about bionics,

本日はみなさんに

which is the popular term

生体工学

for the science of replacing part of a living organism

つまり身体の一部を

with a mechatronic device, or a robot.

メカトロニクス機器やロボットで置き換えるという

It is essentially

科学分野についてお話ししようと思います

the stuff of life meets machine.

これは正に

And specifically, I'd like to talk with you

生体と機械の融合です

about how bionics is evolving

特に 腕を失った人の為に

for people with arm amputations.

生体工学が

This is our motivation.

どう進歩しているかをお話しします

Arm amputation causes a huge disability.

我々の研究動機です

I mean, the functional impairment is clear.

腕を失うとは大変なことです

Our hands are amazing instruments.

単純な不便さは勿論でしょう

And when you lose one, far less both,

手は素晴らしい道具です

it's a lot harder to do the things

片手を失っただけで

we physically need to do.

日常的に必要とされる

There's also a huge emotional impact.

身体的行為が難しくなります

And actually, I spend as much of my time in clinic

そして大きな精神的ダメージ

dealing with the emotional adjustment of patients

私の診療室では 身体的不自由さと

as with the physical disability.

同じくらい 精神的ダメージの治療にも

And finally, there's a profound social impact.

時間をかけています

We talk with our hands.

社交上の問題もあります

We greet with our hands.

我々は手で話し

And we interact with the physical world with our hands.

手で挨拶をし

And when they're missing,

手で外界とやりとりをします

it's a barrier.

手がなくなることは

Arm amputation is usually caused by trauma,

障害を意味します

with things like industrial accidents,

腕の切断の多くは

motor vehicle collisions

工場事故や交通事故

or, very poignantly, war.

そして悲しくも

There are also some children who are born without arms,

戦争による外傷の結果です

called congenital limb deficiency.

生まれつき腕のない子もいます

Unfortunately, we don't do great

先天性四肢欠損です

with upper-limb prosthetics.

残念ながら義手の製作は

There are two general types.

困難を極めています

They're called body-powered prostheses,

義手には２種類あります

which were invented just after the Civil War,

こちらは身体操作型義手といって

refined in World War I and World War II.

南北戦争直後に発明され

Here you see a patent

第１・２次世界大戦中に改良されました

for an arm in 1912.

これが1912年の

It's not a lot different

特許申請書です

than the one you see on my patient.

現在の義手と そう違いはありません

They work by harnessing shoulder power.

肩の筋肉で制御するものです

So when you squish your shoulders, they pull on a bicycle cable.

肩をすぼめるとケーブルが引かれ

And that bicycle cable can open or close a hand or a hook

手やフックを開いたり閉じたり

or bend an elbow.

肘を動かせます

And we still use them commonly,

この義手は今でも使われています

because they're very robust

とても頑丈で単純な構造ですからね

and relatively simple devices.

最先端のものは

The state of the art

筋電義手という義手です

is what we call myoelectric prostheses.

筋肉からのわずかな

These are motorized devices

電気信号により

that are controlled

モーター駆動される義手です

by little electrical signals from your muscle.

筋肉を収縮させる時

Every time you contract a muscle,

わずかな電気信号が流れ

it emits a little electricity

それを電極やアンテナで読み取り

that you can record with antennae or electrodes

義手の操作に用いるのです

and use that to operate the motorized prosthesis.

手を失ったばかりの人の場合

They work pretty well

この義手をとても上手く操作します

for people who have just lost their hand,

手の筋肉がまだ残っていますから

because your hand muscles are still there.

手をすぼめればこの筋肉が収縮し

You squeeze your hand, these muscles contract.

手をひらけばこの筋肉が収縮し

You open it, these muscles contract.

直感的に上手に使うことができます

So it's intuitive, and it works pretty well.

しかしもっと上部で 腕の大半を切断するとどうでしょう

Well how about with higher levels of amputation?

この筋肉だけでなく

Now you've lost your arm above the elbow.

手と肘そのものがありません

You're missing not only these muscles,

どうしましょう？

but your hand and your elbow too.

そのような患者さんは

What do you do?

腕の筋肉だけで

Well our patients have to use

ロボット義手を動かす

very code-y systems

技術を要する方法をとります

of using just their arm muscles

ロボット義手ということです

to operate robotic limbs.

このように様々な種類があります

We have robotic limbs.

開閉する手と 回転する手首と

There are several available on the market, and here you see a few.

肘があります

They contain just a hand that will open and close,

機能はそれだけです

a wrist rotator and an elbow.

機能を増やしても制御方法がありません

There's no other functions.

そこで シカゴリハビリテーション研究所（RIC）では

If they did, how would we tell them what to do?

手首の屈曲と

We built our own arm at the Rehab Institute of Chicago

肩の関節を加え ６つのモーターで

where we've added some wrist flexion and shoulder joints

６自由度を持つ試作品を作りました

to get up to six motors, or six degrees of freedom.

さらに我々は米軍から研究費を得て開発された

And we've had the opportunity to work with some very advanced arms

可動式の手を持ち

that were funded by the U.S. military, using these prototypes,

最大10の自由度を持つ

that had up to 10 different degrees of freedom

進歩した義手を

including movable hands.

使うことができました

But at the end of the day,

しかし結局どう義手に

how do we tell these robotic arms what to do?

命令を伝えたものでしょうか

How do we control them?

どう操作すれば良いのでしょう？

Well we need a neural interface,

その為には神経系あるいは思考過程と

a way to connect to our nervous system

繋ぐことで身体の一部の様に

or our thought processes

直感的かつ自然に操作できる

so that it's intuitive, it's natural,

神経インタフェースが

like for you and I.

必要なのです

Well the body works by starting a motor command in your brain,

脳から発する運動命令は

going down your spinal cord,

脊髄を伝わり末梢神経をとおって

out the nerves and to your periphery.

末梢に伝わります

And your sensation's the exact opposite.

感覚はその反対です

You touch yourself, there's a stimulus

刺激は全く同じ神経を逆に辿り

that comes up those very same nerves back up to your brain.

脳に伝えます

When you lose your arm, that nervous system still works.

腕を失ってもまだ神経系は働きます

Those nerves can put out command signals.

まだ脳の指令を送ることができます

And if I tap the nerve ending

そして退役軍人が失った

on a World War II vet,

腕の端の神経を触ると

he'll still feel his missing hand.

彼はまだ手を感じるのです

So you might say,

それならば脳を開けて

let's go to the brain

脳内に何かを埋め込み

and put something in the brain to record signals,

信号を記録したり

or in the end of the peripheral nerve and record them there.

あるいは末梢神経の末端で

And these are very exciting research areas,

信号を記録したりしてみよう

but it's really, really hard.

確かにそういう研究もありますが

You have to put in

これは恐ろしく難しいのです

hundreds of microscopic wires

数百の微小電極を埋め込み

to record from little tiny individual neurons -- ordinary fibers

信号を発する小さな個々のニューロン - 普通の神経線維 -から

that put out tiny signals

マイクロボルト単位の

that are microvolts.

信号を読み取る

And it's just too hard

必要があります

to use now and for my patients today.

これは現在 技術的に

So we developed a different approach.

難度が高過ぎます

We're using a biological amplifier

そこで違う方法を考えました

to amplify these nerve signals -- muscles.

神経信号を増幅する生体機能

Muscles will amplify the nerve signals

つまり筋肉を使えば良いのです

about a thousand-fold,

筋肉は神経信号を

so that we can record them from on top of the skin,

数千倍に増幅するので

like you saw earlier.

先程お見せしたように 皮膚の上からでも

So our approach is something we call targeted reinnervation.

信号が取れます

Imagine, with somebody who's lost their whole arm,

特定領域への神経支配再確立とでも言えましょう

we still have four major nerves

腕を失っても

that go down your arm.

（腕を支配する）4つの主要な神経が まだ残っている患者を

And we take the nerve away from your chest muscle

想像してみて下さい

and let these nerves grow into it.

その患者の胸筋から神経を取り除き

Now you think, "Close hand," and a little section of your chest contracts.

代わりに腕の神経を埋め込みます

You think, "Bend elbow,"

「手を握ろう」と考えれば胸の一部が収縮し

a different section contracts.

「肘を曲げよう」と考えれば

And we can use electrodes or antennae

胸の別の場所が収縮します

to pick that up and tell the arm to move.

その動きを電極やアンテナで

That's the idea.

読み取り義手を操作すればいい

So this is the first man that we tried it on.

これが我々のアイデアです

His name is Jesse Sullivan.

この義手を初めて試した患者です

He's just a saint of a man --

ジェシー・サリヴァンという名で

54-year-old lineman who touched the wrong wire

とても穏やかな方です

and had both of his arms burnt so badly

架線作業中に触る電線を間違え

they had to be amputated at the shoulder.

両の手に重度の火傷を負い

Jesse came to us at the RIC

肩から先を切断しました

to be fit with these state-of-the-art devices, and here you see them.

そして最先端の義手を試すため

I'm still using that old technology

RICの私たちのところにやって来ました

with a bicycle cable on his right side.

右腕はケーブル操作する

And he picks which joint he wants to move with those chin switches.

旧型の義手を使っています

On the left side he's got a modern motorized prosthesis

動かす関節はアゴのスイッチで選びます

with those three joints,

左では３つの関節を持つ

and he operates little pads in his shoulder

モーター駆動の義手で

that he touches to make the arm go.

肩のパッドで動かしています

And Jesse's a good crane operator,

腕の操作に使うためです

and he did okay by our standards.

ジェシーは操縦が上手く

He also required a revision surgery on his chest.

私たちも満足でした

And that gave us the opportunity

加えて彼は胸の追加手術も必要になりました

to do targeted reinnervation.

これをよい機会に我々は

So my colleague, Dr. Greg Dumanian, did the surgery.

特定領域への神経支配再確立手術を行いました

First, we cut away the nerve to his own muscle,

手術を行ったのは 同僚のグレッグ ドゥマニアン博士です

then we took the arm nerves

まず胸の神経を取り除き

and just kind of had them shift down onto his chest

腕の神経を取り出し

and closed him up.

それを胸に植え込んで

And after about three months,

傷口を塞ぎました

the nerves grew in a little bit and we could get a twitch.

3ヶ月後には神経も少し伸び

And after six months, the nerves grew in well,

胸をピクピク動かせるようになり

and you could see strong contractions.

6ヶ月後には神経も十分に伸びて

And this is what it looks like.

強い収縮も可能になりました

This is what happens when Jesse thinks

このような感じです

open and close his hand,

ジェシーが手を開閉させようと思うと

or bend or straighten your elbow.

この動作がおきます

You can see the movements on his chest,

肘を屈曲したり伸ばそうと思うと

and those little hash marks

胸がこう動きます

are where we put our antennae, or electrodes.

この小さなしるしは

And I challenge anybody in the room

アンテナや電極の位置です

to make their chest go like this.

こんな風に胸を動かせる人が

His brain is thinking about his arm.

もし会場にいれば教えてください

He has not learned how to do this with the chest.

彼の脳は腕のことを考えています

There is not a learning process.

胸をこんな風に動かす方法を 学んだわけではありません

That's why it's intuitive.

学習過程はありません

So here's Jesse in our first little test with him.

直感的なのです

On the left-hand side, you see his original prosthesis,

これが最初の動作テストです

and he's using those switches

左側は元の義手です

to move little blocks from one box to the other.

スイッチを使って

He's had that arm for about 20 months, so he's pretty good with it.

積み木を ひとつの箱からもう一つの箱へ移しています

On the right side,

20ヶ月も使用した義手はよくなじんでいます

two months after we fit him with his targeted reinnervation prosthesis --

右側は私たちの

which, by the way, is the same physical arm,

「特定領域への神経支配再確立」を使って 2ヶ月目の映像です

just programmed a little different --

機器としては同じ義手で

you can see that he's much faster

制御ソフトが違うだけですが

and much smoother as he moves these little blocks.

動作は明らかに速く

And we're only able to use three of the signals at this time.

スムーズに積み木を移しています

Then we had one of those little surprises in science.

この時点で3つの信号を使っているだけです

So we're all motivated to get motor commands

ここで驚くべき科学的発見がありました

to drive robotic arms.

私たちはロボット義手を操作するための

And after a few months,

運動指令を得ようとしていた訳ですが

you touch Jesse on his chest,

数ヶ月後にジェシーの

and he felt his missing hand.

胸に触れると 彼は

His hand sensation grew into his chest again

失った手を感じました

probably because we had also taken away a lot of fat,

手の感覚が胸に戻ったのです

so the skin was right down to the muscle

手術で脂肪を取り去ったので

and deinnervated, if you would, his skin.

筋肉と皮膚が近づき

So you touch Jesse here, he feels his thumb;

以前あった神経支配を取り除いたのでしょう

you touch it here, he feels his pinky.

ここを触れば親指を感じ

He feels light touch

ここを触れば小指です

down to one gram of force.

1 gほどの小さな

He feels hot, cold, sharp, dull,

力でも感じます

all in his missing hand,

熱さ、冷たさ、鋭さ、鈍さ

or both his hand and his chest,

全てを失われた手で感じます

but he can attend to either.

胸の感覚も残っていますが

So this is really exciting for us,

意識できるのは一方です

because now we have a portal,

これはとても面白いことです

a portal, or a way to potentially give back sensation,

なぜなら これは感覚の再現に繋がる可能性があり

so that he might feel what he touches

あるいは末梢神経の末端で

with his prosthetic hand.

触れたものを感じる義手の製作にも

Imagine sensors in the hand

繋がる可能性があるからです

coming up and pressing on this new hand skin.

義手センサーからの信号が

So it was very exciting.

胸の「手」に伝わればいいのです

We've also gone on

これは面白い

with what was initially our primary population

我々はまた 当初注目していた

of people with above-the-elbow amputations.

肘から先を失った多数の患者の

And here we deinnervate, or cut the nerve away,

義手についても考えました

just from little segments of muscle

筋肉の一部から神経を切り離して 神経支配を除き

and leave others alone

ほかの部分では神経をそのままにすると

that give us our up-down signals

上下運動を伝える神経と

and two others that will give us a hand open and close signal.

手の開閉を伝える神経を

This was one of our first patients, Chris.

作れます

You see him with his original device

彼は初期の患者のクリスです

on the left there after eight months of use,

左側は8ヶ月使っている

and on the right, it is two months.

なじみの義手で

He's about four or five times as fast

右は2ヶ月目の義手です

with this simple little performance metric.

4~5倍のスピードで

All right.

動作テストをこなしています

So one of the best parts of my job

この仕事が好きなのは

is working with really great patients

研究仲間である患者さんが

who are also our research collaborators.

同時に共同研究者だからです

And we're fortunate today

本日その一人のアマンダ・キッツが

to have Amanda Kitts come and join us.

会場に来てくれました

Please welcome Amanda Kitts.

アマンダ・キッツです

(Applause)

(拍手)

So Amanda, would you please tell us how you lost your arm?

アマンダ どうして腕を失ったのですか？

Amanda Kitts: Sure. In 2006, I had a car accident.

2006年に交通事故に遭いました

And I was driving home from work,

仕事から帰る途中

and a truck was coming the opposite direction,

反対車線のトラックが突っ込んできて

came over into my lane,

車の前面が潰され その時

ran over the top of my car and his axle tore my arm off.

トラックの車軸に腕を巻き取られました