The medical apparatus for an operating room, especially a heart-lung machine, includes an electrically-powered device for producing data and performing operation steps and a data monitoring and analysis device which is divided into a data monitoring unit and a data analysis unit which is separate from the data monitoring unit and can be located outside the operating room in which the electrically-powered device and monitoring unit are located. The data monitoring unit (14) includes a portable and removable memory card (20). Both the data monitoring unit (14) and the data analysis unit (15) have a receiving slot device in which the memory card can be inserted and held so that data can be transferred between the units (14) and (15) by carrying the memory card from one unit to the other. Thus the data analysis unit (15) can be used with many different types of electrically-powered devices used in the operating room and can be easily located outside of the operating room. Also additional space is freed in the operating room by the arrangement according to the invention.