FDA is supplementing the guidance with “certain biologics license applications (BLA) and investigational new drugs (IND)” in the introduction and is mentioning in the scope that the “guidance applies to medical devices, including in vitro diagnostic products, and accessories that

  • are electrically powered or

  • have functions or sensors that are implemented using electrical or electronic circuitry.

Since EMC requirements now also apply to IVD products, the FDA give IVD manufacturers a year from now to include the information in the submission. For all other device types, the deadline is 6th of August 2022. Manufacturers willing to include the information in the submission before that date (IVD: 6th of June 2023) can do so. The FDA will review the information.

The definition of EMC is unchanged with one exception: “EMC is defined as the ability of a device to function safely and effectively in its intended electromagnetic environment, including immunity to electromagnetic disturbance (interference), without introducing excessive electromagnetic disturbances (emissions) that might interfere with other devices equipment.” With the use of “equipment” FDA wanted to include both medical and non-medical devices that need to be protected by emission limits.

When talking about the use of recognized consensus standards in the context of EMC, the new guidance includes as well (next to the IEC 60601-series) the IEC 80601-series (both “apply to medical devices and systems that directly apply or transfer energy to the patient”) and the IEC 61010-1 standard that applies to laboratory equipment. The up to 100 particular standards as well as standards for active implantable devices that include information on EMC are mentioned as well in the article (in a general manner compared to the direct mentioning of ISO 14708 and ISO 14177 in the old version).

The following information should be included in the submission to alleviate the process.

EMC Information for Premarket Submissions

The FDA requires to have the information in subsections A-K labelled with the section’s headings in the same order as in the guidance document. Unstudied, any reports or test reports summaries should be referenced in the EMC section of the submission if they contain any of the recommended information.

The items A-K have been more or less already integrated in the 2016 version of the EMC guidance document, but with no content behind.

A. EMC-Related Device Characteristics and Intended Use Environments

Next to (another?) device description and the description of the power supply, the FDA wants to know in which environment(s) the device is used. The FDA defines the following environments:

Excerpt from Annex A of guidance document

Furthermore, any wireless technology and any intentional RF emitters in the medical device should be described.

B. Assessment of Medical Device Risks

A summary of risks associated with malfunction, disruption, or degradation of the performance of the device due to EMC disturbances should be listed and the harm should be categorized in:

  • Medical device-related deaths and serious injuries

  • Medical device-related non-serious adverse events

  • Medical device-related events without reported or potential harm

These should as well be considered when determining the pass/fail criteria and in addressing EMI caused by common EM emitters. The IEC 60601-series already uses the risk analysis to determine Essential Performance as basis for pass/fail criteria.

C. Consensus standard

A summary of all voluntary consensus standards used to evaluate EMC should be included in the submission.

The FDA recommends performing EMC tests with the methods described in FDA-recognized consensus standards. Non-recognized standards can be used with relevant justification. If no such standard exits for a particular device, the manufacturer should use one that is most similar. Special attention must be paid to the environment defined under chapter A. The standard might not cover the environment.

FDA categorizes the FDA-recognized consensus standards into:

  1. Non-implantable Medical Devices

  • Consideration of the scope of the consensus standard is critical, for example IEC 60601-series is only limited to medical device safety, but not to effectiveness

  • Particular standards can augment or supersede specifications in IEC 60601-1-2, but not all of them are already recognized (acceptability of use should be ensured)

  • Most lab equipment and IVDS are outside the scope of IEC 60601-1-2. IEC 613267-1:2020 and IEC 61326-2-6:2020 are partially recognized and their test methods are recommended to be used. BUT, acceptance criteria specific to the device´s functions and intended use and test levels specified in IEC 60601-1-2 should be used (or reasonably foreseeable maximum levels should be determined).

  1. Active Implantable Medical Devices (AIMDS)

  • AIMDS are not in the scope of the IEC 60601-1-2, but should be used for the non-implantable subsystems.

  • Often ISO 14117 and ISO 14708 are used to address EMC for AIMDS.

  1. Special environments

When the device is used in a specific environment (e.g. aircraft or helicopter) immunity testing to RTCA DO-160 is recommended.

As some AIMD consensus standards do not specify EMC test parameters for MRI environment, it is recommended to use those described in ISO/TS 10974.

D. Essential performance and Immunity Pass/Fail Criteria

  1. Essential Performance

The Essential Performance should be determined by:

  • identifying the performance of the clinical functions;

  • specifying performance limits for fully functional performance versus loss or degradation of the identified performance;

  • evaluating the risk from the loss, disruption, deviation, degradation, or over-delivery of the identified performance.

If the resulting risk is determined to be unacceptable, then the identified performance is Essential Performance.

A medical device can as have no Essential Performance. The manufacturer then should add a scientific justification and risk analysis. Anyhow, the manufacturer should define immunity pass/fail criteria to demonstrate that the device is safe and performs as intended.

  1. Immunity Pass/Fail Criteria

Immunity pass/fail criteria should be

  • quantitive;

  • specific to the medical device and its functions;

  • observable.

It should be specified how the criteria were derived, quantified, and monitored. It should also be included how the criteria demonstrate that the device remains safe and performs as intended.

The criteria can be different for transient EM phenomena like ESD and continuous phenomena.

General pass/fail criteria that are listed in some standards are not acceptable, but should be specific to the device and its functions. The guidance gives the example of pass/fail criteria for adult patients’ ventilator, which would be different from those for neonatal patients (different physiological characteristic).

As already mentioned, the scope of the IEC 60601 standards is limited to safety. Therefore, FDA recommends using IEC TR 60601-4-2 to assess the immunity of the performance.

E. Medical Device Configuration and Functions Tested

It is important to deliver a detailed description of the medical device under test, including configuration, functions, modes and settings that were tested. Be careful that your test lab is really writing all the necessary information in the test report. It is advisable to present a lot of pictures in the report.

Obviously, FDA recommends doing the testing on the final finished device. If not, justify why.

FDA recommends consideration of the following to have the appropriate configuration tested:

  • include all (non-)medical (non-medical: mobile phones, tablets, etc.)

    • accessories;

    • components;

    • subsystems.

Everything not included should (unstudied) be justified.

  • Apply all applicable EMC-related consensus standards for the whole system

  • If testing is performed on a sub-system basis, each subsystem that is not included in the test should be simulated, including any potential third-party medical devices or connections. This is a little worrying, since there can be many “potential third-party medical devices” in some cases.

  • Testing should be done in battery power mode and in mains power mode

  • Smart batteries should be tested separately for immunity

  • Patient simulators should be used where specified and necessary

  • If wireless technology is used and needed to achieve the intended use, it should be “on”

  • Monitoring methods should as well be described

F. Results of EMC Testing

A summary of EMC testing should be included:

  • Name and location of test facility and date of testing

  • Results for each emission test incl. pass/fail criteria expressed in terms of limits

  • Results for each immunity test incl. any degradation

G. Allowances

All allowances that have been used and a justification should be described.

Allowances are specifications within a consensus standard that permit well-defined or conditional variations, or exemptions from, certain requirements of the standard.

H. Deviations

All deviations along with a justification should be described.

A deviation is when a requirement is intentionally not satisfied, or testing is performed in an alternative way.

I. Modifications

The following should be included in the submission:

  • A description of all changes or modifications that were made in order to pass the testing

  • A statement whether provided EMC test results occurred before or after modification

  • A statement that the modifications will be incorporated into the final finished medical device prior to marketing

  • An analysis as to whether these modifications might impact other aspects of the medical device safety or performance

J. Common Electromagnetic (EM) Emitters

The use environment and emitters commonly found in those should be well-known by the manufacturer. EM emitters that are NOT adequately addressed by FDA-recognized standards are

  • RFID readers;

  • electronic security systems (metal detectors, electronic surveillance);

  • near-field communications (NFC) systems;

  • wireless power transfer (WPT);

  • Cellular 5G;

  • unique medical emitters like electrocautery,

  • MRI;

  • electrosurgical units;

  • diathermy equipment.

EM disturbance caused by those emitters should be considered during the risk management process.

For “Medical device-related events without reported or potential harm” labelling can be used for mentioning the potential for EMI from emitters expected nearby. For “Medical device-related deaths and serious injuries” or “Medical device-related non-serious adverse events” it is recommended to:

  • test according to FDA-recognized standards like AIM 7351731 or IEC 60601-1-2:2020 Clause 8.11 for RFID emitters;

  • use equivalent EMC test methods with justification;

  • if no consensus-standard exists, specific immunity testing should be performed;

  • labelling to specific risks to patients and operators.

K. Labelling

Medical device labelling should include:

  • The environments of use for which the medical device is suitable to be used/exposed (see A).

  • Accessories and other equipment with which the device has been determined to be compatible.

  • The medical device’s functions/performance and a description of what the operator can expect if the functions/performance are lost or degraded due to EM disturbances. For 60601-4-2, these are the functions/performance needed to demonstrate the medical device performs as intended, and for all other 60601 standards this is Basic Safety and Essential Performance.

  • The compliance level for each emission and immunity test.

  • The use of any deviations from, or allowances specified by, the referenced standards.

  • Precautions regarding sources of EM energy that:

    • emit levels of EM energy that exceed the immunity test levels of the referenced EMC standards used, or

    • have other emission characteristics to which the medical device has not been tested for immunity.

  • Specifications of the wireless communication for medical devices with RF wireless functions.

  • Any maintenance instructions needed to ensure that the medical device remains safe and performs as intended with regard to EM disturbances throughout the expected service life.

  • Markings affixed to the medical device and warnings for certain types of known EM environments, such as in or near an MRI scanner. Medical devices intended for use in the MR environment that have not been shown to be MR Safe or MR Conditional should be marked with the ASTM F2503 symbol for MR Unsafe. (See ASTM F2503- 13 Standard Practice for Marking Medical Devices and Other Items for Safety in the Magnetic Resonance Environment.)

  • The FCC term “harmful interference” has a meaning that is different from that of the term “harm” as used in medical device risk management and ANSI/AAMI/ISO 14971 Medical devices – Application of risk management to medical devices. To avoid confusion and concern regarding the FCC term, we recommend adding the note specified below after the FCC warning in the labelling:

    • NOTE: “Harmful interference” is defined in 47 CFR §2.122 by the FCC as follows: Interference which endangers the functioning of a radionavigation service or of other safety services or seriously degrades, obstructs, or repeatedly interrupts a radio communication service operating in accordance with the [ITU] Radio Regulations.”

It is recommended to make a separate EMC guide, otherwise the IFU will get bigger and bigger. The IEC 60601-1-2 already define content for the IFU

EMC Information to Support Investigational Device Exemption (IDE) or Investigational New Drug (IND) Submissions

Favourably all information from A-K mentioned above should be included.

But other appropriate EMC mitigations can be used to support a favourable benefit/risk determination, i.e. in the IDE or IND submission, a description of alternative mitigations, such as ad-hoc testing, and a list of labelling mitigations should be included. Potential risks should be described including a justification how each risk will be mitigated.

Author: Frederike Brühschwein-Mandic