SUB 1
1. A concise list of all parts you will need for the full device:
Arduino Uno, OLED display, MAX30102 optical biosensor, wires, DMM, solder iron, and
a heat gun.
2. A description of why each part is necessary from the perspective of the system/device
architecture
The arduino is the microcontroller that processes all of the information and connects all
of the parts. The OLED is the display that is used to convey the information. And the
MAX30102 is the sensor component. Lastly the DMM, solder iron, and heat gun are
used to form the rest of the connections.
3. Take a picture of the soldered max30102 under the dissecting scope,
4. Describe how the solders look and how you might test their sufficiency
The solders look wet on the board helping to show how the solder is melted and solidified to the
board and the pin. They are also separate and do not interfere with each other. And a good test
would be to jiggle the connections to see if they move.
SUB 2
1. A screenshot of your raw PPG signals (Red & IR) in the Serial Plotter.
2. A written description (short paragraph) explaining:
a. What the AC and DC components represent physiologically.
The DC is the baseline created by the tissue and average volume of the blood
while the AC is the isolated change made by the beating of the heart.
b. How blood volume changes create the observed waveform.
The beating of the heart causes blood to move around the body in pulses, the
high of the pulse is called the systole and the low is the diastole which can be
tracked as more or less blood in the line of the sensor means a lesser or greater
signal.
c. How the MAX30102 performs optical sensing.
The sensor shoots red and inferred light then captures the reflections with a
photodetector. The red light is used to track the pulse as explained in part b and
the red and infrared light together are used to differentiate between oxygenated
and deoxygenated blood cells which is used to find the SPO2 level.
d. A short explanation of how this subtask fits into the input → MCU → output
pipeline of medical device systems (physiology → sensor → digital
representation).
The MAX sensor fits onto the finger and connects physiology → sensor, and the
arduino takes the information, finds meaning, and uses the OLED to connect
digital → representation.
SUB 3
1. A screenshot or printed output showing:
a. Your computed heart rate(example 5)
b. Your computed SpO₂(example 8)
c. A brief written description of:
i. How your algorithm separates AC vs DC components
The AC component is above and changes while the DC component is
relatively constant as it reflects the baseline of the finger. The libraries
downloaded for the MAX sensor do this for us as to only give us the data
from the changing pulses that we use to get the heartbeat.
ii. How the heart rate calculation works
The heart rate calculation simply reads the sensor's values, finds the
highs, and determines the time between the highs. Heart rate is
measured in beats per minute which is the highs per a minute.
iii. How the SpO₂ calculation works
𝑅=
𝐴𝐶𝑟𝑒𝑑/𝐷𝐶𝑟𝑒𝑑
𝐴𝐶𝐼𝑅/𝐷𝐶𝐼𝑅
The calculation is from the equation above. It takes light absorption to signal processing to turn
light into current and electrical signals, then to process and provide the heart rate and SpO2
2. A description linking your computation step(s) to the medical device design hierarchy.
I.e., how does your MCU conceptually convert raw sensor data into clinically meaningful
quantities.
The MAX30102 sensor shines red and infrared LEDs through your skin and measures the
reflected light with a photodetector, detecting changes in blood flow to calculate heart rate and
using the different light absorption of oxygenated vs. deoxygenated blood to determine SpO2
levels.
SUB 4 (the actual prototype)
1. A clear photograph of your OLED displaying the full personalized message with live HR
and SpO₂.
2. Describe how your full system now completes the medical device design pipeline, which
elements serve each function, and how they are generally achieving this.
This system enables noninvasive monitoring of blood oxygen saturation (SpO₂) and heart rate.
The MAX30102 sensor acquires optical signals from the finger, jumper wires carry the data, the
Arduino converts the raw measurements into meaningful physiological parameters, and the
OLED display presents the results. Collectively, these components operate as an integrated
biomedical monitoring system.
3. Why is this loop foundational for all biomedical device design.
This loop runs continuously to ensure that measurements, real-time data, and feedback are
refreshed without delay. In medical devices, fast data processing and output are critical because
healthcare providers depend on prompt information to identify irregularities and take appropriate
action.
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