18 Mar The Role of EMI Shielding in Medical Devices

Posted at 10:48h in Blog, EMI Shielding, Medical Industry by Irwin Lambersky

Electromagnetic Interference (EMI) is a critical challenge for medical device manufacturers, as it can disrupt electronic signals and impair device functionality in healthcare environments. With hospitals and clinics increasingly relying on electronic monitoring, imaging, and life-support systems, equipment manufacturers must integrate EMI shielding to ensure signal integrity, meet regulatory standards, and safeguard patient safety.

At The ID Group, we’ve been providing EMI RFI shielding solutions for many years, so we know how important it is to prevent interference by blocking or redirecting electromagnetic waves in various types of equipment. In this article, I explain why EMI in medical devices poses serious risks for patients and healthcare providers and why it’s essential for medical device manufacturers to seek out effective shielding solutions for their equipment.

But first, let’s start with the basics.

Quick Links

What is EMI Shielding?
Most Common Sources of EMI in Hospitals and Clinics
Risks Associated with EMI Interference in Healthcare
Why is EMI Shielding Essential for Medical Devices?
Regulatory Requirements and Standards
Types of EMI Shielding Used in Healthcare Devices
Conclusion

Key Takeaways

EMI shielding in medical devices prevents signal disruptions that could lead to malfunctions, misdiagnoses, and life-threatening failures in hospitals and clinics.
Common sources of EMI include wireless communication systems, MRI machines, electrosurgical tools, and mobile devices, all of which can interfere with critical medical equipment.
Regulatory compliance is mandatory, with standards like IEC 60601-1 and Health Canada’s Medical Devices Regulations ensuring devices operate safely in electromagnetically dense environments.
Effective EMI shielding solutions for medical devices include conductive gaskets, shielded cables, metal enclosures, and EMI shielding films to protect sensitive electronics from interference.
Early EMI shielding integration is essential for medical device manufacturers to ensure reliability, patient safety, and regulatory approval while avoiding costly failures.

What is EMI Shielding?

EMI shielding is the process whereby electronic devices are protected from unwanted electromagnetic radiation that can induce disruption and malfunction. It requires enclosure of the sensitive aspects of the electronics and wiring within conductive materials – metal enclosures, conductive coatings, mesh, EMI conductive gaskets, and honeycomb vents (where airflow is required) to absorb, reflect, or block electromagnetic waves.

In healthcare, EMI shielding prevents interference in pacemakers, MRI machines, and monitoring systems, ensuring accurate performance and improved patient diagnostics and health outcomes. As the healthcare sector increases its electronic hardware reliance, effective EMI shielding plays an increasing role in device reliability and regulatory compliance.

Learn more about EMI shielding and how it works

Most Common Sources of EMI in Hospitals and Clinics

Electromagnetic interference is a significant problem in medical environments, where the reliability of electronic equipment is essential. Hospitals and clinics are full of various sources of EMI that can potentially affect the performance and reliability of medical equipment. Here are some of the most common ones:

Wireless Communication Systems: Wireless communication systems, including Wi-Fi, Bluetooth, and cellular networks, generate electromagnetic signals that can interfere with sensitive medical equipment, affecting data transmission and device accuracy.
MRI Machines: MRI machines produce powerful magnetic fields and radiofrequency waves, which can disrupt nearby electronic devices and require strict EMI shielding to prevent signal distortion.
Electrosurgical Tools: Electrosurgical tools, such as radiofrequency ablation devices and electric scalpels, emit high-frequency currents that may interfere with monitoring equipment, potentially leading to misreadings.
Mobile devices: Mobile devices, including smartphones and tablets, emit RF signals that can cause unintended interference with life-support systems, infusion pumps, and diagnostic instruments, necessitating strict hospital regulations on device use.

Risks Associated with EMI Interference in Healthcare

Electromagnetic Interference in healthcare can cause malfunctions, misreadings, or failures in critical medical equipment, jeopardizing patient safety.

This is the result of induced currents that can disrupt signals, causing either loss of information as delicate signals are swamped, and also, at times, cause readable false signals that can create false diagnoses or condition responses.

Life-support systems, such as pacemakers and ventilators, can experience unintended disruptions, leading to life-threatening consequences. Diagnostic tools like ECGs, MRIs, and monitors can produce inaccurate results, delaying proper treatment. Infusion pumps and electrosurgical devices may malfunction, affecting medication delivery and surgical precision. Additionally, EMI interference can corrupt wireless communication between medical devices, impairing data transmission.

To mitigate these risks, medical device manufacturers must integrate EMI shielding right from the design phase to ensure that equipment strictly complies with EMI regulations and operates reliably in real hospital environments.

Why is EMI Shielding Essential for Medical Devices?

EMI Shielding Protects Sensitive Medical Equipment

EMI can severely disrupt medical devices, leading to malfunctions, inaccurate readings, and even life-threatening failures. EMI shielding is the crucial solution in preventing these disruptions by blocking, absorbing, or redirecting electromagnetic waves away from sensitive electronics. By implementing EMI shielding in MRI machines, infusion pumps, pacemakers, and monitoring systems, medical device manufacturers ensure signal integrity, device reliability, and patient outcomes.

Consequences of Inadequate EMI Protection

Patient Safety Risks: Without effective EMI shielding, medical devices may experience signal disruptions that compromise patient monitoring and treatment accuracy. For example, a pacemaker affected by EMI can potentially deliver incorrect electrical pulses, while an infusion pump may miscalculate medication delivery, leading to potentially fatal consequences.
Incorrect Diagnoses: Medical imaging and diagnostic tools, such as ECG (electrocardiogram) machines, MRI scanners, and blood pressure monitors, rely on precise signal processing. EMI interference can introduce artifacts, distortions, or false readings, leading to misdiagnosis and inappropriate treatment.
Equipment Failures Resulting in Patient and Litigation Consequences: Hospitals, healthcare providers, and manufacturers are legally liable for ensuring equipment functions correctly. EMI-induced failures easily result in malpractice lawsuits, regulatory violations, and costly equipment replacements. Compromised medical data potentially exposes institutions to financial and reputational damage.

A Real Life Example

In 2016, a significant electromagnetic interference (EMI) incident occurred between a left ventricular assist device (LVAD) and a subcutaneous implantable cardioverter-defibrillator (S-ICD). The case involved a 42-year-old man with nonischemic cardiomyopathy who had received an S-ICD for primary prophylaxis. Shortly after LVAD implantation, the patient experienced 31 inappropriate S-ICD shocks within an hour. This was due to the LVAD’s electrical noise being superimposed on the patient’s diminished R waves, which the S-ICD misinterpreted as a shockable rhythm.

The medical team resolved the issue by explanting the S-ICD and implanting a conventional transvenous ICD. This change proved effective, with no further inappropriate shocks reported during the six-month follow-up period. The case underscores the potential risks of EMI between implantable medical devices and emphasizes the importance of careful monitoring and management of patients with multiple electronic implants, as EMI can lead to serious consequences such as unnecessary and distressing shocks.

Source: https://www.ahajournals.org/doi/10.1161/circep.116.004633

Regulatory Requirements and Standards

The FDA (U.S. Food and Drug Administration) regulates medical devices to ensure EMI resilience, requiring compliance with IEC 60601-1 and IEC 60601-1-2 standards. These standards establish electrical safety, essential performance, and electromagnetic compatibility (EMC) requirements, ensuring that devices function reliably without EMI-related malfunctions.

IEC 60601-2 outlines specific performance criteria for different types of medical equipment, including MRI machines, ventilators, and monitors. EMC compliance ensures that devices can operate in electromagnetically challenging environments without disrupting other equipment or themselves being disrupted by the environment.

In Canada, Health Canada enforces similar regulations under the Medical Devices Regulations (SOR/98-282), requiring medical devices to meet IEC 60601 and EMC standards for market approval. Compliance ensures that healthcare facilities use safe, effective, and interference-resistant medical devices, reducing risks to patients and medical professionals.

Types of EMI Shielding Used in Healthcare Devices

Medical devices must function reliably in environments filled with complex and intermittent electromagnetic signals from a wide range of sources over a broad spectrum of frequencies. The following EMI products are commonly used to block electromagnetic interference in medical devices.

Conductive Gaskets and Seals

Medical equipment requires conductive gaskets and seals to prevent EMI leakage at points of discontinuity in enclosures such as joints, inspection access, and material changes. These materials ensure that high-power imaging devices do not disrupt other medical instruments or external communication systems. Commonly laser cut from conductive foams or molded from conductive elastomers such as electrically conductive silicone gaskets, these components are a central part of our custom solution service.

Shielded Cables and Connectors

Medical equipment relies on EMI-shielded cables and connectors to maintain signal integrity. These components prevent EMI from corrupting critical patient data as signals are carried outside of equipment shielding, ensuring accurate diagnostics and reliable operation.

Metal Enclosures and Coatings

Aluminum, Copper, and Nickel coatings provide robust EMI shielding by providing full coverage conductive barriers that block unwanted electromagnetic waves, carrying the interference to the ground (earth). These are widely used in monitoring devices, infusion pumps, ventilators, etc., ensuring that stray external EMI does not interfere with critical functions. Metal enclosures also help prevent sensitive medical electronics from emitting interference that could affect nearby equipment.

EMI Shielding Films and Tapes

Portable medical devices require lightweight EMI shielding solutions such as shielding films and conductive tapes. These materials offer flexible protection against interference while not overly influencing device weight, making them ideal for wearable health monitors, handheld diagnostic tools, and wireless medical sensors.

For medical device manufacturers, integrating advanced EMI shielding solutions from the early design phase is essential to developing reliable, compliant, and market-ready products. By proactively addressing EMI challenges, manufacturers can prevent costly failures, ensure seamless hospital integration, and build medical devices that meet the highest performance and safety standards.

Conclusion

As healthcare technology advances, the reliance on electronics in medical devices continues to grow in volume and signal/analytical complexity. However, the risk of EMI increases commensurate with this, amplifying the potential for device malfunctions, inaccurate diagnostics, and patient safety risks. Effective EMI shielding is a central element of the equipment development and manufacturing process, maintaining the integrity and performance of critical medical equipment in busy RF spaces.

By incorporating metal enclosures and conductive coatings, conductive seals/gaskets, and low-resistance grounding paths, manufacturers ensure robust protection for all sensitive devices. Conductive gaskets and seals safeguard MRI rooms and enclosure joints/openings, preventing EMI leakage that could compromise imaging accuracy. Shielded cables and connectors protect sensitive signal pathways in ECG, EEG, and ultrasound machines, and the various signal pathways they require, ensuring accurate patient data transmission. Additionally, EMI shielding films and tapes provide lightweight and flexible solutions for portable medical devices, enabling mobility without sacrificing protection.

The ID Group works closely with various manufacturers, including those in the medical device industry, to help them counter the harmful effects of EMI. Contact us if you have any questions about our EMI shielding products, including conductive shielding gaskets in foam, elastomer or metal, honeycomb vents, and many other solutions you may find helpful in your product design.

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The Role of EMI Shielding in Medical Devices