(a) The experimental setup with the subject walking on a treadmill, with all the CPX measurement sensors and wearable patch attached to the body. (b) The wearable patch top and bottom view with snaps for ECG electrodes and internal hardware. (c) Representative ECG and tri-axial SCG signals (head-to-foot, HtoF, dorso-ventral, DV, and lateral, LAT) from one patient in the study.