Improved ppg measurement

Device for measuring a photoplethysmogram (PPG) of a tissue, the device comprising:a tissue contact surface (2) configured to be contacted by the tissue;a plurality of light emitter units (6) for emitting light in the tissue contact surface (2), wherein the plurality of light emitter units (6) comprise at least three light emitter units (6);a plurality of photodetectors (7) for detecting in the tissue contact surface (2) the light emitted by the light emitter units (6), wherein the plurality of photodetectors (7) comprise an at least three photodetectors (7);a signal unit for measuring PPG signals of different optical paths provided by all possible pairs of light emitter units (6) and photodetectors (7).