Three years ago, Mr Lin Hai Qiang's grandfather fell at home and fractured his left knee.
As there was no one else at home, the elderly man was unable to call for help and suffered in pain for hours, lying on the kitchen floor in agony.
The incident inspired Mr Lin, 23, a final-year aerospace electronics student at Singapore Polytechnic (SP), to come up with a fall detection system for his final-year project.
Designed by Mr Lin and his coursemate, Mr Yeo Yong Ming, 20, the system consists of two kinect sensors that measure the speed of a subject's body movements using infrared.
When an unusually high speed is recorded and the subject does not get up after 20 seconds, a warning will be sent via text message to family members.
An alarm outside the subject's house will also ring, alerting neighbours to the fall.
Mr Jaichandar K S, 42, senior lecturer at SP's School of Electrical & Electronic Engineering, said: "When elderly people fall, they may be unable to call for assistance. With this system, the caregiver is alerted once the sensors detect no activity."
The fall detection system is just one of 65 projects on display at SP's annual Engineering Show, which is open to the public and ends today. Admission is free.
Mr Lin's project and another student project, Intellisense Bed, are part of SP's Smart Flat for Elderly display. (See infographics above.)
The polytechnic student said he was glad that he helped to develop the fall detection system.
He said: "Because my grandfather didn't receive treatment immediately, his knee suffered permanent damage.
"Now, he walks with a limp. If this system had been around then, maybe he wouldn't have to suffer so much."
The system also offers more privacy, compared to surveillance cameras.
"Cameras can be a bit intrusive when someone is changing clothes," he said.
The system has a 82 per cent accuracy and Mr Lin and his coursemate hope to keep working on improving it.
"Once it's fine-tuned, I will consider installing it in my grandfather's house.
"If I can't look out for him, at least the system will look out for him."
This article was first published on January 23, 2015.
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