The heart is a robust and strong organ. It works non-stop everyday of our lives and sits at the core of our being. But research into the heart and the diseases that affect its function requires a complex and delicate experimental system. This heart perfusion system is being prepared to support a mouse heart. The balloon at the front will be deflated and inserted into the left ventricle where it can measure how strongly and quickly the heart is beating. The mouse heart is about the size of an adult’s baby fingernail, so preparing the system requires intense concentration and excellent fine motor skills. Each beat of the heart generates tiny forces that are detected by a very small sensor, and this information is fed into a computer. We can analyze the information produced by our system to determine why the heart is failing and whether our treatments are able to improve the function of this key organ.