Pressure sensitive mats (PSM) have been widely used in research for measuring contact pressure. In the field of non-obtrusive patient monitoring, PSM have been used in a number of applications including finding the center of pressure for patients in different positions, monitoring heart and breathing rates of a patient laying on a bed, and monitoring and controlling the amount of time in which a patient remains in the same position, thus avoiding pressure ulcers. However, the cost of such devices remains high, and the deployment of PSMs in clinical practice is rare. This thesis presents the design of a new pressure sensitive mat technology using infrared proximity sensors and evaluates its performance relative to the state of the art. Results suggest that the novel PSM technology can be used in clinical settings for non-obtrusive patient monitoring, with advantages related to low cost, very low noise, and robust linearity of measurements.