P11010 Bernt Gudmestad Alain Hamblet Erik “Flip” Austin Jahnavi Kodali Evan Brent Elizabeth Debartolo : Guide

Agenda Testing Lessons learned Conclusions Questions Objectives Needs/specs Design overview Application Electronics Housing Development Application Electronics Housing

Objectives Design/Implement an electronic equivalent of a multipurpose goniometer Integrate with sensor array developed by P11011

Needs/Specifications Interface must be easy to use Must have a small learning curve Must have a quick setup time Must have various sensors that can track gait movements, joints, etc Must measure static abnormalities Must measure dynamic abnormalities Must have the ability to measure the range of motion of a patient's head Must be accurate Must provide objective, qualitative results Must be reliable Must be durable Must be comfortable Must be portable Must provide real time feedback Must facilitate patient accountability Must be affordable Must be applicable to both clinical and research settings

Design Overview -application Graphical interface based in C Dual USB serial communication Dynamic vector representation of sensor data Data file storage Touch interface

Design Overview -Electronics Li-Ion Battery regulator/charge circuit On/off switch

Design Overview -Housing Machined aluminum 3piece housing

Development -Application GUI code had to be adapted for C instead of C# Compilers do not exist for OMAP Angstrom Enabled USB serial communication to sensor with handshaking algorithm Implement vector calculation for knee and head sensor

Development -electronics Built wiring harness Initial voltage regulation circuit changed Inadequate battery life Implemented 3pin 5v LDO regulator Found that Beagleboard does not work with selected USB hub Requires High-Speed USB 2.0 Hub Old hub is passive low speed Acquired new high speed active hub (problem solved) Currently being integrated into new housing

Development -Housing Measured component dimensions Hand milled from billet aluminum stock Test-fit components and modified to fit properly Updated USB hub cannot fit in current case New case has been modeled/finalized Will be made in the rapid-prototyping lab

Testing Battery life exceeds ideal by more than 3 hours Sensor communication/data storage works fine Power supply exceeds ideal current/voltage needs of the device Data readout is real time and easy to read Data storage capacity exceeds marginal requirements by 1Gb

Lessons Learned Plan for Problems and make contingency plans USB incompatibility / Research host controllers Power supply ground path issue / Insulation Housing design / SolidWorks model Communicate Have individual plans / designs examinated by teammates before proceeding Review integration between teams more often

Conclusions Successfully created a base unit that can integrate with sensors to act as a electronic goniometer Future projects could: Streamline and fine-tune application code Augment sensor algorithm Upgrade to newer revision of Beagleboard Add wireless capability Implement Multi-touch screen and more fluid and dynamic GUI

Questions?

References Knee goniometer (photo)