Project

# Title Team Members TA Documents Sponsor
27 Team Heart Restart
 Brian Chiang
Ethan Moraleda
Will Mendez
 Frey Zhao design_document1.pdf
proposal1.pdf
Team Heart Restart

Team Members:
- William Mendez (wmendez2)
- Ethan Moraleda (ethannm2)
- Brian Chiang (brianc11)

Problem:

Research has found that defibrillators delivering a single shock have a lower survival rate (13.3%) compared to Double Sequential External Defibrillators (DSED), which achieve a survival rate of 30.4%. To deliver a double shock, two separate defibrillators are required. Since ambulances typically carry only one defibrillator/cardiac monitor, DSED is currently not feasible in the field. Current Defibrillators do not have impedance readings which limits their accessibility to different body types.

Solution:

Our solution is to create a singular device that can deliver two sequential shocks. As we now need a total of four pads to administer 2 consecutive shocks, we are now able to read the impedance of the patient, allowing us to calculate a more accurate time and power of the shocks to increase survivability.

Our first subsystem will be our custom PCB board. This board will contain 3 main elements: the electrocardiogram (EKG), the Impedance sensor, and the power supply. The EKG will be used to read the electric signals within the heart from the anterior-posterior (AP) and the anterior-lateral (AL) positions. This will utilize 4 hospital-grade electrode tabs as the sensors. These electrical signals will allow us to understand how the heart is functioning, and when we would initiate the sequential shocks. The impedance sensor will measure the body impedance of the patient. This measurement is essential as it is required to calculate how much power is needed behind each shock and the time between each shock. Different body types require different levels of power to reset their hearts. Lastly, the power supply will be used to supply power to the PCB board and our other subsystems.

Our Second subsystem will be an external microcontroller board. This microcontroller will be in charge of our inputs and outputs. Our three inputs are the EKG reading, the Impedance reading, and the start/stop button. Our output will be an HDMI display, which will display the heart rate and impedance in real time with high accuracy.


For safety and to keep the scope of the project realistic, we will be implementing only the EKG and impedance sensor. A future senior design project can implement our project into a full defibrillator device that can execute sequential shocks. We will be documenting our work to hand it off appropriately.



Solution Components

Subsystem 1 - Main board

Subsystem 1.1 - ECG (Amplifiers and Filters)
The electrocardiogram will comprise multiple filters, which can be built using breadboards and over-the-counter small electronic components. This filter will be placed on a PCB board, which will be connected to the microcontroller. The PCB will most likely have a differential amplifier, with a low-pass filter and a notch filter. This will eliminate a lot of noise and disregard all the higher frequencies that do not occur in the human body.

Subsystem 1.2 - Impedance sensor
High-pass filter: Based on previous research, higher frequencies are used to find the human body’s impedance, which means we will need a high-pass filter to filter out the lower frequencies.
Amplifier: Currents that are traveling through the body will be very sensitive and small. To combat this and make the readings readable, an amplifier will be needed.


Subsystem 1.3 - Power Supply
Power Supply: The Power Supply will take a Power output from a Battery and step it down to the voltages needed to supply the electrocardiogram, impedance sensor, and microcontroller. This will likely use LDOs and/or buck converters.

Subsystem 2 - Microcontroller board
This board will take in the outputs from the ECG, Impedance sensor, and power. The ECG and Impedance sensor readings will then be processed and converted to display to a separate screen.





Criterion For Success
Goal 1: Display heart rate via a graph in real time.
Goal 2: Display impedance readings via a graph in real time.
Goal 3: Design circuitry for EKG and Impedance and implement via PCB
Goal 4: Design a board that can step down power from a battery for EKG and Impedance circuitry
Goal 5: Utilize a microcontroller to process readings
Goal 6: Work with medical students/mentors
Goal 7: Document how to implement this project for future expansion.

Microcontroller-based Occupancy Monitoring (MOM)

Vish Gopal Sekar, John Li, Franklin Moy

Microcontroller-based Occupancy Monitoring (MOM)

Featured Project

# Microcontroller-based Occupancy Monitoring (MOM)

Team Members:

- Franklin Moy (fmoy3)

- Vish Gopal Sekar (vg12)

- John Li (johnwl2)

# Problem

With the campus returning to normalcy from the pandemic, most, if not all, students have returned to campus for the school year. This means that more and more students will be going to the libraries to study, which in turn means that the limited space at the libraries will be filled up with the many students who are now back on campus. Even in the semesters during the pandemic, many students have entered libraries such as Grainger to find study space, only to leave 5 minutes later because all of the seats are taken. This is definitely a loss not only to someone's study time, but maybe also their motivation to study at that point in time.

# Solution

We plan on utilizing a fleet of microcontrollers that will scan for nearby Wi-Fi and Bluetooth network signals in different areas of a building. Since students nowadays will be using phones and/or laptops that emit Wi-Fi and Bluetooth signals, scanning for Wi-Fi and Bluetooth signals is a good way to estimate the fullness of a building. Our microcontrollers, which will be deployed in numerous dedicated areas of a building (called sectors), will be able to detect these connections. The microcontrollers will then conduct some light processing to compile the fullness data for its sector. We will then feed this data into an IoT core in the cloud which will process and interpret the data and send it to a web app that will display this information in a user-friendly format.

# Solution Components

## Microcontrollers with Radio Antenna Suite

Each microcontroller will scan for Wi-Fi and Bluetooth packets in its vicinity, then it will compile this data for a set timeframe and send its findings to the IoT Core in the Cloud subsystem. Each microcontroller will be programmed with custom software that will interface with its different radio antennas, compile the data of detected signals, and send this data to the IoT Core in the Cloud subsystem.

The microcontroller that would suit the job would be the ESP32. It can be programmed to run a suite of real-time operating systems, which are perfect for IoT applications such as this one. This enables straightforward software development and easy connectivity with our IoT Core in the Cloud. The ESP32 also comes equipped with a 2.4 GHz Wi-Fi transceiver, which will be used to connect to the IoT Core, and a Bluetooth Low Energy transceiver, which will be part of the radio antenna suite.

Most UIUC Wi-Fi access points are dual-band, meaning that they communicate using both the 2.4 GHz and 5 GHz frequencies. Because of this, we will need to connect a separate dual-band antenna to the ESP32. The simplest solution is to get a USB dual-band Wi-Fi transceiver, such as the TP-Link Nano AC600, and plug it into a USB Type-A breakout board that we will connect to each ESP32's GPIO pins. Our custom software will interface with the USB Wi-Fi transceiver to scan for Wi-Fi activity, while it will use the ESP32's own Bluetooth Low Energy transceiver to scan for Bluetooth activity.

## Battery Backup

It is possible that the power supply to a microcontroller could fail, either due to a faulty power supply or by human interference, such as pulling the plug. To mitigate the effects that this would have on the system, we plan on including a battery backup subsystem to each microcontroller. The battery backup subsystem will be able to not only power the microcontroller when it is unplugged, but it will also be able to charge the battery when it is plugged in.

Most ESP32 development boards, like the Adafruit HUZZAH32, have this subsystem built in. Should we decide to build this subsystem ourselves, we would use the following parts. Most, if not all, ESP32 microcontrollers use 3.3 volts as its operating voltage, so utilizing a 3.7 volt battery (in either an 18650 or LiPo form factor) with a voltage regulator would supply the necessary voltage for the microcontroller to operate. A battery charging circuit consisting of a charge management controller would also be needed to maintain battery safety and health.

## IoT Core in the Cloud

The IoT Core in the Cloud will handle the main processing of the data sent by the microcontrollers. Each microcontroller is connected to the IoT Core, which will likely be hosted on AWS, through the ESP32's included 2.4GHz Wi-Fi transceiver. We will also host on AWS the web app that interfaces with the IoT Core to display the fullness of the different sectors. This web app will initially be very simple and display only the estimated fullness. The web app will likely be built using a Python web framework such as Flask or Django.

# Criterion For Success

- Identify Wi-Fi and Bluetooth packets from a device and distinguish them from packets sent by different devices.

- Be able to estimate the occupancy of a sector within a reasonable margin of error (15%), as well as being able to compute its fullness relative to that sector's size.

- Display sector capacity information on the web app that is accurate within 5 minutes of a user accessing the page.

- Battery backup system keeps the microcontroller powered for at least 3 hours when the wall outlet is unplugged.

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