All right, I’ll make it super fast.
It’s me, Destin. Welcome back to SmarterEveryDay.
When you’re in a jet, if the cabin depressurizes,
they drop this little mask out of the top.
What happens if you’re in a depressurized cabin and
you’re up above 15,000 feet and you drop your mask?
Something called hypoxia takes effect
and you got to do something about that.
Let’s get smarter every day!
You’ve heard the flight attendants say this before,
“Secure your own mask before helping others.”
Why did they say that?
Is the 30 seconds it takes to put on a kid’s mask next to me
really that important?
15 years ago I learned the answer to this question
when I was selected to participate
in NASA’s Reduced Gravity Student Flight Opportunities Program
at NASA’s Johnson Space Center.
Before I got to ride in the Vomit Comet
I had to undergo physiological training
in a hypobaric chamber at the neutral buoyancy lab.
Fast forward to now.
Today, astronaut Don Pettit is scheduled to renew his hypoxia training certification
and I asked him if it would be okay if I tagged along
let me swim a few laps with him over the International
Space Station mock-up in the neutral buoyancy lab
before we headed over next door for Don’s training.
You look like something the dog dragged in.
I feel like it, too.
The purpose of hypoxia training
is to let astronauts and aviators know
when their brain’s about to stop working correctly,
which is very, very important.
If you’re at a high altitude in an airplane,
the air is thinner but the cabin is pressurized,
so your body gets enough oxygen to operate.
To simulate cabin depressurization,
NASA puts its astronauts in a chamber at sea level
and then pumps the air out to thin it out,
so that it simulates a higher altitude.
Don’s training starts with class work
focused on understanding the specific signs
and symptoms of hypoxia in his own body.
The goal of this training is to understand your own physiological symptoms
so that you can take action quickly.
For example, Don said he experiences
tunnel vision and air hunger,
but I remember for my training 15 years ago
that get really happy and start to tingle all over
I can’t take you seriously because this is what you look like.
What do you mean? I look perfectly normal.
This is the experiment we’re going to do:
Don and I are both going to enter the hypobaric chamber
at the same time and fly to FL250,
at which point we are going to remove our masks
and start to experience the effects of hypoxia.
Don is the control.
He’s a trained astronaut
who recognizes the symptoms for hypoxia
and immediately corrects for them.
I, on the other hand,
am under the direct supervision of a NASA flight surgeon
and after I notice the effects of hypoxia,
I’ve asked if I could delay for about one minute
so we can better understand the physiological effects
of not immediately putting your mask on.
OK, here we go, we’re getting set up.
While Jerry gets me situated,
I’m going to talk about the two types of decompression:
Number one, rapid decompression
this is like being inside of an explosion.
You dump all your pressure instantly,
all the moisture condenses out of the air,
you’re suddenly in a cloud.
Very scary, very violent
Yeah, we’re not going to do that.
What we’re going to do is simulate a slow, steady leak.
We’re going to start at sea level
and ascend at 5,000 feet per minute all the way up to 25,000 feet,
or as aviators call it, flight level 2-5-0
You can see the altimeter right here above Jerry.
He’s pointing it out to you.
so we’re just passing through 10,000 feet of altitude.
I want to start to talk a little about the gas expansion.
You’ll see the gloves here.
Already are starting to show the effects
of the reduced pressure.
So Boyle’s Law obviously is telling us that anytime
we have in the body as long as the temperature remains constant
we go to altitude reduce the pressure
then the gases inside that are going to expand.
I’m experiencing Boyle’s Law in my gut right now.
I am too.
We’re passing gas.
Alright gentlemen we are coming into flight level 2-5-0.
What Sharon is going to do is she’s going to level off at that altitude.
She’s going to give us a little bit of a vent to get rid of
some of that angle of bank you guys were talking about
Now that we’re at 2-5-0
What were going to do is I need you to disconnect your mask from the right-hand side,
so that both of you get hypoxia at the same time
even with the mask disconnected
if you could do that for me
So if you drop your mask from the right hand side
turn your regulator off.
You can look at the surgeon’s gloves.
You can see that they are really experiencing some gas expansion
How are you guys feeling
inside the chamber as far as the gas goes?
so we will start this hypoxia demonstration
Whoever has the toy
if you want to use that for me
so what I’d likely for you to do is
to pick up a a piece.
Hold it up show everybody
and tell me what shape it is.
It’s a triangle.
Alright, so you’re now putting inside the box.
Okay. Next piece.
It’s a cylinder.
It’s a cylinder.
Square.It’s another cube.
This is a cylinder.
We also can see a little purple come around your nose and your lip area.
This is a star.
Now before we do it again.
Let’s put your pulse oximeter on your finger
we haven’t done that yet.
Let’s try to check your O2 saturation to see what were down to.
You’ve been off oxygen now for two minutes by the way.
Don how you doing over there?
I’m starting to feel like I’m going to black and white
and a looney tunes kind of thing
My vision is going into just a central spot.
Alright so Don you can get back on oxygen any time you want to
-you don’t have to stay off.-Yeah.
I’d like to know what the O2 saturation is on your pulse oximeter there
What does it read now?
67 Okay so that’s a critical area here
where you need to start thinking about getting back on oxygen
because once you get below 60
death can occur just like “that” 。
Right? So you’ve go to realize that
you don’t want to die.
Can we try the the shape box one more time?
Just compare a difference between
when you were just starting your demonstration versus right now.
We can tell you’re really starting to feel the effects of hypoxia
What I’m interested in is to see what kind of coordination he has now.
Starting to tingle.
Yeah you’ve been off oxygen for about 3:45, three minutes 45 seconds.
What is that?
And what was that one?
That was a square.
A square. Are you sure that’s this one?
Alright you’ve starting to have a little shake there.
You know your lack of oxygen.
You need to start thinking about getting back on oxygen now Destin.
What would you do
if you felt like you needed to get on oxygen how would you correct for that?
Can you correct for hypoxia for me?
Alright so if you don’t get on oxygen you’re going to die.
You’re not going to be able to survive this.
Go to your regulator, get all three switches up.
I don’t want to die.
好了 找到调节器 把3个开关都打开
Alright go to your regulator, get all three switches on your regulator.
Alright let’s go ahead and put him on for him.
Let’s get him back.
Alright let’s continue on with the shape box.
So we’ve got a square.
Alright! Good deal, good deal.
Look at that. See? That right there proves.
How much he’s already gone from hypoxia
back to feeling 100%.
So this is really important
So this is why on aircraft
they tell you to put your oxygen mask on
before you help younger children.
That’s exactly correct. Yes.
Because you’re then able to have the mental awareness
to be able to save yourself and save others.
If you’re waiting what can happen is that
while you’re trying to reach over and put that oxygen mask on that child
you may end up passing out from the lack of oxygen.
That’s super important.
I’m probably going to pay attention to the man or woman
that’s giving me the preflight briefing again.
OK, I want to make one thing abundantly clear.
We performed this demonstration at 25,000 feet.
I had about three to five minutes of consciousness left.
However, most airliners travel at 35,000 feet.
Look at this chart:
There is way less oxygen up there.
At 35,000 feet
you literally have seconds of useful consciousness at that altitude.
You can go from a normally rational person to someone so helpless
you can even save yourself if your life depends on it.
I don’t wanna die
I don’t tell you this to scare you.
I simply want you to understand the physiology
behind that little preflight announcement.
“Put your mask on first before helping others.”
I can tell you right now
had Susan not been in there with you and gotten your mask back on…
We say it, “You would have died”
you really would have.
Thank you for saving my life, Susan.
I owe you a hamburger.
Look, I don’t want to get too deep or philosophical with this,
but I think there’s a neat metaphor here.
Sometimes it’s easy for me to see
the problems in other people and focus on
that and I get so carried away with fixing other people
that I forget that I have a problem too.
And I think that’s what’s so cool about this demonstration.
Sometimes you just got to put your mask on first
and get yourself sorted before you can help others.
So thanks again for saving my life, by the way.
You’re welcome, it was an honor and a pleasure.
– 救人是应该的- 太好了
– I’d save you all the time.– It was great.
There you go, now we learned
why you need to put your mask on first before you help other people.
You don’t want to get hypoxia.
you’re getting smarter every day,
have a good one.
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I want to say thank you to the awesome people
at NASA’s neutral buoyancy laboratory.
They kept me super safe, super informed
and they educated me and
made me smarter every moment I was with them.
That was really awesome.
Thank you so much, guys!
Anyway, I’m Destin
you’re getting smarter every day.
Have a good one.
What’s the deal here, Don?
Well I cut the regular lens off of the goggles
– OK – and then I took an old pair of glasses
and I cut the plastic to fit my goggles and then I glued them on.
You basically MacGyvered your own goggles,
so that you had correction underwater.
That’s pretty good.