Staff exposure to pulsed magnetic fields during depression treatment with transcranial magnetic stimulation.
BACKGROUND
Transcranial magnetic stimulation or repetitive transcranial magnetic stimulation (TMS/rTMS) are currently used in research and treatments of diseases of the central nervous system, such as recurring depression. Strong electric pulses are used to produce strong pulsed magnetic fields that are directed to the patient's cerebral cortex where the fields induce electric pulses. The pulses may be causing unnecessary exposure of the staff.


METHODS
The MagVenture TMS/rTMS system was investigated, without patient presence, through measurements of magnetic field pulses at varying distances from the emitting coil and different power settings (94-127 A/s).


RESULTS
Fourteen measurements were done which displayed exposures exceeding the given guidelines up until a distance of 40 cm from the transmitting coil.


CONCLUSIONS
The study shows that the exposure of staff in this type of treatment may exceed the given guidelines for occupational exposure, thus confirming previous findings. This necessitates good routines in information and treatment procedures to avoid this exposure.
a Occupational and Environmental Medicine , University of Bergen , Norway.
Ole Jacob
OJ
Møllerløkken
b Health, Safety and Environment Center , Haukeland University Hospital , Norway.
Helen
H
Stavang
c Department of Radiation Sciences , Umeå University , Sweden.
Kjell
K
Hansson Mild
D006801:Humans; D060526:Magnetic Fields; D016273:Occupational Exposure / Q000032:analysis*; D010564:Personnel, Hospital; D011834:Radiation Monitoring; D011871:Radiology; D050781:Transcranial Magnetic Stimulation / Q000295:instrumentation*
occupational exposure; risk assessment; therapy