Final Project Overview

G R O U P M E M B E R S :I r m a B o c o v aR o b B o w m a n

P h e t p h o u v a n h “A w t ” P h o m m a h a x a yK y l e P i l o t e

J e ff R e b m a n nC h r i s R o w l e s

Fa c u l t y G u i d e : D r. E l i z a b e t h D e B a r t o l o

February 19 , 2010

Mechanical Spine Test Platform

P10007

Agenda

• Mission Statement

• Project Description

• Background/Application

• Customer Needs

• Engineering Specifications

• Final Concept Selection

• Mechanical Structures

• Sensor

• Software• LabVIEW Output Architecture

• Validation and Verification

• Specifications Attained

• Project Overview

• Future Iterations

• Project Conclusion

• Acknowledgements

Demo (Time Permitting)

Project Description

Project Title: Mechanical Spine Test Platform

Primary Customer Dr. Sara Gombatto

Professor at Nazareth College of Physical Therapy Dr. JJ Mowder-Tinney

Director of Clinical Education Nazareth College Department of Physical Therapy

Physical therapy patients

Secondary Opportunities Further spinal iterations

Background/Application

Nazareth Physical Therapy Clinic motion capture system Allows motion capture of

PT patients in order to track progress

Validation of existing motion captures

Focus on spinal segments

Secondary Application: Portable Motion Tracking

System calibration Source: http://seneludens.utdallas.edu/images/mocap.jpg

Customer Needs

Three tiered approach to group needs and limit scope Base Plan Aggressive Outstanding

Example Need: Must be moveable in distinct segments Base Plan – Two distinct sections (Lower & Upper Lumbar) Aggressive – Three distinct sections (Lower & Upper Lumbar,

Thoracic) Outstanding – Divide Thoracic segment into multiple segments

Highest Ranked Needs – Base PlanNeeds to be able to measure angle deviations for all sections relative to the section below it

Use a tight tolerance for measurements

Provide measurements in all three planes of space (x, y, z)

Needs distinct sections of the spine to be able to move

Needs to be adjustable lengthwise in order to simulate different size spines

Movements needs to be lockable so that an accurate measurement can be read

The height of the device has to be the level of a spine of a person standing in an upright position

Needs to have a “zero” position for all sensors/joints

Engineering Specifications

Correspond to highest ranked Customer Needs:

Specification UnitsBase Plan Value

Aggressive

Value

Outstanding Value

Must have a minimum tilt in all directions relative to the section below

degrees +/- 20

Angle tolerance degree +/- 0.1

Must have a tilt in all directions relative to the section below

planes 3 (sagittal, transverse, frontal)

Must be movable in distinct sections and a fixed base (pelvis)

movable sections

2 (lower lumbar, upper

lumbar)

3 (thoracic)

Divided thoracic

Should be able to fit all required ranges needed by customer vertically

millimeters

30 - 150 for each lumbar

segment

200 – 300 for

thoracic segment

Joint strength Ft - lbs

Device must mimic a person standing in an upright position - Trochanterior Height

millimeters

750 - 1000

Device has mechanical "zero" position Yes/No Yes Yes Yes

Final Concept Selection

Spinal Structure & User Interface

Marker Placement Diagram

Main Structure Rendering

Mechanical Structure

Three segments separated by tightening ball-joints (lock into static position)

Non-Ferrous (aluminum, brass, and wood)

1 inch increment segments (2-5 inches adjustability per lumbar segment)

Fixed Pelvis ( adjustable height) with wooden base

Horizontal members for reflective markers

Brass set screws Flat black enamel coating

Sensors

Two MicroStrain 3DM Measures roll, pitch and

yaw DC Accelerometers in

orthogonal array with respect to Earth’s gravity

Magnetometers with respect to Earth’s magnetic fields

+/- 1.0 degree of accuracy

Software

LabVIEW Translate

digital outputs of sensors

Outputs compatible to MS Excel spreadsheet

User Interface

User Interface

Validation and Verification

3DM Sensor Mechanical versus electrical Offsite and Onsite testing Within +/- 1.0 degree of

accuracy (roll, pitch and yaw)

Sensor Test

Fixture

YAW Upper Lumbar

Lower Lumbar

Specification Needed

Average Deviation

± 0.296 ⁰ ± 0.375 ⁰ ± 1.0 ⁰

Standard Deviation

0.162 0.262 --

Accuracy Testing (Worst Case)

Validation and Verification

Spine Platform Onsite testing Mechanical and electrical Simultaneous reading of 3DM Interference (magnetic and

infrared) Static holding position (tension

required) Stability (tipping force) Portability (overall weight) User friendly (setup time and

testing time)

1st Iteration Mechanical & Electrical

test

Specifications Attained

Project Overview

Successes Met a tight accuracy tolerance Able to output real time data and capture to an external

spreadsheet for further analysis Created user friendly platform Custom built ball joints and stand Minimized sensor interference

Recommendations Do not underestimate time needed to complete mechanical

tasks Outsource the welding Use CNC machines when possible for accuracy and time

purposes Further understand the sensitivity issues of the

magnetometer in the sensors Have a better general knowledge of software/hardware

integration

Future Iterations

Add a thoracic region to better represent a human spine Break the segments down even further if possible

Incorporate non-electromagnetic interference design

Look into purchasing NI LabVIEW license for Nazareth College

Wireless sensorsPowder coat or anodize to increase durability

of coating Use a plastic material instead of aluminum

Project Conclusion

The specifications for the final spinal structure and user interface were met for all base plan values and for some of the aggressive values and outstanding values

Customer was satisfied with testing and verification

Customer was satisfied with final user output design and functionality

Acknowledgements

Dr. Sara Gombatto Nazareth College Physical Therapy Department

Dr. Elizabeth DeBartolo Faculty Guide – Rochester Institute of Technology

National Science Foundation Project Sponsor

Dr. Robert Bowman EE Professor – Rochester Institute of Technology

Professor John WellinProfessor Madhu NairRIT Machine Shop Staff