I was a college student in engineering.

手術室に初めて入って

I thought it was going to be like on TV,

実際に手術を見学するまで

ominous music playing in the background, beads of sweat pouring down the surgeon’s face.

どんなものなのか イメージも浮かびませんでした

But it wasn’t like that at all.

当時 大学の工学部の学生で

There was music playing on this day. I think it was Madonna’s greatest hits.

テレビで見たようなものを 想像していました

And there was plenty of conversation, not just about the patient’s heart rate,

不吉な音楽が流れる中で

but about sports and weekend plans.

外科医の額からは汗が噴き出している

And since then, the more surgeries I watched, the more I realized this is how it is.

でも 実際は全く違いました

In some weird ways, it’s just another day at the office.

そこで流れていた音楽は

But every so often, the music gets turned down,

マドンナのベストヒットだったと思います （笑）

everyone stops talking, and stares at exactly the same thing.

手術スタッフ同士で よく会話もしています

And that’s when you know that something absolutely critical and dangerous is happening.

患者の心拍数などだけではなく

The first time I saw that I was watching a type of surgery called laparoscopic surgery.

スポーツの話とか 週末に何をするかとか

And for those who are unfamiliar, laparoscopic surgery, instead of the large open incision you might be used to with surgery,

それ以後 手術というものを見学する度に

a laparoscopic surgery is where the surgeon creates these three or more small incisions in the patient.

このようなものだと分かってきました

And then inserts these long, thin instruments and a camera,

いつも通りの日常的な風景があるだけです

and actually does the procedure inside the patient.

でも たまに

This is great because this is much less risk of infections, much less pain, shorter recovery time.

音楽が止み

But there is a trade-off,

突然皆が静かになって

because these incisions are created with a long, pointed device, called the trocar.

全員が何かに注目することあります

And the way the surgeon uses this device is that he takes it

これは 何か重大で 注意を要する危険なことが

and he presses it into the abdomen until it punctures through.

起こっているサインです

And now the reason why everyone in the operating room was staring at that device on that day

最初にそれを目撃したのは

was because he had to be absolutely careful not to plunge it through and puncture it into the organs and blood vessels below.

腹腔鏡手術と呼ばれる

But this problem should seem pretty familiar to all of you,

手術の最中でした

because I’m pretty sure you’ve seen it somewhere else.

ご存知ない方のために 簡単に説明すると

Remember this?

腹腔鏡手術では一般の手術のように

You knew that at any second, that straw was going to plunge through.

大きく開腹する代わりに

And you didn’t know if it was going to go out the other side and straight into your hand,

外科医は このような

or if you were going to get juice everywhere,

小さな穴を 3箇所以上開け

but you were terrified. Right?

そこに この様な長くて細い器具と

Every single time you did this, you experienced the same fundamental physics

カメラも挿入して

that I was watching in the operating room that day.

患者の体内の空間で 手術を行うものです

And it turns out it really is a problem.

この手術の利点は 細菌感染のリスクや

In 2003, the FDA actually came out and said

痛みが大幅に減り 回復も早いことです

that trocar incisions might be the most dangerous step in minimally invasive surgery.

でも欠点もあります

Again in 2009, we see a paper that says that

腹壁に小さな穴を開けるのに

trocars account for over half of all major complications in laparoscopic surgery.

先の尖った細長い

And, oh by the way, this hasn’t changed for 25 years.

「トロッカー」という器具を使いますが

So when I got to graduate school, this is what I wanted to work on.

これを外科医が どのように使うかというと

I was trying to explain to a friend of mine what exactly I was spending my time doing,

患者のお腹にあて

and I said,

腹壁に穴が開くまで

“It’s like when you’re drilling through a wall to hang something in your apartment.

押すわけです

There’s that moment when the drill first punctures through the wall

手術室のスタッフ全員が

and there’s this, plunge. Right?”

この器具に注目していたのは

And he looked at me and he said,

この過程で細心の注意を払い

“You mean like when they drill into people’s brains?”

器具が腹壁を突き破ったときに

And I said, “Excuse me?”

その下にある臓器や血管まで傷つけないように する必要があったからです

And then I looked it up and they do drill into people’s brains.

日常よくある問題と同じですね

A lot of neurosurgical procedures actually start with a drill incision through the skull.

日常よくある問題と同じですね

And if the surgeon isn’t careful, he can plunge directly into the brain.

（笑）

So this is the moment when I started thinking, okay,

皆さんも経験ありますね？

cranial drilling, laparoscopic surgery, why not other areas of medicine?

（拍手）

Because think about it, when was the last time you went to the doctor and you didn’t get stuck with something? Right?

ストローがもう少しで

So the truth is, in medicine puncture is everywhere.

突き刺さるというとき

And here are just a couple of the procedures that I’ve found that involve some tissue puncture step.

反対側まで突き破って パックを持つ手に

And if we take just three of them,

突き刺さってしまうとか

laparoscopic surgery, epidurals and cranial drillings,

ジュースが ドバッと噴出するかとか

these procedures account for over 30,000 complications every year in this country alone.

不安な気分になりましたよね？

I call that a problem worth solving.

皆さんもストローを手に 毎回

So let’s take a look at some of the devices that are used in these types of procedures.

私が手術室で見たものと 物理的には同じ事を

I’ve mentioned epidurals.

やっていたわけです

This is an epidural needle.

実はこれが本当に問題であることが分かりました

It’s used to puncture through the ligaments in the spine and deliver anesthesia during childbirth.

2003年にFDAが

Here’s a set of bone marrow biopsy tools.

トロッカーの刺入が低侵襲手術の

These are actually used to burrow into the bone and collect bone marrow or sample bone lesions.

最も危険な作業であると発表し

Here’s a bayonet from the Civil War.

再び2009年にはトロッカーが

If I had told you it was a medical puncture device, you probably would have believed me.

腹腔鏡手術に伴う重大な問題の

Right? Because what’s the difference?

過半数以上に関係するという論文も発表されました

So the more I did this research, the more I thought there has to be a better way to do this.

にもかかわらず

And for me, the key to this problem is that all these different puncture devices share a common set of fundamental physics.

この器具は過去25年 同じものが使われているのです

So what are those physics? Let’s go back to drilling through a wall.

そこで 大学院では

So you’re applying a force on the drill toward the wall. Right?

これをテーマに研究することにしました

And Newton says, the wall is going to apply force back, equal and opposite.

何に取り組んでいるかを

So as you drill through the wall, those forces balance.

友達に解ってもらおうとして

But then there’s that moment when the drill first punctures through the other side of the wall,

「アパートの壁に何かを掛けるために

and right at that moment, the wall can’t push back anymore.

ドリルで穴を開けていて

But your brain hasn’t reacted to that change in force.

ドリルが内壁を突き破った瞬間

So for that millisecond, or however long it takes you to react, you’re still pushing.

刃が突然 突き抜けてしまった 経験があるだろう？」と言うと

and that unbalanced force causes an acceleration,

刃が突然 突き抜けてしまった 経験があるだろう？」と言うと

and that is the plunge.

彼は私の方を見て こう言いました

But what if…what if right at the moment of puncture,

「頭蓋骨にドリルで穴を開けるときと同じだね？」

you could pull that tip back, actually oppose the forward acceleration?

これにはビックリしました（笑）

That’s what I set out to do.

実際調べてみると 頭の手術にはドリルを使うんです

So imagine you have a device and it’s got some kind of sharp tip to cut through tissue.

脳神経科の手術の多くは

What’s the simplest way you could pull that tip back?

頭蓋骨にドリルで穴を開けることから 始まります

I chose a spring.

外科医が気をつけないと

So when you extend that spring, you extend that tip out so it’s ready to puncture tissue.

ドリルの刃が脳内に突き進んでしまいます

The spring wants to pull the tip back.

これを知り 考え始めました

So how do you keep the tip in place until the moment of puncture?

頭蓋骨に穴を開けたり 腹腔鏡手術

I used this mechanism.

他にも何かあるんじゃないか?

When the tip of the device is pressed against tissue,

だって 医者に行けば 何かで必ず

the mechanism expands outward and wedges in place against the wall.

ブチッと刺されますからね？ （笑）

And the friction that’s generated locks it in place and prevents the spring from retracting the tip.

実際 医療の現場では

But right at the moment of puncture, the tissue can’t push back on the tip anymore.

刺す行為は日常的にあります

So the mechanism unlocks and the spring retracts the tip.

体の様々な組織を刺す医療行為を

Let me show you that happening in slow motion. This is about 2,000 frames a second,

いくつか調べてみました

and I’d like you to notice the tip that’s right there at the bottom, about to puncture through tissue.

ここでは３つだけ 見てみましょう

And you’ll see that right at the moment of puncture,

腹腔鏡手術 硬膜外麻酔 開頭手術ですが

right there, the mechanism unlocks and retracts that tip back.

これらの手術だけで アメリカでは年間

I want to show it to you again, a little closer up.

3万件もの問題が 報告されています

So you’re going to see the sharp bladed tip,

これは 何とかした方が良いと 思ったわけです

and right when it punctures that rubber membrane, it’s going to disappear into this white blunt sheath.

これらの処置に使用される

Right there.

器具をいくつかお見せしましょう

That happens within four 100th of a second after puncture.

硬膜外麻酔に 使われる針がこれです

And because this device is designed to address the physics of puncture

これで背骨の間から靱帯を穿刺して

and not the specifics of cranial drilling or laparoscopic surgery or another procedure,

出産時などの麻酔薬を注入します

it’s applicable across these different medical disciplines and across different length scales.

これは 骨髄生検に使われる器具です

But it didn’t always look like this.

骨の中に突き刺して

This was my first prototype.

骨髄や骨病変のサンプルを採取します

Yes, those are popsicle sticks and there’s a rubber band at the top.

こちらは 南北戦争時代の銃剣です

It took about 30 minutes to do this, but it worked.

（笑）

And it proved to me that my idea worked and justified the next couple years of work on this project.

これが 医療器具だと紹介しても

I worked on this because this problem really fascinated me. It kept me up at night.

きっと誰も疑わないでしょうね

But I think it should fascinate you too,

似たようなものですから

because I said puncture is everywhere,

調べれば調べるほど

that means at some point, it’s going to be your problem too.

さらに良い方法があるべきだと

That first day in the operating room I never expected to find myself on the other end of a trocar.

思うようになりました

But last year, I got appendicitis when I was visiting Greece.

これらの人体に穴を開ける器具に

So I was in the hospital in Athens, and the surgeon was telling me he was going to perform a laparoscopic surgery.

共通の問題も見えてきました

He was going to remove my appendix through these tiny incisions.

物理的な問題です

And he was talking about what I could expect for the recovery and what was going to happen.

物理的に何が起こっているのでしょう？

He said, “Do you have any questions?”

再び壁に穴を開けるのを見てみましょう

And I said, “Just one doc. What kind of trocar do you use?”

ドリルで壁に対して力をかけていますね？

So my favourite quote about laparoscopic surgery comes from a doctor H. C. Jacobaeus.

ニュートンの法則によれば この時 壁が押し返す力は

“It is puncture itself that causes risk.”

同じ強さで逆向きです

And that’s my favorite quote because H. C. Jacobaeus was the first person to ever perform laparoscopic surgery on humans,

穴を開ける過程では

and he wrote that in 1912.

この2つの力は釣り合っています

So this is a problem that’s been injuring and even killing people for over 100 years.

でも ドリルの刃が

So it’s easy to think that for every major problem out there, there’s some team of experts working around the clock to solve it.

壁を貫通した瞬間

The truth is that’s not always the case.

壁はもう押し返す力が無くなります

We have to be better at finding those problems and finding ways to solve them.

でも その変化に人間が反応できないため

So if you come across a problem that grabs you,

ほんのミリ秒間

let it keep you up at night.

反応が起こるまで ドリルを押し続けることになり

Allow yourself to be fascinated,

その一方的な力によって

because there are so many lives to save.

刃が突っ込んでしまうわけです

Thank you.

でも もし貫通の瞬間に