Differential cardiopulmonary monitoring system for artifact-canceled physiological tracking of athletes, workers, and COVID-19 patients.

Soft, skin-integrated electronic sensors can provide continuous measurements of diverse physiological parameters, with broad relevance to the future of human health care. Motion artifacts can, however, corrupt the recorded signals, particularly those associated with mechanical signatures of cardiopulmonary processes. Design strategies introduced here address this limitation through differential operation of a matched, time-synchronized pair of high-bandwidth accelerometers located on parts of the anatomy that exhibit strong spatial gradients in motion characteristics. When mounted at a location that spans the suprasternal notch and the sternal manubrium, these dual-sensing devices allow measurements of heart rate and sounds, respiratory activities, body temperature, body orientation, and activity level, along with swallowing, coughing, talking, and related processes, without sensitivity to ambient conditions during routine daily activities, vigorous exercises, intense manual labor, and even swimming. Deployments on patients with COVID-19 allow clinical-grade ambulatory monitoring of the key symptoms of the disease even during rehabilitation protocols.

Medium-distance affordable, flexible and wireless epidermal sensor for pH monitoring in sweat.

In the last decade, wearable sensors have gained a key role on biomedical research field for reliable health state monitoring. A wide plethora of physics marker sensors is already commercially available, including activity tracker, heart rate devices, and fitness smartwatch. On the contrary, wearable and epidermal sensors for chemical biomarker monitoring in several biofluids are not ready yet. Herein, we report a wireless and flexible epidermal device for pH monitoring in sweat, fabricated by encompassing a screen-printed potentiometric sensor, an integrated circuit, and antenna embedded onto the same Kapton substrate. An iridium oxide film was electrodeposited onto the graphite working electrode providing the pH sensitive layer, while the integrated circuit board allows for data acquisition and storing. Furthermore, a radio frequency identification antenna surrounding the entire system enables data transmission to an external reader up to nearly 2 m in the most favourable case. The potentiometric sensor was firstly characterised by cyclic voltammetry experiments, then the iridium oxide electrodeposition procedure was optimised. Next, the sensor was tested toward pH detection in buffer solutions with a near-Nernstian response equal to -0.079 ± 0.002 V for unit of pH. Interference studies of common sweat ions, including Na+, K+ and Cl-, showed any influence on the pH sensor response. Finally, the integrated epidermal device was tested for real-time on-body pH sweat monitoring during a running activity. Data recorded for a running subject were wireless transmitted to an external receiver, showing a pH value close to 5.5, in agreement with value obtained by pH-meter reference measurement.