Development of a Murine Perfusion System Nicola Asgill Fredrick Hilliard George Kittos

Objectives Langendorff perfusion system  Requirements: Miniature scale Fluid temperature controlled Inter-changeable components Drug introduction into perfusate

Background Langendorff Perfusion System  Simulates natural blood flow  Retrograde fluid flow Attached to aorta  Examine effects of drug on heart

Background (cont.) Current technology  ADInstruments Mouse, rat and guinea pig analysis BP ECG HR Cardiac output Flow rate

Considerations for project Why will this work?  Controlled temperature, flow rate and pressure Improvement of heat stability Multi-drug delivery capability  Disposable components Why is this important?  Possible testing applications: Drug delivery Cardiac cell response

Prototype

Components Peltier Elements Beakers  Teflon  Polyethylene Peristaltic Pump Tygon Tubing Drug Infusion Apparatus Temperature Sensor Flow Sensor Valves

Peltier Element Max Current7.6A Max Power76 W Max Voltage16.3 V dT Max72°C Dimensions48x48x4.8mm 3

Peltier Element Test Goals  Show functionality – Heating capabilities  Calculate Time Constant To heat from room temperature to 37 ± 1°C  Determine appropriate input voltage

Peltier Element Test Protocol  8mL of water in Teflon Beaker  Place on Peltier element  Turn on element and measure temperature at 5 second intervals for 5 minutes

Peltier Element Test Input Voltage – 8V Time Constant (25°C - 37°) = 149 sec

Peltier Element Test Input Voltage – 12V Time Constant (25°C - 37°) = sec

Peltier Element Test Input Voltage – 15V Time Constant (25°C - 37°) = 62 sec

Peltier Element Test Conclusion:  Input Voltage of 8V – longer time to heat sample, needs to be faster to perfusate at constant temp.  Input Voltage of 15V – faster heating, but found that this voltage will cause the device to fail.  Input Voltage of 12V – faster heating and the device did not malfunction

Current Work Heating Perfusate to 37 ± 1°C Designing and manufacturing transparent heart chamber Testing Peristaltic Pump  Need a Flow Rate of about 250mL/min Tygon Tubing Peltier Element

Future Work Create a LabView Module for controlling and maintaining constant temperature Acquiring additional components Assembling Prototype

Thanks Questions?