New developments in real-time computing and body-worn sensor technology allow us to explore not just visible gestures using inertial sensors, but also invisible changes in an individual’s physiological state using bio-sensors (Kim & André 2008). This creates an opportunity for a more intimate interaction between the observer and technology-based art (Gonsalves 2008). We present a technical overview of the AffecTech system; a bio-signal based interactive audiovisual installation commissioned as part of the pre-ISEA symposium in November 2008. Observers were invited to sit on one of 2 sensor-enhanced chairs (Coghlan & Knapp 2008), which transmitted physiological data about the occupant to a central control system. This data was used to control and modulate interactive visuals, live video feeds and a surround sound score, with events and interactions dependent on the observers’ affective/emotional state and the disparity or similarity between the bio-signals of the chairs occupants. This technical overview is followed by an examination of the outcomes of the project, from both the artistic and technical viewpoints, with recommendations for modification in future implementations.