La Crosse, WI

Energy Management System for Prosthetic Limbs

The Logan High School InvenTeam invented an energy harvesting system to extend the battery life for vacuum socket units in above and below knee prostheses. 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 88 N of force. 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 Bluetoothâ„¢ communication link allows the user to monitor the energy storage system using a compatible cell phone and app.

Recent Team Blogs

May 28, 2019
We hosted a media day at Logan HS to demonstrate our Energy Management System for a Prosthetic Limb invention and practice our presentation for EurekaFest. Attendance was very good and we had a number of sponsors, parents, business partners and politicians show up along with three TV Channels and...
March 29, 2019
With spring sports in full swing we have to start our work nights later to allow many of our team members to get their practice in before we have our meeting. It makes for some long days and late nights but we continue to move forward as we near our target date for completion. Tonight we wanted...
March 11, 2019
We gave our prototype system its first full test which integrated all of our systems. The motor generation system using only one generator outputed the correct voltage to our storage system. It was then converted in our Buck Boost system where the voltage was then sent to the charge controller/...
February 20, 2019
On Thursday, February 7th, our InvenTeam had our Mid-Technical Grant Review. After working for weeks on a version of our prototype and testing machine, we were able to present the concept at this occasion. We began with a presentation where Paige Treakle and Thomas Kujak talked to the group about...
January 24, 2019
Caitlin Coffey, our sustainability lead, completed the SOLIDWORKS® course and earned her certificate. This certificate has proven Caitlin has learned the life cycle of products and how to lessen the environmental impacts a product has. She will continue to ensure our team will...
January 3, 2019
Things are progressing smoothly. We did our first test of the artificial limb tester and after a few wiring issues, everything ran smoothly. Our neutral wire was not connected properly to the capacitor circuit that drives the motor. The tester still needs to be modified to allow for more of a...
December 2, 2018
This week we worked on our testing equipment and app development. We began our first steps in assembling our tester by drilling holes and fitting boxes onto it. Later, we will attach our other electrical and mechanical components and begin testing. During our workday, we went over...
November 21, 2018
Logan High School Students Receive Invention Grant to Create an Energy Management System for Prosthetic Limbs Lemelson-MIT InvenTeam Initiative Inspires a New Generation of Inventors La Crosse, WI October 24th — Logan High School was recently awarded a Lemelson-MIT InvenTeam™...