A Plethysmographic Sensor Based on FBG Embedded in a Soft Silicone Patch

Cardiovascular diseases are the main cause of disability and global death, and their rapid spread is a sign of strong concern for the scientific community. In this scenario, devices, able to continuously and non-invasively monitor heart parameters could be very useful for timely diagnosis, essential for the prevention of premature deaths. Recently, among the most popular wearable devices, sensors based on Fiber Bragg Grating (FBG) play an important role. FBG, in fact, allows to monitor different physiological parameters such as heart rate, body temperature, blood pressure and respiratory rate. The continuous monitoring of these parameters is of extreme importance from the clinical point of view, as it allows detecting physiological warning signals in a timely manner, which in some cases could be fatal. This is due to the many advantages provided by FBG, in fact, in addition to being minimally invasive, they are immune to electromagnetic interference, biocompatible, highly sensitive and allow for the multiplexing. In this work, we propose, therefore, a new sensor based on FBG for plethysmography of peripheral arteries. The proposed sensor is embedded in a soft silicone matrix capable of increasing wearability and sensitivity, also allowing to protect the sensor from external stress. The preliminary results show that the obtained sensor can record continuously and non-invasively the plethysmographic signal with a clear distinction of the systolic and diastolic peaks, in whose waveform important cardiovascular information is contained.