Sheila Nirenberg: A prosthetic eye to treat blindness

Translator: Lenka Tušar Reviewer: Tilen Pigac - EFZG

I study how the brain processes

Pri svojem delu preučujem, kako možgani

information. That is, how it takes

obdelujejo podatke oz. kako podatke

information in from the outside world, and

iz zunanjega sveta spremenijo

converts it into patterns of electrical activity,

v vzorce električne dejavnosti

and then how it uses those patterns

in kako nam preko teh vzorcev

to allow you to do things --

omogočajo, da vidimo,

to see, hear, to reach for an object.

slišimo ali sežemo po predmetu.

So I'm really a basic scientist, not

Moje preučevanje je zastavljeno osnovno,

a clinician, but in the last year and a half

ne klinično, a v zadnjem letu in pol

I've started to switch over, to use what

sem se preusmerila v uporabo

we've been learning about these patterns

ugotovitev o teh vzorcih delovanja

of activity to develop prosthetic devices,

za razvoj prostetičnih naprav

and what I wanted to do today is show you

in danes bi vam rada predstavila

an example of this.

primer take naprave.

It's really our first foray into this.

To je naš prvi tak podvig.

It's the development of a prosthetic device

Gre za razvoj prostetične naprave

for treating blindness.

za zdravljenje slepote.

So let me start in on that problem.

Naj začnem s tem problemom.

There are 10 million people in the U.S.

V ZDA je 10 milijonov ljudi,

and many more worldwide who are blind

po svetu pa še mnogo več, ki so slepi

or are facing blindness due to diseases

ali pa se s slepoto soočajo zaradi

of the retina, diseases like

bolezni očesne mrežnice,

macular degeneration, and there's little

kot je degeneracija rumene pege,

that can be done for them.

a zanje ni veliko upanja.

There are some drug treatments, but

Obstajajo sicer zdravila, ki pa

they're only effective on a small fraction

učinkujejo le na majhnem delu ljudi.

of the population. And so, for the vast

Za veliko večino bolnikov je torej

majority of patients, their best hope for

največ upanja za obnovo vida

regaining sight is through prosthetic devices.

prav v prostetičnih napravah.

The problem is that current prosthetics

Težava pa je, da trenutno obstoječe

don't work very well. They're still very

protetične naprave niso zelo učinkovite.

limited in the vision that they can provide.

Podobe, ki jih omogočajo, so še vedno zelo omejene.

And so, you know, for example, with these

Preko takih naprav lahko

devices, patients can see simple things

bolniki vidijo preproste stvari, kot so

like bright lights and high contrast edges,

močna svetloba ali visoki kontrasti,

not very much more, so nothing close

a ne veliko več, zato ne omogočajo

to normal vision has been possible.

primerljivosti z normalnim vidom.

So what I'm going to tell you about today

Danes vam bom pripovedovala o napravi,

is a device that we've been working on

ki jo razvijamo in za katero menim,

that I think has the potential to make

da lahko predstavlja napredek

a difference, to be much more effective,

in je precej bolj učinkovita,

and what I wanted to do is show you

zato bi vam rada pokazala, kako deluje.

how it works. Okay, so let me back up a

Za začetek pa naj pokažem,

little bit and show you how a normal retina

kako deluje zdrava očesna mrežnica,

works first so you can see the problem

da boste videli težavo,

that we were trying to solve.

ki jo poskušamo rešiti.

Here you have a retina.

V sredini je očesna mrežnica.

So you have an image, a retina, and a brain.

Imamo sliko, mrežnico in možgane.

So when you look at something, like this image

Ko nekaj vidite, v tem primeru sliko

of this baby's face, it goes into your eye

otroškega obraza, se podoba projicira

and it lands on your retina, on the front-end

na vaši mrežnici, na prvi vrsti celic

cells here, the photoreceptors.

oz. fotoreceptorjih.

Then what happens is the retinal circuitry,

Nato živčno vezje na mrežnici

the middle part, goes to work on it,

oz. srednji del to podobo obdela,

and what it does is it performs operations

z njo upravlja

on it, it extracts information from it, and it

in iz nje zbere podatke,

converts that information into a code.

ki jih spremeni v kodo.

And the code is in the form of these patterns

Koda se v obliki vzorcev

of electrical pulses that get sent

električnih signalov prenese v možgane,

up to the brain, and so the key thing is

ključnega pomena je torej,

that the image ultimately gets converted

da se podoba pretvori v kodo.

into a code. And when I say code,

Izraz kodo v tem primeru

I do literally mean code.

pomeni dobesedno to.

Like this pattern of pulses here actually means "baby's face,"

Ta vzorec signalov pomeni "otroški obraz"

and so when the brain gets this pattern

in ko ga možgani sprejmejo,

of pulses, it knows that what was out there

izvejo, da smo videli

was a baby's face, and if it

otroški obraz

got a different pattern it would know

in bi ob drugačnem vzorcu izvedeli,

that what was out there was, say, a dog,

da smo videli, na primer, psa,

or another pattern would be a house.

ob spet drugačnem pa morda hišo.

Anyway, you get the idea.

Razumete, kaj želim povedati.

And, of course, in real life, it's all dynamic,

V resničnem življenju je seveda vse gibljivo

meaning that it's changing all the time,

in se stalno spreminja,

so the patterns of pulses are changing

zato se tudi vzorci signalov nenehno spreminjajo

all the time because the world you're

hkrati s svetom, ki ga gledamo

looking at is changing all the time too.

in ki se prav tako stalno spreminja.

So, you know, it's sort of a complicated

Gre torej za zapleteno stvar.

thing. You have these patterns of pulses

Ti vzorci signalov iz vaših oči

coming out of your eye every millisecond

vsako milisekundo sporočajo

telling your brain what it is that you're seeing.

vašim možganom, kaj vidite.

So what happens when a person

Kaj pa se zgodi, ko oseba zboli za

gets a retinal degenerative disease like

degenerativno boleznijo,

macular degeneration? What happens is

kot je degeneracija rumene pege?

is that, the front-end cells die,

V tem primeru celice v ospredju

the photoreceptors die, and over time,

oz. fotoreceptorji odmrejo

all the cells and the circuits that are

in sčasoma odmrejo tudi vse celice

connected to them, they die too.

in vezja, ki so z njimi povezana.

Until the only things that you have left

Na koncu ostanejo le še te celice,

are these cells here, the output cells,

izhodne celice, ki pošiljajo

the ones that send the signals to the brain,

signale možganom,

but because of all that degeneration

a zaradi neaktivnih celic pred njimi

they aren't sending any signals anymore.

ni več niti signalov.

They aren't getting any input, so

Ker ničesar ne sprejemajo,

the person's brain no longer gets

tudi možgani ne prejmejo

any visual information --

nobenih vizualnih podatkov,

that is, he or she is blind.

kar povzroči slepoto.

So, a solution to the problem, then,

Rešitev tega problema bi torej bil

would be to build a device that could mimic

razvoj naprave, ki bi posnemala

the actions of that front-end circuitry

dejanja živčnih vezij v ospredju

and send signals to the retina's output cells,

in pošiljala signale izhodnim celicam mrežnice,

and they can go back to doing their

ki bi lahko nadaljevale z običajnim

normal job of sending signals to the brain.

pošiljanjem signalov možganom.

So this is what we've been working on,

S tem smo se torej ukvarjali

and this is what our prosthetic does.

in tako deluje naša prostetična naprava.

So it consists of two parts, what we call

Sestavljena je iz dveh delov, ki jim pravimo

an encoder and a transducer.

kodirnik in pretvornik.

And so the encoder does just

Naloga kodirnika je torej, kot rečeno,

what I was saying: it mimics the actions

posnemanje dejavnosti sprednjih

of the front-end circuitry -- so it takes images

vezij mrežnice -- sprejemanje podob

in and converts them into the retina's code.

in njihovo pretvarjanje v kodo na mrežnici.

And then the transducer then makes the

Pretvornik nato omogoči

output cells send the code on up

izhodnim celicam,

to the brain, and the result is

da pošljejo kodo v možgane,

a retinal prosthetic that can produce

rezultat tega je torej prostetična mrežnica,

normal retinal output.

ki lahko izvede običajen prenos podatkov na mrežnici.

So a completely blind retina,

To omogoči tudi popolnoma slepi mrežnici,

even one with no front-end circuitry at all,

celo taki brez sprednjih vezij,

no photoreceptors,

brez fotoreceptorjev,

can now send out normal signals,

da v možgane pošlje normalne signale,

signals that the brain can understand.

ki jih lahko možgani razumejo.

So no other device has been able

Nobena druga naprava

to do this.

še ni tega omogočala.

Okay, so I just want to take

Rada bi povedala še

a sentence or two to say something about

stavek ali dva

the encoder and what it's doing, because

o kodirniku in njegovem delu,

it's really the key part and it's

saj gre za ključen del,

sort of interesting and kind of cool.

ki je zanimiv in na nek način kul.

I'm not sure "cool" is really the right word, but

Morda "kul" ni ravno prava beseda,

you know what I mean.

a vseeno razumete, kaj želim povedati.

So what it's doing is, it's replacing

Naloga kodirnika je torej, da nadomesti

the retinal circuitry, really the guts of

bistvo živčnih vezij na mrežnici

the retinal circuitry, with a set of equations,

z vrsto enačb,

a set of equations that we can implement

ki jih lahko vnesemo na čip.

on a chip. So it's just math.

Gre torej za čisto matematiko.

In other words, we're not literally replacing

Z drugimi besedami, ne gre dobesedno za

the components of the retina.

nadomeščanje sestavnih delov mrežnice.

It's not like we're making a little mini-device

Ne razvijamo majčkene napravice

for each of the different cell types.

za vsako od različnih tipov celic.

We've just abstracted what the

Le povzeli smo način,

retina's doing with a set of equations.

kako mrežnica upravlja vrsto enačb.

And so, in a way, the equations are serving

Na nek način te enačbe predstavljajo

as sort of a codebook. An image comes in,

neke vrste kodirno knjigo.

goes through the set of equations,

Ko podoba vstopi, gre preko vrste enačb,

and out comes streams of electrical pulses,

njen izid pa so tokovi električnih signalov,

just like a normal retina would produce.

taki, kot bi nastali na zdravi mrežnici.

Now let me put my money

Naj zdaj preidem od besed k dejanjem

where my mouth is and show you that

in vam pokažem,

we can actually produce normal output,

da lahko dejansko ustvarimo običajen podatek

and what the implications of this are.

in kako lahko to uporabimo.

Here are three sets of

Tu imamo tri različne vzorce signalov.

firing patterns. The top one is from

Zgornji predstavlja signale pri zdravi živali,

a normal animal, the middle one is from

srednji signale pri slepi, ki jo zdravimo

a blind animal that's been treated with

z našo napravo s kodirnikom in pretvornikom,

this encoder-transducer device, and the

spodnja pa predstavlja

bottom one is from a blind animal treated

signale pri slepi živali, ki jo zdravimo

with a standard prosthetic.

z običajno prostetično napravo.

So the bottom one is the state-of-the-art

Gre za najsodobnejšo prostetično

device that's out there right now, which is

napravo, ki je trenutno na voljo,

basically made up of light detectors,

in ki jo sestavljajo detektorji svetlobe,

but no encoder. So what we did was we

ne pa tudi kodirnik.

presented movies of everyday things --

Predvajali smo posnetke vsakdanjih stvari --

people, babies, park benches,

ljudi, otrok, klopi v parku --

you know, regular things happening -- and

stvari okoli nas

we recorded the responses from the retinas

in beležili odzive mrežnic

of these three groups of animals.

teh treh skupin živali.

Now just to orient you, each box is showing

Za boljšo predstavo, vsak okvir prikazuje

the firing patterns of several cells,

vzorce signalov večih celic

and just as in the previous slides,

in tako kot ste videli prej,

each row is a different cell,

vsaka vrsta predstavlja drugačne celice,

and I just made the pulses a little bit smaller

signali pa so nekoliko skrajšani in zoženi,

and thinner so I could show you

da lahko prikažem

a long stretch of data.

širši obseg podatkov.

So as you can see, the firing patterns

Kot vidite, vzorci signalov pri

from the blind animal treated with

slepi živali, ki jo zdravimo s sistemom

the encoder-transducer really do very

kodirnika in pretvornika,

closely match the normal firing patterns --

so zelo podobni običajnim vzorcem --

and it's not perfect, but it's pretty good --

niso identični, a je podobnost velika --

and the blind animal treated with

medtem ko se signali pri živali,

the standard prosthetic,

zdravljeni z običajnimi prostetiki,

the responses really don't.

od zdravih precej razlikujejo.

And so with the standard method,

Pri običajni metodi

the cells do fire, they just don't fire

celice širijo signale,

in the normal firing patterns because

ki pa ne tvorijo običajnega vzorca signalov,

they don't have the right code.

ker nimajo prave kode.

How important is this?

Kako pomembno je to?

What's the potential impact

Kako lahko to odkritje vpliva

on a patient's ability to see?

na bolnikove možnosti, da spet vidi?

So I'm just going to show you one

Namesto odgovora vam bom pokazala

bottom-line experiment that answers this,

bistveni poskus,

and of course I've got a lot of other data,

seveda pa imam še veliko drugih podatkov,

so if you're interested I'm happy

ki jih z veseljem delim z vami,

to show more. So the experiment

če vas zanimajo.

is called a reconstruction experiment.

Gre za poskus rekonstrukcije.

So what we did is we took a moment

Pri tem smo se osredotočili na

in time from these recordings and asked,

določen trenutek v teh posnetkih in se vprašali,

what was the retina seeing at that moment?

kaj v tem trenutku mrežnica zaznava?

Can we reconstruct what the retina

Ali lahko obnovimo podatke,

was seeing from the responses

ki jih mrežnica zazna

from the firing patterns?

iz odziva na vzorce signalov?

So, when we did this for responses

Zanimali so nas odzivi

from the standard method and from

pri običajni metodi

our encoder and transducer.

ter pri našem kodirniku in pretvorniku.

So let me show you, and I'm going to

Za začetek naj vam pokažem

start with the standard method first.

izsledke pri običajni metodi.

So you can see that it's pretty limited,

Vidite, da je podoba zelo nejasna

and because the firing patterns aren't

in ker vzorci signalov

in the right code, they're very limited in

niso v pravi kodi,

what they can tell you about

možganom zelo omejeno poročajo o videnem.

what's out there. So you can see that

Vidite, da gre za nek predmet,

there's something there, but it's not so clear

a ne veste, za kaj točno gre,

what that something is, and this just sort of

kar zopet povzema to,

circles back to what I was saying in the

o čemer sem govorila na začetku,

beginning, that with the standard method,

namreč da pri običajni metodi

patients can see high-contrast edges, they

bolniki zaznavajo le visoke kontraste

can see light, but it doesn't easily go

in svetlobo, največkrat pa je to vse.

further than that. So what was

Kaj je torej na sliki?

the image? It was a baby's face.

Otroški obraz.

So what about with our approach,

Kaj pa se zgodi pri našem pristopu

adding the code? And you can see

in uporabi dodane kode?

that it's much better. Not only can you

Vidite, da je dosti bolje. Ne samo,

tell that it's a baby's face, but you can

da zaznate, da gre za otroški obraz,

tell that it's this baby's face, which is a

pač pa, da gre za točno določenega otroka,

really challenging task.

kar je še posebej zahtevna naloga.

So on the left is the encoder

Slika v sredini na levi predstavlja le kodirnik,

alone, and on the right is from an actual

desna slika pa dejanski prikaz na slepi mrežnici,

blind retina, so the encoder and the transducer.

torej kombinacijo kodirnika in pretvornika.

But the key one really is the encoder alone,

Ključen pa je predvsem kodirnik,

because we can team up the encoder with

saj ga lahko priključimo na

the different transducer.

drugačen pretvornik.

This is just actually the first one that we tried.

Tu vidimo le primer prvega, ki smo ga uporabili.

I just wanted to say something about the standard method.

Želela bi povedati nekaj o običajni metodi.

When this first came out, it was just a really

Ko so jo razvili, je bila navdušujoča

exciting thing, the idea that you

misel, da se lahko omogoči

even make a blind retina respond at all.

odzivanje celo slepi mrežnici.

But there was this limiting factor,

Obstajala pa je tudi omejitev,

the issue of the code, and how to make

in sicer problem kode ter vprašanje,

the cells respond better,

kako izboljšati odziv celic,

produce normal responses,

da bi bil čim bližje običajnemu

and so this was our contribution.

in temu smo se posvetili mi.

Now I just want to wrap up,

Želela bi povzeti povedano

and as I was mentioning earlier

in -- kot že rečeno --

of course I have a lot of other data

lahko z vami delim še veliko drugih podatkov,

if you're interested, but I just wanted to give

a danes sem želela le predstaviti

this sort of basic idea

to osnovno zamisel

of being able to communicate

sposobnosti sporazumevanja

with the brain in its language, and

z možgani v njihovem jeziku

the potential power of being able to do that.

in pomen te možnosti za bolnike.

So it's different from the motor prosthetics

Gre torej za drugačen način od motoričnih prostetikov,

where you're communicating from the brain

pri katerih sporazumevanje poteka

to a device. Here we have to communicate

od možganov do naprave.

from the outside world

V našem primeru pa iz okolice pošiljamo

into the brain and be understood,

signale v možgane,

and be understood by the brain.

kjer jih dešifriramo in razumemo.

And then the last thing I wanted

Kot zaključek

to say, really, is to emphasize

sem želela izpostaviti

that the idea generalizes.

možnost posplošitve te metode.

So the same strategy that we used

Enako strategijo, kot smo jo uporabili

to find the code for the retina we can also

za iskanje kode za mrežnico,

use to find the code for other areas,

lahko uporabimo za iskanje kode za druga področja,

for example, the auditory system and

na primer slušni ali motorični sistem,

the motor system, so for treating deafness

torej za zdravljenje gluhosti

and for motor disorders.

in motoričnih okvar.

So just the same way that we were able to

Na enak način, kot smo

jump over the damaged

preskočili okvarjena vezja v mrežnici

circuitry in the retina to get to the retina's

in prešli na izhodne celice mrežnice,

output cells, we can jump over the

lahko tudi preskočimo

damaged circuitry in the cochlea

okvarjena vezja v ušesnem polžu

to get the auditory nerve,

in preidemo na slušne živce,

or jump over damaged areas in the cortex,

ali pa preskočimo okvarjena področja v

in the motor cortex, to bridge the gap

motorični skorji možganov in tako

produced by a stroke.

premagamo vrzel, nastalo po možganski kapi.

I just want to end with a simple

Želela bi končati s preprostim sporočilom,

message that understanding the code

da je razumevanje kode

is really, really important, and if we

resnično izjemnega pomena

can understand the code,

in če razumemo kodo

the language of the brain, things become

oz. jezik možganov, lahko omogočimo stvari,

possible that didn't seem obviously

ki se prej niso zdele mogoče.

possible before. Thank you.

Hvala lepa.

(Applause)

(Aplavz)