The development and modelling of devices and paradigms for transcranial magnetic stimulation

Abstract

Magnetic stimulation is a non-invasive neurostimulation technique that can evoke action potentials and modulate neural circuits through induced electric fields. Biophysical models of magnetic stimulation have become a major driver for technological developments and the understanding of the mechanisms of magnetic neurostimulation and neuromodulation. Major technological developments involve stimulation coils with different spatial characteristics and pulse sources to control the pulse waveform. While early technological developments were the result of manual design and invention processes, there is a trend in both stimulation coil and pulse source design to mathematically optimize parameters with the help of computational models. To date, macroscopically highly realistic spatial models of the brain, as well as peripheral targets, and user-friendly software packages enable researchers and practitioners to simulate the treatment-specific and induced electric field distribution in the brains of individual subjects and patients. Neuron models further introduce the microscopic level of neural activation to understand the influence of activation dynamics in response to different pulse shapes. A number of models that were designed for online calibration to extract otherwise covert information and biomarkers from the neural system recently form a third branch of modelling.

Keywords:

• Transcranial magnetic stimulation
• TMS
• biophysical modelling
• neuroscience
• neurostimulation
• neuromodulation
• medical technology

Disclosure of interest

Dr Deng is an inventor on patents and patent applications related to TMS technology owned by Columbia University. Dr Deng is supported by the Intramural Research Program of the National Institute of Mental Health. At Duke University, Dr Deng was supported in part by a grant from the National Institutes of Health/National Center for Advancing Translational Sciences (KL2 TR001115). Dr Goetz is an inventor on patents and patent applications on technology of transcranial magnetic stimulation. Furthermore, he has received royalties through his current and previous employers, as well as patent application support and research funding from Magstim Co.

Additional information

Funding

Dr Deng is supported by the Intramural Research Program of the National Institute of Mental Health. At Duke University, Dr Deng was supported in part by a grant from the National Institutes of Health/National Center for Advancing Translational Sciences (KL2 TR001115). Dr Goetz was supported in part by research funding from Magstim Co., the National Science Foundation (NSF) under Grant 1608929, and a NARSAD Grant.