Case study-MRI facility in hospital environment

Hospitals are equipped with the latest medical electronics to diagnose and perform complicated surgery. To fulfill the above, hospitals are equipped with various general utilities like air conditioning plants, DG sets, elevators, electrical power tools for maintenance, communication sets etc. These facilities are prone to create electromagnetic interference (EMI) which may affect the operation of sophisticated diagnostic tools. In addition, systems like MRI and X-rays can emit harmful EM and X-rays to inflict severe effects on an operator who performs duties continuously near the system. To install such facilities in hospital electromagnetic environments, a chamber with a good shielding capability with an attenuation of 80 dB or more is essential for the operation of the system. This paper outlines the need for such a shielded chamber for an MRI facility in the hospital EM environment and tests experience encountered while testing for the shielding effectiveness of the chamber. The test setup used in the measurement, problems observed and necessary corrective measures are discussed.