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 ever experienced, and it was also the first incident that informed us that my grandfather had Alzheimer’s disease.

Over the years, his condition got worse, and his wandering in particular caused numerous accidents and tremendous stress to my family. About two years ago, his wandering out of bed at night became much more frequent, and my aunt, his primary caregiver, struggled to stay awake at night to keep an eye on him and even then often failed to catch him leaving the bed. I became concerned about my aunt’s wellbeing as well as my grandfather’s safety. I searched extensively for but couldn’t find a solution to my family’s problems.

Later, I found out that the struggles faced by my family were just a snapshot of a much larger societal burden. There are 5.2 million Alzheimer’s patients in the U.S., more than 65% of whom wander. Caring for them cost the nation $220 billion in 2013 alone, a number that is expected to multiply five times by the year 2050.

This overwhelming societal challenge, coupled with my concern for my family’s struggles, motivated me to find a solution. But how?

One night, I was looking after my grandfather as I saw him stepping out of the bed. The moment his foot landed on the floor, a lightbulb flashed in my head. I thought: Why don’t I put a pressure sensor on the heel of his foot? Once he steps onto the floor, the sensor would wirelessly send an audible alert to my aunt’s smartphone, waking her up. That way, she could sleep much better at night.

My desire to create a sensor-based system perhaps stemmed from my lifelong passion for sensors. When I was six years old, an elderly family friend fell down in the bathroom and suffered severe injuries. I became concerned about my own grandparents and decided to create a “Smart Bathroom,” a motion sensor system that detects the falls of elderly patients and alerts caregivers wirelessly at their wristwatches. This and other research experience prepared me to create my system.

My seemingly simple idea, however, later proved to be very challenging for me to realize. When I laid out my plan, I found out that I faced three main challenges: creating a sensor, designing a circuit, and coding a Smartphone app that would alert the caregiver.

First, I had to create a sensor that was thin and flexible enough not to affect the comfort of walking. After extensive research and testing of multiple materials, I decided to print a film sensor with pressure-sensitive, conductive ink. Once pressure is applied, the conductivity between the ink particles increases. Therefore, I could design a circuit that would measure force by measuring electrical resistance.

Next, I had to design a wearable, wireless circuit. But wireless signal transmission consumes lots of power and requires heavy, bulky batteries. Fortunately, I was able to find out about the cutting-edge Bluetooth Low Energy technology, which consumes very little power and can be driven by a coin-sized battery.

I also had to code a Smartphone app that would transform the caregiver’s Smartphone into a remote monitor. For this, I had to expand upon my knowledge of Java and XCode, and I also had to learn a lot about how to code for Bluetooth Low Energy devices.

Integrating these components, I was able to create two prototypes: a sensor sock and a re-attachable sensor assembly. I’ve tested the prototypes on my grandfather for over ten months now, and they’ve had a 100% success rate in detecting the known cases of his wandering. Encouraged by these results, I decided to form my own start-up, SensaRx, to commercialize my technology and deliver it to those in need.

Over the summer, I beta tested my device at several residential care facilities and am incorporating the feedback to further improve the technology into a marketable product.

Through the beta test, I learned that the usage of Bluetooth Low Energy in my circuit limited the signal transmission range. Therefore, I am working on another solution that uses WiFi to transmit longer-range signals between the sensor and the caregiver’s Smartphone.

I am also hoping to incorporate cloud software into my system to enable better service and big data analytics. For example, the system can collect data about the time and frequency of a patient’s wandering and examine correlations with the patient’s daily activities and diet.

And that’s just the beginning. With wearable technology, we can pave the way for a healthier life in which self-monitoring will enable early diagnosis and prevention of diseases.

I’ll never forget the time when my device first caught my grandfather’s wandering out of bed at night. At that moment, I was struck by the power of technology to change lives. My research has inspired me to unlock the mysteries of the brain and find treatments for those who are suffering from mental conditions. I may not be able to cure my Grandfather of Alzheimer’s disease, but I hope that I can prevent future generations from combatting this tragic illness.

To learn more about SafeWander and to join the interest list for the product, visit

Leave a Reply