Scott McCain Aims for Better Blood Alcohol Sensor

March 14, 2006

Scott McCainIf third-year engineering graduate student Scott McCain gets his way, the fight against drunk driving may soon be waged with a new, non-invasive blood alcohol sensor that could make standard blood or breath sample tests obsolete. The St. Louis native’s interdisciplinary research -- a combination of engineering, physics and computer science -- aims to build a small and inexpensive optical device capable of using harmless light to pass through skin and directly determine blood alcohol concentration.

“The device uses light at wavelengths at which skin essentially becomes transparent,” McCain said. “We shine a laser through tissue where it interacts with blood. By analyzing the scattered light that comes back out, we can determine much about the blood’s chemical content.”

In addition to its potential use by law enforcement, the sensor might also prove beneficial in clinical settings such as a detox unit, where it could be used to monitor a patient’s blood alcohol levels over time, he added. The device could also serve as a useful tool for continuously measuring the rise and fall of blood alcohol in research aimed at understanding alcohol abuse or addiction. The work is funded by the National Institute on Alcohol Abuse and Alcoholism.

Similar devices hold promise for determining other constituents of blood. For example, they could measure cholesterol or blood sugar in a matter of minutes, McCain said. Ultimately, the goal is to have a sensor that could report a medical reading in less than 10 seconds.

McCain conducts his research in the lab of Addy Family Professor David Brady in Pratt’s department of electrical and computer engineering along with other researchers who have the diverse expertise required to make their tool a success. Brady is also the director of Duke Integrated Sensing and Processing, a computational optical sensors research program in the Fitzpatrick Institute for Photonics.

It was the Fitzpatrick Center program that drew McCain to Duke, where he is also president of the student chapter of the Optical Society of America (OSA). “Most programs offer optics as part of a department, but not a whole center. Here at Duke, there is a whole floor dedicated to optical diagnostics.”

As a kid, McCain said he went to computer shows with his uncle, where they would buy motherboards and assemble them into computers. His interest in optics grew as an undergraduate and then master’s student in electrical engineering at the University of Illinois, where he worked to develop microcircuits that could emit light for biological assays. His focus then wasn’t so much on the applications, he said, but rather on the basic optical physics presented by the problem.

After completing his master’s degree, McCain spent one year in Germany working at Siemens, where he designed electronic components for electric motors in cars. He soon found himself itching to return to academics and applied to the Ph.D. program at Duke.

McCain’s optical research at the Pratt School offers a challenging blend of optical physics and computer science, while maintaining the hands-on tinkering he has always enjoyed, he said.

“Optics is a rich and exciting field because it is still so new,” McCain said. “Many of the components I work with weren’t available just 10 years ago.”

McCain draws on his background in electrical engineering to integrate the knowledge and ideas of the rest of the team into a plan of action.

“It’s fun because it’s interdisciplinary,” he said. “Some members of the team are more practical, while others are more on the theoretical side. I have to get everyone on the same page because I ultimately have to build the device and make it work.”

While the promise of their device has yet to be proven, a spin-off company called Centice, run by former members of the Brady lab, is ready to commercialize the technique when it is, McCain said. McCain’s team keeps commercial feasibility very much in mind in engineering the blood alcohol sensor. While others have developed methods to analyze chemical content optically, those techniques have been impractically expensive and complex, he noted.

“We are trying to develop techniques that transfer the complexity to a computer -- to design optics with the post-processing in mind,” McCain said.

“Other devices have had lots of moving parts, while ours are static,” he continued. “We are working to create something that is compact, cheaper and easier to produce.”

So far, the team has tested their device on ” phantoms,” models that mimic natural tissue. They are also examining the utility of their sensor in mouse studies -- measuring the blood alcohol concentrations of mice injected with ethanol before testing it on people.

“We don’t yet know if our blood alcohol sensor will really work,” said McCain. “It wouldn’t be research if we knew what it was all about.”

Indeed, it’s the element of excitement about the unknown that seems to drive him, although McCain said he also appreciates having a clear goal in mind.

“Doing science for its own sake is good,” he said. “But it’s nice to have a definite problem in mind that you are trying to solve.

“It can be easy to make something work one time in the lab,” he added, “but making something that is robust and reliable in the real world adds substantially to the engineering challenge.”

Already, McCain is named on a few patents related to their technology. He also received the Outstanding Young Researcher Award at the OSA’s Optics in the Southeast conference held in Atlanta in October 2005.

As for his personal life, congratulations are in order. McCain and his fiancé, Robin Parker, a math teacher at Jordan High School in Durham, are to wed in July 2006.