Sheila Nirenberg: A prosthetic eye to treat blindness

Translator: Elena Calvelo Reviewer: traduceTED USC

Eu estudo como o cerebro procesa a información,

ou sexa, como recolle información

do mundo exterior

e a converte en padróns

de actividade eléctrica,

e como usa eses padróns

para permitirnos facer cousas:

I study how the brain processes

ver, ouvir, acadar obxectos.

information. That is, how it takes

Son máis ben científica,

information in from the outside world, and

non doutora, mais desde hai un ano e medio

converts it into patterns of electrical activity,

comecei a mudar e a usar

and then how it uses those patterns

aquilo que aprendín sobre estes padróns

to allow you to do things --

de actividade para desenvolver próteses.

to see, hear, to reach for an object.

So I'm really a basic scientist, not

O que quero facer hoxe é

mostrarvos un exemplo disto.

a clinician, but in the last year and a half

É realmente a nosa primeira tentativa.

I've started to switch over, to use what

É o desenvolvemento dunha prótese

we've been learning about these patterns

para tratar a cegueira.

of activity to develop prosthetic devices,

Permitídeme presentar o problema.

and what I wanted to do today is show you

Hai 10 millóns de persoas nos EUA

an example of this.

e moitas máis no mundo que son cegas

It's really our first foray into this.

ou que se enfrontan á cegueira debido a doenzas da retina,

It's the development of a prosthetic device

for treating blindness.

como a dexeneración macular, e non hai moito

So let me start in on that problem.

que poida facerse por elas.

There are 10 million people in the U.S.

Hai tratamentos farmacolóxicos, mais só fan efecto nunha pequena parte

and many more worldwide who are blind

da poboación. Para a gran maioría de pacientes, a maior esperanza

or are facing blindness due to diseases

of the retina, diseases like

de recuperaren a visión son as próteses.

macular degeneration, and there's little

that can be done for them.

O problema é que as próteses actuais

There are some drug treatments, but

non funcionan moi ben. Aínda son

they're only effective on a small fraction

moi limitadas en canto á visión que ofrecen.

of the population. And so, for the vast

Por exemplo, con estes aparellos, os pacientes poden ver cousas simples,

majority of patients, their best hope for

regaining sight is through prosthetic devices.

como luces brillantes e cantos de alto contraste, pero non moito máis.

The problem is that current prosthetics

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

Non se conseguiu nada parecido á visión normal.

limited in the vision that they can provide.

And so, you know, for example, with these

Hoxe vouvos falar dun aparello no que estiven traballando

devices, patients can see simple things

e que creo que ten o potencial para marcar a diferenza, para ser máis eficaz.

like bright lights and high contrast edges,

not very much more, so nothing close

Quería amosarvos como funciona.

to normal vision has been possible.

Imos un chisco atrás para ensinarvos

So what I'm going to tell you about today

como funciona unha retina normal

is a device that we've been working on

e que problema tentamos resolver.

that I think has the potential to make

Velaquí unha retina.

Hai unha imaxe, unha retina e un cerebro.

a difference, to be much more effective,

and what I wanted to do is show you

Ao mirar algo, coma esta imaxe

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

da face dun bebé, chega ao ollo

little bit and show you how a normal retina

e colócase na retina, nestas células frontais, chamadas fotorreceptores.

works first so you can see the problem

that we were trying to solve.

Despois, o circuíto retiniano,

Here you have a retina.

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

na parte central, traballa a imaxe,

So when you look at something, like this image

opera sobre ela

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

e extrae información

que converte nun código.

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

cells here, the photoreceptors.

O código ten a forma destes padróns

Then what happens is the retinal circuitry,

de pulsos eléctricos enviados ao cerebro,

the middle part, goes to work on it,

polo que a clave é que a imaxe quede finalmente convertida

and what it does is it performs operations

on it, it extracts information from it, and it

nun código. E, cando digo código, dígoo en sentido literal.

converts that information into a code.

And the code is in the form of these patterns

Igual que este padrón de impulsos

of electrical pulses that get sent

significa “face dun bebé”, polo que,

up to the brain, and so the key thing is

cando o cerebro recibe este padrón, sabe

that the image ultimately gets converted

que o que tiña en fronte era a face dun bebé,

into a code. And when I say code,

I do literally mean code.

de ter un padrón distinto sabería

que tiña en fronte, por exemplo, un can ou outro padrón, como unha casa.

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

and so when the brain gets this pattern

Xa entendedes a idea.

of pulses, it knows that what was out there

Na vida real, isto é sen dúbida dinámico,

was a baby's face, and if it

é dicir, está en constante cambio.

got a different pattern it would know

Os padróns de impulsos mudan constantemente porque o mundo

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

or another pattern would be a house.

que observamos tamén o fai.

Anyway, you get the idea.

Xa que logo, é un asunto ben complexo.

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

Temos estes padróns de impulsos

meaning that it's changing all the time,

provenientes dos ollos cada milisegundo

so the patterns of pulses are changing

dicíndolle ao cerebro que é o que ven.

all the time because the world you're

Que pasa cando unha persoa padece

looking at is changing all the time too.

unha enfermidade dexenerativa da retina

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

como dexeneración macular? As células frontais morren,

thing. You have these patterns of pulses

coming out of your eye every millisecond

os fotorreceptores morren e, co tempo,

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

todas as células e circuítos

So what happens when a person

conectados a elas morren tamén,

gets a retinal degenerative disease like

ata que o único que resta

macular degeneration? What happens is

son estas células, as células de saída,

is that, the front-end cells die,

que envían os sinais ao cerebro,

the photoreceptors die, and over time,

mais que, debido á dexeneración, xa non poden mandar sinais.

all the cells and the circuits that are

connected to them, they die too.

Ao non recibir sinais de entrada, o cerebro non obtén

Until the only things that you have left

are these cells here, the output cells,

ningunha información visual,

ou sexa, a persoa está cega.

the ones that send the signals to the brain,

but because of all that degeneration

Xa que logo, a solución a este problema

they aren't sending any signals anymore.

sería construírmos un dispositivo

They aren't getting any input, so

que imite as accións do circuíto frontal e envíe sinais ás células de saída

the person's brain no longer gets

any visual information --

da retina para que estas volvesen mandar sinais ao cerebro.

that is, he or she is blind.

So, a solution to the problem, then,

Isto é no que estivemos traballando e é o que fai a nosa prótese.

would be to build a device that could mimic

the actions of that front-end circuitry

Consiste en dúas partes ás que chamamos

and send signals to the retina's output cells,

o codificador e o transdutor.

and they can go back to doing their

O codificador fai o que dixen antes:

normal job of sending signals to the brain.

imita as accións do circuíto frontal,

So this is what we've been working on,

polo que capta imaxes e convérteas en códigos retinais.

and this is what our prosthetic does.

So it consists of two parts, what we call

Logo o transdutor fai que as células

an encoder and a transducer.

de saída manden o código

And so the encoder does just

ao cerebro. O resultado é

what I was saying: it mimics the actions

unha retina protésica capaz de producir

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

unha saída da retina normal.

in and converts them into the retina's code.

And then the transducer then makes the

Así, unha retina completamente cega

output cells send the code on up

que carece incluso

de circuíto frontal e fotorreceptores,

to the brain, and the result is

xa é capaz de mandar sinais comúns

a retinal prosthetic that can produce

que o cerebro pode entender.

normal retinal output.

Ningún outro dispositivo

So a completely blind retina,

conseguiu facer isto.

even one with no front-end circuitry at all,

Só quero dedicar unhas verbas a explicar

no photoreceptors,

can now send out normal signals,

que é e que fai o codificador,

signals that the brain can understand.

xa que é sen dúbida a parte central, ademais de ser

interesante e moi guai.

So no other device has been able

Non sei se guai é a palabra correcta,

to do this.

pero xa me entendedes.

Okay, so I just want to take

O que fai é substituír

a sentence or two to say something about

o circuíto retinal, todo el,

the encoder and what it's doing, because

it's really the key part and it's

cun conxunto de ecuacións,

sort of interesting and kind of cool.

conxunto que podemos inserir

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

nun chip. Só se trata de matemática.

you know what I mean.

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

Noutras palabras, non estamos substituíndo

the retinal circuitry, really the guts of

os compoñentes da retina.

Non é que construamos un miniaparello

the retinal circuitry, with a set of equations,

para cada tipo de célula.

a set of equations that we can implement

Simplemente abstraemos o funcionamento

on a chip. So it's just math.

da retina cun conxunto de ecuacións.

In other words, we're not literally replacing

Dunha maneira, as ecuacións funcionan como unha especie de libro de códigos.

the components of the retina.

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

A imaxe entra, pasa polas ecuacións

for each of the different cell types.

We've just abstracted what the

e sae un fluxo de pulsos eléctricos,

retina's doing with a set of equations.

igual que unha retina normal.

And so, in a way, the equations are serving

Permitídeme demostrar con feitos

as sort of a codebook. An image comes in,

goes through the set of equations,

que o que digo é verdade

e o que isto implica.

and out comes streams of electrical pulses,

just like a normal retina would produce.

Aquí vemos tres series

de padróns de disparo. O de arriba é

Now let me put my money

dun animal común, o do medio é

where my mouth is and show you that

dun animal cego que tratamos

we can actually produce normal output,

con este instrumento codificador-transdutor

and what the implications of this are.

e o último é dun animal cego tratado

Here are three sets of

cunha prótese común.

firing patterns. The top one is from

O último é o aparello de alta tecnoloxía

a normal animal, the middle one is from

que se usa agora, feito con detectores de luz,

a blind animal that's been treated with

pero sen codificador. Así,

this encoder-transducer device, and the

proxectamos filmes da vida cotiá:

bottom one is from a blind animal treated

persoas, crianzas, cadeiras…

with a standard prosthetic.

xa sabedes, cousas comúns,

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

e gravamos as respostas das retinas

device that's out there right now, which is

destes tres grupos de animais.

basically made up of light detectors,

but no encoder. So what we did was we

Como orientación, cada imaxe mostra

presented movies of everyday things --

os padróns de varias células e,

people, babies, park benches,

como nas diapositivas anteriores,

you know, regular things happening -- and

cada fila é unha célula diferente.

we recorded the responses from the retinas

Só fixen os pulsos un chisco máis pequenos

of these three groups of animals.

Now just to orient you, each box is showing

e delgados para vos ensinar

unha cadea longa de datos.

the firing patterns of several cells,

and just as in the previous slides,

Como vedes, os padróns de disparo

each row is a different cell,

do animal cego tratado

co codificador-transdutor son case iguais

and I just made the pulses a little bit smaller

and thinner so I could show you

que os padróns dun animal común.

a long stretch of data.

Non é perfecto, pero si bastante bo.

So as you can see, the firing patterns

Porén, as respostas

from the blind animal treated with

do animal cego tratado

coa prótese común non se parecen.

the encoder-transducer really do very

O mesmo ocorre co método estándar,

closely match the normal firing patterns --

no que as células emiten sinais, mais non co padrón normal,

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

and the blind animal treated with

xa que non teñen o código correcto.

the standard prosthetic,

Cal é a importancia disto?

the responses really don't.

And so with the standard method,

Cal é o impacto potencial

na capacidade de ver dun paciente?

the cells do fire, they just don't fire

Vou mostrarvos as conclusións

in the normal firing patterns because

dun experimento que resolve esta cuestión.

they don't have the right code.

How important is this?

Por suposto, teño máis datos

What's the potential impact

que vos mostrarei encantada.

on a patient's ability to see?

O experimento chámase

“Experimento de reconstrución”.

So I'm just going to show you one

O que fixemos foi seleccionar un momento

bottom-line experiment that answers this,

desas gravacións e preguntármonos

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

so if you're interested I'm happy

que é o que vía a retina naquel momento.

to show more. So the experiment

Poderiamos reconstruír o que a retina vía

is called a reconstruction experiment.

mediante as respostas

dos padróns de disparo?

So what we did is we took a moment

Probamos isto para as respostas

in time from these recordings and asked,

what was the retina seeing at that moment?

do método estándar

Can we reconstruct what the retina

e do noso método codificador-transdutor.

was seeing from the responses

Mostraréivolo. Comezarei

from the firing patterns?

polo método estándar.

So, when we did this for responses

Veredes que é moi limitado e,

from the standard method and from

xa que os padróns de sinais non están no código correcto, son moi limitados

our encoder and transducer.

con respecto ao que poden ver.

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

Podedes observar

que aí hai algo, mais non está claro

start with the standard method first.

o que é, e isto lévanos

So you can see that it's pretty limited,

ao que dicía ao inicio, de que, co método estándar,

and because the firing patterns aren't

in the right code, they're very limited in

os pacientes conseguen ver formas

what they can tell you about

de alto contraste. Ven luz, pero non ven

what's out there. So you can see that

moito máis ca iso. Entón, cal era

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

what that something is, and this just sort of

a imaxe? Era a faciana dun bebé.

circles back to what I was saying in the

beginning, that with the standard method,

Que ocorre coa nosa abordaxe ao engadirmos

patients can see high-contrast edges, they

o código? Como vedes, é moito mellor.

can see light, but it doesn't easily go

Non só podedes apreciar que é a face dun bebé,

further than that. So what was

senón que distinguides que bebé é,

the image? It was a baby's face.

o que é unha tarefa moi complexa.

Á esquerda atópase só o codificador

So what about with our approach,

adding the code? And you can see

e á dereita unha retina cega,

that it's much better. Not only can you

ou sexa, o codificador e o transdutor.

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

Mais a chave disto é o codificador,

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

xa que podemos combinalo

cun transdutor diferente.

really challenging task.

Este é o primeiro que probamos.

So on the left is the encoder

Quero engadir algo sobre o método común.

alone, and on the right is from an actual

Cando saíu orixinalmente

blind retina, so the encoder and the transducer.

foi algo moi emocionante o feito

But the key one really is the encoder alone,

because we can team up the encoder with

de facer que unha retina cega respondese.

the different transducer.

Pero estaba este factor restritivo,

This is just actually the first one that we tried.

I just wanted to say something about the standard method.

o problema do código e como facer

que as células respondan mellor e produzan respostas normais,

When this first came out, it was just a really

exciting thing, the idea that you

así que esta foi a nosa contribución.

even make a blind retina respond at all.

Para rematar,

But there was this limiting factor,

e como vos mencionaba anteriormente,

the issue of the code, and how to make

teño moitos máis datos

the cells respond better,

por se tedes interese, mais quería

produce normal responses,

achegar esta idea básica

and so this was our contribution.

da capacidade que temos de comunicármonos

Now I just want to wrap up,

and as I was mentioning earlier

co cerebro na súa linguaxe,

of course I have a lot of other data

e o poder latente de conseguirmos isto.

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

É distinto das próteses motoras, onde a comunicación cun dispositivo ocorre

this sort of basic idea

of being able to communicate

a través do cerebro. Aquí temos

with the brain in its language, and

que comunicarnos desde o mundo exterior ata o cerebro e conseguir

the potential power of being able to do that.

que este nos entenda.

So it's different from the motor prosthetics

O último que quero facer

where you're communicating from the brain

é resaltar que a idea pode xeneralizarse.

to a device. Here we have to communicate

from the outside world

A mesma estratexia que usamos

into the brain and be understood,

para atoparmos o código da retina tamén podemos usala para achar o código

and be understood by the brain.

doutras zonas, como o sistema auditivo

And then the last thing I wanted

to say, really, is to emphasize

e o sistema motriz, para tratarmos

that the idea generalizes.

a xordeira e as deficiencias motrices.

So the same strategy that we used

Igual que conseguimos

to find the code for the retina we can also

evitar os circuítos danados

use to find the code for other areas,

da retina para chegarmos ás células

for example, the auditory system and

de saída, tamén podemos evitar

the motor system, so for treating deafness

o circuíto danado da cóclea

and for motor disorders.

para chegarmos ao nervio auditivo,

So just the same way that we were able to

ou evitarmos as zonas danadas

jump over the damaged

na cortiza motora, para evitarmos

circuitry in the retina to get to the retina's

a fractura que produce un ictus.

output cells, we can jump over the

Quero rematar cunha mensaxe simple:

damaged circuitry in the cochlea

to get the auditory nerve,

entendermos o código é moi

moi importante e, de entendermos o código,

or jump over damaged areas in the cortex,

in the motor cortex, to bridge the gap

que é a linguaxe do cerebro, as cousas

que antes non parecían posíbeis

produced by a stroke.

tórnanse agora factíbeis.

I just want to end with a simple

Grazas.

message that understanding the code

(Aplausos)

is really, really important, and if we

can understand the code,

the language of the brain, things become

possible that didn't seem obviously

possible before. Thank you.

(Applause)