OBJECTIVE

We were tasked with creating a virtual and physical processing unit that models a device which detects when someone is likely having a heart attack based on indicators of elevated troponin, ST changes on ECG readout, and drops in SpO2

At Specific Intervals, the Monitor Will:

Illuminate a green LED - No indicators are present
Illuminate a yellow LED - One indicator is present
Illuminate a red LED & transmit symptoms to healthcare provider - Two indicators are present
Sound Alarm & Contact Emergency Services - All three indicators are present

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Practice Diagram -
Rock, Paper, and Scissors

One of our group members engineered a logic circuit to simulate a Rock-Paper-Scissors game by using AND gates to process all possible outcomes (for example, paper vs. rock or scissors vs. paper). We mapped every potential input combination in a truth table and used this framework to test how the circuit determined whether a player won or if the result was a draw. To clearly indicate each outcome, we arranged diodes to direct varying currents to two LEDs. If the top or bottom LEDs illuminate, it signifies one of the two players winning. If the middle LED illuminates, it represents a tie and the win count remains unchanged.

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Microbit Coding Challenge

In this session, our group used the accelerometer in a BBC Microbit to create a program that reacts to movement by displaying random images. The accelerometer is a motion sensor that detects how the Microbit responds to external interference, such as being tilted or shaken. In this experiment, we tested its response to shaking. We also learned about variables, loops, and if-else statements, which helped us understand the code more deeply. In the video below, the Microbit shows how shaking the device triggers different LED patterns, and in the first few seconds, you can see how the count is tallied and reset.

Diagram for the Patient Monitoring Detection Circuit

We planned out our design on EveryCircuit before we started creating our physical model. This helped us map out and confirm that our logic worked on paper prior to the physical model being built. This was a crucial part in our design process.

Essentials Questions:

How can logical operations be used to simulate decision making in medical devices?
Why is reliable timing and signal clarity critical for life saving circuit designs?
How does the accuracy of physical indicators (like ECG, SpO₂, troponin levels) influence electronic decision outputs?

Students Will Be Able To Answer The Following Questions:

When does adding more complexity to a logic circuit increase function versus increasing risk of error or delay?
Would I trust this cardiac alert system to monitor a real patient in a high stakes environment?

Students Should Be Able To:

Distinguish between hardware logic components (ex: gates and flip-flops) and embedded software solutions in medical tech.
Use logic gates (AND, OR, NOT) and flip-flops to build multi-stage alert systems.
Optimize the sequencing and input weighting of patient indicators to create accurate and timely medical alerts.

Students Will Know:

How to use Boolean logic to model real-world medical scenarios and decision trees.
How to design and test circuits using 7400-series logic chips and 555 timers.
That trade offs between circuit simplicity, speed, and reliability are critical in biomedical applications.
How to physically prototype and troubleshoot logic circuits in a patient monitoring context.
How to communicate their design process to engineers and healthcare professionals.
How timing, memory storage, and real-time evaluation are implemented in critical safety devices.

Alarm Circuit

How does it work?

The battery pack powers the circuit.
The 555 timer is configured in astable mode, generating a square wave output at a frequency set by the resistors and capacitors.
The output pin of the timer sends this signal to the speaker, causing it to oscillate and make sound.
The capacitors help shape the waveform and may smooth the signal to avoid harsh noise or interference.

When we attached the alarm circuit to our primary circuit, the first issue we encountered was that no current was running through the 555 chip, so we tried directly connecting the batteries to the alarm circuit. As a result, we got the alarm working; however, it was producing very low electrical signals, which were essentially inaudible.

Flip-Flop

What is a Flip-Flop?

-Stores a single bit of data: either HIGH (1) or LOW (0).

-Changes state only when triggered (by a clock or input signal).

-Remembers its state until it’s told to change.

-Essential in building counters, memory, registers, and sequential logic.

Our experience with a flip-flop:

In our circuit, we never managed to get the flip-flop to work. We kept running into issues like short circuits or various malfunctions, which almost fried the entire circuit; however, this was the first time we got to experiment with this unknown technology. Therefore, there is still much to learn and skills to sharpen.

Design Process for Patient Monitoring Detection System

Identify the Problem
Define the need and objectives of the monitoring device.

Concept Development
Explore/brainstorm the current and past system technologies.

Select a Solution
Analyze and choose the optimal design approach.

System Design Specification
Develop detailed logic diagrams as well as construction plans.

Design Justification
Present evidence supporting the selected solution’s effectiveness

Prototype Construction
Build, simulate, and test the functional prototype in controlled scenarios.

Performance Assessment
Evaluate device accuracy, reliability, and compliance with requirements.

The Team

Completed Monitoring System

Reflection/Reason for Failure:

For most of our group, this was our first time working with circuits and wires. We tried to do research and work as a team but in the end we were not able to construct a fully functioning model. The due date and time got the best. Additionally, during construction, we are pretty sure that we fried a circuit or even the breadboard as we smelled smoke and parts of our wires got extremely hot. Outside of that, we were also handed wrong parts during construction which affected our ability to complete the project. If we were to do this again, we would definitely manage our time better and not make irrational decisions that burn our wires.

Summary

Electrical Engineering

Electrical engineering is the study and design of systems that use electricity, electronics, and electromagnetism. It’s all about how electricity works and how we can use it to power devices such as phones, computers, robots, and power grids.

Key Concepts:

Circuits and how they work (voltage, current, resistance)
Power systems (ex: how your home receives electricity)
Microcontrollers and computers

Careers in EE: Electrical engineer, circuit designer, robotics engineer, power systems engineer.

Bio-Medical Engineering

Biomedical engineering is where engineering meets medicine. It focuses on using technology to solve problems in healthcare such as making medical devices, imaging machines, or even artificial limbs!