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EM pulse coil = small-scale model of a Transcranial Magnetic Stimulator (TMS)

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Proud Mary

Sun Jan 16 2011, 08:21PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Milarepa108 wrote ...

Proud Mary wrote ...

Milarepa108 wrote ...

Proud Mary what's your point? Where am I talking bollocks? I know all these papers...
Just stating they prove I'm wrong is not really a valid argument. Besides, it's also a bit offtopic.
I'm thankful for any advice on the project!

You most clearly wrote "TMS is not a treatment for anything"

But it is - or at least many psychiatrists believe it so.

Sure and they might even be right and one day TMS will actually be used in the standard repertoire of psychiatrists and not only in pilot projects of enthusiastic researchers.... I sure would like to see that!

In 2008 the U.S. Food and Drug Administration (FDA) cleared the "NeuroStar TMS (Transcranial Magnetic Stimulation) Therapy" system for the treatment of Major Depressive Disorder in adults.

Milarepa108

Sun Jan 16 2011, 08:37PM

Registered Member #3620 Joined: Sat Jan 15 2011, 04:16PM
Location:
Posts: 11

@ProudMary
Yeah, the FDA says the Neurostar TMS device can legally be used for treatment. I tell you we can go into a long discussion about what exactly that means if you want to. (But please in another thread.) My point being that TMS is mainly a tool in research is not even being touched by this matter... And whether we this justifies spamming with offtopic stuff is more than questionable. (From here on out I will stop feeding, btw...)

What do you think about the small scale model? I looked at your posts and do believe that you have some awesome ideas on the topic. It would be a shame if you'd refrain from contributing because of a careless remark on my side. TMS is a great technology and the model I'm building would be of real help educating students about the technology they're about to use.

Carbon_Rod

Sun Jan 16 2011, 11:19PM

Registered Member #65 Joined: Thu Feb 09 2006, 06:43AM
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Posts: 1155

You could also try a culture dish with a thin layer of iron powder if it is a LF pulse.

Milarepa108 wrote ...

@Carbon_Rod

TMS is just a modern day form of Trepanning.

How would you get to this preposterous hypothesis? TMS is not a treatment for anything, it's a tool of the cognitive neuroscientist and among scientists there is not really any about it's validity. Sometimes it's used for diagnostic purposes, but that's about it. Are you sure you're not talking about something else?

@Milarepa108
My clearly stated opinion is indeed biased as I personally know subjects (i.e. healthy volunteers from the academic institution) that have gone through the procedure. The history of neurology studies does not feature in this case, as I have witnessed the subtle changes in peoples behavior several weeks after a session.

In my observations, it seems to bear a striking resemblance to the symptoms of mild hypoxiation.

Individuals must have a clear definition of "harmless" when evaluating the therapeutic value.

Milarepa108

Sun Jan 16 2011, 11:34PM

Registered Member #3620 Joined: Sat Jan 15 2011, 04:16PM
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Posts: 11

Carbon_Rod wrote ...

You could also try a culture dish with a thin layer of iron powder if it is a LF pulse.

Awesome idea, thanks! I have both lying around but didn't put them together. Will make one epoxied together for durability!

Carbon_Rod wrote ...

@Milarepa108
My clearly stated opinion is indeed biased as I personally know subjects (i.e. healthy volunteers from the academic institution) that have gone through the procedure. The history of neurology studies does not feature in this case, as I have witnessed the subtle changes in peoples behavior several weeks after a session.

In my observations, it seems to bear a striking resemblance to the symptoms of mild hypoxiation.

Individuals must have to have a clear definition of "harmless" when evaluating the therapeutic value.

I completely agree. One example. As mentioned above there are several approaches to using different frequencies of pulses to change neural activity. One of those, (theta-burst stimulation) has been found to evoke changes that can last for weeks after a single application. Nobody knows why. The specificity of the magnetic pulse is very high, the effects are relatively focal. (ie you can miss the spot really easily and land somewhere entirely different, producing unwanted/adverse effects) Especially when the coils are positioned by hand, you hardly know which area you are stimulating and the error has been shown to be really large. Appropriate positioning can only be guaranteed with previous fMRI localizer procedure AND quite expensive tracking equipment. The error is so large that for the same study used with guided vs unguided TMS, you need about 10 times (!!!) as many participants to have the same statistical power. While I trust single pulse stimulation protocols to be relatively safe, I would not (and have yet declined all requests from colleques) participate in a study using theta burst stimulation and also would not participate in a long term treatment using any kind of unguided TMS stimulation.

Thanks for your answer and your helpful hint regarding the petri dishes!
Greetings
Milarepa

ed:
and if anyone cares, here are two accessible pieces from 2007. Slightly old, but the main points are still valid and even explicitly mentioned in the (2010 and 2011) reviews 'cited' by proud mary...

pauleddy

Mon Jan 17 2011, 01:20AM

Registered Member #2909 Joined: Wed Jun 09 2010, 12:31AM
Location: fort belvoir, Va USA ( south of DC)
Posts: 145

I have a small demo device like what you want and i have used the green magnetic sheets to show the EM pulse, i can take pics and mak a vid if you wish i just have to dig it up the Gizmo

Milarepa108

Mon Jan 17 2011, 02:11AM

Registered Member #3620 Joined: Sat Jan 15 2011, 04:16PM
Location:
Posts: 11

pauleddy wrote ...

I have a small demo device like what you want and i have used the green magnetic sheets to show the EM pulse, i can take pics and mak a vid if you wish i just have to dig it up the Gizmo

Sounds awesome I'd love to get some picture of further specs if it's not too much trouble.
What did you use it for?
Is the magnetic pulse really visible on magnetic visualisation sheets? If so that would be really cool!

Also, I'm thinking about getting some ferrofluid. I also read some posts about it here it seems to work great with static magnetic fields. Any guesses about how this would behave when exposed to a magnetic pulse?

pauleddy

Mon Jan 17 2011, 05:36AM

Registered Member #2909 Joined: Wed Jun 09 2010, 12:31AM
Location: fort belvoir, Va USA ( south of DC)
Posts: 145

i have some ferro fluid as well but never thought of using it with the gizmo, mostly when it pulse it atracts iron things, it does launch litle alumium disks about 3M into the air, i have found it it needs new batteries i try to post some pics tomarrrow, it runs off of 8-10 flash caps and a charging board from a disposible camra, it was part of menny demos i built for a regional sci fair to expain magnetic iteractions with non-ferrus conductive materials.

Ash Small

Mon Jan 17 2011, 05:41AM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

Ferrofluid 'recipe' here:

Milarepa108

Mon Jan 17 2011, 05:53AM

Registered Member #3620 Joined: Sat Jan 15 2011, 04:16PM
Location:
Posts: 11

Ash Small wrote ...

Ferrofluid 'recipe' here:

Thanks, this is a nicer writeup of what I've found.
Particle size is reported to be usually in the nanometer scale. Does anyone know if a larger particle size can work reasonably well? Found some "< 45 Âµm" Fe3O4 sold cheaply as a pigment, which could do the trick. A friend of mine is a chemist and could source the components, but the really small particles normally used are quite expensive. Making them using the method above might actually be the cheapest option.

Milarepa108

Mon Jan 17 2011, 05:59AM

Registered Member #3620 Joined: Sat Jan 15 2011, 04:16PM
Location:
Posts: 11

pauleddy wrote ...

i have some ferro fluid as well but never thought of using it with the gizmo, mostly when it pulse it atracts iron things, it does launch litle alumium disks about 3M into the air, i have found it it needs new batteries i try to post some pics tomarrrow, it runs off of 8-10 flash caps and a charging board from a disposible camra, it was part of menny demos i built for a regional sci fair to expain magnetic iteractions with non-ferrus conductive materials.

Launching a little disk in the air is really a cool effect. It doesn't need to reach 3m, though.
What kind of coil did you find to work best with your device? Did you use any additional circuitry? How long does it take for your caps to load?

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