UA researchers create wireless biosensors

Technology

By: Evan Billingsley

Posted: 8/20/07

Electrical engineering researchers at the UA have developed small, wireless biosensors that can read vital signs when placed directly on the body or implanted in clothing, a UA researcher said.

These biosensors may radically change diagnostic techniques in a variety of circumstances including casual, recreational activity to neurological disorders such as Parkinson's disease and Alzheimer's disease, said Vijay Varadan, distinguished professor of electrical engineering in the College of Engineering.

Research into the possible applications for the biosensors has been continuous since 2005 under the direction of Varadan who co-teaches a course in microsensors and micro-electro-mechanical systems, the nanomachines on which the biosensors re based.

"We're trying to move diagnostic testing out of the laboratory and directly to the patient," said Taeksoo Ji, assistant professor of electrical engineering, in a press release. And to accomplish that goal, Ji, Varadan and others have developed a variety of biosensors that measure different physiological signs in the body, like temperature and respiration rate. The effectiveness of each biosensor is dependent on where it is placed on or in the patient being treated.

"If the sensor is placed in the shirt it can measure the skin conditions, but it won't tell you the heart conditions," Varadan said.

For that, the sensor must be injected into the body, where an antenna relays diagnostic information over a wireless network. The body will not reject the biosensor as foreign because the biosensor is made out of a carbon polymer instead of the more expensive silicon alternative. Still, there are limits to how far the current technology can be placed into the body, Varadan said.

"We cannot insert these sensors very far into the body, because of all the liquid," Varadan said. "That is where we run into problems, in areas such as the gall bladder. However, the brain is fine, the heart is fine."

Biosensors placed into the brain can measure electrical and chemical activity there, stimulating neurons. When a sensor measures an increase in tremors in a patient with Parkinson's disease, it could trigger the release of dopamine a neurochemical through that stimulation, Veradan said.

Meanwhile, another biosensor that can be placed directly on the skin, or in a wristwatch, could measure the glucose level of a person without a blood sample, determining the necessity of insulin for a patient with diabetes.

The human body is not the only thing biosensors can monitor. Pending Federal Drug Administration approval, radio frequency identification tags could be placed in fresh fruits to measure the levels of any toxins within.

Other biosensors can focus on more extreme environmental dangers.

"This sensor is so tiny, you could put it in a button," Varadan said of a biosensor designed to determine the toxicity of a room. This function would be helpful to firefighters and other professionals in dangerous environments, varadan said

The biosensors also provide numerous benefits for athletics. Placing a sensor in the helmet, shirt or shoes of those in training for sports "shows how much pressure is put on the body during training," Varadan said.

Meanwhile, those who play golf can look forward to purchasing a smart club outfitted with sensors that can predict the optimal swing for a certain distance. Similarly, smart balls for sports like football and baseball will relay information to the athlete on the best way to throw the ball, Varadan said.

With business arrangements not yet finalized between the UA, Varadan's own company and Penn State, it could be several years before biosensors are integrated into products, Varadan said.