You should contact Hamamatsu for this. 2 concerns about underwater: 1) the electronics are not designed for water submersion and 2) contact/light shielding may be an issue. Perhaps there is a way that you can waterproof the system so that you address the 2 above concerns...

Thanks Celena. I wrote to Hamamatsu, and hopefully they will get back to me soon. I thought about how best to make the sensors waterproof, possibly by encasing them in a plastic case, which would have a waterproof seal. But that just speculation, if it would work. Maybe someone has tried this already.

Check the literature in brain NIRS use (cooling). They might be under moisture conditions because of the ice.

Good idea!

Hi, you can check out this article " Influence of postexercise cooling on muscle oxygenation and blood volume changes."

http://www.ncbi.nlm.nih.gov/pubmed/23247707

Thanks Hui!

For anyone that is interested, I contacted the Hamamatsu company concenring this matter. I was informed that full water immersion of the probes may not be damaging to the actual sensor, but the real danger posed are the NIRO sensors shocking a human subject under water. Granted, this is only theoretical knowledge, as no experiment with a human underwater was performed by the company. However, with Tegaderm tape, one could make the sensors water-proof. The questions is, how to avoid any danger to someone wearing the sensors under-water.

Hi Michael,

this might be of interest to you, though it's single channel nirs:

http://biomedicaloptics.spiedigitallibrary.org/article.aspx?articleid=2022244

Disclaimer: I am working for Artinis

Cool, thanks Jörn, ill take a look at the link later today.

The NIRO300 uses laser light and therefore is using fiberoptic cables and therefore, electrocution or water should not be a problem as long as the water is kept from getting between the probes and the skin. This is unlike the Coviden NIRS.    

Hey Edwin.

Thats what I was thinking, but, the question is, the best way to waterproof the probes. Tegaderm tape is not completely water-proof. Possibly building some sort of plastic case? Duct tape?

Hi, Michael, 

I'm not sure but if there isn't too much manipulation under water putting torque on the probes while in use under water, you might just try using the sticky applicator provided with the probes making sure the skin is thoroughly cleaned with alcohol and wiped dry before applying the probes.  It should keep the water out from between the skin and the probes.  Duct tape over the entire thing may stabilize it further.  If water gets between the probes and skin you should see it in the readings you get. 

Good luck, 

Edwin

Thanks for the advice Edwin. Ill let you know what happens.

I'll be interested in hearing how it works. 

Best, 

Edwin

If you just use fibre optics for source and detector should work

http://repository.essex.ac.uk/12150/1/JBO_19_12_127002.pdf

Hey David, thanks for the article recomendation. After reading it, it appears that using something like the Iswim (a waterproof seal for smart phones) may work to our advantage, with a few modifications.

Hi Michael,

Stumbling upon this question I realized we did an underwater NIRS-measurement for a Japanse TV show called 'Miracle Body'. Even though this question was posted a while ago the footage might be of special interest to you:

https://www.youtube.com/watch?v=eI_hQzfldqQ

The device used in this show was a waterproofed Portamon which actually worked very well underwater. At 58 seconds into the movie the device itself is shown.  

Best regards,

Mathijs Bronkhorst

A small disclaimer, I work for Artinis who build and waterproofed this device.