Logan Ranger Energy Management System for a Prosthetic Limb: Logan InvenTeam Energy Management System for a Prosthetic Limb

Logan InvenTeam Energy Management System for a Prosthetic Limb

During the 2018-19 school year, Logan High School in La Crosse, Wisconsin was one of 15 schools in the nation to be selected as an InvenTeam and awarded a grant through the Lemelson-MIT program.

The Logan InvenTeam designed and built an energy harvesting system to extend the battery life for vacuum socket units in above and below knee prostheses. This will greatly improve an amputee’s freedom by extending the time he/she can use the limb without being restricted to plugging it into a wall socket to recharge.

The Amputee Coalition of America estimates that there are 185,000 new lower extremity amputations each year just within the United States and that there is an estimated population of 2 million American amputees. Many removed limbs are replaced by prosthetics.

By harvesting heel strike energy while walking, the system extends operating battery life beyond the current 24 hours. The invention is mounted by a prosthetic outfitter within the natural contour of the prosthetic foot and lower leg, requiring no prosthetic modification. The user will notice minimal to no change in the feel or use of the modified prosthetic. The system device weighs 376 grams with a total volume of 491 cm3. Current is generated using heel strike deflections with durations of 10-100 msec with 20 lbf. Energy harvesting is done using two spring coupled fast responding coreless rotor DC motors, which generate from 12 to 18 V and 25 to 100 mA. Rectification and charge storage in a capacitor array, subsequent power conversion, and regulation with a charge controller for the battery completes the power system. A Bluetooth™ communication link allows the user to monitor the energy storage system using a compatible cell phone and app

DESIGNED AND FABRICATED BY THE LOGAN INVENTEAM:

Caitlin Coffey, Alex Magnuson, Thomas Kujak, Tanner Boge, Seth Petersen, Austin Sather, Avery Schams, Paige Treakle, and Thaying Vang

INSTRUCTORS: Joanne Cappuccio, Logan HS English Language Learning Dept. & Steve Johnston, Logan HS Technology and Engineering Dept.

CONTRIBUTORS (TECHNICAL EXPERTISE):
David Foye, Electrical Engineering Consultant
Dr. Scott Escher, MD-Gundersen Health System
Clint Accinni, 5280 Prosthetics, LLC
Mike Wettestein, Industrial Automation
Bob Loper, Branch Manager and CPO - Hanger Clinic
Joe Van Der Bosch, CPO - Limb Lab
Art Butterworth, Mechanical Engineering Consultant
William Beres, Patent Consultant
Gary Moe, Guest Speaker (Amputee)
Justin Pitz, Logan HS Technology and Engineering Instructor
Ryan Schreiner, Logan HS Technology and Engineering Instructor
Terry Curtis, Logan HS Technology and Engineering Instructor

Engineering Blog: http://loganrangeressystemprostheticlimb.blogspot.com

YouTube Video link: https://www.youtube.com/watch?v=kUZrXbu30p0