Sound comparison of seven TMS coils at matched stimulation strength.

ABSTRACT:

Background

Accurate data on the sound emitted by transcranial magnetic stimulation (TMS) coils is lacking.

Methods

We recorded the sound waveforms of seven coils with high bandwidth. We estimated the neural stimulation strength by measuring the induced electric field and applying a strength-duration model to account for different waveforms.

Results

Across coils, at maximum stimulator output and 25 cm distance, the sound pressure level (SPL) was 98-125 dB(Z) per pulse and 76-98 dB(A) for a 20 Hz pulse train. At 5 cm distance, these values were estimated to increase to 112-139 dB(Z) and 90-112 dB(A), respectively.

Conclusions

The coils' airborne sound can exceed some exposure limits for TMS subjects and, in some cases, for operators. These findings are consistent

SUBMITTER: Koponen LM 

PROVIDER: S-EPMC7263763 | biostudies-literature | 2020 May - Jun

REPOSITORIES: biostudies-literature