An apnea monitor and system for treatment includes a detector in a fixed console that projects a detection beam at a sleep surface. The detection beam is reflected off a patient on the surface and return light is analyzed to develop a signal which varies with external motion of the patient's upper body. The motion signals are then fed to a pattern recognizer which identifies breath signals and analyzes them to detect cessation or excessive pauses in breathing, and trigger an alarm or intervention to restore breathing regularity. The monitor includes a laser for generating radiation. The radiation is reflected from the patient and is directed onto a detector. The detector produces output signals corresponding to the impinging reflected light, which are processed by a control element to determine the change of movement, e.g., the breathing rate, of the patient.