Dr. Glen Jeffery

So it is absorbed by deoxygenated blood.

So you get fantastic pictures of your veins in your hand or in your head.

But the most obvious thing that you think is that long wavelength light will be blocked by something thick like a skull.

The answer is no.

Yes, and I had exactly the same problem.

I had exactly the same problem.

If you put a radiometer and a spectrometer to measure the energy and the wavelength on one side of someone's head and a light source on the other side of someone's head, you get a clear result.

Now, interestingly, it's not a sideline.

It's actually a very important issue.

A biomedical engineer, Elias Tachtanidis at UCL, has used this because he works on, some of his work is on neonates that have had stroke.

And he takes the neonate and actually does exactly that experiment.

He passes red light, wavelengths of light, through the side of the neonate's head and records them coming out the other side.

And he can use that as a metric of how well the mitochondria are functioning in that damaged brain.

And the readouts that he gets are readouts that are indicative of the potential survival of that neonate.

Wow.

Now, I think there are lots of wows here.

First of all, he's got his work into a major London teaching and research hospital.

He's got it into kids.

And we've acknowledged that this is not dangerous.

He's gone through loads of ethics committees.