µPET/CT Heating Device Team Leader – Eric Printz Communicator – Justin Schmidt BWIG – Ryan Carroll BSAC – Ben Engel Client – Dr. Robert Jeraj Ph.D Advisor – Professor Brenda Ogle Ph.D

Overview Background Information Proposal/Client Requirements Design Alternatives Design Matrix Future Work

Background Information µPET/CT medical imaging tool Used to study cancerous cells in small animals PET tracks intensity of cells metabolic rate CT provides detailed anatomy image Together they represent complete image [3] [2 ] [1] [1] [2] [3] Image courtesy of Dr. Jeraj

Background Information During scans animals are anesthetized Under anesthesia animals metabolic rate greatly reduced Can lead to hypothermia or death Constant body temperature important for consistency of images Currently heat lamps provide non-uniform temperatures

Proposal/Client Requirements Design a heating device to prevent hypothermia and help increase accuracy of scans Client Requirements –No metal parts in µPET/CT field of view –Provide controllable temperature –Temperature constant near subjects body temperature –No moving parts –Device must fit inside µPET/CT scanning chamber (10 cm. diameter)

PVC Tube Heater High resistance nichrome wire produces heat Air pump used to produce air flow Mouse is located in plexiglas box Polyvinyl chloride provides good insulation

PVC Tube Heater Continued Advantages Temperature easily adjustable Very small potential to harm machine Low production cost Disadvantages Custom power supply Complex calibration required

Water Pump Heater Similar to in-floor heating Circulating water pump/heater Controllable in-line heat source Water coil system for heat transfer

Water Pump Heater Continued Advantages Water pumps readily available Water has high specific heat Disadvantages Device may leak Heat loss through transfer stages Slow response time

Heat Gun Heat Source: Triac PID heat gun Electronic controllable temperature Digital temperature display Produces air flow

Heat Gun Continued Advantages Onboard temperature control Heat and air flow in one device No need to assemble and calibrate Disadvantages 10°F temperature increments Transition between metal tip and plastic tubing Standard operating temperature ~200°F Expensive ~$500

Design Matrix CategoryWeightWater PumpPVC HeaterHeat Gun Cost Temperature Range Safety of PET/CT Machine Mouse Surface Stability Heat Transfer Temperature Adjustability TOTALS

Future Work Buy materials Build prototype Constant Temperature –Voltage calibration of nichrome wire –Flow calibration of air pump –Fine tune outlet air rate –Desired pressure and temperature Customized power supply

Questions?

References Hrapkiewicz, Medina, and Holmes, Clinical Laboratory Animal Medicine: An Introduction, 2nd Edn., Iowa State University Press, MatWeb – Online Material Data Sheet. Online. Plastics Materials Polyvinyl Chloride PVC. British Plastics Federation. Online. TRIAC PID. Leister. Online ef c3ebfd&subcatalog=&product= dfc2-4aac-98b6-f25572d998b4http:// ef c3ebfd&subcatalog=&product= dfc2-4aac-98b6-f25572d998b4 Webster, J. G Bioinstrumentation. Hoboken, NJ: John Wiley & Sons, Inc. Wire: Nichrome. Wiretronic. Online.