(a) Abstract view of the system design highlighting the location of the printed circuit board (PCB), U-shaped sensor band, and ECG electrodes. (bi) External view of VitalCore prototype when electronics and sensors are attached to the rear side of the fabric using interfacing. The dashed box highlights the region where the electronics are placed. (bii) Top side of the PCB and the U-shaped carbon black conductive rubber sensor. The PCB shows the microcontroller unit (MCU), Bluetooth antenna, analogue to digital converter (ADC), secure digital (SD) cardholder and four placeholders to connect two electroresistive bands (ERBs).