sponsored links
TEDxBeaconStreet

Nikolai Begg: A tool to fix one of the most dangerous moments in surgery

November 12, 2013

Surgeons are required every day to puncture human skin before procedures — with the risk of damaging what's on the other side. In a fascinating talk, find out how mechanical engineer Nikolai Begg is using physics to update an important medical device, called the trocar, and improve one of the most dangerous moments in many common surgeries.

Nikolai Begg - Mechanical engineer
Nikolai Begg is a PhD candidate in mechanical engineering whose passion is rethinking medical devices. Full bio

sponsored links
Double-click the English subtitles below to play the video.
The first time I stood
in the operating room
00:12
and watched a real surgery,
00:14
I had no idea what to expect.
00:16
I was a college student in engineering.
00:19
I thought it was going to be like on TV.
00:21
Ominous music playing in the background,
00:23
beads of sweat pouring down the surgeon's face.
00:25
But it wasn't like that at all.
00:28
There was music playing on this day,
00:30
I think it was Madonna's greatest hits. (Laughter)
00:31
And there was plenty of conversation,
00:34
not just about the patient's heart rate,
00:36
but about sports and weekend plans.
00:38
And since then, the more surgeries I watched,
00:41
the more I realized this is how it is.
00:43
In some weird way, it's just
another day at the office.
00:45
But every so often
00:48
the music gets turned down,
00:50
everyone stops talking,
00:52
and stares at exactly the same thing.
00:53
And that's when you know
that something absolutely critical
00:56
and dangerous is happening.
00:58
The first time I saw that
01:01
I was watching a type of surgery
01:02
called laparoscopic surgery
01:03
And for those of you who are unfamiliar,
01:05
laparoscopic surgery, instead of the large
01:08
open incision you might
be used to with surgery,
01:10
a laparoscopic surgery
is where the surgeon creates
01:13
these three or more small
incisions in the patient.
01:15
And then inserts these long, thin instruments
01:18
and a camera,
01:21
and actually does the procedure inside the patient.
01:22
This is great because there's
much less risk of infection,
01:26
much less pain, shorter recovery time.
01:28
But there is a trade-off,
01:31
because these incisions are created
01:34
with a long, pointed device
01:36
called a trocar.
01:38
And the way the surgeon uses this device
01:40
is that he takes it
01:42
and he presses it into the abdomen
01:43
until it punctures through.
01:45
And now the reason why
everyone in the operating room
01:49
was staring at that device on that day
01:52
was because he had to be absolutely careful
01:54
not to plunge it through
01:58
and puncture it into the organs
and blood vessels below.
01:59
But this problem should seem
pretty familiar to all of you
02:03
because I'm pretty sure
you've seen it somewhere else.
02:05
(Laughter)
02:08
Remember this?
02:09
(Applause)
02:11
You knew that at any second
02:15
that straw was going to plunge through,
02:17
and you didn't know if it was
going to go out the other side
02:19
and straight into your hand,
02:21
or if you were going to
get juice everywhere,
02:22
but you were terrified. Right?
02:24
Every single time you did this,
02:27
you experienced the same
fundamental physics
02:29
that I was watching in the operating room that day.
02:31
And it turns out it really is a problem.
02:35
In 2003, the FDA actually came out and said
02:37
that trocar incisions might
be the most dangerous step
02:40
in minimally invasive surgery.
02:43
Again in 2009, we see a paper that says
02:45
that trocars account for over half
02:48
of all major complications in laparoscopic surgery.
02:50
And, oh by the way,
02:54
this hasn't changed for 25 years.
02:55
So when I got to graduate school,
02:58
this is what I wanted to work on.
03:00
I was trying to explain to a friend of mine
03:02
what exactly I was spending my time doing,
03:03
and I said,
03:06
"It's like when you're drilling through a wall
03:07
to hang something in your apartment.
03:10
There's that moment when the drill
first punctures through the wall
03:13
and there's this plunge. Right?
03:17
And he looked at me and he said,
03:23
"You mean like when they drill
into people's brains?"
03:25
And I said, "Excuse me?" (Laughter)
03:28
And then I looked it up and they
do drill into people's brains.
03:31
A lot of neurosurgical procedures
03:34
actually start with a drill
incision through the skull.
03:36
And if the surgeon isn't careful,
03:39
he can plunge directly into the brain.
03:41
So this is the moment when I started thinking,
03:45
okay, cranial drilling, laparoscopic surgery,
03:47
why not other areas of medicine?
03:50
Because think about it, when was
the last time you went to the doctor
03:52
and you didn't get stuck with something? Right?
03:54
So the truth is
03:57
in medicine puncture is everywhere.
03:58
And here are just a couple
of the procedures that I've found
04:01
that involve some tissue puncture step.
04:03
And if we take just three of them —
04:07
laparoscopic surgery,
epidurals, and cranial drilling —
04:09
these procedures account
for over 30,000 complications
04:13
every year in this country alone.
04:17
I call that a problem worth solving.
04:20
So let's take a look at some of the devices
04:22
that are used in these types of procedures.
04:25
I mentioned epidurals. This is an epidural needle.
04:27
It's used to puncture through
the ligaments in the spine
04:30
and deliver anesthesia during childbirth.
04:33
Here's a set of bone marrow biopsy tools.
04:35
These are actually used
to burrow into the bone
04:38
and collect bone marrow
or sample bone lesions.
04:40
Here's a bayonette from the Civil War.
04:43
(Laughter)
04:45
If I had told you it was a
medical puncture device
04:48
you probably would have believed me.
04:51
Because what's the difference?
04:53
So, the more I did this research
04:55
the more I thought there has to be
04:57
a better way to do this.
04:58
And for me the key to this problem
05:01
is that all these different puncture devices
05:03
share a common set of fundamental physics.
05:05
So what are those physics?
05:09
Let's go back to drilling through a wall.
05:11
So you're applying a force
on a drill towards the wall.
05:12
And Newton says the wall
is going to apply force back,
05:16
equal and opposite.
05:19
So, as you drill through the wall,
05:21
those forces balance.
05:22
But then there's that moment
05:24
when the drill first punctures
through the other side of the wall,
05:26
and right at that moment
the wall can't push back anymore.
05:28
But your brain hasn't reacted
to that change in force.
05:31
So for that millisecond,
05:34
or however long it takes you
to react, you're still pushing,
05:35
and that unbalanced force
causes an acceleration,
05:38
and that is the plunge.
05:41
But what if right at the moment of puncture
05:44
you could pull that tip back,
05:48
actually oppose the forward acceleration?
05:49
That's what I set out to do.
05:52
So imagine you have a device
05:54
and it's got some kind of sharp tip
to cut through tissue.
05:56
What's the simplest way
you could pull that tip back?
05:59
I chose a spring.
06:02
So when you extend that spring,
you extend that tip out
06:04
so it's ready to puncture tissue,
06:07
the spring wants to pull the tip back.
06:09
How do you keep the tip in place
06:10
until the moment of puncture?
06:12
I used this mechanism.
06:14
When the tip of the device
is pressed against tissue,
06:17
the mechanism expands outwards
and wedges in place against the wall.
06:19
And the friction that's generated
06:23
locks it in place and prevents
the spring from retracting the tip.
06:25
But right at the moment of puncture,
06:28
the tissue can't push back
on the tip anymore.
06:30
So the mechanism unlocks
and the spring retracts the tip.
06:32
Let me show you that
happening in slow motion.
06:35
This is about 2,000 frames a second,
06:37
and I'd like you to notice the tip
06:39
that's right there on the bottom,
about to puncture through tissue.
06:40
And you'll see that
right at the moment of puncture,
06:43
right there, the mechanism unlocks
and retracts that tip back.
06:48
I want to show it to you again, a little closer up.
06:51
You're going to see the sharp bladed tip,
06:54
and right when it punctures
that rubber membrane
06:56
it's going to disappear
into this white blunt sheath.
06:58
Right there.
07:02
That happens within four 100ths
of a second after puncture.
07:04
And because this device is designed
to address the physics of puncture
07:08
and not the specifics of cranial drilling
07:12
or laparoscopic surgery,
or another procedure,
07:14
it's applicable across these
different medical disciplines
07:16
and across different length scales.
07:19
But it didn't always look like this.
07:22
This was my first prototype.
07:24
Yes, those are popsicle sticks,
07:26
and there's a rubber band at the top.
07:29
It took about 30 minutes to do this, but it worked.
07:31
And it proved to me that my idea worked
07:34
and it justified the next couple
years of work on this project.
07:36
I worked on this because
07:39
this problem really fascinated me.
07:41
It kept me up at night.
07:43
But I think it should fascinate you too,
07:45
because I said puncture is everywhere.
07:48
That means at some point
it's going to be your problem too.
07:50
That first day in the operating room
07:54
I never expected to find myself
on the other end of a trocar.
07:56
But last year, I got appendicitis
when I was visiting Greece.
07:59
So I was in the hospital in Athens,
08:02
and the surgeon was telling me
08:04
he was going to perform
a laparoscopic surgery.
08:06
He was going to remove my appendix
through these tiny incisions,
08:08
and he was talking about what
I could expect for the recovery,
08:11
and what was going to happen.
08:13
He said, "Do you have any questions?"
And I said, "Just one, doc.
08:15
What kind of trocar do you use?"
08:17
So my favorite quote
about laparoscopic surgery
08:21
comes from a Doctor H. C. Jacobaeus:
08:24
"It is puncture itself that causes risk."
08:27
That's my favorite quote
because H.C. Jacobaeus
08:31
was the first person to ever perform
laparoscopic surgery on humans,
08:34
and he wrote that in 1912.
08:38
This is a problem that's been injuring and
even killing people for over 100 years.
08:41
So it's easy to think that for
every major problem out there
08:47
there's some team of experts
working around the clock to solve it.
08:49
The truth is that's not always the case.
08:53
We have to be better at finding those problems
08:56
and finding ways to solve them.
08:59
So if you come across a problem that grabs you,
09:02
let it keep you up at night.
09:05
Allow yourself to be fascinated,
09:07
because there are so many lives to save.
09:09
(Applause)
09:12
Translator:Bob Prottas
Reviewer:Ariana Bleau Lugo

sponsored links

Nikolai Begg - Mechanical engineer
Nikolai Begg is a PhD candidate in mechanical engineering whose passion is rethinking medical devices.

Why you should listen
Since Nikolai Begg first saw robotic surgery performed as a thirteen-year-old, he has been in love with building things to help others. Now as a PhD Candidate in mechanical engineering at MIT, Begg works on designs to improve any number of things in people's lives -- from salt and pepper shakers that always stay in the same position relative to one another to a non-invasive female urinary catheter. He's especially passionate about how he can apply physics and mechanical principles to medical devices. In 2013 he won the annual Lemelson-MIT Student Prize for Invention, for a product that makes more precise incisions during surgery.
sponsored links

If you need translations, you can install "Google Translate" extension into your Chrome Browser.
Furthermore, you can change playback rate by installing "Video Speed Controller" extension.

Data provided by TED.

This website is owned and operated by Tokyo English Network.
The developer's blog is here.