Evaluation of radio based, optical and barometric localization for indoor altitude estimation in medical applications

The advances of electronics provide options for improved monitoring of patients in clinical environment. Medical applications like blood pressure monitoring require precise and wireless altitude measurement in indoor environment. An error of more than a few centimeters bears a risk of mistreatment of patients. Furthermore, user requirements like small form factor, usability and robust operation are important in the medical field. Existing evaluations of indoor positioning systems focus on accuracy analysis of x- and y-coordinates, not on the z-coordinate (altitude). In this paper, we define evaluation criteria for altitude estimation in medical applications. We compare an Ultra-Wide-Band indoor positioning system, an optical Microsoft Kinect camera system and our own development of a wireless barometric sensor against these criteria. We present a comparative measurement setup, results and a final evaluation of the three systems in an indoor environment.