Wednesday, March 23, 2005

BrainGate Chip Shows Progress in Clinical Tests

A clinical trial at a Warwick rehabilitation center of a sensor that would allow quadriplegics to use thoughts to control devices is "encouraging," a principal investigator for the study said.

The BrainGate Neural Interface System is being developed by Foxboro-based Cyberkinetics Neurotechnology Systems and is an outgrowth of research conducted by a Brown University researcher.

"The patient can use his thoughts to move a cursor on the screen of the computer, for his television," said Dr. Jon Mukand, an investigator and medical director for the Southern New England Rehabilitation Center. The television controls operate through an infrared system and allow the patient to change channels, control the volume and turn the set on and off.

The study is being conducted at the Sargent Rehabilitation Center in Warwick. It is the first study site that Cyberkinetics has chosen. The sensor was placed on the patient?s brain during a surgery at Rhode Island Hospital.

The BrainGate system used in the trial was provided by Cyberkinetics, the sponsor of the study. The system stems from research conducted in the lab of Dr. John Donoghue, chairman of neuroscience at Brown University.

The BrainGate sensor was implanted on the primary motor cortex portion of the brain of a man with a three-year-old spinal cord injury. One hundred micro electrodes were placed on the brain. Researchers then recorded activity on the neurons.

As Mukand describes it, researchers directed the patient to imagine moving an arm. Doctors recorded that activity to program the computer connected to the BrainGate microchip.

"When you see a pattern of electrical activity, that information is then used to control the cursor," Mukand said. The technique is called "linear regression" - correlating movements with patterns of electrical activity.

Once it was programmed, the patient was then able to use his thoughts to control the cursor, television and able to manipulate a prosthetic hand that?s linked to the computer system. "This means there is potential for helping people with severe disabilities control external devices with their thoughts," Mukand said.

Investigators at Sargent recorded results from the study over a six-month period. They found no bleeding at the implantation site, and the patient has had no headaches, Mukand said.

Investigators can ensure the device is working by asking the patient to move the cursor on the screen to other points, Mukand said.

"He can control the cursor merely by thinking about it," he said. The patient can also play computer games like Pong, open simulated e-mail messages and other more complex computer tasks by using thoughts.

The next step in the development of the device, which has been in progress for a decade, is to recruit more patients for the study of the device. The FDA approved the BrainGate study for five patients, Mukand said, and investigators are actively having discussions with a number of people. The study is expected to last for about 13 months for each patient, who will perform tasks with the device. At the end of the study, each patient will undergo another surgery to have the device removed or could have the option to participate in future studies.

"Since this is the first human study, we need to be very selective," Mukand said. The device was previously tested on monkeys at Brown University.

The goal is to eventually miniaturize the BrainGate sensor and reduce the size of the external hardware to make the program more easily usable, Mukand said.

"Then we hope the device will be functional and more easily used by the patient and control a variety of systems that will eventually make them more independent," Mukand said.

While the patient in the clinical trial sustained a spinal cord injury, the device can be used on quadriplegia induced by strokes, other injuries or muscular dystrophy.

The BrainGate system may not be available commercially for another five to 10 years, Mukand said. The length of time it takes for study depends on how the research progresses, he said.

The principal investigator, Mukand is also on the faculty of Brown University, Boston University and Tufts University. The surgery to implant the sensor was conducted at Rhode Island Hospital in Providence by Dr. Gerhard M. Friehs, director of functional neurosurgery and associate professor of clinical neurosciences at Brown Medical School.

By: Katie Haughey