Medical systems are combinations of devices, medical with other medical or nonmedical devices that are required to achieve the intended medical purpose. The development of magnetically controlled medical devices (e.g., catheters) and anchored intracorporal surgical instruments, retractors, and cameras have helped advance surgical practice. Medical devices may expose patients even to much higher levels provided their benefit outweighs potential risks. Medical devices may also be incorporated, and they become Electromagnetic fields sources in close contact to tissue and organs such as transmitters of electronic implants for data exchange, permanent magnets for navigation, or magnetic nanoparticles for tracking, targeting, heating, and magnetic resonance imaging contrast enhancement. Diathermy and hyperthermia applications are restricted to industrial, scientific, and medical frequencies and generate intended exposures of the patient well limits but may also cause relevant exposures of medical staff and unintended exposure of sensitive regions within the patient.