How we can use light to see deep inside our bodies and brains Mary Lou Jepsen
People don’t realize
that red light and benign
near-infrared light
go right through your hand,
just like this.
This fact could enable better,
faster and cheaper health care.
Our translucence is key here.
I’m going to show you how we use
this key and a couple of other keys
to see deep inside our bodies and brains.
OK, so first up …
You see this laser pointer
and the spot it makes on my hand?
The light goes right through my hand –
if we could bring
the lights down, please –
as I’ve already shown.
But you can no longer see that laser spot.
You see my hand glow.
That’s because the light
spreads out, it scatters.
I need you to understand
what scattering is,
so I can show you how we get rid of it
and see deep inside our bodies and brains.
So, I’ve got a piece of chicken back here.
(Laughter)
It’s raw.
Putting on some gloves.
It’s got the same
optical properties as human flesh.
So, here’s the chicken …
putting it on the light.
Can you see, the light goes right through?
I also implanted a tumor in that chicken.
Can you see it?
Audience: Yes.
Mary Lou Jepsen: So this means,
using red light and infrared light,
we can see tumors in human flesh.
But there’s a catch.
When I throw another
piece of chicken on it,
the light still goes through,
but you can no longer see the tumor.
That’s because the light scatters.
So we have to do something
about the scatter
so we can see the tumor.
We have to de-scatter the light.
So …
A technology I spent
the early part of my career on
enables de-scattering.
It’s called holography.
And it won the Nobel Prize
in physics in the 70s,
because of the fantastic things
it enables you to do with light.
This is a hologram.
It captures all of the light,
all of the rays, all of the photons
at all of the positions
and all of the angles, simultaneously.
It’s amazing.
To see what we can do with holography …
You see these marbles?
Look at these marbles
bouncing off of the barriers,
as an analogy to light
being scattered by our bodies.
As the marbles get to the bottom
of the scattering maze,
they’re chaotic, they’re scattering
and bouncing everywhere.
If we record a hologram
at the bottom inside of the screen,
we can record the position and angle
of each marble exiting the maze.
And then we can bring in
marbles from below
and have the hologram direct each marble
to exactly the right position and angle,
such as they emerge in a line
at the top of the scatter matrix.
We’re going to do that with this.
This is optically similar to human brain.
I’m going to switch to green light now,
because green light is brighter
to your eyes than red or infrared,
and I really need you to see this.
So we’re going to put a hologram
in front of this brain
and make a stream of light come out of it.
Seems impossible but it isn’t.
This is the setup you’re going to see.
Green light.
Hologram here, green light going in,
that’s our brain.
And a stream of light comes out of it.
We just made a brain lase
of densely scattering tissue.
Seems impossible,
no one’s done this before,
you’re the first public audience
to ever see this.
(Applause)
What this means is
that we can focus deep into tissue.
Our translucency is the first key.
Holography enabling de-scattering
is the second key
to enable us to see deep inside
of our bodies and brains.
You’re probably thinking,
“Sounds good, but what about
skull and bones?
How are you going to see through the brain
without seeing through bone?”
Well, this is real human skull.
We ordered it at skullsunlimited.com.
(Laughter)
No kidding.
But we treat this skull with great respect
at our lab and here at TED.
And as you can see,
the red light goes right through it.
Goes through our bones.
So we can go through skull
and bones and flesh with just red light.
Gamma rays and X-rays do that, too,
but they cause tumors.
Red light is all around us.
So, using that, I’m going
to come back here
and show you something more useful
than making a brain lase.
We challenged ourselves to see how fine
we could focus through brain tissue.
Focusing through this brain,
it was such a fine focus,
we put a bare camera die in front of it.
And the bare camera die …
Could you turn down the spotlight?
OK, there it is.
Do you see that?
Each pixel is two-thousandths
of a millimeter wide.
Two microns.
That means that spot focus –
full width half max –
is six to eight microns.
To give you an idea of what that means:
that’s the diameter of the smallest neuron
in the human brain.
So that means we can focus
through skull and brain to a neuron.
No one has seen this before,
we’re doing this for the first time here.
It’s not impossible.
(Applause)
We made it work with our system,
so we’ve made a breakthrough.
(Laughter)
Just to give an idea – like,
that’s not just 50 marbles.
That’s billions, trillion of photons,
all falling in line as directed
by the hologram,
to ricochet through
densely scattering brain,
and emerge as a focus.
It’s pretty cool.
We’re excited about it.
This is an MRI machine.
It’s a few million dollars,
it fills a room,
many people have probably been in one.
I’ve spent a lot of time in one.
It has a focus of about a millimeter –
kind of chunky, compared to
what I just showed you.
A system based on our technology
could enable dramatically lower cost,
higher resolution
and smaller medical imaging.
So that’s what we’ve started to do.
My team and I have built a rig, a lab rig
to scan out tissue.
And here it is in action.
We wanted to see how good we could do.
We’ve built this over the last year.
And the result is,
we’re able to find tumors
in this sample –
70 millimeters deep,
the light going in here,
half a millimeter resolution,
and that’s the tumor it found.
You’re probably looking at this,
like, “Sounds good,
but that’s kind of a big system.
It’s smaller than
a honking-big MRI machine,
monster MRI machine,
but can you do something
to shrink it down?”
And the answer is:
of course.
We can replace each
big element in that system
with a smaller component –
a little integrated circuit,
a display chip the size
of a child’s fingernail.
A bit about my background:
I’ve spent the last two decades
inventing, prototype-developing
and then shipping billions of dollars
of consumer electronics –
with full custom chips –
on the hairy edge of optical physics.
So my team and I built the big lab rig
to perfect our architecture
and test the corner cases
and really fine-tune our chip designs,
before spending the millions of dollars
to fabricate each chip.
Our new chip inventions
slim down the system, speed it up
and enable rapid scanning
and de-scattering of light
to see deep into our bodies.
This is the third key to enable
better, faster and cheaper health care.
This is a mock-up of something
that can replace the functionality
of a multimillion-dollar MRI machine
into a consumer electronics price point,
that you could wear as a bandage,
line a ski hat, put inside a pillow.
That’s what we’re building.
(Applause)
Oh, thanks!
(Applause)
So you’re probably thinking,
“I get the light going through our bodies.
I even get the holography
de-scattering the light.
But how do we use these new
chip inventions, exactly,
to do the scanning?”
Well, we have a sound approach.
No, literally – we use sound.
Here, these three discs represent
the integrated circuits
that we’ve designed,
that massively reduce the size
of our current bulky system.
One of the spots, one of the chips,
emits a sonic ping,
and it focuses down,
and then we turn red light on.
And the red light that goes
through that sonic spot
changes color slightly,
much like the pitch
of the police car siren changes
as it speeds past you.
So.
There’s this other thing about holography
I haven’t told you yet,
that you need to know.
Only two beams of exactly the same color
can make a hologram.
So, that’s the orange light
that’s coming off of the sonic spot,
that’s changed color slightly,
and we create a glowing disc
of orange light
underneath a neighboring chip
and then record a hologram
on the camera chip.
Like so.
From that hologram, we can extract
information just about that sonic spot,
because we filter out
all of the red light.
Then, we can optionally
focus the light back down into the brain
to stimulate a neuron
or part of the brain.
And then we move on
to shift the sonic focus to another spot.
And that way, spot by spot,
we scan out the brain.
Our chips decode holograms
a bit like Rosalind Franklin decoded
this iconic image of X-ray diffraction
to reveal the structure of DNA
for the first time.
We’re doing that electronically
with our chips,
recording the image
and decoding the information,
in a millionth of a second.
We scan fast.
Our system may be extraordinary
at finding blood.
And that’s because blood absorbs
red light and infrared light.
Blood is red.
Here’s a beaker of blood.
I’m going to show you.
And here’s our laser,
going right through it.
It really is a laser,
you can see it on the – there it is.
In comparison to my pound of flesh,
where you can see
the light goes everywhere.
So let’s see that again, blood.
This is really key: blood absorbs light,
flesh scatters light.
This is significant,
because every tumor bigger
than a cubic millimeter or two
has five times the amount of blood
as normal flesh.
So with our system, you can imagine
detecting cancers early,
when intervention is easy,
or tracking the size of your tumor
as it grows or shrinks.
Our system also should be extraordinary
at finding out where blood isn’t,
like a clogged artery,
or the color change in blood
as it carries oxygen
versus not carrying oxygen,
which is a way to measure neural activity.
There’s a saying that “sunlight”
is the best disinfectant.
It’s literally true.
Researchers are killing pneumonia in lungs
by shining light deep inside of lungs.
Our system could enable this
noninvasively.
Let me give you three more examples
of what this technology can do.
One: stroke.
There’s two major kinds of stroke:
the one caused by clogs
and another caused by rupture.
If you can determine the type of stroke
within an hour or two,
you can give medication to massively
reduce the damage to the brain.
Get the drug wrong,
and the patient dies.
Today, that means access to an MRI scanner
within an hour or two of a stroke.
Tomorrow, with compact, portable,
inexpensive imaging,
every ambulance and every clinic
can decode the type of stroke
and get the right therapy on time.
(Applause)
Thanks.
Two:
two-thirds of humanity
lacks access to medical imaging.
Compact, portable, inexpensive
medical imaging can save countless lives.
And three:
brain-computer communication.
I’ve shown here onstage our system
focusing through skull and brain
to the diameter of the smallest neuron.
Using light and sound,
you can activate or inhibit neurons,
and simultaneously,
we can match spec by spec
the resolution of an fMRI scanner,
which measures oxygen use in the brain.
We do that by looking
at the color change in the blood,
rather than using a two-ton magnet.
So you can imagine
that with fMRI scanners today,
we can decode the imagined words,
images and dreams of those being scanned.
We’re working on a system
that puts all three of these capabilities
into the same system –
neural read and write
with light and sound,
while simultaneously
mapping oxygen use in the brain –
all together in a noninvasive portable
that can enable
brain-computer communication,
no implants, no surgery,
no optional brain surgery required.
This can do enormous good
for the two billion people
that suffer globally with brain disease.
(Applause)
People ask me how deep we can go.
And the answer is:
the whole body’s in reach.
But here’s another way to look at it.
(Laughter)
My whole head just lit up,
you want to see it again?
Audience: Yes!
(Laughter)
MLJ: This looks scary, but it’s not.
What’s truly scary
is not knowing about our bodies,
our brains and our diseases
so we can effectively treat them.
This technology can help.
Thank you.
(Applause)
Thank you.
(Applause)