Subcutaneous chip delivers more precise clinical measurements
27 May 2015
Researchers have developed a biosensor chip that can be placed beneath the skin to measure pH, temperature and metabolism-related molecules.
Several Ecole Polytechnique Fédérale de Lausanne (EPFL) laboratories are working on devices that enable continual clinical analyses. Their latest development is this biosensor chip, created by researchers in EPFL's Integrated Systems Laboratory, working in collaboration with the Radio Frequency Integrated Circuit Group. Sandro Carrara unveiled it this week at the International Symposium on Circuits and Systems (ISCAS) in Lisbon.
"This is the world's first chip capable of measuring not just pH and temperature, but also metabolism-related molecules like glucose, lactate and cholesterol, as well as drugs," Dr Carrara claims.
A group of electrochemical sensors works with or without enzymes, which means the device can react to a wide range of compounds, and it can do so for several days or even weeks.
This one-centimetre square device contains three main components: a circuit with six sensors, a control unit that analyses incoming signals, and a radio transmission module. It also has an induction coil that draws power from an external battery attached to the skin by a patch.
"A simple plaster holds together the battery, the coil and a Bluetooth module used to send the results immediately to a mobile phone," says Dr Carrara.
The chip was successfully tested in vivo on mice at the Institute for Research in Biomedicine (IRB) in Bellinzona, where researchers were able to constantly monitor glucose and paracetamol levels without a wire tracker getting in the way of the animals' daily activities.
The results were reported to be "extremely promising" which means that clinical tests on humans could take place in three to five years - especially since the procedure is only minimally invasive, with the chip being implanted just under the epidermis.
"Knowing the precise and real-time effect of drugs on the metabolism is one of the keys to the type of personalised, precision medicine that we are striving for," says Dr Carrara.