Temperature Rise due to Medical Implants Niels Kuster Earl Zastrow
Thursday, May 28, 15
Temperature Rise due to Medical Implants
ICNIRP Thermal Workshop, Istanbul Turkey, May 26-28, 2015
RF Coupling Mechanisms w/ External Fields
Thursday, May 28, 15
Temperature Rise due to Medical Implants
ICNIRP Thermal Workshop, Istanbul Turkey, May 26-28, 2015
RF Coupling Mechanisms w/ External Fields From J. M. Henderson, et al., "Permanent Neurological Deficit Related to Magnetic Resonance Imaging in a Patient with Implanted Deep Brain Stimulation Electrodes for Parkinson's Disease: Case Report", Neurosurg., 57(5), 2005
in silico
Thursday, May 28, 15
in vivo
Temperature Rise due to Medical Implants
ICNIRP Thermal Workshop, Istanbul Turkey, May 26-28, 2015
RF Coupling Mechanisms: Simple Wires
Thursday, May 28, 15
Temperature Rise due to Medical Implants
ICNIRP Thermal Workshop, Istanbul Turkey, May 26-28, 2015
RF Coupling Mechanisms: Simple Wire in Tissues
Thursday, May 28, 15
Temperature Rise due to Medical Implants
ICNIRP Thermal Workshop, Istanbul Turkey, May 26-28, 2015
RF Coupling Mechanisms: Simple Wire in Tissues
ξ=0 rad/m ξ=4 rad/m ξ=9 rad/m ξ=15 rad/m
Thursday, May 28, 15
Temperature Rise due to Medical Implants
ICNIRP Thermal Workshop, Istanbul Turkey, May 26-28, 2015
Content •
IT’IS activities on implant safety
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hypotheses
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exposure limits & FDA safety considerations
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localized heating due to generic implants
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demonstration of MRI-safe implants
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temperature rise during MRI exposure & risk management
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conclusions
Thursday, May 28, 15
Temperature Rise due to Medical Implants
ICNIRP Thermal Workshop, Istanbul Turkey, May 26-28, 2015
IT’IS Activities: Virtual Population (ViP)
GLENN male elderly 1.73m, 65kg
Thursday, May 28, 15
FATS obese male 1.78m, 120kg
DUKE male adult 1.74m, 70kg
ELLA female adult 1.60m, 58kg
BILLIE girl 11y 1.46m, 36kg
THELONIOUS boy 6y 1.17m, 20kg LOUIS boy 14y 1.65m, 50kg
EARTHA girl 8y 1.35m, 30kg
DIZZY boy 8y 1.40m, 26kg
ROBERTA girl 5y 1.09m, 16kg
Temperature Rise due to Medical Implants
ICNIRP Thermal Workshop, Istanbul Turkey, May 26-28, 2015
IT’IS Activities: Multi-Physics Solvers
Thursday, May 28, 15
Temperature Rise due to Medical Implants
ICNIRP Thermal Workshop, Istanbul Turkey, May 26-28, 2015
IT’IS Activities: Testing Systems
Thursday, May 28, 15
Temperature Rise due to Medical Implants
IT’IS Activities: V&V
Thursday, May 28, 15
ICNIRP Thermal Workshop, Istanbul Turkey, May 26-28, 2015
Temperature Rise due to Medical Implants
ICNIRP Thermal Workshop, Istanbul Turkey, May 26-28, 2015
Hypotheses •
a significant portion of the population (people w/ passive or active medical implants) is not protected from serious health hazards below 100 MHz (e.g., MRI, wireless power transfer)
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spatial averaging mass of 10g is too large for localized exposure
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risk-benefit considerations needed for implants in MRI
Thursday, May 28, 15
Temperature Rise due to Medical Implants
ICNIRP Thermal Workshop, Istanbul Turkey, May 26-28, 2015
Exposure Safety Limits •
temperature Limits - FDA: no special consideration needed for
