UB researchers are developing a network of wireless body sensors

The military has for decades used sonar for underwater communication.

Now, researchers at the University at Buffalo are developing a miniaturized version of the same technology to be applied inside the human body to treat diseases such as diabetes and heart failure in real time.

The advancement relies on sensors that use ultrasounds - the same inaudible sound waves used by the navy for sonar and doctors for sonograms - to wirelessly share information between medical devices implanted in or worn by people.

"This is a biomedical advancement that could revolutionize the way we care for people suffering from the major diseases of our time," said Tommaso Melodia, PhD, UB associate professor of electrical engineering.

His research, "Towards Ultrasonic Networking for Implantable Biomedical Device," is supported by a five-year, $449,000 National Science Foundation (NSF) CAREER grant. The CAREER award is the foundation's most prestigious for young investigators.

The idea of creating a network of wireless body sensors, also called a "body area network," is not new. Development of the technology began roughly 10 years ago.

But most work has focused on linking sensors together via electromagnetic radio frequency waves - the same type used in cellular phones, GPS units and other common wireless devices.

Radio waves can be effective but they have drawbacks such as the heat they generate. Also, because radio waves propagate poorly through skin, muscle and other body tissue, they require relatively large amounts of energy, he said.

Ultrasounds may be a more efficient way to share information, Melodia said, because roughly 65 percent of the body is composed of water. This suggests that medical devices, such as a pacemaker and an instrument that measures blood oxygen levels, could communicate more effectively via ultrasounds compared to radio waves.

"Think of how the Navy uses sonar to communicate between submarines and detect enemy ships," Melodia said. "It's the same principle, only applied to ultrasonic sensors that are small enough to work together inside the human body and more effectively help treat diseases."

Another example involves connecting blood glucose sensors with implantable insulin pumps. The sensors would monitor the blood and regulate, through the pumps, the dosage of insulin as needed in real time.

"We are really just scratching the surface of what's possible. There are countless potential applications," he said.

Melodia will use the NSF grant to do more modeling and conduct experiments with ultrasonic, wireless body sensor networks. The grant will support PhD student G. Enrico Santagati, who already has contributed significantly to the project, as well as undergraduate students.

The research will address issues such as how to:

•design transmission schemes to accurately relay information between sensors without causing body tissue to overheat

•design networking protocols specialized for intra-body sensors

•how to model ultrasonic interference

•accurately simulate ultrasonic networks

•design the first existing reconfigurable testbed for experimental evaluation of ultrasonic networks.