P10005: Balance Rehabilitation

Testing Detailed Concepts

Table of Contents

Image:== Testing product concepts == ÿ0ÿStructureÿ1ÿ ;Force needed to fall ***Insert calculation of what angle the tower can tip before it becomes unstable*** ;Full Graph Tower 50lb displacement [[Image:Full Graph Tower 50lb displacement.jpg

Single Side Deflection 50lb Displacement

Image:Single Side Deflection 50lb Displacement.jpg

Hand Calculations for Deflection

Force Needed to Fall

Screw Shear and Screw Hole Calculations


Base Detailed Concept Generation

Exploded base design

Image:Chosen Base Material.jpg


An analysis was done to see if lifting the 25lbs structure to determine if it would be damaging to the PT if they had to perform this task. NIOSH of Lifting Tower Conclusion: The lift index is below 1 which means that given the assumptions and correct posture it is not a dangerous operation.

Push force of patient

Angle was determined above in force needed to fall to be 24.5 degrees

Top of Tower(60") = 24.9" Required force:

Middle of Tower(30") = 12.45" Required force:

Base of tower(10") = 4.15" Required force:

Force able to push at that distance:

Maximum distance the patient can push is 12" not 24" proven by 3DSSPP.

3DSSPP Seated 1

3DSSPP Seated 2


Distance to Patient and Functional Reach

Detailed Selection Sensor

Sensor Research

Sensor Testing

Back up measurement tools:

  1. Laser Tape measure
  2. Mechanical Tape Measure
  3. Mat with tower locations


Detailed Screen Selection

Chosen Screen


Spark Fun Electronics
Serial Enabled 20x4 LCD - Black on Green 5V

An LED display screen will be utilized in the main tower to display current status, control actions, setup communication, and choose games. Additionally, it will display relevant information following the exercise for the PT to record.

Screen Schematic

Buttons to choose options on screen



Concern with having low power mode.

Solution: Image:Switch.jpg

Image:Detailed Switch.jpg


Power Selection Matrix

Power Calculations

For ease of use, a pair of interchangable and rechargeable batteries will be used to operate the device. By utilizing a battery-powered solution, we maximize the portability of the device.


Detailed Wireless Selection

Chosen Wireless:

ZigBee Wireless (802.15.4)

During powerup of the main tower, and bootup out of low-power mode, ZigBee wireless communitcations will be enabled to retreive information about surrounding towers. If other towers are found, a message confirming this will appear on the status screen. While in 'game' mode, with multiple towers enabled, all targets will be utilized, regardless of the number of towers. This plan allows for maximum expandability in both number of towers, and number of buttons available during exercises.


Board Selection

For the needs of our current design, the MSP430-F16(11/12) appears to be the best option. Offering ZigBee wireless connectivity, for communication between towers, as well as an extremely low power design, the MSP430 offers a large number of digial inputs and outputs and ~50k flash memory.

Power Supplies Schematic

Input Output Schematic

Core MSP Module Schematic

MSP430 Schematic