesthetic mask.

Fits inside MR tray Recessed in tray for proper brain alignment.

Advantages◦ Inexpensive

Disadvantages◦ Difficult to move

heated air efficiently◦ Air has less effective

heat transfer◦ Larger volume of air

to heat

Advantages◦ Easy to manufacture◦ Water has better

thermal conductivity◦ Accessory parts

inexpensive Disadvantages

◦ 3D printing expensive

◦ Possibility water could leak

Advantages◦ Easy to manufacture◦ No possibility of leaking water

Disadvantages◦ Air has low thermal conductivity◦ Difficult to move heated air through small

diameter tube

Cost (0.05)

Durability (0.20)

Heat Consistency- Quality of Circulation (0.30)

Heat Transfer - Efficiency (0.25)

Ease of Manufacturing (0.20)

Total

Air Chamber

8 (.4) 8 (1.6) 4 (1.2) 6 (1.5) 6 (1.2) 5.9

Fluid Piping

5 (.25)

7 (1.4) 9 (2.7) 8 (2) 7 (1.4) 7.75

Air Piping 6 (.3) 8 (1.6) 7 (2.1) 5 (1.25) 6 (1.2) 6.55

Research:◦ Pumping/Heating design

Start up time Efficiency

Testing:◦ Heat lost through piping◦ Durability of 3D printing material◦ Temperature of heating pad◦ Temperature of fluid