The revised International Medical Safety EMC Standard, IEC 60601-1-2 Edition 4, which takes effect in Europe, USA (new applications), and Canada, sets out the basic and essential performance for medical equipment regarding emissions and immunity to electromagnetic disturbances.
Edition 4 responds to the increasing number of electrical devices being used directly by patients in the home healthcare environment, outside of hospitals or professional healthcare facilities. It shifts classification of the EMC requirements from relating to the usage of a medical electrical device (life supporting or non-life supporting) to the intended user and environment of a medical electrical device (home healthcare, hospital, special environment).
Immunity requirements have been revised to ensure that the devices can be operated safely in the home environment which commonly feature a greater number of mobile transmitters located close to medical electrical devices. Electrical discharge immunity (IEC 61000-4-2), radiated RF field immunity (IEC 61000-4-3) and radiated magnetic field immunity (IEC 61000-4-8) requirements now have much higher requirements.
In addition, requirements for conducted RF immunity take into account ISM and radio amateur frequencies. The radiated RF field immunity testing has been extended to cover a near field immunity testing which simulates the close proximity of external transmitters. For the devices to be installed in a vehicle a new EMC requirement of conducted transients (ISO 7632) has been introduced.
Emission requirements remain much the same - for information and multimedia equipment a product standard of CISPR 32 may be used and a new test for the patient cables emissions has been introduced as an informative annex.
The revised standard requires manufacturers to take EMC into account in the risk management process and, in the risk management file, identify all risks affecting the basic safety of a medical electrical device. The practical outcome of a risk management file is a detailed EMC test plan which the manufacturer, ideally involving the EMC testing laboratory, will need to prepare prior to testing.
The main elements in an EMC test plan are:
- Essential performances of the equipment (affecting basic safety)
- Detailed PASS / FAIL criteria for each essential performance
- The method of monitoring each essential performance while testing
- Test setups of the equipment under test (accessories, cables, operating modes etc.)
Tuomo Hietanen, project manager for SGS said, “The concept of risk management is something new to many manufacturers and to many EMC testing laboratories and, although manufacturers still have a few months to prepare for the new EMC requirements, we’d urge them not to leave it too late.”
“SGS operates the biggest, fully equipped and most effective network of EMC testing facilities in the world. Our personnel are fully trained and ready to help customers through the new procedures and requirements of the revised publication and support the manufacturer in testing and confirming the compliance of all medical electrical equipment to the new EMC requirements,” added Hietanen.