Development and evaluation of cooling devices for brain and spinal cord injury

1.  Brain cooling induced by an interstitial cooling device on the carotid artery.  A cooling device is designed to be placed on the surface of one of the carotid arteries to cool the warm arterial bood supplied to the brain tissue.  As a result of the cooling device, significant temperature reductions occur in the brain gray and white matter regions, from 37.3C under normal conditions to 34.7C after the cooling device is implemented.  Previous studies have suggested that a brain temperature reduction of 1 or 2C is beneficial to patients suffering brain injury due to stroke, accident, etc.

Image_brain cooling

2. Cooling penetration from an intraparenchymal brian cooling probe.  The movie shows how cooling is penetrating from a brain cooling probe inserted into the brain tissue.  For most brain injury patients, probes are routinely inplemented to monitor patients’ recovery and to relieve intracranial pressure.  It is concervible to place a cooling probe alongside to directly lower the brain tissue temperature.  In the simulation, the cooling probe has a surface temperature of 6C.  Depending on the local blood perfusion rate, the penetration region can be at least 1.5 cm from the probe surface.

3. Cooling in spinal cord using a cooling pad on a torso is shown in the figure.  Spinal cord has similar low tolerance to injury as brain tissue.  This project is to simulate how much temperature reduction can be achieved in the spinal cord if a simple cooling pad is placed on the back surface of a torso.  Our results have shown that it takes less than one hour to establish steady state and temperature reduction in the spinal cord is larger than 1.5C.  Another potential benefit of the cooling approach may be cooling of the brain tissue since the spinal fluid is also cooled during the process.