Medical devices are one area where EMC covers both safety and reliability, and thus the system design guidelines require multiple approaches not seen in other commercial products. Furthermore, there are more numerous and more stringent EMC standards imposed on medical devices due to their requirement for perpetual uptime and patient safety.
The intersection between user safety and reliability always leads to more specialized PCB design approaches that are not always seen in other commercial products. Before starting your next medical device PCB layout, make sure the specific EMC tests and emissions/immunity targets are well-understood. This guide will present some PCB layout practices that can aid EMC compliance in medical devices.
Due to this interplay between EMC and patient safety, EMC requirements are explicitly referenced in FDA regulations for electronic medical devices.
Before starting your next medical device PCB layout, ensure the specific EMC tests and emissions/immunity targets are well-understood.
Regulators often wrap these with submission expectations and labeling: FDA’s EMC guidance applies broadly (including IVD), and if you have radios you also inherit “wireless-specific” expectations (i.e., FDA wireless guidance).
| Product Type | Primary EMC Standard | Purpose |
|---|---|---|
| Medical Electrical (ME) Equipment | IEC 60601-1-2 (collateral to IEC 60601-1) | Device maintains basic safety and essential performance under EM disturbances; limits emissions |
| In-Vitro Diagnostics (IVD) | IEC 61326 family, especially IEC 61326-2-6 | Basic safety + essential performance for IVD equipment and environments |
| Implantable Devices | ISO 14708 family |
Device-specific EMC immunity for implantable therapy/sensing + lead system interactions |
Before starting this is some level design or PCB layout for a medical device, the relevant EMC standards should be known and understood. EMC compliance is not just a requirement for medical products to be legally released to markets around the world, it is also part of patient safety. Due to interplay between EMC and patient safety, EMC requirements are explicitly referenced in the FDA regulations for electronic medical devices.
The main set of industry EMC standards for medical devices are:
This is the primary EMC collateral standard for medical electrical equipment and systems. Key coverage includes:
Source: IEC 60601-1-2:2014+AMD1:2020
Specifies immunity testing methods referenced by IEC 60601-1-2, including:
Frequently cited by regulators for in-vitro diagnostics (IVD) equipment. FDA's recognized consensus standards include IVD-focused 61326 parts.
Specifies requirements for implantable devices, including active implantable electronic devices. Device-specific standards supplement the base ISO 14708 standard — for example, ISO 14117 covers cardiovascular implants.
Source: ISO 14117 — Cardiovascular Implants
The following examples address common EMC design challenges in medical devices.
Medical devices frequently contain sensors that interface directly with patients or monitor critical parameters. These sensors are often highly susceptible to noise, with low signal-to-noise ratios (SNR).
PCB layout practices for sensor EMC:
Interference most often comes from failure to understand return paths, leading to inaccurate sensor readings, emissions, or device failure.
Patient safety focuses on two primary EMC issues:
Design approach:
Treat every port on the device as a potential source or sink of currents and radiated emissions.
Key practices:
Excessive leakage current can interact with patients (as ESD), creating safety risks. Multiple diagnostic devices may interfere with each other, causing functional failures.
Wearable medical devices often use flexible or rigid-flex designs with direct body contact for diagnostics like temperature monitoring or pulse oximetry.
Challenge: Flexible PCB sections typically use hatched ground planes (not solid) for mechanical flexibility. Hatched ground planes allow high-frequency radiation to pass through openings.
Immunity solutions:
These approaches balance EMC performance with the flexibility requirements of wearable devices.
Edition 4.1 (IEC 60601-1-2:2014+AMD1:2020) is the current edition, published in September 2020. This consolidated version includes the fourth edition and Amendment 1.
Medical device EMC testing requires that basic safety and essential performance be maintained during immunity tests — not just that the device survives. The device must continue performing its intended medical function.
Medical devices must address both patient safety (exposure to emissions, leakage currents) and operational reliability (perpetual uptime, interference with other equipment). This dual requirement creates more numerous and stricter standards.
Essential performance refers to the device functions necessary for safety. During EMC testing, these functions must continue operating within specification. For example, an infusion pump must maintain accurate flow rates during immunity tests.
The medical device EMC standards landscape can be confusing, especially as it pertains to government regulations and design practices. That's why companies working in highly regulated industries like medical devices work with specialised EMC partners for design guidance.
DENPAFLUX provides on-demand EMC expertise for medical device teams. Based on an analysis of design files, product specifications, or Gerber outputs, DENPAFLUX experts can identify and recommend solutions to complex medical EMC challenges in PCBs.