Wearable belt with built-in textile electrodes for cardio-respiratory monitoring
Unobtrusive and continuous monitoring of vital signs is becoming more and more important
both for patient monitoring in the home environment and for sports activity tracking. Even though
many gadgets and clinical systems exist, the need for simple, low-cost and easily applicable solutions
still remains, especially in view of a more widespread use within everyone’s reach. The paper presents
a fully wearable and wireless sensorized belt, suitable to simultaneously acquire respiratory and
cardiac signals employing a single acquisition channel. The adopted method relies on a 50-kHz
current injected in the subject thorax through a couple of textile electrodes and on envelope detection
of the trans-thoracic voltage acquired from a couple of dfferent embedded electrodes. The resulting
signal contains both the baseband electrocardiogram (ECG) signal and the trans-thoracic impedance
signal, which encodes respiratory acts. The two signals can be easily separated through suitable
filtering and the cardio–respiratory rates extracted. The proposed solution yields performances
comparable to those of a spirometer and a two-lead ECG. The whole system, with a realization
cost below 100 €, a wireless interface, and several hours (or even days) of autonomy, is a suitable
candidate for everyday use, especially if complemented by motion artifact removal techniques,
currently under implementation.