Team Members: Team Leader- Jeremy Glynn Communicator- Jeremy Schaefer BSAC- Mike Conrardy BWIG- Adam Goon Client- Ian Rowland, Ph.D., Department Of Radiology Advisor- Professor Bill Murphy

Overview  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

Problem Statement MRI Coil for imaging rats Captured 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 Motivation

 Can’t interfere with MRI images  Animals brain must be centrally aligned in MRI  Heating device to warm animal ◦ Within 5 o of 37 o C  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 Client Requirements

 David KOPF Instruments ◦ Model 324 MRI Head Holder for Rat ◦ Model 325 MRI Head Holder for Mouse ◦ Model 923M MRI Mouse Gas Anesthesia Adaptor  Enzyme Research Facility Existing Stereotactic Devices StereotaxicPrintables/ 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 Air Chamber

 Advantages ◦ Easy to manufacture ◦ Water has better thermal conductivity ◦ Accessory parts inexpensive  Disadvantages ◦ 3D printing expensive ◦ Possibility water could leak Fluid Piping

 Advantages ◦ Easy to manufacture ◦ No possibility of leaking water  Disadvantages ◦ Air has low thermal conductivity ◦ Difficult to move heated air through small diameter tube Air Piping

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 Piping6 (.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