E. Cantatore: Biopotential Interfaces Based on Large-area Fexible Electronics

In bio potential measurements, electrodes enable a capacitive or resistive coupling to voltage signals distributed on the body surface. The signals are then transferred to readout circuitry using cables. Examples include Electrocardiography (ECG), electroencephalography (EEG), electromyography (EMG), electrohysterography (EHG) for heart, brain, neuromuscular and uterine signals, respectively. Biopotential measurements are of invaluable utility to diagnose heart, brain and muscular conditions, or to monitor pregnancies (EHG). Important drawbacks affect biopotential measurements in present clinical practice:

- Multi-channel biopotential measurement systems are bulky, obtrusive and patient unfriendly.

- High spatial resolution and/or large number of channels are limited by the complex wiring involved, and by the cost of the multichannel electronics needed.

- Relative movements between the electrodes and the skin create unwanted signals (Motion Artefacts, MAs) that can be orders of magnitude larger than the biopotentials.

For these reasons, entirely new biopotential measurement systems are needed, that should be characterized by: ultra-thin and stretchable form factor for maximum user comfort; high resolution together with low cost, enabling disposable use; extremely light weight, conformability to the skin and the possibility to integrate adhesives for minimum MAs. In this vision biopotential measurement systems must become a kind of "second skin" which can be worn comfortably during the diagnostic procedure, to be disposed after use. Exploiting IGZO TFT technology, we are designing and fabricating biopotential measurement systems that satisfy these needs. The talk will provide details on this work.