Elderly safety device using bluetooth low energy

Abstract

Singapore is facing an aging population and residential fires can cause damage to property and lives, especially so for the elderly. The Kansas fire department has shown that people aged 65-74 are nearly twice as likely to die in a fire. [1] They are also more susceptible to dementia and might forget to switch off the gas or other cooking appliance. Their reflexes are also slower and prevents some of them from controlling switches fast enough. Especially if the person has physical disabilities. This project aims to allow the elderly or people with dementia to conveniently forget to switch off appliances and just walk away. On detection that the user is away, the device will switch off the appliance on the user's behalf. It is able to be retrofit onto current appliances and is very user friendly. There will be mainly 2 processes the device will be involved in. The first is to scan the environment for calibrated devices and read their signal strength. The data is then smoothed using an algorithm and the distance is derived using the formula as disclosed within. The next process is to activate the safety device. The scanning and calibrating of devices has been done successfully and uses Bluetooth Low Energy along with a recorded propagation constant to get the estimated distance. Because we record the propagation constant of the environment, the device is able to estimate the distance more accurately after smoothing the data for outliers. The activation of the safety device is done using a custom circuit board that controls a DPDT relay to toggle the attached device. It also acts as a protection to ensure a power surge or unstable power supply does not damage the device. This report will discuss the proposed approach for scanning, calibrating and activation of the safety device. It will also include how the data is smoothed and how the accuracy of the system is increased. In addition the plan for commercialization and future enhancements are also discussed.