Jump to content
Mechanical Engineering

Vibration Sensor compatible with MRI


Recommended Posts

Hello fellow engineers,

I am working with a 7 Tesla MRI system and I would like to measure the vibrations caused by the system during the scanning.

I am looking for a sensor which is compatible with MRIs. Or, alternatively, I am looking for the vibration measurement methods for MRI systems.

Would appreciate if you can share your knowledge in this field.
Thanks in advance,
Ender

Link to comment
Share on other sites

Hi there

I think your best bet may be to "throw together" a non-metallic seismometer.

With electronics, you'll get an analogue output (which may then be digitised). The problem with an MRI - particularly one of 7T - is you'll get a EM induction in the wires as a result of the oscillating field, so electronic sensors are a problem.

If you make up a rotating drum with a graph paper and have the pencil-stylus retained on - say - a bamboo BBQ skewer (readily available). For springs, I'd use a couple of thin (light) elastic bands.

It is not enough to utilise non-ferrous metals as their movement through a magnetic field (or within one) will induce magnetic field vortices within the metal, which will completely deaden (or amplify) their response, so you need to move away from that risk completely.

The drum can be driven by a rubber belt driven by a motor from a safe distance (I think it's an inverse-square-law for a mag field...but that is an assumption, so CHECK!)

The key is to avoid metals completely and use very dry materials.

It should be relatively straightforward to calculate and verify the sensitivity of the unit by testing.

I have to ask...is that the UCL Unit at the Wellcome centre..?

I do hope this helps!

 

Bruce

Link to comment
Share on other sites

Hello Bruce,

Thank you for you detailed explanation, very helpful indeed.  

I was thinking about using shielded accelerometers and asked for a quotation form different companies. However, it seems that MEMS solutions are more logical in this case. 

Your solution with seismometer is very interesting, I will discuss it with my colleagues. Hope I will be able to do it. 

No, I am not working at the UCL. This is for a project at a company I am working in Germany.

Thank you one more time for your answer.

Ender

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Join Mechanical Engineering network

    Join us (login) to get full access : Please sign up to connect and participate.

    To download files...please login

  • Who's Online   0 Members, 0 Anonymous, 5 Guests (See full list)






×
×
  • Create New...