The live demonstration presents the innovative concept of a portable pen-device able to sense anaesthetic compounds over time for improved anaesthesiology practice. A custom Printed Circuit Board (PCB) manage in the event-based quasi-digital domain the sampling procedure, while a commercial Screen Printed Electrode (SPE) acts as an electrochemical sensor for measuring paracetamol (APAP) as benchmark drug. The system is controlled by an FPGA board implementing a custom logic and the results are displayed through a Matlab ® graphical user interface. The visitors can experience and confirm on real-time the reliability of the here presented portable pen for anaesthetic monitoring.