SUMMER STEM-HEALTH CAMP
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  • 2025 RCC Camp
    • Day 1: Basic Coding >
      • Button Control
      • Multicolor LED
      • Fading multicolor led
      • Melody (sound)
    • Day 2: Servos and Potentiometers >
      • DC Motor
      • Ultrasound
      • Potentiometer and Motors
      • 2 servo control >
        • Analog Stick Control
      • PIR Motion Sensor
      • IR Light Proximity Sensor
    • Day 3 Making an ECG/EKG! >
      • ECG/EKG health lesson
      • OLED Screen Basics
      • Pictures to OLED
      • BPM on OLED
    • Day 4: Measuring Pulse >
      • Scrolling Screen Graph
      • How the body absorbs light
      • Screen Pictures
      • IR Temp Sensor And Screen
    • Day 5: Finishing up/Show >
      • IR Light Proximity Sensor
      • PIR Motion Sensor
      • CO2 Sensor
      • Ultrasound distance sensor
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    • 2024 Health-STEM Coding Camp >
      • Home (2024)
      • The Teachers
      • Day 1: Basics and Lights
    • 2024 Coding/Robotics Camp >
      • Day 1: Basic Coding >
        • Saving your codes
        • Engineering design
      • Day 2 Servos >
        • 2 Servos, one potentiometer
        • Multicolor LED >
          • Fading multicolor led
    • Pictures from prior years
    • 2023 3D Design Camp >
      • Day 1: 2D design
      • Day 2: 3D design basics
      • Day 3: Constraints
    • 2023 Health-STEM Coding Camp >
      • PreAcademy prep
      • Day 1: Basics and Lights >
        • Multicolor LED
        • Button Control
      • Day 2: Ultrasound >
        • Ultrasound Health Lesson
        • Supplement Melody
        • Supplement: Servo >
          • Potentiometer and Motors
          • 2 servo control
      • Day 3: Measuring Pulse >
        • How the body absorbs light
        • OLED Screen Basics >
          • Scrolling Screen Graph
      • Day 4 Making an ECG/EKG! >
        • ECG Health Lesson
        • Pictures to OLED
        • BPM on OLED
      • Day 5: Finishing up/Show
    • 2021 STEM Camp (HS) >
      • The Teachers (2021)
      • PreAcademy prep
      • Day 1: Basics, Lights, and Temperature Sensor >
        • Day 1 Supplement: Measure Temperature
        • Day 1 Supplement: IR Temp Sensor
        • Day 1 Supplement: Identifying Resistors
        • Supplement: Controlling A Servo
      • Day 2: Measuring Pulse >
        • How the body absorbs light
        • IR Light Proximity Sensor
        • PIR Motion Sensor
      • Day 3 Supplement: OLED Screen Basics >
        • Display Screen Temperature
        • Scrolling Screen Graph
      • Day 4: Finishing up/Show
    • 2021 STEM Camp (MS) >
      • PreAcademy prep
      • Day 1: Basics, Lights, and Temperature Sensor >
        • Day 1 Supplement: Identifying Resistors
        • Day 1 Supplement: Measure Temperature
        • Day 1 Supplement: IR Light Proximity Sensor
      • Day 2: Ultrasound >
        • Day 2 Supplement: IR Temp Sensor
        • Day 2 Supplement: Controlling A Servo
      • Day 3: Measuring Pulse
    • 2020 STEM Camp
    • 2018 Lessons
    • 2017 Camp
  • Contact Us!

The Visible Light Spectrum

White light includes all primary colors (ROYGBV). Remember prisms from elementary school? This prism separates Red, Orange, Yellow, Green, Blue, and Violet from white light! I do want to point out, Violet does not mean purple! It is the "roses are red, violets are blue" color.
Violet is a flower. Click here to see some. 
https://en.wikipedia.org/wiki/Viola_(plant)
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Picture source: ​http://blogs.nature.com/ofschemesandmemes/files/2015/02/Week-2-Blog-Dispersive-Prism.jpg

ROYGBV is just the visible light wavelengths! 

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Light penetration

You can see red light penetrate through your finger if you put it in front of a flashlight. You see red on the other side because most of the other colors were absorbed in your finger. Try this at home! Put your phone flashlight, or any white flashlight, on one side of your finger. Then look at what color makes it to the other side! 
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www.researchgate.net/publication/316712743/figure/fig13/AS:668385360744448@1536366896067/a-Tissue-penetration-depth-of-light-with-different-wavelengths-NIR-light-penetrates.png
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https://images.theconversation.com/files/201297/original/file-20180109-83559-19kt3yi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip

Red light can be used to see inside your body. 

Something is not right with this finger!
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Got an X-ray and yep, something is there.
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Images are sourced from: ​http://www.eatonhand.com/img/img00087.htm
Let's shine red light on it. Yep, it's darker where something is sitting. That means there is not good blood flow there.
​There is more deoxygenated blood in that spot.  
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Click this button see what was taken out after surgery. ​Warning: somewhat graphic image. 
Link to post surgery picture.

Seeing your Heartbeat with Light! 


The color of blood

Have you ever heard that blood gets darker if it does not have oxygen in it? Well, that's true. The more oxygen blood has, the more deep red light it absorbs so it reflects less deep red. 
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All sketches for this section come from this source: ​https://www.youtube.com/watch?v=MHPgamGQmDY

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The oxygenated hemoglobin (HbO2) in the arterial blood has the characteristic of absorbing IR light. The redder the blood (the higher the hemoglobin), the more IR light is absorbed. As the blood is pumped through the finger with each heartbeat, the amount of reflected light changes, creating a changing waveform at the output of the photodetector. As you continue to shine light and take photodetector readings, you quickly start to get a heart-beat (HR) pulse reading.

Graphing blood's light absorption by wavelength

This is a rough sketch showing how much hemoglobin (Hb) absorbs different light wavelengths  depending on if it is oxygenated.  

Red light at a 660 nm wavelength is used in pulse oximeters. This is because it is the max difference between light absorbance.
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  • Home
  • 2025 RCC Camp
    • Day 1: Basic Coding >
      • Button Control
      • Multicolor LED
      • Fading multicolor led
      • Melody (sound)
    • Day 2: Servos and Potentiometers >
      • DC Motor
      • Ultrasound
      • Potentiometer and Motors
      • 2 servo control >
        • Analog Stick Control
      • PIR Motion Sensor
      • IR Light Proximity Sensor
    • Day 3 Making an ECG/EKG! >
      • ECG/EKG health lesson
      • OLED Screen Basics
      • Pictures to OLED
      • BPM on OLED
    • Day 4: Measuring Pulse >
      • Scrolling Screen Graph
      • How the body absorbs light
      • Screen Pictures
      • IR Temp Sensor And Screen
    • Day 5: Finishing up/Show >
      • IR Light Proximity Sensor
      • PIR Motion Sensor
      • CO2 Sensor
      • Ultrasound distance sensor
  • The Teachers
  • Our Partners
  • Archive
    • 2024 Health-STEM Coding Camp >
      • Home (2024)
      • The Teachers
      • Day 1: Basics and Lights
    • 2024 Coding/Robotics Camp >
      • Day 1: Basic Coding >
        • Saving your codes
        • Engineering design
      • Day 2 Servos >
        • 2 Servos, one potentiometer
        • Multicolor LED >
          • Fading multicolor led
    • Pictures from prior years
    • 2023 3D Design Camp >
      • Day 1: 2D design
      • Day 2: 3D design basics
      • Day 3: Constraints
    • 2023 Health-STEM Coding Camp >
      • PreAcademy prep
      • Day 1: Basics and Lights >
        • Multicolor LED
        • Button Control
      • Day 2: Ultrasound >
        • Ultrasound Health Lesson
        • Supplement Melody
        • Supplement: Servo >
          • Potentiometer and Motors
          • 2 servo control
      • Day 3: Measuring Pulse >
        • How the body absorbs light
        • OLED Screen Basics >
          • Scrolling Screen Graph
      • Day 4 Making an ECG/EKG! >
        • ECG Health Lesson
        • Pictures to OLED
        • BPM on OLED
      • Day 5: Finishing up/Show
    • 2021 STEM Camp (HS) >
      • The Teachers (2021)
      • PreAcademy prep
      • Day 1: Basics, Lights, and Temperature Sensor >
        • Day 1 Supplement: Measure Temperature
        • Day 1 Supplement: IR Temp Sensor
        • Day 1 Supplement: Identifying Resistors
        • Supplement: Controlling A Servo
      • Day 2: Measuring Pulse >
        • How the body absorbs light
        • IR Light Proximity Sensor
        • PIR Motion Sensor
      • Day 3 Supplement: OLED Screen Basics >
        • Display Screen Temperature
        • Scrolling Screen Graph
      • Day 4: Finishing up/Show
    • 2021 STEM Camp (MS) >
      • PreAcademy prep
      • Day 1: Basics, Lights, and Temperature Sensor >
        • Day 1 Supplement: Identifying Resistors
        • Day 1 Supplement: Measure Temperature
        • Day 1 Supplement: IR Light Proximity Sensor
      • Day 2: Ultrasound >
        • Day 2 Supplement: IR Temp Sensor
        • Day 2 Supplement: Controlling A Servo
      • Day 3: Measuring Pulse
    • 2020 STEM Camp
    • 2018 Lessons
    • 2017 Camp
  • Contact Us!