When it comes to curbing the spread of infectious diseases, time is of the essence. To diagnose a patient’s illness, doctors usually take a sample of blood, send it to a lab and wait for a technician’s analysis. The process can take days or weeks, depending on location. During that time, a contagious person could spread the disease to many others.
IEEE Senior Member Jennifer Blain Christen is developing a disposable biosensor to more rapidly diagnose infectious diseases including the flu, measles, and the Zika virus. The adhesive patch, embedded with sensors and circuits, would be placed on the body to measure biomarkers in a person’s sweat. Blain Christen is an associate professor of electrical engineering at Arizona State University, in Tempe. She received a US $1.8 million Smart and Connected Health award in May from the U.S. National Science Foundation to support her research.
The Institute asked Blain Christen how her biosensor works, what led to her interest in the biomedical field, and how IEEE has helped her career.
Did you discover the connection of biomarkers in sweat, or is it well known?
Biomarkers have been shown in sweat for many years. My research colleagues and I have found many previously undiscovered biomarkers, and we are planning to publish our findings soon.
How does the sensor detect the biomarkers in the sweat?
Through a fluorescent tag, or fluorophore. Fluorophores are molecules that absorb light at one wavelength and emit it at another. LEDs provide the light that is absorbed. Filters help detect only the emitted light. The amount of emitted light detected is related to the number of fluorophores present. Since the fluorophores are tied to the protein molecules of interest, we get an intensity proportional to the concentration of the protein. So far, we’ve only worked with hormones and proteins, including immunoglobulins and cytokines that bind to a receptor—for example, antibodies to antigens. Immunoglobulins are the antibodies that help the immune system. The antibodies we’re looking at flag pathogens so the immune system can recognize them and fight them off.
How many biomarkers do the sensors recognize?
Currently four, but we will be expanding this number.
Is the patch specific to one disease?
No, it’s multipurpose. We are working on several different applications. We use precision dispensing to deposit receptor molecules that could be used to sense any number of proteins.
How big is the patch?
It’s currently 2 millimeters by 2 mm per channel/biomarker. The spacing between the channels is 11.5 mm center to center, but we are working to minimize this. The final size will depend on the specific biomarkers’ concentrations and how well we optimize our detection method.
What about your device makes it faster and less expensive than the traditional diagnostic method?
One of the reasons it takes so long to make a diagnosis is that a trained person is needed to draw the blood along with laboratory equipment to analyze the sample. The cost of diagnosis is paying for these professionals and the equipment. Our process takes less than 30 minutes and doesn’t require medical personnel, like a phlebotomist, doctor, or nurse. The patch’s electronics will perform the basic measurements, and the information is sent via Bluetooth to a computer or a smartphone to be read by a person who could be trained in only a few minutes.
What got you interested in the biomedical field?
I’ve always been interested in medicine. When I was considering where to go to college, I thought about medical school, but I was also drawn to engineering, computers, and technology. I like finding someone working in an area of medicine or biology that I’m not familiar with and helping them come up with ways to improve what they’re doing through technology.
Tell us about your IEEE volunteer work and how the organization has helped you.
I’ve been involved with IEEE since I was an undergraduate. I was chair of the IEEE student chapter at Johns Hopkins University’s Whiting School of Engineering, in Baltimore. I’m involved with the IEEE Phoenix Section, and I belong to the IEEE Circuits and Systems, IEEE Solid-State Circuits, and IEEE Engineering in Medicine and Biology societies. I’m also an associate editor of the IEEE Transactions on Biomedical Circuits and Systems. And I sit on the IEEE Circuits and Systems Society board of governors.
IEEE provides a sense of comradery. It’s really nice to have a network of people to bounce ideas off, talk about things that you may be struggling with, or get unbiased career advice. And by being in the organization, I’ve been exposed to so many new ways of thinking, new ideas, and new applications. I value my membership very highly.