[Simnibs-discuss] info about cTBS

[Guilherme B Saturnino]

Hello,


In TMS, the time component and the spatial component of the fields are 
decoupled. That means that we can write

E(x, t) = E(x)T(t)

E(x) is a component which is dependent on coil geometry, coil position, 
and subject head geometry. That is what SimNIBS calculates.

T(t) Depends only in pulse shape and stimulation intensity. It does not 
affect the spatial distribution of the field, but rather acts as a 
scaling parameter. For TMS, T(t) = dI(t)/dt, that is, the rate of change 
of current through the coil. This means that SimNIBS does not assume any 
particular time dynamics. Rather, it takes a snapshot at the field at a 
single time point, typically at the peak dI/dt value. For more time 
points, all you need to do is to scale the field accordingly.

However, the peak dI/dt value is dependent on coil model, stimulator 
model, pulse shape and pulse intensity. In some stimulator models, this 
value is shown in the screen after a pulse.

For more information, please see: 
https://simnibs.github.io/simnibs/build/html/faq.html#what-is-the-di-dt-in-tms-simulations


Best,

Guilherme


On 13/03/2020 13.00, Mariacarla Memeo wrote:
>
> To whom it may concerns,
>
> I’m Mariacarla Memeo and I work at the Italian Institute of 
> technology, in the Cognition Motion and Neuroscience (CMON 
> <https://www.iit.it/research/lines/cognition-motion-and-neuroscience>) 
> Unit. We usually use the TMS with a single pulse protocol but recently 
> we used a continuous theta burst stimulation as in Huang et al., 2005 
> (DOI: 10.1016/j.neuron.2004.12.033): cTBS with three pulses at 50 Hz 
> repeatedly applied at intervals of 200 ms (5 Hz) for 40 s.
>
> I tried your software for a single pulse protocol and I find it really 
> useful but I was wondering if there is a way to implement other TMS 
> protocols, like the one I reported.
>
> Thank you for your time.
>
> Best,
>
> ********************************************************
>
> *Mariacarla Memeo*, PhD
>
> C’MON Unit - Fondazione Istituto Italiano di Tecnologia
>
> Center for Human Technologies
>
> Via Enrico Melen 83, 16152 , building B, 7° floor
>
> Phone: +39 010 8172239
>
> IIT webpage: https://www.iit.it/people/mariacarla-memeo
>
> RG webpage: https://www.researchgate.net/profile/Mariacarla_Memeo
>
> ********************************************************
>
>
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