The Wireless controller for a hospital bed project targets paralyzed quadriplegics patients who are bed-ridden and cannot push buttons on a hand pendant that adjust their electrically driven bed to perform the following the functions: head-up, head-down, foot-up, foot-down, bed-raise, bed-lower. Designing, developing and implementing a prototype of a wireless con- troller for an electrically driven bed is the objective of this project because this would make installation and operation much simpler. Presently, the EZRA II QUAD-CONTROL is a system that enables severely disabled people to control di?erent devices like home appliances by using their breath. The EZRA II QUAD-CONTROL system currently uses a wired in- terface between the breath sensing and the device to be controlled and the system will have a DB9 connector on it to interface with an electric bed. There are certain constraints during the course of working on this project. Such constraints include keeping the cost within a few hundred dollars or keeping cost low, meeting safety issues for the user.

The requirements that the design must meet are to create a wireless receiving device that works to provide communication between the existing EZRA II system and a hospital bed. The major sub-systems of the receiver will involve analog circuitry to interface the In- vacare hospital bed to the desired micro-controller logic levels; a micro-controller based processing unit that will convert the digital signals from the EZRA II via a wireless commu- nication protocol that will communicate with the wireless transmission subsystem. The receiving unit will also require the ability to have the manual bed control pendant operating in parallel such that any assistant to the user may also operate the bed. The timing requirements from initial user input to bed response must not result in a delay of greater than 0.5 seconds as this would inhibit the user from accurately operating the hospital bed. Important factors that must be taken in to consideration in the design process are that the costs for manufacture must be kept to an absolute minimum while still providing all of the desired features in a reliable fashion, and that the device must also be simple and intuitive to install and maintain for the end user and his or her assistants.