Recently, Zephyr Sleep Technologies developed a portable device that avoids this requirement and can be used in a multi-night test in the home. Using a feedback controlled mandibular positioner (FCMP), the device measures and analyzes respiratory airflow and oxygen saturation and makes decisions in real-time about moving the mandible. The FCMP device was tested in a blinded, bi-phase clinical study in which participants with mild-to-severe sleep apnea (n=202) underwent two full-night studies in the home. Data from phase 1 were used to develop a predictive method, and data from phase 2 were used to prospectively test the accuracy of the predictive method. An efficacious mandibular position was also predicted, and each participant was treated with a custom oral appliance set to that position. Data from both phases were used to evaluate the feasibility of use of the device in the home.