Problem:     A major supplier of hospital beds needed an embedded controller to provide heating, zoned mattress pressure, and patient orientation. The system needed to be inexpensive, highly reliable and patient safe. Since the bed was used to treat burn and other critical patients, the control systems needed to be free from any system related problem that might endanger a patient.

Solution:     The system was broken into two separate subsystems: a user interface module that was mounted on the bed's foot rail, and a main control unit that was mounted under the bed. These units communicate between each other across an RS-485 link. The main control unit performs all of the bed control functions. These functions include, head/foot position, blower head pressure, individual zone pressures, and blower air temperature. The user interface module provides the nurse/operator with a keypad and status display. This allows the individual patient parameters (height. weight) to be input so that the beds operating characteristics may be calculated for optimum therapeutic value.

Because of the therapeutic nature of the bed, it underwent not only the normal regulatory approvals (UL, CE) but also was subjected to the FDA approval cycle which not only considers the final product but also the rigor and quality of the development process.