This only works on white patients, so if it actually becomes clinically useful it will be pretty controversial.
> This only works on white patients
Where did you read that in the article? I couldn't find it.
Photon transport through the entire adult human head
21–29 of 29 posts
Re: Photon transport through the entire adult human head
#22This only works on white patients, so if it actually becomes clinically useful it will be pretty controversial.
> This only works on white patients Where did you read that in the article? I couldn't find it.
First paragraph of the "4. Discussion and Conclusion" section
> We speculate that the participant’s fair skin and lack of hair were significant factors that reduced the attenuation of light to feasibly detect a signal. In addition to the participant wherein a signal was observed, the experiment also included trials on seven other subjects. The details of the subject pool are as follows: two females and six males; 25 to 35 years old; 14.5 to 15.5 cm head diameter; Fitzpatrick skin types: 3 type I, 4 type II, and 1 type V; hair types: 1 bald, 4 short and light-colored, and three dense and dark-colored. We did not observe any significant time-correlated signals above background noise for the seven other subjects.
Re: Photon transport through the entire adult human head
#23Wow, weak signal... "The measured experimental attenuation was found to be of the order 10^18, corresponding to a detection of around one photon per second for a 1.2 W source."
So, around a factor of 10 per cm. I would have expected way worse.
Re: Photon transport through the entire adult human head
#24Earlier quoted context omitted.
> Moreover, an advantage of standard fNIRS is the high spatial specificity, and it is not clear how to actually translate the light intensity data in their case to brain activation (and probably it is going to be very noisy) as the light transverses all the head. The X-rays in CT scans also transverse all the head. Would it be possible to use the same algorithms as CT to construct a 3D image with this tech?
IIRC the highly diffractive nature of the medium limits resolution to something like 1 cm^3. I’m not an expert but I talked with some people working in the field a few years ago and this is what I remember. The computational problem is almost intractable. No short term brain computer interface with optical techniques just yet.
No thought screening in airports and public spaces either. ;)
Re: Photon transport through the entire adult human head
#25Earlier quoted context omitted.
inserting a medical light bulb in the pattients mouth will decrease the distance the light has to travel, and presumably it could be a high intensity "flash" tuned to conditions with very precisely known timing
In the nose as well.
Suddenly, the idea of aliens sticking probes into various orifices takes on a new light...
Re: Photon transport through the entire adult human head
#26Clicked it because I thought they teleported a photon through a head.
Teleport is not a thing a photon can do. Leave alone across brain
Re: Photon transport through the entire adult human head
#27This uses near-infrared light, building on current techniques of using near-infrared light in shorter source/detector paths to measure fluctuations of oxygenated/deoxygenated haemoglobin on the cortex of the brain as a proxy of brain activity. The standard technique is called functional near-infrared spectroscopy, and is similar to fMRI but can only look into superficial brain tissue and not subcortical brain structu…
> Moreover, an advantage of standard fNIRS is the high spatial specificity, and it is not clear how to actually translate the light intensity data in their case to brain activation (and probably it is going to be very noisy) as the light transverses all the head. The X-rays in CT scans also transverse all the head. Would it be possible to use the same algorithms as CT to construct a 3D image with this tech?
that was the premise of Mary Lou Jepsen's startup, OpenWater. I was fascinated by it but I'm not sure what became of it.
Re: Photon transport through the entire adult human head
#28Clicked it because I thought they teleported a photon through a head.
Teleport is not a thing a photon can do. Leave alone across brain
I don’t think we know enough about science to know whether teleporting a photon is something we can do or not, for example maybe we can via micro wormholes or quantum tunneling or some other frequency anomaly that cancels out strong/weak atomic forces so that an object can be accurately displaced (“teleported”) through other objects.
Once you figure out the “through other objects” part, I guess it just becomes an energy control problem, ie how to get object A to location B accurately, and decelerate it, before the effect wears off. Which is maybe not so hard when you have a teleport sender and receiver that can do the acceleration and deceleration.
Hypothetically the sender would estimate the trajectory required to hit the receiver then sync/teleport an inert beam of atoms (photos or something) with it. Then, once sync has been established you would know the trajectory settings to use, perhaps it would be a giga-energy problem to ie phase the object, accelerate it to light speed, then receive it at the destination and un-phase it. This would allow you to ie teleport living things without the morale dilemma of losing their original consciousness.
The practical distance would be based on the achievable speed ie how far can we shoot something before it phases back. You can cover a pretty big distance in 1us at the speed of light! Around 300m. If you can keep something phased for 10ms, you could go 3000km, at which point you just form a network of receivers.
(Just an exercise, don’t take it seriously!)
Re: Photon transport through the entire adult human head
#29Earlier quoted context omitted.
Teleport is not a thing a photon can do. Leave alone across brain
I don’t think we know enough about science to know whether teleporting a photon is something we can do or not, for example maybe we can via micro wormholes or quantum tunneling or some other frequency anomaly that cancels out strong/weak atomic forces so that an object can be accurately displaced (“teleported”) through other objects. Once you figure out the “through other objects” part, I guess it just becomes an ene…
Hypothetically my ancestors were cheetah and not hominoid apes. One needs to prove foundational hypothesis before larger claims that can be built on top of those.