The Assignment: Begin work on your final project

My Project:

For my final project, I wanted to create a wearable device that would prevent people from touching their face and spreading disease. While I wait for parts that I’ve ordered to come in, I worked this week to devise potential approaches using accelerometers and ultrasonic sensors to make the project a reality

Idea 1: Ultrasound sensor and accelerometer

The first idea I had would make use of both an ultrasonic sensor and an accelerometer to make a singular device that would sense face touching. The build relies on two base premises: First, that the usual state of your wrist is at rest. Second, that because your wrist is on a gliding joint with your hand and your body is on the same plane as your face, your wrist must face your body to touch your face. Keeping both of these in mind, I hope to use the accelerometer to detect when your hand is at a “rest state.” When the hand leaves the rest state, the ultrasonic sensor should be able to tell when the anterior face of your body is coming closer, given the earlier premises. This in turn would allow for me to sense face touching with a singular device.

Idea 2: Two Ultrasound sensors and position triangulation

Alternatively, the project could be completed by using two devices each with an ultrasonic sensor. One sensor could form a sort of ultrasonic threshold at the neck level (probably in the form of a necklace. The other sensor then would be able to be tracked when it crosses that threshold. I found the following tutorial online on how to rig two ultrasonic sensors to calculate distance between two points.

Primary Anticipated Challenges:

Positional Accuracy – Human body movements are complicated and multi-axial. Thus, it can be hard to determine the exact location of a hand or fingers in space. The final solution should have some mechanism for measuring the hand’s distance from other objects.

False Positives – It is important that the device would allow a wearer to complete normal day-to-day tasks without giving them false positives on face touching. Any final solution must control for and distinguish facial touching from other touching.

Scale and Usability – This is not necessarily a challenge that can be surmounted in quarantine, but an ideal solution should be low-profile and wearable in a way that does not disrupt day-to-day activities. However, this will likely not be feasible given material constraints and availability.