1. Instrumented Walker Project Manager : Jairus Potts Rockwell Shields
Christopher Barnett
Skyler Bullington
Larson Stacy
Tommy FrankenBerger

2. Background
-The walker is being developed for the Mayo Clinic in Rochester, MN
-The walker will be implemented with load cells and will determine forces in the z-direction that are applied by the patient.
-This data will be transmitted from the walker using Arduino and to MotionMonitor.
-The data will be analyzed in Motion Monitor and will help with developing improved rehabilitation plans for patients with spinal injuries.

3. Design Criteria Light weight Removable
Accurately determine applied forces
Ability to communicate to Motion Monitor for analysis

4. Work Completed Sensor Selection Load Cell Attachment Prototype
Preliminary Testing
Power Regulation Circuit Prototype
Load Cell signal Amplification preliminary design

5. Sensors Selection •Load Cells
Single axis load cell that will be used to determine the forces in the z-direction being applied to each leg.

6. Attachment Design - Load cells will be placed in all four feet
- An attachment has been designed, and 3D printed currently, the final Aluminum attachment has had a work order placed at the Machine Shop.

7. Attachment

8. Power Regulation Circuit
Proper Regulation of Excitation Voltage to 10 Vdc
Designed for use with Li-ion Battery
Redesigned board printed

9. Board Design Amplification Circuit Designed 24 bit Resolution
Low Pass filter selected for post amplification signal
Boards printed for component installation

10. Calibration Testing -The testing method has been redesigned
-Using a newer reference board, Eliminates Oscillator
-Will help to shorten the timetable for calibration of all 4 load cells
-Goal is to develop 4 separate input formulae

11. Sample Calibration

12. Testing/Analysis
Currently establishing a bench testing station for load cell calibration
Testing apparatus designed and 3D printed for weight testing
Detailed Calibration method and procedure
Initial testing has commenced
Individual load cell testing will begin this week
Determined:
Load cell output signal voltage ranges and behavior
Signal Output frequency characteristics
Initial Amplification Board added excessive noise

14. Programming & Motion Monitor
Data will be analyzed using motion monitor
The Voltage output received will be used to determine the corresponding forces on the walker
Formulae will be provided to convert voltage into applied force
Applied forces combined into total applied weight

16. Crutch Design
- Crutches will be implemented with the load cells at the feet
- Attachment design will be modified: Lengthened and thickened to accommodate the greater forces at each leg.
- Data will be collected and analyzed in Motion Monitor, same as the walker.
- Same micro controller configuration

17. Upcoming Tasks Completion of Load cell Calibration Power Supply
Board re-design phase
Complete initial crutch design
- Motion monitor integration

18. Gantt Chart