FitECG: Validating contact pressure prediction model for inclusive wearable health monitoring with sports bra: Sensors and Actuators A: Physical

The integration of wearable biosignal monitoring systems into daily healthcare has marked a significant advancement in medical care. Yet, the design of these devices often neglects the anatomical specificity of individual bodies, compromising both functionality and comfort. This oversight is particularly pronounced in research on the effective placement of 3-lead electrodes, selecting suitable materials, and customizing fit for women's diverse body shapes. To address this gap, this research introduces a novel design methodology for the development of advanced wearable health-monitoring garments, focusing on smart sports bras as a case study. This approach emphasizes contact pressure (CP) optimization for electrode placement, material selection, and sizing to enhance biosignal acquisition and comfort for the wearer. The study identifies optimal horizontal 3-lead electrode placements and configurations, the most effective across three female participants with diverse body mass indices (BMIs). Furthermore, the research employs a simulation-based contact pressure model (CP model) to precisely engineer desired pressure levels through strategic material selection and sizing adjustments. Guided by the CP model, screen-printed silver/silver chloride electrodes are incorporated into single jersey knit fabric, adjusted by a 20 % pattern size reduction for a tailored electrocardiogram (ECG) chest band in the optimized configuration. This achieves a signal-to-noise ratio (SNR) of 40.9 dB, closely comparable to the 41.9 dB obtained with traditional wet electrodes, while also exhibiting a higher QRS amplitude above 0.84 mV, benchmarked against 12-lead electrodes for reliability. The study further identifies an optimal contact pressure range of 0.56–1.24 kPa for ECG chest bands and a subjective pressure tolerance range of 0.93–1.8 kPa in the chest area across female subjects. Finally, the smart sports bra integration demonstrates clear QRS complexes and high biopotential amplitude, which are compatible with conventional wet electrodes, validating the effectiveness of the tailored design. These findings endorse a customized design methodology that considers anatomical variations, electrode placement, material choice, sizing, and wearer comfort with enhanced ECG signal acquisition in wearable health monitoring devices. © 2025