Interference of Cardiovascular Implantable Electronic Devices by Static Electric and Magnetic Fields

Expert review of medical devices · 2021 · Harm · Low evidence

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HarmLow evidencePaper 1206

Study snapshot

PublicationExpert review of medical devices · 2021

Study typereview

Reported directionHarm

Evidence ratingLow

Abstract

Interference of Cardiovascular Implantable Electronic Devices by Static Electric and Magnetic Fields Kai Jagielski, Thomas Kraus, Dominik Stunder. Interference of Cardiovascular Implantable Electronic Devices by Static Electric and Magnetic Fields. Expert Rev Med Devices. 2021 Mar 12. doi: 10.1080/17434440.2021.1902802. Abstract Introduction: Electromagnetic interference (EMI) of cardiovascular implantable electronic devices (CIED) can lead to malfunctions and pose a danger for implant carriers. The increased use of DC technologies, e.g., in electric mobility, creates more static fields representing an increasing hazard for implant carriers. Areas covered: A combination of approaches was used to determine thresholds for EMI by static fields. A literature search was conducted to identify relevant EMI mechanisms and to extract possible thresholds. The literature search revealed four interference mechanisms caused by static magnetic fields and none for static electric fields. Due to the scarce information on motion-induced EMI, numerical simulations were performed to obtain a threshold. The simulation results were evaluated using medical product standards and benchmark tests on commercially available CIEDs. The results show that motion-induced interference should not occur below the activation of the magnetic safety switch (reed switch or Hall-effect sensor, MSS). Expert opinion: The determined threshold for motion-induced EMI at 24.8 mT shows that the MSS activation is still the most relevant mechanism that can occur at 0.8 mT. Limit values for the general population do not protect implant carriers from EMI. pubmed.ncbi.nlm.nih.gov Conclusion The aim of this study was the assessment of risks for CIED patients by SEF and SMF. Regarding SEF, no indication was found that CIED can be interfered with when implant wearers are exposed to SEF. This does not include potential EMI from contact currents as they may occur from charged objects in the vicinity of SEF. Contact currents were not the focus of this study due to the significantly different scenario between field exposure and contact current, in which skin resistance and voltage level play a decisive role. Under the influence of SEF exposure, the shielding of the human body as a Faraday cage is sufficient to prevent electric induction into CIED that are located entirely under the human skin. Regarding SMF, four interference mechanisms have been identified. As a reed switch or Hall effect sensor, the unintended activation of the MSS is the most investigated effect and can occur at SMF greater than 0.8 mT. Magnetic forces on CIED may be relevant for strong magnetic fields in the magnitude of teslas as they arise from MRI devices. A parameter reset or reprogramming of the CIED by SMF seems to be relatively uncommon, and only one publication reported a reproducible case with a PM by earphones. Rather few publications treat motion-induced EMI with the iEGM of the CIED, which has been investigated with numerical simulations and benchmark tests in this study. In this study, activation thresholds for motion-induced EMI were determined and published for the first time. However, an estimated occurrence starting at 24.8 mT shows that motion-induced EMIs are less relevant than the activation of MSS that can already occur at 0.8 mT. However, motion-induced EMIs still pose a potential risk to implant wearers because the CIED may not provide the necessary therapy. Other DC technologies and SMF sources will likely emerge in the future, both in professional and private environments. As a result, EMI from static fields will continue to be significant. The question arises whether the triggering of MSS around 1 mT is still practical, where even today, many technical applications already generate static magnetic fields of more than 1 mT, or whether there is a need for innovation on the part of the manufacturers.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typereview

Effect directionharm

PopulationCardiovascular implantable electronic device (CIED) carriers (implant wearers)

Sample sizeNot supplied

Exposurestatic

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

A literature search identified four interference mechanisms caused by static magnetic fields and none for static electric fields. The authors report that motion-induced interference should not occur below magnetic safety switch (reed switch or Hall-effect sensor) activation; they determined a threshold for motion-induced EMI of 24.8 mT, while unintended magnetic safety switch activation can occur at static magnetic fields >0.8 mT. They conclude that general-population limit values do not protect implant carriers from EMI.

Outcomes measured

Electromagnetic interference (EMI) / device malfunction
Thresholds for interference mechanisms (e.g., magnetic safety switch activation; motion-induced EMI)

Limitations

Threshold for motion-induced EMI was derived using numerical simulations and benchmark tests due to scarce literature information.
Contact currents from charged objects near static electric fields were not assessed and were explicitly excluded from the study scope.
The abstract notes relatively few publications on motion-induced EMI and only one publication reporting a reproducible parameter reset/reprogramming case (pacemaker by earphones).

View raw extracted JSON

{
  "study_type": "review",
  "exposure": {
    "band": "static",
    "source": "DC technologies (e.g., electric mobility); static electric fields (SEF) and static magnetic fields (SMF)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Cardiovascular implantable electronic device (CIED) carriers (implant wearers)",
  "sample_size": null,
  "outcomes": [
    "Electromagnetic interference (EMI) / device malfunction",
    "Thresholds for interference mechanisms (e.g., magnetic safety switch activation; motion-induced EMI)"
  ],
  "main_findings": "A literature search identified four interference mechanisms caused by static magnetic fields and none for static electric fields. The authors report that motion-induced interference should not occur below magnetic safety switch (reed switch or Hall-effect sensor) activation; they determined a threshold for motion-induced EMI of 24.8 mT, while unintended magnetic safety switch activation can occur at static magnetic fields >0.8 mT. They conclude that general-population limit values do not protect implant carriers from EMI.",
  "effect_direction": "harm",
  "limitations": [
    "Threshold for motion-induced EMI was derived using numerical simulations and benchmark tests due to scarce literature information.",
    "Contact currents from charged objects near static electric fields were not assessed and were explicitly excluded from the study scope.",
    "The abstract notes relatively few publications on motion-induced EMI and only one publication reporting a reproducible parameter reset/reprogramming case (pacemaker by earphones)."
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "cardiovascular implantable electronic devices",
    "CIED",
    "electromagnetic interference",
    "static electric fields",
    "static magnetic fields",
    "DC technologies",
    "electric mobility",
    "magnetic safety switch",
    "reed switch",
    "Hall-effect sensor",
    "motion-induced EMI",
    "threshold",
    "mT"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.5,
      "reason": "Discusses DC technologies and static-field sources emerging in professional environments and associated risks for implant carriers."
    }
  ]
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1080/17434440.2021.1902802
PubMed: 33710950

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