An interpretive software program intended to be installed on an off-the-shelf smartphone/tablet for use by a patient/layperson in the home to record and analyse patient physiological data collected during sleep using a home-use device (e.g., CPAP/BPAP unit therapy analyser, microphone), for self-analysis of sleep/sleep therapy. It may be used to assist a patient to refine their sleep therapy, or to better understand their sleep behaviour, and might in addition be intended to assist a healthcare professional to treat/understand a sleep disorder.