Fig. 4: Other competitive skin-based HWDs.
a Schematic of the Heart Failure Prediction System. Reproduced with permission from Hafid et al.48 Copyright © IEEE Journal Of Biomedical and Health Informatics,2018. b Oura Ring with miniaturized sensors on it to diagnose different illnesses. Reproduced with permission50 Copyright © Oura Ring, 2020. c Position of sensors for the detection of bradykinesia and tremor features of PD. Reproduced with permission from Lonini et al.71 Copyright © npj Digital Medicine, 2018. d Earphones for the portable acquisition of EEG with reference and ground electrodes on left earphone and source electrode on right earphone. e Power Spectral Density (PSD) for the differentiation of the state of drowsiness and awake state using EEG from HWD as illustrated in d. Reproduced with permission from Lee et al.78 Copyright © ACS Applied Materials and Interfaces, 2018.
