Laser Focus World - April 2009
NSM vibration isolation critical to neuronal measurement
Posted by Gail Overtonr, Senior Editor
When air tables, stacked air tables, and active electronic
vibration-isolation systems failed to reduce vibrations
to a level allowing measurement of neuronal brain activity
for researchers at Georgetown University Medical Center
(Washington, D.C.), professor Jian-Young Wu and colleagues
were able to implement a negative-stiffness vibration-isolation
system from Minus K Technology (Inglewood, CA) to isolate
vibrations down to the required level of 1 Hz.
Wu's team
uses voltage-sensitive dye imaging that visualizes patterns
in the brain's cortex. Neocortical columns-containing
as many as 60,000 neurons- correspond to a sensory stimulus
input to the human body. When imaged in motion, patterns
such as spiraling waves can be seen during epileptic
seizures and in the heart during cardiac fibrillation,
shedding light on the relationship of brain patterns
to trauma and disease. Because voltage-sensitive dye
signals are small (typically a 0.1% to 1.0% change in
illumination intensity), extreme vibration isolation
is required to exclude external vibrations from air
conditioning or ambulatory movement of lab personnel,
insuring that only the neuronal fluctuations are imaged.
Contact David Platus at sales@minusk.com.