The Aeon Phocus is a magnetic control device for use in what are known as hybrid operating theatres. With the help of imaging techniques it forms the basis for minimally invasive operations on the inner organs, especially in connection with cardiac surgery. The ultra-precise, computer-supported control of the surgical instruments in the body of the patient reduces the time of treatment significantly and minimises exposure to X-rays. In formal, ergonomic and functional terms, the design of the treatment unit has been based – within the bounds of technical possibility – on the needs of the patient, who remains conscious during the operation. So in spite of its impressive size, the system is designed to inspire confidence and at the same time gives a highly professional impression. The development of the peripheral components, like the 3D surgical joystick, was based on close cooperation with doctors. The joystick forms a central interface between the operator and the treatment unit.