Flexible Multimodal Tactile Sensor for Contactless Vital Sign Monitoring

We present a contactless vital sign monitoring system utilizing a multimodal tactile sensor for accurate and unobtrusive heart rate and respiration measurement. The proposed system integrates a flexible piezoelectric-piezoresistive sensor beneath a mattress to capture ballistocardiography (BCG) signals with high sensitivity. A continuous wavelet transformation (CWT)-based signal processing pipeline is employed to enhance heartbeat detection and reduce the influence of respiratory-induced amplitude variations. Validation against electrocardiography (ECG) reference data demonstrates mean heart rate deviations below 0.3 bpm during stable conditions. Compared to existing wearables and radar-based solutions, this system offers a cost-effective, minimally intrusive alternative for home-based sleep monitoring. Future work will focus on motion artifact reduction and expanded validation in diverse sleep environments.