Sheila Nirenberg: A prosthetic eye to treat blindness

翻译人员: Chunxiang Qian 校对人员: Ting Huang

I study how the brain processes

我研究的是大脑如何处理信息

information. That is, how it takes

也就是

information in from the outside world, and

大脑如何接受外界信息

converts it into patterns of electrical activity,

并把它转换成脑电活动模式

and then how it uses those patterns

然后又如何利用那些模式

to allow you to do things --

来控制行为－

to see, hear, to reach for an object.

看，听，拿东西

So I'm really a basic scientist, not

我是个理论基础科学家

a clinician, but in the last year and a half

但在过去的一年半里

I've started to switch over, to use what

我开始转变方向

we've been learning about these patterns

利用对刚刚所说的模型的了解

of activity to develop prosthetic devices,

来开发假体装置

and what I wanted to do today is show you

我今天想给各位展示

an example of this.

其中一个例子

It's really our first foray into this.

这是我们对此做的第一个尝试

It's the development of a prosthetic device

是一个用于治疗失明的

for treating blindness.

假体装置

So let me start in on that problem.

首先从失明这个问题谈起

There are 10 million people in the U.S.

由于视网膜病变

and many more worldwide who are blind

而全球失明的人数更多

or are facing blindness due to diseases

他们因为视网膜的疾病

of the retina, diseases like

或者黄斑部变性这样的问题失去视力

macular degeneration, and there's little

然而，

that can be done for them.

人们对此却无能为力

There are some drug treatments, but

虽然有一些治疗性药物

they're only effective on a small fraction

但它们只对很少一部分患者有效

of the population. And so, for the vast

而对于大部分病人来说

majority of patients, their best hope for

他们恢复视力的希望

regaining sight is through prosthetic devices.

就得寄托于假体设备

The problem is that current prosthetics

问题就是目前的假体效果并不好

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

这些假体仍然

limited in the vision that they can provide.

他们提供的视觉范围还是很有限

And so, you know, for example, with these

比如说

devices, patients can see simple things

这些装置只能帮病人看到

like bright lights and high contrast edges,

亮光和高对比度的轮廓

not very much more, so nothing close

几乎没有其他影像

to normal vision has been possible.

所以它们没办法让病人看到正常视觉范围的影像

So what I'm going to tell you about today

今天我想告诉诸位的是

is a device that we've been working on

我们正在研制的一个设备

that I think has the potential to make

将有可能改变这一切

a difference, to be much more effective,

这个设备将会更加有效

and what I wanted to do is show you

我想在这里展示一下它的工作原理

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

首先我会讲一点背景知识

little bit and show you how a normal retina

让大家了解一下正常视网膜的工作原理

works first so you can see the problem

这样你就可以明白

that we were trying to solve.

我们要解决的问题是什么

Here you have a retina.

这是一个视网膜

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

现在你可以看到一张图片，一个视网膜和大脑

So when you look at something, like this image

当你看着面前的事物

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

比如这张婴儿的脸的图片

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

图像进入你的眼睛并停留在你的视网膜上，

cells here, the photoreceptors.

它停留在视网膜的前端细胞上，也叫感光器

Then what happens is the retinal circuitry,

然后视网膜的中间部分，即它的电路系统

the middle part, goes to work on it,

就开始处理这个图像

and what it does is it performs operations

它开始对图像进行操作，

on it, it extracts information from it, and it

从图像中提取信息

converts that information into a code.

然后把信息转换成代码

And the code is in the form of these patterns

代码以电脉冲的形式

of electrical pulses that get sent

送入大脑

up to the brain, and so the key thing is

所以关键环节就是

that the image ultimately gets converted

把图像转换成代码

into a code. And when I say code,

我所说的代码

I do literally mean code.

就是字面意思的代码

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

就像这里的脉冲就是“婴儿脸”的意思

and so when the brain gets this pattern

所以当大脑得到脉冲的模型

of pulses, it knows that what was out there

就知道了

was a baby's face, and if it

这是个婴儿的脸

got a different pattern it would know

如果是不同的模型

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

那它就知道是别的，比如一条狗

or another pattern would be a house.

或者房子

Anyway, you get the idea.

总之 就是这个意思

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

当然现实生活是动态的

meaning that it's changing all the time,

物体总是变化的

so the patterns of pulses are changing

所以脉冲模型也一直变化

all the time because the world you're

因为你看到的世界

looking at is changing all the time too.

是一直在变化的

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

所以这就有点复杂了

thing. You have these patterns of pulses

你的眼睛每一毫秒

coming out of your eye every millisecond

都会发送不同的脉冲模型

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

告诉大脑你看到的事物

So what happens when a person

如果一个人

gets a retinal degenerative disease like

的视网膜变性

macular degeneration? What happens is

比如患上黄斑部变性，情况会怎么样呢？

is that, the front-end cells die,

这时前端细胞就会死亡

the photoreceptors die, and over time,

感光器死亡

all the cells and the circuits that are

接着所有的细胞和联结这些细胞的组织

connected to them, they die too.

都会死亡

Until the only things that you have left

最后剩下的只有

are these cells here, the output cells,

那些输出细胞

the ones that send the signals to the brain,

就是那些把信号送入大脑的细胞

but because of all that degeneration

但是因为这些变性

they aren't sending any signals anymore.

那些细胞就没有信号可输出了

They aren't getting any input, so

没有信号输入它们

the person's brain no longer gets

人的大脑就失去了

any visual information --

视觉信息

that is, he or she is blind.

这样他就失明了

So, a solution to the problem, then,

一个解决方案就是

would be to build a device that could mimic

制造一个设备来模仿

the actions of that front-end circuitry

前端细胞电路系统的功能

and send signals to the retina's output cells,

把信号传给视网膜的输出细胞

and they can go back to doing their

这样它们就能重新开始正常工作，

normal job of sending signals to the brain.

把信号输入大脑

So this is what we've been working on,

这是我们的研究

and this is what our prosthetic does.

这就是我们制作的假体的功能

So it consists of two parts, what we call

它由两部分组成

an encoder and a transducer.

我们称为编码器和传感器

And so the encoder does just

就像我之前提到的，编码器

what I was saying: it mimics the actions

模仿前段细胞的功能－

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

接受图像，并把它转换成

in and converts them into the retina's code.

视网膜能接受的编码

And then the transducer then makes the

然后传感器使

output cells send the code on up

输出细胞把编码

to the brain, and the result is

送进大脑

a retinal prosthetic that can produce

这样视网膜假体就能产生

normal retinal output.

正常的视网膜输出

So a completely blind retina,

因此一个完全失明的视网膜

even one with no front-end circuitry at all,

即使前端细胞完全不能工作

no photoreceptors,

没有感光器

can now send out normal signals,

也能够输出正常信号

signals that the brain can understand.

并且大脑能理解这些信号

So no other device has been able

还没有其他的设备能

to do this.

做到这点

Okay, so I just want to take

下面

a sentence or two to say something about

我简略说一下

the encoder and what it's doing, because

编码器的功能

it's really the key part and it's

因为这真的是个关键部分

sort of interesting and kind of cool.

很有意思也很酷

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

我也不知道该不该用“酷”形容

you know what I mean.

不过就是那个意思

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

它的功能就是

the retinal circuitry, really the guts of

用一套方程式来替代视网膜电路系统

the retinal circuitry, with a set of equations,

而且是它最重要的部分

a set of equations that we can implement

我们可以把这些方程式植入芯片中

on a chip. So it's just math.

所以这其实就是数学

In other words, we're not literally replacing

也就是说我们没有

the components of the retina.

真的换掉视网膜的构成部分

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

不是说我们做了个迷你设备

for each of the different cell types.

来替代每一个不同的细胞

We've just abstracted what the

我们只是用方程式

retina's doing with a set of equations.

来提取视网膜的工作原理

And so, in a way, the equations are serving

这样，这些方程式的功能就

as sort of a codebook. An image comes in,

类似于密码本

goes through the set of equations,

一个图像穿过方程式

and out comes streams of electrical pulses,

变成一串电脉冲

just like a normal retina would produce.

就像正常视网膜所产生的效果一样

Now let me put my money

下面我就来用

where my mouth is and show you that

实际行动展示一下

we can actually produce normal output,

证明我们确实能够产生输出信号

and what the implications of this are.

以及这么做的意义

Here are three sets of

这是三个放电模型

firing patterns. The top one is from

最上面的来自

a normal animal, the middle one is from

一个正常动物

a blind animal that's been treated with

中间的来自一支使用编码传感设备的

this encoder-transducer device, and the

失明的动物

bottom one is from a blind animal treated

最下面的来自一个使用标准假体的

with a standard prosthetic.

失明动物

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

最下面是目前能找到的

device that's out there right now, which is

最尖端的科技设备

basically made up of light detectors,

主要就是由光探测器组成的

but no encoder. So what we did was we

但是没有编码器

presented movies of everyday things --

我们做的就是把日常事物－

people, babies, park benches,

人，婴儿，公园座椅等

you know, regular things happening -- and

这些日常生活中的东西给它们看

we recorded the responses from the retinas

然后记录下三组动物视网膜

of these three groups of animals.

的不同反应

Now just to orient you, each box is showing

首先要说明的是，每个长方形都表示

the firing patterns of several cells,

几个细胞的放电模型

and just as in the previous slides,

和前几张幻灯片中一样

each row is a different cell,

每一行是一个不同的细胞

and I just made the pulses a little bit smaller

我把脉冲做得更小更细

and thinner so I could show you

这样你可以看到

a long stretch of data.

更详细的数据

So as you can see, the firing patterns

如图所示

from the blind animal treated with

使用编码传感器设备的

the encoder-transducer really do very

失明动物的模型能够

closely match the normal firing patterns --

很好地与正常模型吻合－

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

虽不完美但已经很好了－

and the blind animal treated with

而使用普通假体的

the standard prosthetic,

失明动物的模型

the responses really don't.

效果就不行

And so with the standard method,

用普通假体的时候

the cells do fire, they just don't fire

细胞的确可以放电

in the normal firing patterns because

但是并不是以正常的放电方式进行

they don't have the right code.

因为它们没有正确的编码

How important is this?

编码有多重要呢？

What's the potential impact

它对病人的视力

on a patient's ability to see?

有多大潜在影响？

So I'm just going to show you one

我会向各位展示一个

bottom-line experiment that answers this,

基础实验来回来这个问题

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

当然我还有别的数据

so if you're interested I'm happy

如果你有兴趣

to show more. So the experiment

我可以展示更多

is called a reconstruction experiment.

这实验被称作重建实验

So what we did is we took a moment

我们从记录里

in time from these recordings and asked,

截取某一刻

what was the retina seeing at that moment?

看看那一刻视网膜都看到了什么？

Can we reconstruct what the retina

我们能不能重建

was seeing from the responses

视网膜从那三种放电模型中

from the firing patterns?

看到的东西？

So, when we did this for responses

我们对普通假体

from the standard method and from

和编码传感器的反应

our encoder and transducer.

各做了实验

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

首先我来说明

start with the standard method first.

普通假体的实验结果

So you can see that it's pretty limited,

可以看出效果很有限

and because the firing patterns aren't

因为放电模型没有正确编码

in the right code, they're very limited in

所以它很难看出来

what they can tell you about

究竟是什么图像

what's out there. So you can see that

你可以看到

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

那里是有些什么东西，但是不清楚到底是什么

what that something is, and this just sort of

这又回到了

circles back to what I was saying in the

我在开头的时候说的

beginning, that with the standard method,

关于普通假体的问题

patients can see high-contrast edges, they

安装普通假体的病人可以看到高对比度的轮廓

can see light, but it doesn't easily go

他们能看见亮光

further than that. So what was

但是仅此而已

the image? It was a baby's face.

到底是什么图像？是婴儿的脸

So what about with our approach,

我们加入了编码后的方法

adding the code? And you can see

是什么效果呢？

that it's much better. Not only can you

你可以看出来，效果好多了

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

你不仅能看出是婴儿的脸

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

而且还能看清是这样一个孩子的脸

really challenging task.

这真是个很具挑战性的任务

So on the left is the encoder

左边是单用编码器的结果

alone, and on the right is from an actual

右边是一个实际的失明视网膜

blind retina, so the encoder and the transducer.

和编码传感器™

But the key one really is the encoder alone,

但是最关键的就是编码器

because we can team up the encoder with

因为我们可以把不同的传感器和

the different transducer.

编码器结合起来

This is just actually the first one that we tried.

这是仅仅是我们尝试的头一个

I just wanted to say something about the standard method.

我想说一些关于普通假体的问题

When this first came out, it was just a really

它刚刚面世的时候

exciting thing, the idea that you

确实令人振奋

even make a blind retina respond at all.

因为这能让一个失明的视网膜有反应

But there was this limiting factor,

但是缺陷就

the issue of the code, and how to make

在于编码

the cells respond better,

怎样才能让细胞更好地反应

produce normal responses,

产生正常的反应

and so this was our contribution.

这就是我们作出的贡献

Now I just want to wrap up,

现在我总结一下

and as I was mentioning earlier

就像我之前说的那样

of course I have a lot of other data

如果你感兴趣的话

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

我还有很多其他数据

this sort of basic idea

这里我只简单地说一下

of being able to communicate

这种可以用自己的语言

with the brain in its language, and

和大脑交流的方法

the potential power of being able to do that.

以及这个方法的潜在力量

So it's different from the motor prosthetics

这跟运动修复术不同

where you're communicating from the brain

运动修复术是把大脑的指令

to a device. Here we have to communicate

传递给一个设备

from the outside world

而我们是要把外界信息

into the brain and be understood,

输入大脑

and be understood by the brain.

并且要使其被大脑理解

And then the last thing I wanted

最后我想

to say, really, is to emphasize

强调一下的

that the idea generalizes.

是这个方法是广泛适用的

So the same strategy that we used

我们用来研究视网膜编码的技术

to find the code for the retina we can also

同样也可以

use to find the code for other areas,

用于研究其他领域

for example, the auditory system and

比如听觉系统

the motor system, so for treating deafness

和运动系统，已解决听力障碍

and for motor disorders.

和四肢运动障碍

So just the same way that we were able to

其原理跟我们

jump over the damaged

绕过受损的视网膜电路系统

circuitry in the retina to get to the retina's

直接进入视网膜输出细胞一样

output cells, we can jump over the

我们也可以绕过

damaged circuitry in the cochlea

损坏的耳蜗电路系统

to get the auditory nerve,

直达听神经

or jump over damaged areas in the cortex,

或者绕开运动皮质里坏死的区域

in the motor cortex, to bridge the gap

来消除中风带来的

produced by a stroke.

损害

I just want to end with a simple

最后

message that understanding the code

我想说掌握代码

is really, really important, and if we

非常非常重要

can understand the code,

如果我们能掌握代码

the language of the brain, things become

也就是大脑的语言

possible that didn't seem obviously

一切都豁然开朗

possible before. Thank you.

谢谢

(Applause)

（掌声）