<p>For experimental purposes, an electrode array or comparable 2D device can be mounted and re-mounted on the same spot by using <strong>visual markers</strong>, e.g. with water resistant ink. By using a matrix of actuators with a back and front, and a clearly defined "up and down" (and/or left and right) one could suffice by just two little spots on the skin.</p>

<p>Alternatively, stable <strong>bodily features</strong> can be used when applicable. For example ribs and vertebrae are stable positions that can serve as markers.</p>

<p>A more sophisticated means is a <strong>stereotactic procedure</strong>. For example the head can be easily fixated using a chin rest and head support on the forehead. This pretty much fixates the head. This is for example used with repetitive transcranial magnetic stimulation, as shown in the figure below:</p>

<p><img src="https://i.sstatic.net/ki78R.png" alt="stereotactic frame"><br>
<sup>Source: <a href="https://www.google.com.au/url?sa=i&amp;rct=j&amp;q=&amp;esrc=s&amp;source=images&amp;cd=&amp;cad=rja&amp;uact=8&amp;ved=0CAUQjhw&amp;url=http%3A%2F%2Fwww.hospimedicaintl.com%2Findex.php%3FcPath%3D9_54%26crdID%3D133b9d822eea155e9a3b457aa2c2e89b&amp;ei=JpMSVdmVIsqD8gWDn4DgAQ&amp;bvm=bv.89217033,d.dGc&amp;psig=AFQjCNHwgqUaGHFVsvRD9BFLleESiGThuQ&amp;ust=1427367020161719" rel="nofollow noreferrer">Hospimedica</a></sup></p>

<p>Although this list is not exhaustive, it gives an idea of possibilities.</p>

CC BY-SA 3.0
2015-03-25T11:03:57.507Z
2015-03-25T11:03:57.507Z
AliceD
<p>I am interested in knowing if there are state-of-the-art, non-invasive techniques that could be put on, and taken off from the user's body several times without compromising positioning accuracies. </p>

<p>For example an array of electrodes that is meant to repeatedly stimulate some exact spots on the skin. For example, putting such actuators on a T-shirt or on the sole of a shoe wouldn't be very accurate and deterministic.</p>

CC BY-SA 3.0
2015-01-11T12:51:24.593Z
Could you specify what 'non-invasive techniques' you are exactly interested in? Your example of an electrode array could be realized by using water resistant ink and marking two or more spots on the skin. Too easy. For example, to give an example of two very different techniques - TMS targeting specific brain regions is often applied multiple times for several sessions, and radiotherapy in cancer patients relies on strictly defined radiation beam trajectories across multiple treatment sessions. ps: I edied your question somewhat to increase clarity, feel free to roll back.
AliceD
CC BY-SA 3.0
2015-01-13T01:33:07.500Z
Thanks for editing. What I mean by not invasive is that it can be removed and put on easily without leaving permanent marks on the body. Ink would be a solution but I would need much more than two spots, maybe few hundreds. I first have to check how high is the resolution of the skin to feel two stimulated close spots as spatially different.
Mehdi
CC BY-SA 3.0
2015-01-13T01:53:54.520Z
If you mount the electrodes on a solid, square-shaped carrier then 2 points suffice. What exactly are you planning to do?
AliceD
CC BY-SA 3.0
2015-01-22T05:19:01.550Z
Sounds a lot like the work of Bach-y-Rita: http://en.wikipedia.org/wiki/Sensory_substitution#Tactile.E2.80.93visual_substitution, maybe check those studies to see what technology they use...
Arnon Weinberg
CC BY-SA 3.0
2015-01-22T07:48:02.910Z
You guessed right, I was fascinated by those experiments and was curious about how far one can further exploit brain plasticity by having a permanent stimulating feedback instead of only during few sessions.
Mehdi
CC BY-SA 3.0
2015-01-25T14:20:42.137Z
If that work is what fascinated you, referencing it would help us understand what you're asking.
Seanny123
CC BY-SA 3.0
2015-02-07T06:44:05.420Z
@ChrisStronks thanks but you might haven't noticed that that question is also mine :D
Mehdi
CC BY-SA 3.0
2015-02-10T12:55:44.463Z
The question is getting increasingly more votes to be closed due to lack of question clarity. If you could clarify your answer? There have been a lot of useful comments.
AliceD
CC BY-SA 3.0
2015-02-11T02:59:15.657Z
@ChrisStronks please feel free to put your first and third comments as an answer.
Mehdi
<stimulation>
Methods for stimulating exact positions in the body
Mehdi
# Methods for stimulating exact positions in the body

(Asked by: username_0 on 2015-01-11)

I am interested in knowing if there are state-of-the-art, non-invasive techniques that could be put on, and taken off from the user's body several times without compromising positioning accuracies.

For example an array of electrodes that is meant to repeatedly stimulate some exact spots on the skin. For example, putting such actuators on a T-shirt or on the sole of a shoe wouldn't be very accurate and deterministic.

**Tags:** stimulation

> **Comments:**
> **username_1**: Could you specify what 'non-invasive techniques' you are exactly interested in? Your example of an electrode array could be realized by using water resistant ink and marking two or more spots on the skin. Too easy. For example, to give an example of two very different techniques - TMS targeting specific brain regions is often applied multiple times for several sessions, and radiotherapy in cancer patients relies on strictly defined radiation beam trajectories across multiple treatment sessions. ps: I edied your question somewhat to increase clarity, feel free to roll back.  
> **username_0**: Thanks for editing. What I mean by not invasive is that it can be removed and put on easily without leaving permanent marks on the body. Ink would be a solution but I would need much more than two spots, maybe few hundreds. I first have to check how high is the resolution of the skin to feel two stimulated close spots as spatially different.  
> **username_1**: If you mount the electrodes on a solid, square-shaped carrier then 2 points suffice. What exactly are you planning to do?  
> **username_2**: Sounds a lot like the work of Bach-y-Rita: http://en.wikipedia.org/wiki/Sensory_substitution#Tactile.E2.80.93visual_substitution, maybe check those studies to see what technology they use...  
> **username_0**: You guessed right, I was fascinated by those experiments and was curious about how far one can further exploit brain plasticity by having a permanent stimulating feedback instead of only during few sessions.  
> **username_3**: If that work is what fascinated you, referencing it would help us understand what you're asking.  
> **username_0**: @ChrisStronks thanks but you might haven't noticed that that question is also mine :D  
> **username_1**: The question is getting increasingly more votes to be closed due to lack of question clarity. If you could clarify your answer? There have been a lot of useful comments.  
> **username_0**: @ChrisStronks please feel free to put your first and third comments as an answer.  

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## 1 answers

### Answer by username_1 on 2015-03-25. Score: 4 | Accepted answer

For experimental purposes, an electrode array or comparable 2D device can be mounted and re-mounted on the same spot by using **visual markers**, e.g. with water resistant ink. By using a matrix of actuators with a back and front, and a clearly defined "up and down" (and/or left and right) one could suffice by just two little spots on the skin.

Alternatively, stable **bodily features** can be used when applicable. For example ribs and vertebrae are stable positions that can serve as markers.

A more sophisticated means is a **stereotactic procedure**. For example the head can be easily fixated using a chin rest and head support on the forehead. This pretty much fixates the head. This is for example used with repetitive transcranial magnetic stimulation, as shown in the figure below:

![stereotactic frame](https://i.sstatic.net/ki78R.png)  
Source: [Hospimedica](https://www.google.com.au/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAUQjhw&url=http%3A%2F%2Fwww.hospimedicaintl.com%2Findex.php%3FcPath%3D9_54%26crdID%3D133b9d822eea155e9a3b457aa2c2e89b&ei=JpMSVdmVIsqD8gWDn4DgAQ&bvm=bv.89217033,d.dGc&psig=AFQjCNHwgqUaGHFVsvRD9BFLleESiGThuQ&ust=1427367020161719)

Although this list is not exhaustive, it gives an idea of possibilities.


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