Using light to bring people back to life?

By Casey Frye, CCNN Writer

defib via light
An illustration of the computer program the researchers used.

It happens in about every episode of House M.D. I’ve ever seen: the beeping on a heart rate machine flatlines, and the doctors rush in! They pull out the paddles of a defibrillator machine and charge the baby up. They count down, “3!….2!…1!.. CLEAR!” and deliver a jolt of electricity to the dying patient’s chest. After a couple more tries, the beeping on the machine returns and the patient is brought back to life!

However, the miracle is not without consequences. Did you know the shock delivery from a defibrillator machine can damage tissue, cause pain, and have other serious side effects? It’s true, which is why biomedical engineers from the Johns Hopkins University and Stony Brook University plan to replace the electric shock… with light.

“Applying electricity to the heart has its drawbacks,” said the project’s supervisor, Natalia Trayanova, a professor of biomedical engineering at Johns Hopkins. “When we use a defibrillator, it’s like blasting open a door because we don’t have the key. It applies too much force and too little finesse. We want to control this treatment in a more intelligent way. We think it’s possible to use light to reshape the behavior of the heart without blasting it.”

There are light-responsive proteins called opsins, commonly found in our eyes. When light shines on these proteins, tiny molecules create an electrical charge inside a cell. A field of science called “optogenetics” focuses on how to reproduce this effect in the brain. When researchers from Johns Hopkins University and Stony Brook University used the same technique on a virtual heart, they managed to get the same type of shock! “The most promising thing about having a digital framework that is so accurate and reliable is that we can anticipate which experiments are really worth doing to move this technology along more quickly,” said Patrick M. Boyle, a postdoctoral fellow in Trayanova’s lab. “One of the great things about using light is that it can be directed at very specific areas. It also involves very little energy. In many cases, it’s less harmful and more efficient than electricity.”

After the researchers test the technology more thoroughly, they plan to incorporate it into defibrillators to give weakened hearts a safer and gentler kick-start!

Image of computer program courtesy of Johns Hopkins University.