Non-intrusive monitoring of heart rate by an office chair instrumentated with optical fiber sensors

The continuous monitoring of vital signals is crucial in the diagnosis of cardiovascular diseases. With the focus on a continuous and non-intrusive acquisition of ballistocardiographic signal, a mobile seat instrumentalized with optical fiber sensors based on fiber Bragg gratings (FBGs) is proposed. The development of a six-sensor network will allow the study of the feasibility of their positioning to aim a greater efficiency. To calculate the heart rate, a time domain algorithm was developed based on the determination of the period between J-peaks of the ballistocardiograph. This model was tested on ten volunteers, in a sitting position, with data acquisitions carried out in periods of three minutes. To evaluate its performance, the results were compared with a wearable reference system, obtaining an accuracy greater than 95% for the majority of the participants, thus verifying that the developed system overcame the proposed objective.