A new way to monitor vital signs (that can see through walls) | Dina Katabi

When I was a kid,

I was, like many of you in this room, very much fascinated by Star Wars,

and what fascinated me the most is this notion of the Force,

this energy that connects all people and all objects

and allows you to feel people that you can't even see.

And I remember many nights, I would be sitting at home,

just, like, concentrating and focusing, trying to feel the Force,

and I didn't feel anything, don't worry.

(Laughter)

And later in life, I became a scientist.

I joined the MIT faculty and started working on wireless signals.

These are things like Wi-Fi or cellular systems,

and I did a lot of work in that domain.

But then, again, this Force thing kept nagging me,

and at some point, I was just like,

"Wait a minute, these wireless signals -- they are like the Force."

So if you think about it,

wireless signals, they travel through space,

they go through obstacles and walls and occlusions,

and some of them,

they reflect off our bodies, because our bodies are full of water,

and some of these minute reflections,

they come back.

And if, just if, I had a device that can just sense these minute reflections,

then I would be able to feel people that I cannot see.

So I started working with my students on building such a device,

and I want to show you some of our early results.

So here, you see my student standing,

and here is our device.

And we are going to put the device in the other office, behind the wall,

and we are going to monitor him as he moves.

This red dot is tracking him using wireless signals.

And as you can see, the red dot is tracking his movements very accurately,

purely based on how his body interacts with the surrounding wireless signals.

Pretty accurate, isn't it?

He has no wearables, nothing.

(Applause)

Now you might be wondering,

how is it possible that we can sense people

and track them, without any wearables, through walls,

and the easiest analogy to think about is radar.

I'm sure many of you have seen this picture.

You transmit a wireless signal to the sky,

it reflects off some airplane, comes back to you,

and you start detecting these airplanes.

But if it were just radar,

then we would have this 50 years ago.

So it's not just radar.

There are two key differences.

So the first difference, of course --

you can't, like radar, just blast wireless power at somebody.

You're going to fry them like if they were in a microwave.

Don't do that.

So it means that you have to be able to deal with very weak signals,

and that means that your device has to be very sensitive.

The second difference is that, unlike the sky, where it's empty --

if you are lucky, there is one airplane that you can catch there.

Like, look at the room

and look how many objects and people there are.

So in indoor environments, the signal not only reflects off the person,

if reflects off the person, off the floor, the ceiling,

off other people around,

and you get very complex reflections

where the same signal reflects off me and then off you,

and then off the ceiling, then off the floor.

And you have to make sense of that mess.

But we were lucky.

We were coming at the right time.

So two things helped us.

The first thing is radiotechnologies have evolved a lot,

and over the last decade,

radio technology became much more powerful,

so we were able to build very sensitive radios

that can sense weak and minute RF signals.

The second thing: machine learning.

So you keep hearing about machine learning

and there was a revolution of machine learning recently,

in deep learning,

and that allowed us to build machine-learning models

that can understand wireless signals and interpret them

so they would know what happened in the environment.

So if you think of it, the radio is like the ear of our device

and the machine learning is like the brain,

and together, they have a very powerful device.

So what else can we sense about people using wireless signals?

Sleep.

Sleep, actually, is something very dear to my heart,

because my sleep is a disaster.

(Laughter)

So one thing is when you start working on some physiological signal

and you discover that yours sucks.

(Laughter)

So you can see why we can capture sleep,

because the person walks and the device sees him as he walks to bed,

when he stops tossing around in bed,

when he steps out of bed,

and that measure of sleep is what people call actigraphy.

It's based on motion.

But it turned out that we can actually get sleep

at a much more important level.

We can understand the change in the brain waves

that occur during sleep.

So, many of you probably know that as we go to sleep,

our brainwaves change and we enter different stages:

awake, light sleep, deep sleep and REM, or rapid eye movement.

These stages are of course related to sleep disorders,

but they are also related to various diseases.

So for example, disturbances in REM are associated with depression.

Disturbances in deep sleep are associated with Alzheimer's.

So if you want to get sleep staging,

today, you will send the person to the hospital,

they put all of these electrodes on their head,

and they ask them to sleep like that.

(Laughter)

It's not really a happy experience.

So what if I tell you that I can do the same thing

but without any of these electrodes on the person's body?

So here is our device,

transmitting very low power wireless signal,

analyzes the reflections using AI

and spits out the sleep stages throughout the night.

So we know, for example, when this person is dreaming.

Not just that ...

we can even get your breathing while you are sitting like that,

and without touching you.

So he is sitting and reading

and this is his inhales, exhales.

We asked him to hold his breath,

and you see the signal staying at a steady level

because he exhaled.

He did not inhale.

And I want to zoom in on the signal.

And this is the same signal as before.

These are the inhales,

these are the exhales.

And you see these blips on the signal?

These are not noise.

They are his heartbeats.

And you can see them beat by beat.

So I want to stop here for a moment and show you a live demo.

Zach is going to help me with the demo,

and we're going to use the device to monitor Zach's breathing.

So this white box that you see here is the device,

and Zach is turning it on ...

and let's see whether he breathes well.

So we're going to do exactly what we did in the video with the other guy,

so the wireless signal is going through,

it's touching Zach's body,

and it's reflecting back to the device,

and we want to monitor his breathing, his inhale-exhale motion.

So we see the inhales, exhales --

so see, these ups and downs are Zach breathing.

Inhaling, exhaling.

(Applause)

So, he can breathe.

(Laughter)

Zach, can you hold your breath, please?

OK, so now he's holding his breath,

so you see the signal stays at a steady level,

and these are his heartbeats.

Beat, beat, beat, beat, beat.

(Applause)

OK, Zach, you can breathe again.

(Laughter)

We don't want accidents here.

(Laughter)

OK, thank you.

(Applause)

So as you can see, we have this device

that can monitor so many physiological signals for you,

and what is really interesting about this device

is that it does all this without any wearables,

without asking the person to change his behavior

or to wear anything or charge anything special.

And that got doctors very excited,

because doctors,

they always want to know more information about their patients,

particularly at home,

and this is particularly true in chronic diseases,

like pulmonary diseases, like COPD,

or heart failure or Alzheimer's and even depression.

All of these chronic diseases are very important.

In fact -- perhaps you know --

two-thirds of the cost of health care in the US

is due to chronic diseases.

But what is really interesting about chronic diseases

is that when the person, for example,

has a problem that leads to the hospital and the emergency room,

this problem doesn't happen overnight.

Actually, things happen gradually.

So if we can monitor chronic disease patients in their home,

we can detect changes in their breathing, heartbeat, mobility, sleep --

and we can detect emergencies before they occur

and have the doctor intervene earlier

so that we can avoid hospitalization.

And indeed, today we are working with multiple doctors

in different disease categories.

So I'm really excited

because we have deployed the device with many patients.

We have deployed the device with patients that have COPD,

which is a pulmonary disease,

patients that have Alzheimer's,

patients that have depression and anxiety

and people that have Parkinson's.

And we are working with the doctors on improving their life,

understanding the disease better.

So when I started, I told you

that I'm really fascinated with Star Wars and the Force in Star Wars,

and indeed, I'm still very much fascinated,

even now, as a grown-up, with Star Wars,

waiting for the next movie.

But I'm very fascinated now and excited

about this new Force of wireless signals,

and the potential of changing health care with this new force.

One of the patients with whom we deployed is actually my aunt.

She has heart failure,

and I'm sure many of you guys in the audience

have parents, grandparents, loved ones who have chronic diseases.

So I want you to imagine with me a future

where in every home that has a chronic disease patient,

there is a device like this device sitting in the background

and just monitoring passively

sleep, breathing, the health of this chronic disease patient,

and before an emergency occurs,

it would detect the degradation in the physiological signal

and alert the doctor

so that we can avoid hospitalization.

This can change health care as we know it today,

improve how we understand chronic diseases

and also save many lives.

Thank you.

(Applause)

Helen Walters: Dina, thank you so much.

Thank you too, Zach.

So glad you're breathing.

So Dina, this is amazing.

The positive applications are incredible.

What is the framework, though, like the ethical framework around this?

What are you doing to prevent this technology from being used

for other, perhaps less positive types of applications?

Dina Katabi: Yeah, this is a very important question, of course,

like, what about misuse,

or what about, I guess you could say, about the Dark Side of the Force?

HW: Right, right.

(Laughter)

DK: So we actually have technologies

that prevent people from trying to use this device

to monitor somebody without their consent.

Because the device understands space,

it will ask you to prove, by doing certain movements,

that you have access to the space

and you are the person who you are asking the device to monitor.

So technology-wise,

we have technology that we integrate to prevent misuse,

but also, I think there is a role for policy, like everything else,

and hopefully, with the two of them, we can control any misuse.

HW: Amazing. Thank you so much.

DK: Thank you.

(Applause)