# Title Team Members TA Documents Sponsor
33 Air pollution mapping bands
Chirag Nanda
Vatsin Ninad Shah
Vedant Agrawal
Amr Ghoname design_document1.pdf
# Air pollution mapping bands

Team Members:
- Chirag Nanda (cnanda2)
- Vedant Agrawal (vsa3)
- Vatsin Ninad Shah (vns2)

# Problem

Many cities are reaching CO2 levels that are becoming toxic. Cities keep track of these pollution levels using the air quality index, which defines pollution levels of the whole city. Nonetheless, the air quality is often worse in specific parts of the city and it changes over the course of the day depending on a variety of factors including traffic, population density, the operation of office buildings, and factories. A more dynamic calculation of air quality can help people decide which routes to take and which places to avoid. Also, there are certain gasses like LPG and methane that in pure form do not have any odor and hence can be hard to detect, making them very dangerous because of how flammable they are. This can especially be a hazard in industries that use these gasses in their pure form where workers need to be notified of leaks.

# Solution

To improve tracking of pollution levels in smaller localities, we plan on creating a wrist band and an accompanying mobile app that will continuously monitor the air quality around the user. The broader idea is to have thousands of users wear this band to help contribute to a city wide map that everyone can access. Nevertheless, within the time constraints of the course we plan to first create a proof of concept of the band and a simple application that gives alerts to the user about their general vicinity. The app can keep a personal record of air pollutant levels of the places they visited on a map. Additionally, the app can serve as a warning device in indoor spaces.

# Solution Components

## Power Subsystem

We want to use 2 or 3 flat 3v cells to power the bracelet as this is the most compact solution for powering our microcontroller and sensors. We will decide the number of cells needed experimentally. 2 cells might quickly go below 2.5V each under load, in which case they will not be able to supply the required 5V. Since our components need a stable 5V and 3.3V power supply, we will use buck converters to bring this voltage down. A buck converter will lose much less power than a linear regulator, so that is the better solution for a longer battery life. Another advantage of using the buck converters is the stability of the 5V and 3.3V power supplies. Because of the feedback loops, we can ensure that the supply will be stable and no part will be damaged.

## Sensor Subsystem

We wish to sense a number of potentially harmful gasses, which (with sensor part number) are:

- Carbon Dioxide (MQ135)
- Hydrogen Sulphide (SEN - 10916)
- Natural Gas, Propane (SEN - 17049)
- Carbon Monoxide, Natural Gas (SEN - 17050)
- LPG gas - (SEN - 09405)
- Ammonia - (SEN - 17053)

These will all be connected to the microcontroller through analog inputs on the ESP32 microcontroller.

## Microcontroller Subsystem

The microcontroller we wish to use is the ESP32 since it has 18 channels of analog inputs, which is more than enough for our application. It also has Bluetooth and WiFi capabilities which will help us send the data collected to the app. The data collected on the analog pins will be appropriately packaged by the microcontroller and sent to the app over Bluetooth or WiFi.

## app Subsystem

Alongside our band, we plan to create an application that will take the pollution data and update a map with the detected pollutant concentrations. The app will use the phone’s GPS as well as the Google map API to maintain a dynamic record of the air pollution of different areas of the city. The app will also give alerts of which areas should be avoided based on the pollutant data.

# Criterion For Success

- Being able to successfully detect increased concentrations of mentioned harmful gasses and successfully placing them on a dynamic map.
- Notifying the user when they enter an area with increased concentration of mentioned gasses.

Recovery-Monitoring Knee Brace

Dong Hyun Lee, Jong Yoon Lee, Dennis Ryu

Featured Project


Thanks to modern technology, it is easy to encounter a wide variety of wearable fitness devices such as Fitbit and Apple Watch in the market. Such devices are designed for average consumers who wish to track their lifestyle by counting steps or measuring heartbeats. However, it is rare to find a product for the actual patients who require both the real-time monitoring of a wearable device and the hard protection of a brace.

Personally, one of our teammates ruptured his front knee ACL and received reconstruction surgery a few years ago. After ACL surgery, it is common to wear a knee brace for about two to three months for protection from outside impacts, fast recovery, and restriction of movement. For a patient who is situated in rehabilitation after surgery, knee protection is an imperative recovery stage, but is often overlooked. One cannot deny that such a brace is also cumbersome to put on in the first place.



Our group aims to make a wearable device for people who require a knee brace by adding a health monitoring system onto an existing knee brace. The fundamental purpose is to protect the knee, but by adding a monitoring system we want to provide data and a platform for both doctor and patients so they can easily check the current status/progress of the injury.



1) Average person with leg problems

2) Athletes with leg injuries

3) Elderly people with discomforts



Temperature sensors : perhaps in the form of electrodes, they will be used to measure the temperature of the swelling of the knee, which will indicate if recovery is going smoothly.

Pressure sensors : they will be calibrated such that a certain threshold of force must be applied by the brace to the leg. A snug fit is required for the brace to fulfill its job.

EMG circuit : we plan on constructing an EMG circuit based on op-amps, resistors, and capacitors. This will be the circuit that is intended for doctors, as it will detect muscle movement.

Development board: our main board will transmit the data from each of the sensors to a mobile interface via. Bluetooth. The user will be notified when the pressure sensors are not tight enough. For our purposes, the battery on the development will suffice, and we will not need additional dry cells.

The data will be transmitted to a mobile system, where it would also remind the user to wear the brace if taken off. To make sure the brace has a secure enough fit, pressure sensors will be calibrated to determine accordingly. We want to emphasize the hardware circuits that will be supplemented onto the leg brace.

We want to emphasize on the hardware circuit portion this brace contains. We have tested the temperature and pressure resistors on a breadboard by soldering them to resistors, and confirmed they work as intended by checking with a multimeter.

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