Redesigning existing transcranial magnetic stimulation coils to reduce energy: application to low field magnetic stimulation.
Published
Journal Article
OBJECTIVE: To present a systematic framework and exemplar for the development of a compact and energy-efficient coil that replicates the electric field (E-field) distribution induced by an existing transcranial magnetic stimulation coil. APPROACH: The E-field generated by a conventional low field magnetic stimulation (LFMS) coil was measured for a spherical head model and simulated in both spherical and realistic head models. Then, using a spherical head model and spatial harmonic decomposition, a spherical-shaped cap coil was synthesized such that its windings conformed to a spherical surface and replicated the E-field on the cortical surface while requiring less energy. A prototype coil was built and electrically characterized. The effect of constraining the windings to the upper half of the head was also explored via an alternative coil design. MAIN RESULTS: The LFMS E-field distribution resembled that of a large double-cone coil, with a peak field strength around 350 mV m-1 in the cortex. The E-field distributions of the cap coil designs were validated against the original coil, with mean errors of 1%-3%. The cap coil required as little as 2% of the original coil energy and was significantly smaller in size. SIGNIFICANCE: The redesigned LFMS coil is substantially smaller and more energy-efficient than the original, improving cost, power consumption, and portability. These improvements could facilitate deployment of LFMS in the clinic and potentially at home. This coil redesign approach can also be applied to other magnetic stimulation paradigms. Finally, the anatomically-accurate E-field simulation of LFMS can be used to interpret clinical LFMS data.
Full Text
Duke Authors
Cited Authors
- Wang, B; Shen, MR; Deng, Z-D; Smith, JE; Tharayil, JJ; Gurrey, CJ; Gomez, LJ; Peterchev, AV
Published Date
- June 2018
Published In
Volume / Issue
- 15 / 3
Start / End Page
- 036022 -
PubMed ID
- 29300001
Pubmed Central ID
- 29300001
Electronic International Standard Serial Number (EISSN)
- 1741-2552
Digital Object Identifier (DOI)
- 10.1088/1741-2552/aaa505
Language
- eng
Conference Location
- England