Inducing Hypothermia in Neonatal ECMO Cases

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Inducing Hypothermia in Neonatal ECMO Cases
University of Pittsburgh Senior Design -
BioE1160 February 17, 2004

• Adam Abdulally
• Erin Aghamehdi
• Kim Albrecht
• Rebecca Hrutkay

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Refresher

• There is no means of rapidly cooling neonatal
  ECMO patients.
• Cooling offers a way to provide neurological
  protection for the patient.
• Solution A heat exchanger that will work in
  conjunction with ECMO circuit
• Current Re-design
• More efficient heat exchanger
• Counter-current cooled fluid

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Project Goals

• February
• Find effective metal for heat transfer
• Calculation of heat transfer coefficient for
  biocompatible metal
• Idealized (SA) and non-idealized (SA) surface
  area calculations
• Incorporation of SA into heat exchanger to
  achieve minimal priming volume
• March
• Design, Building, Begin testing in ECMO circuit
• April
• Finish Testing in ECMO circuit

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Surface Area Calculations

• Heat transfer from patient to blood can be
  correlated by the Pennes equation
• Mathematical modeling was used to find a desired
  surfaces areas, SA SA
• Incorporation of SA into heat exchanger to
  achieve minimal priming volume and rapid cooling

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Heat Transfer

• Used the Pennes Eq. to determine T(blood,out)
• Counter-current flow
• Used heat transfer model in Momentum, Heat, and
  Mass Transfer Fundamentals by Kessler and
  Greenhorn, 1999
• Still need to find U (heat transfer coefficient)

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Projected Methods

• Simulate a patient using a(n) X L carboy filled
  with H20
• Heat patient to 37ºC and attempt to cool with
  the re-designed heat exchanger to 32ºC
• Maintain hypothermic temperature for desired
  period of time
• Operate system at various flow rates and patient
  volumes
• Record data at 30 second time intervals

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Whos in charge ?
Heat Transfer SA SA Minimal Priming Volume Heat Exchanger Re-Design Testing Analysis Paper
Kim
Erin
Becka
Adam
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Current Status

• Milestones
• Redesign decision
• Heat transfer calculations
• Methods of testing re-design
• Rough draft of scientific paper
• Specific pump determination

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Acknowledgements

• Dr. Carcillo
• Mark
• Michael Shaver
• Leighann Burdis
• Childrens ICU
• Dr. Kameneva

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Questions?