~ By MORNSUN POWER
When designing electronic products, electromagnetic compatibility is a concern for all engineers, and product regulations often require conformity to strict EMC rules. This is particularly true for medical power supplies, whose performance and reliability can have a direct impact on a person’s health and safety.
For this reason, EMC testing is a critical part of a product’s design journey. In particular, testing of power supplies for medical devices requires a more rigorous approach than other products due to the type of environment they are placed into. Below we will review more details on the importance and the EMC requirements for medical power supplies.
Differences between the 3rd and 4th Edition of IEC 60601-1-2
High-risk electrical and electronic medical devices can be affected by electromagnetic interference, which can lead to potential malfunctioning, causing not only an inconvenience but – even more importantly – potential life-threatening situations. EMC testing helps to ensure that different electrical systems in a medical device can operate in the same environment without interfering with each other.
For medical power supplies, the IEC 60601-1-2 is the key standard for EMC for medical devices, which is often referred to in Europe as EN 60601-1-2 and in Canada as CSA C22.2 NO. 60601-1-2. This standard specifies the basic safety and essential performance of medical equipment in the presence of electromagnetic disturbances. While the original IEC 60601-1 standard has existed for 40 years, technology has evolved, and the environments where medical equipment is used have become more complex. This has led to the consideration of risks due to EMI, a collateral standard on EMC, and a new version of this standard (often referred to as the 4th edition) published in 2014.
This fourth edition constitutes a technical revision of the original standard, replacing the third edition of IEC 60601-1-2. One of the great changes is that the fourth edition has imposed stricter regulations on EMC test indicators and requirements for wireless technology in medical equipment. In addition, it guides the adjustments of immunity test levels when special considerations of mitigations are applicable, as well as guidance on risk management for basic safety and essential performance concerning electromagnetic disturbances. The following are the differences between IEC 60601-1-2’s third and fourth editions.
1. Define the Intended Use Environment
The fourth edition removes the classifications of “life support” and “non-life support” from the third edition, using three intended use immunity categories:
●Professional healthcare institutions such as hospitals, clinics, and other medical facilities
● Home healthcare environment
● Special environments, such as industrial areas and military areas
This revision aligns the IEC 60601-1-2 standard for the intended use environment with the corresponding provisions in other parallel and specific standards of the IEC 60601 series.
2. Introduce Risk Management Methods
The fourth edition standard applies the risk management principles proposed in edition 3.1 of IEC60601-1 to medical device safety issues.
According to the requirements of ISO14971 Medical Devices – Risk Management for the application of medical devices, manufacturers need to carry out an EMC risk assessment for each medical device.
In addition, the risk assessment must include the device’s specific operating conditions and experimental levels in the intended use environment.
3. Emphasize the Importance of Basic Performance and Safety
The fourth edition specifies compliance or non-compliance limits for specific emissions and immunity to ensure that basic safety and performance are not affected by the “reasonably foreseeable” maximum electromagnetic interference in the intended use environment.
In addition, the fourth edition of the standard has improved the electrostatic discharge (ESD) immunity test level, raising the ESD values for contact discharges from 6 to 8 kV and for air discharges from 8 to 15 kV. With the addition of testing for non-medical ITE equipment, the highest frequency for radiated immunity has risen from 2,500 to 2,700 MHz. The manufacturer must examine if a wireless link’s existence (or absence) impacts the equipment’s fundamental safety or performance when considering the EMC for a wireless device. A wireless device’s performance would suffer, and the device would compromise its intended functionality if it could not communicate.
As more and more devices are created for wireless use, the radio spectrum is getting more congested, which raises the probability of interference. For example, Bluetooth, Wi-Fi, ZigBee, and ANT+ all operate in the 2.4GHz ISM band and must coexist to ensure their function as intended.
Only when a smartphone is used as a component of a medical decision-making process to expedite a crucial evaluation process the loss of Wi-Fi could be a minor annoyance. Wi-Fi-based remote alarms to a nurse station could have a major impact if they were utilized to warn of a patient’s serious symptoms or an IV drug failure. It is possible to ensure that these vital operations continue to run well in an environment that is getting more congested by appropriate radio interference and immunity testing of medical devices.)It imposes stringent criteria on the immunity of wireless devices and proposes new requirements for particular port immunity tests and experimental levels. In addition, the fourth edition of IEC 60601-1-2 excludes I/O cables under three meters from immunity testing.
The best solution to keep on top of complex, evolving standards is to buy ready-qualified units. By selecting a pre-certified model, electrical engineers and medical device manufacturers can lessen the burden of ensuring compliance when it comes to medical device design. Equipment designers should choose medical-grade power supplies that adhere to IEC 60601-1 edition 3.1 and the 4th edition EMC standards because of the immunity requirements outlined by the 4th edition of the power supply design. Below we will present some of the EN60601-1-certified medical power supply solutions we at MORNSUN can offer.
MORNSUN’s Medical Power Supply Solutions
Safety is a common concern when designing electric circuits, but it is even more crucial when dealing with medical applications. MORNSUN can provide a wide range of reliable, cost-effective, high-performing power supplies for a wide range of applications.
In particular, MORNSUN’s medical power supplies meet the most stringent industry standards, including EN60601-1 and ANSI/AAMI ES60601-1 standards (2xMOPP). We put our 24 years of experience in this industry at the service of our customers by offering only quality power supplies that can be used even in harsh EMC environments.
Our medical power supplies feature a reinforced insulation design, 4000VAC high isolation, low leakage current, and low standby power consumption. All these characteristics make the MORNSUN power supply solutions suitable for a wide range of medical applications, including injection pumps, incubators, and more multi-functional medical devices.
If you would like to request more information or receive a sample, contact us here, and we will be more than glad to assist you at any time.
For more information, please visit www.mornsun-power.com