Oxygen is indispensable for cellular activities and is important to maintain it at the proper level which is different for each human organ. Organ-on-a-chip systems are designed to simulate human tissue and organs. Their response are monitored by sensors, so that data can be measured in-situ and analyzed continuously in real-time. In the field of drug research, most of the focus is in simulation and prediction of human organs response to external stress and requests due to drug delivery. Animal models are often not enough similar to human beings in order to obtain an accurate identification of the side effect of drugs in human.