**Abstract**

This chapter presents an inclusion of 3D optical (RGB-D) sensors into medical clinical practice, as an alternative to the conventional imaging and diagnostic methods, which are expensive in many aspects. It focuses on obstructive sleep apnea, the respiratory syndrome that occurs in an increasing proportion of the population, including children. We introduce the novel application, a response to the request for an alternative pre-diagnostic method for obstructive sleep apnea in the region of Slovakia. The main objective of the proposed system is to obtain an extensive dataset of scans (head and face) from various views and add detailed information about patient. The application consists of the 3D craniofacial scanning system using multiple depth camera sensors. Several technologies are presented with the proposed methodology for their comprehensive comparison based on depth sensing and evaluation of their suitability for parallel multi-view scanning (mutual interference, noise parameters). The application also includes the assistance algorithm guaranteeing the patient's head positioning, graphical interface for scanning management, and standardized EU medical sleep questionnaire. Compared to polysomnography, which is the golden standard for this diagnostics, the needed data acquisition time is reduced significantly, the same with the price and accessibility.

**Keywords:** RGB-D sensors, multi-sensor system, 3D imaging, medical applications, obstructive sleep apnea, time of flight sensor, structured light sensor, stereo vision
