Monday, January 28th, 2008
Show and Tell: The Geodesic Sensor Net, Baby Edition
Thing-reader David Borland dropped us a note after seeing our brief mention of a Geodesic Sensor Net mentioned in Five Links for Looking, Volume 8.
David is a senior software engineer at Electrical Geodesics, Inc., the company that makes the sensor net. Photos of his son Zander are used here with his permission. Zander was six-months-old in the photos when he helped test a next generation version of the net.
Here is David’s description of the two devices pictured, with my clarifications in italics.
"The Geodesic Sensor Net is a system of electrodes that are placed on a subject’s head. The electrodes are connected to an amplifier and the electrical activity [brainwaves] on the scalp is measured. This system of electrodes is preferable to the more traditional methods of EEG because it requires no abrasion of the scalp and it is easy to place a large number of electrodes on the head quickly."
"The Geodesic Photogrammetry System [the dodecahedron pictured above] is a system of 11 cameras. The subject sits in the center of the cameras and has 11 pictures taken simultaneously. The system can be used for either adults or children. The software is then used to locate all the sensors on the net in each image. This information from the 2D pictures is used to create a 3D model of the net. The 3D coordinates are then used in our software to display where the [electrical activity] comes from on a head, and to help localize where the sources of the [electrical activity] could have been generated in the brain."
My wife had old fashioned EEGs performed every six months from infancy until she was 12-years-old due to epilepsy. Her comment upon looking at these photos was, "This would have made things easier. I had long, thick curly hair. It took forever for them to place and remove electrodes and the goo they used to attach the electrodes did not wash out. The only good thing I got out of it was treats from Dairy Queen." So, score one for modern technology making life easier. Hopefully kids still get a trip to Dairy Queen even if the hospital ordeal isn’t as much of an ordeal anymore.