Design of insusceptibility detection and processing system of the ballistocardiogram signal based on CPLD

Balistocardiogram(BCG) is a method to record body vibrations caused by heart activity, which can be detected at the spine axis of body by sensitive force sensor. The raw BCG signal is so weak and often involves a lot of noise that some device should be designed to extract a clean BCG signal. According to the characteristics of BCG signal, a new insusceptibility detection and processing system of the BCG signal based on CPLD (Complex Programmable Logic Device) is presented in this paper, which can acquire BCG signal from resistance strain weighing sensors mounted on the chair designed to look like a normal home chair without attaching any electrodes to the subject. The system is composed of two modules, signal processing module and signal acquisition module, which can obtain clean BCG signal synchronously with cardiac cycles for long time in practice, shows that the design is reasonable.