Which medical devices have strong magnetic effect?

Magnets are harmless to human body. There is nuclear magnetism in medical equipment, and the high magnetic field is more than 3T, which is harmless to human body. It is recognized that nuclear magnetic resonance is the safest of all medical equipment in radiology. In other words, people are not afraid of magnetic fields, but even more afraid of rays. Strong magnetic field does have some negative effects on human body, but the content of magnets in a magnet is limited, so it is impossible to have any impact on human body. Some people claim that magnets provide magnetic force to change physiological tissues, and even think that every cell has positive and negative poles, while others claim that magnets can improve blood circulation. In fact, there is no evidence that there is any interaction between human tissues and cells or between blood and magnetic fields. Iron ions in red blood cells are not ferromagnetic or even diamagnetic, and will not be attracted by magnetic fields. Therefore, it is neither good nor bad to always carry a magnet with you.