BioRhythm is an interactive bio-feedback installation controlled by the cardiovascular system. Data from a photoplethysmograph (PPG) sensor controls sonification and visualization parameters in real-time. Biological signals areobtained using the techniques of Resonance Theory in Hemodynamics and mapped to audiovisual cues via the Five Element Philosophy. The result is a new media interface utilizing sound synthesis and spatialization with advanced graphics rendering. BioRhythm serves as an artistic explorationof the harmonic spectra of pulse waves.