Improvements in a bed pre exit patient monitor to determine when a patient has moved to an edge of a bed prior to the patient leaving the bed by measuring load on a single wheel by slightly lifting the wheel with load sensing rods that measure the wheel load. A variety of different alarm signals are used signal to warn a care giver. The device is self-contained, self-secures and removes itself from a variety of different diameter wheels. The device can auto calibration when the wheel is initially lifted and also calibrate when a patient is resting on a bed. The monitoring establishes a threshold load without a patient and with a patient to allow the software to determine when the on an edge of a bed and also when a patient has completely left the bed. Software filtering rejects patient movement to prevent false alarms.