13. Applications and implications¶
Learning Outcomes:
- Define the scope of a project
- Develop a project plan including a bill of materials (BOM)
What will it do?¶
The dedicated 3D hand scanner automates capturing precise 3D hand models using photogrammetry. It features a user-friendly interface, automatic hand detection, and control via an OLED screen, potentiometer, and buttons, streamlining custom splint fabrication.
Who has done what beforehand?¶
Photogrammetry and 3D scanning are common in various fields, including medical applications. However, no widely documented or commercialized dedicated 3D hand scanner for custom splint production with these specific features exists.
One similar project is Curatio, which uses multiple cameras with Raspberry Pis attached to a ring to take multiple photos simultaneously. While Curatio also uses photogrammetry, I opted for a phone with a rotating platform to capture video. This approach simplifies the setup and potentially lowers costs while achieving similar results.
What will you design?¶
I will design a user-friendly 3D hand scanner, including: - A mechanism to hold and rotate the phone. - An interface with an OLED screen, potentiometer, and buttons. - An automatic hand detection system using an ultrasonic sensor. - Integration with a phone to start and stop video recording.
What materials and components will be used?¶
- Xiao RP2040 microcontroller
- Ultrasonic sensor
- OLED screen
- Potentiometer
- Buttons
- Stepper motor with driver
- LED strip
- Relay
- Frame materials (plywood)
Where will they come from?¶
Components will be sourced from local electronics suppliers, and existing materials in the lab. Frame materials will be obtained from local hardware stores or from the lab.
How much will they cost?¶
- Xiao RP2040 microcontroller: $10
- Ultrasonic sensor: $2-5
- OLED screen: $10-15
- Potentiometer: $1-3
- Buttons: $1-3
- Stepper motor with driver: $15-25
- LED strip: $10-20
- Relay: $2-5
- Frame materials: $20-50 Total estimated cost: $66-136
What parts and systems will be made?¶
- Main frame and rotating mechanism
- Control interface (OLED screen, potentiometer, buttons)
- Ultrasonic sensor mount and integration
- Stepper motor mount and control system
- Integration with the phone via the relay
What processes will be used?¶
- Laser cutting and CNC milling for the frame
- PCB design and milling
- Soldering and assembling electronic components
- Programming the microcontroller
- 3D printing for custom mounts and parts
- Wiring and integration of the electronics
What questions need to be answered?¶
- How precise and accurate is the hand detection system?
- How reliable is the stepper motor control for smooth rotation?
- Does the integration with the phone work consistently for starting/stopping recording?
- How effective is the photogrammetry process in creating accurate 3D models?
How will it be evaluated?¶
The project will be evaluated based on: - The accuracy and consistency of the 3D hand models produced - The user-friendliness of the interface - The reliability of the automatic hand detection and scanning process - The overall improvement in efficiency and consistency of custom splint fabrication compared to manual methods
Bill of Materials (BOM)¶
| Component | Quantity | Cost (per unit) | Total Cost |
|---|---|---|---|
| Xiao RP2040 Microcontroller | 1 | $10 | $10 |
| Ultrasonic Sensor | 1 | $2-5 | $2-5 |
| OLED Screen | 1 | $10-15 | $10-15 |
| Potentiometer | 1 | $1-3 | $1-3 |
| Buttons | 2 | $1-3 | $2-6 |
| Stepper Motor with Driver | 1 | $15-25 | $15-25 |
| LED Strip | 1 | $10-20 | $10-20 |
| Relay | 1 | $2-5 | $2-5 |
| Frame Materials (Plywood) | N/A | $20-50 | $20-50 |
| Headers and Connectors | N/A | $5-10 | $5-10 |
| Bearings | 2 | $1-3 | $2-6 |
| GT2 Pulleys | 1 | $3-5 | $3-5 |
| GT2 Belt | 1 | $5-10 | $5-10 |
| Cable Clips | N/A | $1-3 | $1-3 |
| Power Jack Connector | 1 | $1-3 | $1-3 |
| Screws and Fasteners | N/A | $1-5 | $1-5 |
| Miscellaneous Components | N/A | $5-10 | $5-10 |
| Total Estimated Cost | $96-186 |