1. BME 301/201 Client: Ugo Faraguna Advisor: Dr. Mitch Tyler
Brain Cooling
BME 301/201
Client: Ugo Faraguna
Advisor: Dr. Mitch Tyler
Jay Sekhon (Leader)
Jon Seaton (Communicator)
David Leinweber (BSAC)
Mark Reagan (BWIG)

2. Background Client is looking for the mechanism behind sleep
Hypothesis: Sleep linked to neural activity
Neural & Metabolic changes are reflected in sleep
Reducing these changes could change sleep/waking cycle
Experiment: Silence local neural activity
Silencing possible by cooling tissue

3. Client Requirements Cool 3mm diameter area of brain tissue
Cannot cause tissue damage/kill cells
Cooling must be done in 30 min to 1 hour
Must maintain tissue temperature for 6 hours
Must cool tissue to ~20°C
Must be easy to use, efficient, and mobile
Must cause no interference with EEG

4. Thermodynamics Relevant Equations: Q=mCpΔT
Heat liberated to reach 20°C:
         Btus =
        J
Density of Tissue = 1.05 g/cm3
Heat Capacity of Tissue = 0.85
(Tanaka et al. 2008)

5. Option 1: Peltier Cells Directional electron flow removes heat
Directional electron flow removes heat
"Hot" side needs to be cooled
Cell size can be very small: <3mm
Adapted from:

6. Option 2: Vortex Tube Requires pressurized air Relevant Equations:
~ psi
Relevant Equations:
PV = nRT

7. Option 3: Liquid Cooling
Absorbs heat via convection
Similar to some computer cooling devices

8. Option 4: Phase Change Cooling
Uses energy change between gas/liquid phases
Similar setup to liquid cooling

9. Design Matrix

10. Future Work Fabricated device
Combination of Peltier cell and other design
Run tests to choose secondary cooling device
Test for EEG signal interruption

11. References
Cespuglio, R., et al. "Alterations in the Sleep-Waking Cycle Induced by Cooling of the Locus Coeruleus Area." Electroencephalography and clinical neurophysiology 54.5 (1982):
Imoto, H., et al. "Use of a Peltier Chip with a Newly Devised Local Brain-Cooling System for Neocortical Seizures in the Rat. Technical Note." Journal of neurosurgery (2006):
Rothman, S., and X. F. Yang. "Local Cooling: A Therapy for Intractable Neocortical Epilepsy." Epilepsy currents / American Epilepsy Society 3.5 (2003):
Tanaka, N., et al. "Effective Suppression of Hippocampal Seizures in Rats by Direct Hippocampal Cooling with a Peltier Chip." Journal of neurosurgery (2008):