What's the fastest growing threat to Americans' health? Cancer? Heart attacks? Diabetes?↵
The answer is actually none of these; it's Alzheimer's disease.↵
Every 67 seconds, someone in the United States is diagnosed with Alzheimer's.↵
As the number of Alzheimer's patients triples by the year 2050, caring for them, as well as the rest of the aging population, will become an overwhelming societal challenge.↵
My family has experienced firsthand the struggles of caring for an Alzheimer's patient.↵
Growing up in a family with three generations, I've always been very close to my grandfather.↵
When I was four years old, my grandfather and I were walking in a park in Japan when he suddenly got lost.↵
It was one of the scariest moments I've ever experienced in my life, and it was also the first instance that informed us that my grandfather had Alzheimer's disease.↵
Over the past 12 years, his condition got worse and worse, and his wandering in particular caused my family a lot of stress.↵
Integrating these components, I was able to successfully create two prototypes, one in which the sensor is embedded inside a sock, and another that's a re-attachable sensor assembly that can be adhered anywhere that makes contact with the bottom of the patient's foot.↵
I've tested the device on my grandfather for about a year now, and it's had a 100 percent success rate in detecting the over 900 known cases of his wandering.↵
Last summer, I was able to beta test my device at several residential care facilities in California, and I'm currently incorporating the feedback to further improve the device into a marketable product.↵
Testing the device on a number of patients made me realize that I needed to invent solutions for people who didn't want to wear socks to sleep at night.↵
So sensor data, collected on a vast number of patients, can be useful for improving patient care and also leading to a cure for the disease, possibly.↵
For example, I'm currently examining correlations between the frequency of a patient's nightly wandering and his or her daily activities and diet.↵
One thing I'll never forget is when my device first caught my grandfather's wandering out of bed at night.↵
At that moment, I was really struck by the power of technology to change lives for the better. People living happily and healthfully - that's the world that I imagine.↵
Thank you very much.

In 1965, 17-year-old high school student, Randy Gardner stayed awake for 264 hours.↵
That's 11 days to see how he'd cope without sleep.↵
On the second day, his eyes stopped focusing.↵
Next, he lost the ability to identify objects by touch.↵
By day three, Gardner was moody and uncoordinated.↵
At the end of the experiment, he was struggling to concentrate, had trouble with short-term memory, became paranoid, and started hallucinating.↵
Although Gardner recovered without long-term psychological or physical damage, for others, losing shuteye can result in hormonal imbalance, illness, and, in extreme cases, death.↵
We're only beginning to understand why we sleep to begin with, but we do know it's essential.↵
Adults need seven to eight hours of sleep a night, and adolescents need about ten.↵
We grow sleepy due to signals from our body telling our brain we are tired, and signals from the environment telling us it's dark outside.↵
The rise in sleep-inducing chemicals, like adenosine and melatonin, send us into a light doze that grows deeper, making our breathing and heart rate slow down and our muscles relax.↵
This non-REM sleep is when DNA is repaired and our bodies replenish themselves for the day ahead.↵
In the United States, it's estimated that 30% of adults and 66% of adolescents are regularly sleep-deprived.↵
This isn't just a minor inconvenience.↵
Staying awake can cause serious bodily harm.↵
When we lose sleep, learning, memory, mood, and reaction time are affected.↵
Sleeplessness may also cause inflammation, halluciations, high blood pressure, and it's even been linked to diabetes and obesity.↵
How can sleep deprivation cause such immense suffering?↵
Scientists think the answer lies with the accumulation of waste prducts in the brain.↵
During our waking hours, our cells are busy using up our day's energy sources, which get broken down into various byproducts, including adenosine.↵
As adenosine builds up, it increases the urge to sleep, also known as sleep pressure.↵
In fact, caffeine works by blocking adenosine's receptor pathways.↵
Other waste products also build up in the brain, and if they're not cleared away, they collectively overload the brain and are thought to lead to the many negative symptoms of sleep deprivation.↵
So, what's happening in our brain when we sleep to prevent this?↵
Scientists found something called the glymphatic system, a clean-up mechanism that removes this buildup and is much more active when we're asleep.↵
It works by using cerebrospinal fluid to flush away toxic byproducts that accumulate between cells.↵
Lymphatic vessels, which serve as pathways for immune cells, have recently been discovered in the brain, and they may also play a role in clearing out the brain's daily waste products.↵
While scientists continue exploring the restorative mechanisms behind sleep, we can be sure that slipping into slumber is a necessity if we want to maintain our health and our sanity.