A wheelchair alarm system and method for preventing falls for patients at risk by recognizing the gesture of a patient attempting to stand. The wheelchair alarm system uses an array of proximity sensors and pressure sensors to create a map of the patient's sitting position, and then uses gesture recognition algorithms to determine when a patient is attempting to stand up. The wheelchair alarm system responds with light and voice alarms that can encourage the patient to remain seated and/or to make use of the system's integrated nurse-call function. The wheelchair alarm system can be seamlessly integrated into existing hospital WiFi networks, sending messages to the nurse call system as well as providing the patient's location.