Scientists have developed a tiny implant which can analyse in real time substances present in the human body. Longer term, the device should improve monitoring of patents suffering from chronic illnesses.

Small Electronic Implant Enables Mobile Health Tracking

Sensors which enable monitoring of patients suffering from serious illnesses are now being developed all the time, including, as we reported not long ago, those embedded in electronic tattoos. Now a team led by Giovanni de Micheli and Sandro Carrara at EPFL, the Lausanne-based Swiss Federal Institute of Technology, has been working on a minuscule device which, once implanted just under the skin, provides immediate analysis and measurement of up to five substances – proteins and organic acids, such as lactic acid - in the body. A radio module can then transmit the results directly to a medical practitioner over the cellular phone network. The device was initially designed to monitor cancer patients undergoing chemotherapy, but is likely to prove useful in the detection of chronic illness even before the first overt symptoms appear. This device therefore appears to have great potential for the many cases where doctors need to monitor the progression of an illness or assess the patient’s tolerance of a new treatment.

Results transmitted via mobile phone network

The EPFL researchers have succeeded in incorporating in this minuscule device, measuring only a few cubic millimetres in volume, five sensors, a radio transmitter and a power delivery system. The implant is in fact powered from outside the body, with a battery patch providing – through the skin – the one-tenth watt of power needed for the device to work. There is therefore no need to operate on the patient every time the battery needs changing. Information is routed through a series of stages, from the patient's body to the doctor's computer screen. The implant emits radio waves over a safe frequency. The patch collects the data and transmits them via Bluetooth to a mobile phone, which then sends them on to the doctor over the cellular network.

Towards personalised patient support

This approach will enable closer, more personalised medical tracking than the system of blood tests in general use today and patients undergoing chemotherapy or suffering from chronic illness will be among the first to benefit. At the moment, if an oncologist wishes to assess a patient’s response and tolerance to a particular treatment dosage, s/he has to carry out successive blood tests. In these conditions, it is very difficult to administer the optimal dose. By analysing substances present in the body in real time, this new device represents considerable progress towards more personalised treatment. The system allows continuous monitoring based on a patient’s individual tolerance to the treatment rather than on occasional tests. The prototype is still at the experimental stage, but it has already proved its reliability in detecting the presence of several substances regularly monitored in medical procedures.

By Pauline Trassard