West Virginia University scientists have manipulated chemical waves in experiments that may one day lead to controlling abnormal electrical waves in the heart or brain to ward off a heart attack or epileptic seizure.
The researchers, led by chemistry Professor Ken Showalter, reported in the cover story of the June 14 issue of Science that they have controlled the movements of photosensitive chemical waves with light from a computer-controlled video projector.
“Weve learned we can control the motion of these waves through methods of control theory,”said Dr. Showalter, who co-authored the article with post-doctoral associates Eugene Mihaliuk and Tatsunari Sakurai and Florin Chirila, a physics graduate student.
The article,”Design and Control of Patterns of Wave Propagation in Excitable Media,”is also available on the Science Web site at www.sciencexpress.org . Science is a journal of the American Association for the Advancement of Science.
The experiments in Showalters chemistry lab involved monitoring and controlling chemical waves on a photosensitive Belousov-Zhabotinsky medium, a widely used chemical reaction for studying wave behavior. The researchers captured images of the waves with a video camera, then altered the direction the waves travel with light from the video projector in real time. They were able to produce various wave patterns using this method, from a simple circular pattern to complex shapes resembling roads on a map.
Although the teams work is basic research, Showalter is optimistic the findings could one day be of use in the medical field.
“There are what we call propagating waves throughout all living systems,”he said.”These biological wave systems are difficult to study, so we study chemical model systems instead. What we learn from simple chemical systems we can then apply to understanding more complicated biological systems.”
One such complicated biological wave system is in the heart, Showalter said. A disruption in the heart wave motion causes the formation of spiral waves. Medical researchers believe spiral waves lead to tachycardia, or rapid heart beat, often a precursor to a heart attack.
Waves also travel through brain tissue, he added. Electrical wave behavior on the surface of the brain is complex and without apparent order. In people with epilepsy, a region of the brain sends out waves in a rhythmic pattern that leads to a seizure.
Showalter said the researcherswork holds particular promise for people with heart disease or epilepsy. For example, medical researchers might develop miniature computers that, when implanted in the chest or brain, could deliver a small shock at the sign of any irregular wave activity, preventing the onset of a heart attack or seizure.
Currently there are pacemakers or implanted defibrillators to shock an irregular heartbeat back into normal rhythm, but the jolt is so strong that it is very difficult for patients, Showalter said. No such therapy exists for people with epilepsy, he added.
Showalter, whose work is supported by the National Science Foundation and others, has been studying propagating chemical waves for several years and has written numerous scientific papers on his research. This is the third article he has authored for Science, and he has also written four articles that have appeared in the British journal Nature.
He joined the chemistry faculty in the Eberly College of Arts and Sciences in 1978. He has held the C. Eugene Bennett Chair in Chemistry since 1996, and before that he was the Eberly Family Professor of Chemistry. He obtained his doctorate from the University of Colorado. He is spending the summer in Berlin, Germany, for professional development studies made possible by an Alexander von Humboldt Foundation Senior Scientist Award he won in 1999.