defibrillator implants: bruce murdoch phd chp clso argonne national laboratory argonne, il usa...

Defibrillator Implants:

Bruce Murdoch PhD CHP CLSOArgonne National LaboratoryArgonne, IL USAbtmurdoch@anl.gov

AIHce 2011, Portland OR Roundtable Session RT 201

Occupational Exposure to Electromagnetic Radiation

Typical ICD Device

Dimensions: 2” X 2.5” X 0.2”

AIHce 2011, Portland OR

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Implant Placement

EM Vulnerabilities Leads Control Unit

Failure Modes False Trigger Stopping

AIHce 2011, Portland OR

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Source: www.defibrillator-help.com

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CASE STUDY

Where? APS (Advanced Photon Source)

Who? Accelerator Operator w/ICD

Why? Work Clearance

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APS Control Room

Manufacturer Test Standard

ANSI/AAMA PC69 - 2007

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Typical Manufacturer (Medtronic) Exposure Limit Recommendations Static B-Field B ≤ 0.5 mT (5G)

50/60 Hz B ≤ 0.1 mT (1G) E ≤ 6000 V/m

≥ 10 kHz B ≤ 1.25 mT (12.5 G)

R-F E-Field (≥ 150 kHz) E ≤ 100 V/m

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ACGIH 2010 TLV Book Exposure Limit Recommendations

Static B-Field B ≤ 0.5 mT (5G)

ELF (5 Hz–2kHz) B ≤ 0.1 mT (1G)

VLF (2kHz–400 kHz) No recommendation

R-F (100 kHz–3GHZ) E ≤ 3-10 V/m

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Static B-Fields

MetroLab Model ETM-1

3-Axis Magnetometer

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ELF

Holaday HI-3627ELF Magnetic Field Meterw/ HI-3602 Probe

30 Hz – 2 KHz

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VLF

Holaday HI-3637VLF Magnetic Field Meterw/ HI-3091 Probe

2kHz – 400 KHz

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R-F

Narda NBM-520RF Survey Meterw/ EF3091 E-Field Probe

100 kHz – 3 GHz

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Spectrum Coverage

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RF

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The Instrument Ensemble

Survey Plan

Daily Control Room work area

Weekly maintenance walkthroughs

ESH Coordinator guidance

84 specific survey locations plus area sweeps

Full spectrum survey at each location

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Control Room Panels

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Electrical Distribution RoomELF: B ≤ 0.4 G @ 6 inches from transformerRF: E ≤ 4 V/m

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Mezzanine RF System Freq = 325 MHz E(RF) up to 3.5 V/m @ 6 in.

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Power Control Systems

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Pulser Power Transformers

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RF Distribution Waveguides

Freq = 325 mHz

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Linac KlystronsFreq = 2.8565 GHzE(RF) = 2 V/m @ 1 ft

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Case Study Results

Employee barred from

– Fundamental RF Room: 7 V/m RF

– Electrical Distribution Room: 4 V/m RF

Cautions

– Some instrument racks: 4 V/m RF @ 12”

– Some waveguides: 3.5 V/m RF @ 12”

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Credits

Technical Assistance– Mary Malik– Adam Sauter

Photography– George Joch– Edmund Chang

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