PHOTOPLETHYSMOGRAPHY SENSOR APPARATUS AND METHOD Russian patent published in 2018 - IPC A61B5/24 A61B5/295 

FIELD: medicine.

SUBSTANCE: group of inventions relates to medicine, specifically the measurement of a three-dimensional organ by optical means. Apparatus enables to perform a method of operating a photoplethysmography sensor that comprises the steps of generating a first light signal by a light source unit. Second light signal is observed by a photodetector unit, wherein said second light signal is indicative of an absorption of said first light signal in the object. In response to observing said second light signal, a photodetector output signal is received by an ambient light compensating feedback loop comprising a track-and-hold unit and an amplifying unit. Output signal of the track-and-hold unit is compared to reference signal (V_R), wherein said output signal of said track-and-hold unit is based on said photodetector output signal. Compensation current is supplied by the amplifying unit to the track-and-hold unit based on said comparison. Computer readable memory stores computer program code means for causing the photoplethysmography sensor apparatus to perform steps of the operating method of the photoplethysmography sensor apparatus, when the computer program is run on a computer controlling the photoplethysmography sensor apparatus.

EFFECT: group of inventions allows to measure a photoplethmographic signal without interference from ambient light.

14 cl, 4 dwg