Development of a Murine Perfusion SystemNicola Asgill

Fredrick Hilliard

George Kittos

Objectives

Langendorff perfusion systemRequirements:

Miniature scale Fluid temperature controlled Inter-changeable components Drug introduction into perfusate

Background

Langendorff Perfusion SystemSimulates natural blood flowRetrograde 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 Current 7.6A

Max Power 76 W

Max Voltage 16.3 V

dT Max 72°C

Dimensions 48x48x4.8mm3

Peltier Element Test

GoalsShow functionality – Heating capabilitiesCalculate Time Constant

To heat from room temperature to 37 ± 1°C

Determine appropriate input voltage

Peltier Element Test

Protocol8mL of water in Teflon BeakerPlace on Peltier elementTurn 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

Input Voltage - 8V

252729313335373941

0 50 100 150 200

Time (Sec)

Tem

p. (D

eg

ree C

)

Peltier Element Test

Input Voltage – 12V Time Constant (25°C - 37°) = 86.34 sec

Input Voltage - 12V

25

30

35

40

45

50

55

0 50 100 150 200

Time (Sec)

Tem

p. (D

eg

ree C

)

Peltier Element Test

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

Input Voltage - 15V

24

34

44

54

64

74

0 50 100 150 200

Time (Sec.)

Tem

p. (

Deg

ree

C)

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 PumpNeed 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?