A device for monitoring occupants of seats in a passenger compartment of a vehicle comprises a heat sink divided into a plurality of sections. Each of the sections comprises a base and cooling fins. The bases extend along a common axis and define a central niche therebetween. Structured light sources are attached to the sections. The structured light sources have an optical element for forming a structured light pattern. The structured light sources are oriented along the common axis and at oblique angles to the central niche, such that the structured light patterns, in combination, are directed such that they would cover occupants of seats of the vehicle. A camera is attached to the niche and configured to capture image patterns resulting from distortion of the plurality of structured light patterns by the occupants of the seats.