Design of a Wireless, Passive, Single-Use Emergency Call System

In order to improve patient access to nurses during emergencies, a wireless wrist-mounted call button system was developed. The goal of this project was to create a simple, easy-to-use system that features a completely passive, wireless call button. Three major problems in existing systems — inability for patients to locate or reach the button, unnecessary user interface complexity, and the introduction of a potential vector for hospital-contracted illness — were addressed in the design. The wireless nature of the device ensures that it is always near the patient. A single-button interface considerably simplifies its use in comparison to multi-button systems, eliminating the possibility of incorrect button presses. Finally, the proposed call button uses inexpensive technologies and can be manufactured for such a low cost that it can be offered as a single-use device, eliminating the possibility of patient-to-patient disease transmission. Using radio-frequency identification (RFID) technology, patients are able to call for hospital staff from any location in the hospital that is covered by readers. The call button uses a passive RFID tag that can be turned on or off by a mechanical switch. A second tag is used to notify the system when a patient is out of range. The design was prototyped and tested, and future improvements are suggested.