The painful finger-pricks diabetics are forced to endure when checking their blood sugar levels could become a thing of the past thanks to the work of engineering researchers at Texas A&M.
Gerard Coté, Charles H. & Bettye Barclay Professor and head of the Department of Biomedical Engineering, and Michael Pishko, Stewart & Stevenson Professor II in biomedical engineering are working on a new less invasive way to monitor blood sugar levels that could alleviate the bothersome finger-pricks for patients.
The team is developing a process that would allow individuals to check their blood sugars with the mere glance at a wristwatch-like meter.
Developing the idea for “smart” tattoos
The idea for the nonsticking technology came to Coté while he was attending a conference and heard a doctor’s presentation on using lasers to remove tattoos. The lecturer mentioned how it would be nice if someone could come up with a “smart” tattoo that actually did something beyond displaying “Mom” or a rose on the shoulder.
“I was already working in the glucose sensing area for diabetics,” Coté says, “and I thought, maybe there is an implant we could develop that I could optically interrogate.”
Upon returning from the conference, Coté contacted Pishko, who at the time was an assistant professor at Texas A&M.
Together, the two started forming the chemistry, polymer materials, and optics to measure blood sugar levels.
Initial concepts of their idea provided enough promise to receive funding from the National Science Foundation and the State of Texas Advance Research Program. This allowed the idea to take shape and grow, quickly gaining momentum toward revolutionizing diabetes management.
How it works
Their technology works by encapsulating fluorescent chemistry in a cylindrical implant – ideally not much bigger than a strand of human hair – and inserting it into the wrist of a diabetic patient, just below the skin. The sheath is invisible, but when you shine a small laser on it, it glows and changes color in response to changes in blood sugar levels.
The laser illuminates the implant and its color changes in response to the levels of glucose that, once implanted, offers a painless visual monitor for the patient.
The information would be provided in real time to the patient through some sort of device – a wristwatch, for instance – that would provide a digital readout of glucose levels and alert the wearer to dangerous fluctuations in blood sugar levels.
Improving on current techniques
This technology dramatically improves upon current diabetes monitoring in two ways. First, it would allow diabetics to check their glucose levels without having to draw blood. Second, and more important, it would provide reliable and consistent monitoring, especially when it is sometimes difficult: when the diabetic is sleeping.
“The watch-type device, you could wear at night,” Coté says. “One of the big things for diabetics is that sometimes at night, their glucose levels crash down, and there is no reliable way to monitor that.
“About 50 percent of patients will sweat when they are about to go into a diabetic coma. Thus, many spouses or significant others will lie next to their partner, wake up several times and check on them to assess if they are sweating, effectively acting as the biosensor.”
Not every diabetic can count on such close observation. And even with a watchful eye, it is dangerous guesswork where a wrong answer could lead to a fatal diabetic coma or death.
This technology works to eliminate that by alerting the diabetic when his or her blood sugar levels start to decline.
“There is no reason why we can’t incorporate an alarm into the monitor so a patient would be alerted when their glucose starts to go into a critical path upward or a critical path downward,” Coté says.
Among the challenges Coté and his colleagues have faced was how to successfully implant the sheath into the wrist of the diabetic patient and have it work properly without a negative reaction from the body. When the human body detects a foreign object, it typically reacts by trying to push it back out or by forming a capsule around it. Either reaction would hinder the device’s ability to monitor glucose levels.
So Coté enlisted another colleague to contribute to the project.
Melissa Grunlan, an associate professor in biomedical engineering, works with smart polymer materials and is helping to develop the sheath.
Grunlan, along with Coté and Pishko, received a grant from the National Institutes of Health during the summer of 2009 to develop the biocompatible polymer sheath for glucose monitoring.
The researchers have conducted two preliminary studies in rats. In the first study the chemistry did fluoresce under the rats’ skin and the fluorescent response changed when there was a change in the glucose level in the rat. Coté cautions, however, that these are “very, very” preliminary studies.
“We injected the material into the abdomens of the rats in two different locations and then we gave them an injection of glucose,” Coté says. “We monitored the locations and saw that the changes correlated to the glucose in both locations. Now we need to do extended studies. In the second study we injected the new thermoresponsive material developed by Grunlan and saw improvement in the tissue response.”
Early tests positive
Though the sensor is still in the preliminary stages of development, interest is already high. As word of his research spread, Coté says he began receiving inquiries from patients interested in the technology. It even caught the attention of Reader’s Digest magazine, appearing in an article in the March 2008 edition.
Additionally, KAMU-TV and Brazos Valley Magazine, a weekly community affairs show, will air an interview with Coté this summer that will discuss his work in optical sensors for in vitro and in vivo medical diagnosis and monitoring.
Story by Tim Schnettler, Texas A&M Engineering Media Communications Coordinator