Bad posture detection and alerting system:

                                                                      Figure 1. Full Block Diagram

The system consist of 

• One Arduino uno r3
• One LCD display(16x2)
• One buzzer
• Two ultrasonic Sensor
• Two potentiometer

Methodology:

1. The two ultrasonic sensor is placed at two different location of the chair one at the middle of the chair and another at the head rest of the chair. 
2. When a person sits in this chair the distance of the person's head and back of person from chair is calculated using two ultrasonic sensor. 
3. The Arduino compares the distance value between the person back from chair and distance of the persons head from the chair, If the “difference” between them is not greater than the set value(calibration value) the Arduino detects it as bad posture.
4. The  amount of difference value(calibration value) that can be accepted as good posture can be increased via a 10k ohm potentiometer and it can be viewed in the LCD ( 16x2 ) display.
5.  When the system detects the person’s sitting on the smart chair as bad posture the buzzer is activated after a delay. 
6. This delay for activating the buzzer after detecting bad posture can be seen in the LCD display and can be adjusted using a another 10kohm potentiometer present in the system for our convenience.

Figure 3. Circuit diagram

Figure 4. Practical implementation picture

Practical implementation video:

Video link: https://drive.google.com/file/d/15x9HEyHdfJyudJRNDUvzpOqQ_QKfIDu6/view?usp=drivesdk

why to ultrasonic sensor?

when use one sensor to measure distance of person from chair (from headrest) 

• case 1: if the person sitting straight when leaning in chair it detects it as good posture
• case 2:if the person sitting hunched in chair when leaning in chair it detects it as bad posture as the distance value increases from the sensor at the headrest.
• case 3: if the person sitting  little ahead of backrest but in a straight position but this system detects it as bad posture .
• 
• case 4: if the person sitting  little ahead of backrest but in a hunched position this system detects it as bad posture.

To prevent case 3 from happening we are using a 2nd ultrasonic senser for getting correct information.

CONCLUSION & FUTURE SCOPE:

The system attached to a chair is used to alert the user in case of an unhealthy postural situations, such as sitting with a hunchback or remaining idle for long periods of time. The user will acquire awareness of their own posture using a system which uses two ultrasonic sensor data to detect bad posture and alert the person sitting in the chair by generating sound using buzzer when it detects bad siting posture to help people maintain the key parts of a person’s body are correctly aligned.

Future scopes:

• A system can be connected to a mobile by adding Bluetooth module to Arduino to display the data in mobile
• Then the posture data can be represented graphically in the mobile by using "ThingSpeak.com" platform.