A Swiss team from Ecole Polytechnique Fédérale de Lausanne (EPFL) has developed a tiny implant that can monitor the concentration of a number of proteins and organic acids in the body while transmitting that information to an external device. The implant itself does not have a battery, but is continuously powered through induction by an electronic patch on top of the skin that delivers 1/10 watt of current. The patch also functions as a data relay, receiving readings from the implant and transmitting them via Bluetooth to a smartphone, for example, where they can be analyzed.
The implant itself includes five sensors (or seven if you trust the video below), and offers a new approach to monitoring disease, assessing the effectiveness of chemotherapy, and a variety of other clinical uses.
The prototype, still in the experimental stages, has demonstrated that it can reliably detect several commonly traced substances. The research results will be published and presented March 20, 2013 in Europe’s largest electronics conference, DATE 13.
To capture the targeted substance in the body – such as lactate, glucose, or ATP – each sensor’s surface is covered with an enzyme. “Potentially, we could detect just about anything,” explains De Micheli. “But the enzymes have a limited lifespan, and we have to design them to last as long as possible.” The enzymes currently being tested are good for about a month and a half; that’s already long enough for many applications. “In addition, it’s very easy to remove and replace the implant, since it’s so small.”
The implant could be particularly useful in chemotherapy applications. Currently, oncologists use occasional blood tests to evaluate their patients’ tolerance to a particular treatment dosage. In these conditions, it is very difficult to administer the optimal dose. De Micheli is convinced his system will be an important step towards better, more personalized medicine. “It will allow direct and continuous monitoring based on a patient’s individual tolerance, and not on age and weight charts or weekly blood tests.”
EPFL press release: Under the skin, a tiny laboratory