Transcript

HELEN:

So now we're going to do a practical experiment, which is going to show you how your vital signs change depending on what you're doing. We're going to do an experiment that measures our respiration rate and our pulse rate. First, either just when we wake up or when we've been lying down for a long time, second, when we've been sitting resting for a while, and third, when we've been doing some exercise. And then we're going to take averages of these results that we measure. And then we're going to compare those with what happens to astronauts when they're in microgravity environments.

So let's start by getting together all the equipment we really need. First, you need a timing device. You can either use a shower timer, a stopwatch if you happen to have one around or, to be honest this is ideal, your smartphone. So let's start with the first part of the experiment, lying down.

The best time to do this is as you wake up. Set your timer on your smartphone to five minutes, and press Start. And now leave that until the alarm goes off.

The great thing is you could have this extra five minutes in bed. But if it's later in the day and you haven't had a chance, you're rushing off to school or work, then you can alternatively do this experiment by lying down and raising your feet slightly in the air, as Tom is demonstrating here. Lie very still. Stay resting until your buzzer goes off. But please remember that, if you have any kind of medical condition or problem that precludes you from doing this, we have provided an alternative set of data for you to look at after you've watched this video so that you can still understand what's going on without doing the experiment.

[PHONE ALARM RINGING]

So, when your five minutes resting is up, what we need to do is we need to measure your pulse and also your respiration rate. And we need to repeat each of those measurements three times. All the details of how to then average this information is included in the text. But let's have a quick look at how we make those measurements.

You'll notice, in fact, that, while Tom is lying down and I'm sitting here, that makes it a little bit easier to make the measurements. But don't worry. It's perfectly possible to do this on your own.

You need two key pieces of equipment for this stage. You might actually use if, you have one, a fitness belt, or a watch, or anything that actually measures your heart rate. That can give you the number quite quickly and easily and saves you doing the measurement.

But let's have a look, just in case you haven't got one of those. Tom's now going to show you very carefully how he measures his pulse. He takes the first two fingers of one hand and puts them carefully against his wrist just below where the angle comes from his thumb to his wrist.

If you press gently, not too hard, you should be able to feel your pulse slowly pulsating against your fingers. Never use your thumb to take your pulse, because inside your thumb, there actually is a pulse. And then it will be very difficult to measure.

So Tom would, if he was doing it on his own, and luckily I'm here to help him, then start his timer for one minute. And I'm going to ask Tom, when I say go, to count out loud every time he can feel his pulse going. Are you ready to, Tom?

TOM:

I am, Helen.

HELEN:

Excellent. Ready, steady, go.

TOM:

1, 2, 3, 4, 5, 6... 54, 55, 56.

[PHONE ALARM RINGING]

HELEN:

56. So I've written down the number of pulses that we measured for Tom in a minute. And we're going to repeat that measurement two more times so that, later on, by looking at the text, we can average them. The next thing we need to do is to measure his respiration rate.

And actually, that isn't as easy as it seems. Because quite often, if you count it yourself, you can speed up and slow down. So I'm going to have a look at how Tom's chest is rising and falling as he breathes and time that over a minute. So are you ready, Tom?

TOM:

Yes.

HELEN:

Excellent. Let's go. 1, 2... 11.

[PHONE ALARM RINGING]

I'm going to write that down, 11. And then I'm going to repeat that measurement two more times. And all of that information concludes the information we have about your vital signs, your pulse, and your respiration rate when you're lying down or, if you did it when you woke up first thing in the morning, when you're waking up first thing in the morning before you get out of bed.