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The first time I stood
in the operating room
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and watched a real surgery
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I had no idea what to expect.
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I was a college student in engineering.
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I thought it was going to be like on TV.
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Ominous music playing in the background,
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beads of sweat
pouring down a surgeon's face.
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But it wasn't like that at all.
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There was music playing on this day,
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I think it was Madonna's Greatest Hits.
(Laughter)
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And there was plenty of conversation.
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Not just about the patient's heart rate,
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but about sports and weekend plans.
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And since then
the more surgeries I watched,
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the more I realized this is how it is.
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In some weird way,
it's just another day at the office.
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But every so often
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the music gets turned down,
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everyone stops talking,
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and stares at exactly the same thing.
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And that's when you know
that something absolutely critical
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and dangerous is happening.
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The first time I saw that
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I was watching a type of surgery
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called "laparoscopic surgery"
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And for those of you who are unfamiliar
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laparoscopic surgery instead of the large
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open incision you might be used to
with surgery,
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a laparoscopic surgery
is where the surgeon creates
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these three or more
small incisions in the patient.
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And then inserts these long,
thin instruments
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and a camera,
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and actually does the procedure
inside the patient.
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This is great because
there's much less risk of infection,
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much less pain, shorter recovery time.
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But there is a trade off.
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Because these incisions are created
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with a long pointed device
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called a "trocar".
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And the way the surgeon uses this device
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is that he takes it
and he presses it into the abdomen
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until it punctures through.
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And now the reason why
everyone in the operating room
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was staring at that device on that day
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was because he had to be
absolutely careful
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not to plunge it through
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and puncture it into the organs
and blood vessels below.
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But this problem should seem
pretty familiar to all of you
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because I'm pretty sure
you've seen it somewhere else.
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(Laughter)
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Remember this?
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(Applause)
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You knew that at any second
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that straw was going to plunge through,
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and you didn't know
if it was going to go out the other side
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and straight into your hand,
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or if you were going to get
juice everywhere,
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but you were terrified. Right?
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Every single time you did this,
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you experienced
the same fundamental physics
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that I was watching
in the operating room that day.
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And it turns out it really is a problem.
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In 2003, the FDA actually came out
and said
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that trocar incisions
might be the most dangerous step
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in minimally invasive surgery.
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Again in 2009, we see a paper that says
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that trocars account for
over half of all major complications
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in laproscopic surgery.
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And, by the way,
this hasn't changed for 25 years.
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So when I got to graduate school
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this is what I wanted to work on.
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I was trying to explain to a friend of mine
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what exactly I was spending my time doing
and I said,
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"It's like when you're drilling through a wall
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to hang something in your apartment.
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There's that moment when the drill
first punctures through the wall
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and there's this plunge. Right?
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And he looked at me and he said,
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"You mean like when they drill
into people's brains?"
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And I said, "Excuse me?"
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(Laughter)
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And then I looked it up
and they do drill into people's brains.
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A lot of neurosurgical procedures
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actually start with a drill incision
through the skull.
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And if the surgeon isn't careful,
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he can plunge directly into the brain.
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This is the moment when I started thinking,
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OK, cranial drilling, laproscopic surgery,
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why not other areas of medicine?
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Because think about it, when was
the last time you went to the doctor
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and you didn't get stuck with something?
(Laughter)
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So the truth is
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in medicine puncture is everywhere.
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And here are just a couple
of the procedures that I've found
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that involve some tissue puncture step.
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And if we take just three of them
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Laparoscopic Surgery,
Epidurals and Cranial Drilling,
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these procedures account
for over 30,000 complications
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every year in this country alone.
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I call that a problem worth solving.
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Let's take a look at some of the devices
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that are used in these types of procedures.
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I mentioned Epidurals,
this is an epidural needle.
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It's used to puncture through
the ligaments in the spine
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and deliver anesthesia during childbirth.
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Here's a set of bone marrow biopsy tools.
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These are actually used
to burrow into the bone,
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and collect bone marrow,
or sample boney lesions.
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And I already showed you
a laproscopic surgery trocar,
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but here it is again.
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Here's a bayonette from the Civil War.
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(Laughter)
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If I had told you
it was a medical puncture device
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you probably would have believed me.
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Because what's the difference?
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So, the more I did this research
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the more I thought
there has to be a better way to do this.
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And for me the key to this problem
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is that
all these different puncture devices
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share a common set of fundamental physics.
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So what are those physics?
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Let's go back to drilling through a wall.
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So you're applying a force
on a drill towards the wall. Right?
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And Newton says,
the wall is going to apply force back,
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equal and opposite.
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So, as you drill through the wall,
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those forces balance.
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But then there's that moment
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when the drill first punctures
through the other side of the wall,
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and right at that moment
the wall can't push back anymore.
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But your brain hasn't reacted
to that change in force.
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So for that millisecond,
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or however long it takes you
to react, you're still pushing,
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and that unbalanced force
causes an acceleration,
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and that is the plunge.
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But what if, what if
right at the moment of puncture
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you could pull that tip back?
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Actually oppose the forward acceleration.
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That's what I set out to do.
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So imagine that you have a device
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and it's got some kind of sharp tip
to cut through tissue.
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What's the simplest way
you could pull that tip back?
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I chose a spring.
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So when you extend that spring,
you extend that tip out
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so it's ready to puncture tissue,
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the spring wants to pull the tip back.
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How do you keep the tip in place
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until the moment of puncture?
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I use this mechanism.
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When the tip of the device
is pressed against tissue,
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the mechanism expands outwards
and wedges in place against the wall.
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And the friction that's generated
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locks it in place and prevents the spring
from retracting the tip.
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But right at the moment of puncture,
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the tissue can't push back
on the tip anymore.
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So the mechanism unlocks
and the spring retracts the tip.
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Let me show you that
happening in slow motion.
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This is about 2,000 frames a second,
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and I'd like you to notice the tip
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right there on the bottom,
about to puncture through tissue.
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And you'll see that
right at the moment of puncture,
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right there, the mechanism unlocks
and retracts that tip back.
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I want to show it to you again,
a little closer up.
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You're going to see the sharp bladed tip,
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and right when it punctures
that rubber membrane
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it's going to disappear
into this white blunt sheath.
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Right there.
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That happens within 4 100ths
of a second after puncture.
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And because this device is designed
to address the physics of puncture
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and not the specifics of cranial drilling,
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or laproscopic surgery,
or another procedure,
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it's applicable across
these different medical disciplines,
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and across different length scales.
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But it didn't always look like this.
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This was my first prototype.
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Yes, those are popsicle sticks
(Laughter)
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and there's a rubber band at the top.
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It took about 30 minutes to do this,
but it worked.
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And it proved to me that my idea worked
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and justified the next couple years
of work on this project.
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I worked on this because
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this problem really fascinated me.
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I mean it kept me up at night.
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But I think it should fascinate you too.
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Because I said puncture is everywhere.
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That means at some point
it's going to be your problem too.
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That first day in the operating room
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I never expected to find myself
on the other end of a trocar.
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But last year, I got appendicitis
when I was visiting Greece.
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So I was in the hospital in Athens,
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and the surgeon was telling me
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he was going to perform
a laproscopic surgery.
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He was going to remove my appendix
through these tiny incisions.
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He was talking about
what I could expect for the recovery,
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and what was going to happen.
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He said "Do you have any questions?"
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"Just one, doc.
What kind of trocar do you use?"
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So my favorite quote
about laproscopic surgery
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comes from a doctor H. C. Jacobaeus.
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And he said,
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"It is puncture itself that causes risk."
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That's my favorite quote
because H.C. Jacobaeus