LIFE!

LIFE! : Light inspector for detecting falls

Prevention of falls is crucial for the elderly.

In the elderly, falls are the main cause of injury and other complications. The complications can vary from minimal to life threatening, including disability, handicap, and infection. A solution that warns before a fall, or detects after a fall has occurred, can help solve some of these issues.

Many approaches from many makers around the world have been produced in order to prevent falls. The most common of these approaches is to use a wearable device that the elderly wear somewhere on the body, such as on the wrist or head. The wearable uses an accelerometer or motion sensor to detect activity before or after falling.

LIFE! is a surveillance system that can detect a wet floor and alert with different color lights. It can also detect a falling person within a configurable area and notify the caregiver.

LIFE! Architecture

LIFE! has 3 main components as in the following picture.

• Input sensor

To detect water on the floor, we need to use temperature sensor. The concept is wet floor is cooler than normal floor. The sensor we use in this project is the Grid eye.

The Grid-EYE is a high precision infrared array sensor based on advanced MEMS technology. It is capable of measuring temperatures across a grid of 8x8 (64 pixels) up to ten times per second over the following temperature ranges:

Temperature range of measured object:

High gain: +32°F to +176°F (0°C to 80°C)

Low gain: –4°F to +212°F (–20°C to 100°C)

If this module is not available, we can use other IR temperature sensor to detect whether the area is wet or not, example is mlx90620 IR thermal array sensor.

• Microcontroller

We choose the Arduino Yun board for this project because of the compact size and processor capability. The microprocessor of this board (ATmega32U4) communicate with the Grid-EYE and RGB LED module via I2C bus and PWM signal respectively. After that, the AR9331 processor will process the data from the sensor. The result, the floor is wet or not, will send back to RGB LED with color stratification (eg, blue means dry, red means wet) and also the AR9331 part have linux built in and it can act as web server to display the config or result to computer or other devices. In case of remote access, we can use the temboo service to connect with the microcontroller.

• RGB LED

We can config condition as much as we want to match the desire color, eg wet or dry floor, Is there a falling person on the floor, etc. If needed, we can change the RGB LED part to other light source such as C by GE LED light bulb and config it to blink with the desire condition.

3D rendered of the finished product

For the enclosure, we use openSCAD to make a model for use with 3D printer to make a custom casing.

LIFE! Usability

• When install at bathroom ceiling, it can tell whether the floor is wet or not before enter.

• If multiple installation on different rooms, we can config it as falling detection alarm in every rooms.

• Also, it can config as intrusion detection system if install at entrance or exit ceiling.