Easily usable human-device interface for microwave therapy apparatus

In this paper we investigate the possibility of using a large dot matrix LCD (Liquid Crystal Display) as the essential part of a low cost, user friendly human-device interface which is driving a microwave diathermy medical apparatus. The human-device interface uses only four buttons with multiple functionalities, an analog encoder and the said dot matrix LCD. The interface is a part of the embedded system that drives the entire unit, as a stand alone hardware and complex firmware program. This interface can handle the medical treatment parameters in an ergonomic and simple way. The human-device interface has been designed in agreement with the EN60601-1 and EN60601-1-4 requirements using “the simple to complex” writing and validation algorithm. The interface has been manufactured as prototype and tested on our own proprietary microwave hyperthermia and diathermy device and proves to be intuitive and easy to use. The human-device interface firmware is portable to other scientific apparatus as well; however, a reconfiguration of all displayed information is necessary, depending on the purpose of the served equipment. Compared with a colour graphic LCD equipped with touch screen, the interface presented here is definitely less expensive, can be implemented faster and uses less hardware resources.