People in medical settings can be quite weak, and if there is any current leakage, it can adversely affect their health. While the same amount of leakage would likely not cause any harm to a healthy person using a device in industrial settings, it can cause real damage in medical applications, so making low leakage power supplies is very important. IEC 60601 standards establish medical power supply leakage requirements to ensure patients are protected from currents that might harm their health.

There are many of the devices using power supplies, such as patient monitoring devices, use low-level signals to work. This makes the equipment more susceptible to electromagnetic interference (EMI). Electromagnetic compatibility (EMC) is one factor of IEC 60601 standards. The power supplies with EMI filters have capacitors that permit a certain amount of leakage current, and the more effective the EMI filter, the more leakage.

None of commercial power supplies contact directly with the human body, so their design is less concerned with safety in this regard. Medical power supplies equip extra insulation in more aspects, to keep both patients and device operators protected from electrical shock.

Besides the IEC60601-1 standard, there is other medical equipment standards must be considered, such as IEC60601-1-2, which outlines the requirements for electromagnetic compatibility. There are a large number of different concurrent standards related to specific medical applications and hazards, and it is critical to determine which standards apply to your application and how they affect your power supply selection. Because medical devices almost always operate in relatively close proximity, their electromagnetic energy must not affect other nearby devices.

The risks are much higher for medical equipment. If a power supply fails during a surgery, life is at risk. Medical equipment must have the utmost reliability to be a good instrument. Manufacturing devices for medical power supplies should be by ISO certified to ensure each product is built to be most reliable.

In order to ensure compliance with UL/EN60601-1 safety standards, equipment with a protective earth ground requires fusing on the line and neutral wires. This can be accomplished through the power supply or externally within the system.