title: Time resolved dosimetry of human brain exposed to low frequency pulsed magnetic fields.
abstract: An accurate dosimetry is a key issue to understanding brain stimulation and related interaction mechanisms with neuronal tissues at the basis of the increasing amount of literature revealing the effects on human brain induced by low-level, low frequency pulsed magnetic fields (PMFs). Most literature on brain dosimetry estimates the maximum E field value reached inside the tissue without considering its time pattern or tissue dispersivity. Nevertheless a time-resolved dosimetry, accounting for dispersive tissues behavior, becomes necessary considering that the threshold for an effect onset may vary depending on the pulse waveform and that tissues may filter the applied stimulatory fields altering the predicted stimulatory waveform's size and shape. In this paper a time-resolved dosimetry has been applied on a realistic brain model exposed to the signal presented in Capone et al (2009 J. Neural Transm. 116 257-65), accounting for the broadband dispersivity of brain tissues up to several kHz, to accurately reconstruct electric field and current density waveforms inside different brain tissues. The results obtained by exposing the Duke's brain model to this PMF signal show that the E peak in the brain is considerably underestimated if a simple monochromatic dosimetry is carried out at the pulse repetition frequency of 75 Hz.
authors.affiliation: Department of Information Engineering, Electronics and Telecommunications, Sapienza University of Rome, via Eudossiana 18, 00184 Rome, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Paffi
authors.forename: Francesca
authors.initials: F
authors.lastname: Camera
authors.forename: Elena
authors.initials: E
authors.lastname: Lucano
authors.forename: Francesca
authors.initials: F
authors.lastname: Apollonio
authors.forename: Micaela
authors.initials: M
authors.lastname: Liberti
mesh_terms: D001921:Brain / Q000528:radiation effects*; D006801:Humans; D060526:Magnetic Fields; D011829:Radiation Dosage; D050781:Transcranial Magnetic Stimulation / Q000379:methods* / Q000592:standards