A combined sensor adapted to measure at least one medical or clinical sign is provided. The combined sensor comprises a textile sensor configured so as to determine pressure applied to the combined sensor and an optical sensor. The optical sensor typically comprises at least one fibre- optic sensor (FOS) and may function as a photoplethysmography (PPG) sensor, optionally a reflectance mode photoplethysmography (PPG) sensor. The combined sensor is able to eliminate motion artefacts caused by movement of a subject wearing the sensor thereby facilitating long-term ambulatory monitoring of subjects.
