A real-time readout system enabling vital function monitoring with textile-integrated sensors

Abstract Textile integrated electronics have emerged as a promising avenue for the development of innovative biosensors for vital function monitoring. This work presents an approach to integrate electronics and sensors by means of additive manufacturing, in particular inkjet printing and dispensing, for the direct fabrication of electronic board layouts onto textiles as substrates. Three sensor modules have been fabricated; a heart rate sensor, a breath rate sensor and an accelerometer. The process starts with printing dielectric islands, the insulating layer, followed by the layout using conductive ink. Finally, the integrated circuits are assembled using anisotropic conductive tape which facilitates the seamless integration and ensures robust electrical connections and mechanical stability. Lastly, an advanced readout and data logging scheme based on the Eclipse ThreadX real-time Operating System (RTOS) has been developed. The read-out electronics are based on the STM32L4+ microcontroller unit family. Its ultra-low power modes and computational power allow complex data processing which enables a new generation of wearable devices. The Eclipse ThreadX is an open source RTOS with considerable advantages over its counterparts, namely, its performance, determinism, code quality and functional safety. We present an advanced read-out software architecture for logging data from the three sensor modules. The integration of these cutting-edge components enhances computational capabilities but also ensures real-time data processing and communication for the proposed vital function monitoring system, opening new possibilities for wearable applications in healthcare.