Combined optical-electromechanical wearable sensors for cardiac health monitoring.

Significance: Integrating multiple biosensors improves the sensitivity and precision of physiological measurements in healthcare monitoring. By combining sensors that target different physiological parameters, a more comprehensive assessment of a subject's health can be achieved.

Aim: We evaluate the performance of two biosensors for extracting cardiac parameters: a textile-based strain sensor for measuring respiratory rate and an optical sensor for measuring heart rate, ${\mathrm{SpO}}_2$ , and respiratory rate. The objective is to determine optimal placement conditions for each sensor and assess their feasibility for integration into a single wearable system.

Approach: Two experimental setups were tested. In the first, the strain sensor was placed on the subject's shirt, while the optical sensor was positioned on the external wrist. In the second, both sensors were placed on the chest, under the shirt. The accuracy and performance of each sensor were analyzed in both configurations.

Results: The optical sensor demonstrated improved accuracy when placed on the chest compared to the wrist, whereas the strain sensor provided similar results for both configurations.

Conclusions: We demonstrate that sensor placement significantly affects measurement quality, emphasizing the importance of optimizing placement when integrating multiple biosensors. Future work will focus on developing a unified wearable system that leverages the strengths of both sensors for comprehensive physiological monitoring.