Prosthetic Engineering and Hardware Testing | LIMBS, Part 1

The Challenge of Testing Prosthetic Engineering

Did you know there are 30-40 million amputees in low and middle income countries? But only 5% have access to prosthetic devices or assistance? These are stunning statistics. For millions of people in the developing world, becoming an amputee through accident, infection, substandard medical care, diabetes, war, or natural disaster means greater hardship – the kind we don’t typically see or appreciate. From job loss and poverty to being rejected by their societies as outcasts, their life challenges are immense.

image provided by LIMBs

“In the developing world, losing a leg is devastating – because the ability to walk means everything. It is the beginning of a cycle of hardship resulting in the loss of jobs, family and friends, self-esteem, social acceptance – and ultimately, hope.” – LIMBS International

But because of the charitable prosthetic engineering work of LIMBS International, there is hope for the disadvantaged 95% that do not have access to affordable prosthetics.

image provided by LIMBs
Doctor Roger Gonzalez and his Team at LeTourneau University

Doctor Roger Gonzalez and his Team at LeTourneau University

Back in 2004, engineering professor, Roger Gonzalez, Ph.D., at LeTourneau University in Longview, Texas, recognized that most of the research and development effort in the world was focused on costly solutions developed for that 5% of high income countries. So he “challenged a group of students to create an inexpensive, highly functional knee that could be fabricated using simple materials and tools, right in the countries where they were desperately needed.”

The result: the first LIMBS prototype of a polycentric knee which was field-tested in Kenya by the team and garnered positive feedback from patients and clinicians.

LIMBS International was subsequently founded as a nonprofit to develop high quality prosthetic technologies that are affordable and accessible to amputees in the developing world. Through their dedicated charitable work and prosthetic development, over 10,000 low-income amputees in 50 countries have received affordable prosthetic devices to date.

But they don’t stop there. A key component to their success is their focus on creating effective and holistic partnerships in the field so that the local needs of amputees in low and middle income countries (LMICs). They work to ensure appropriate and accessible prosthetics are uniquely coupled with rehabilitation support. As a result, amputees not only recover the ability to walk and find employment but also regain social acceptance and a hopeful future.

image provided by LIMBs

LIMBS is the only nonprofit organization in the world that provides a full leg prosthetic system as well as a rehabilitation program to improve the quality of life for amputees and their families.

Because of their successful holistic approach, LIMBS was honored with a Drucker Prize in 2019 for combining “technology with community support to transform the lives of amputees in developing countries.”

Our Partnership for Hardware Testing

LIMBS continuously innovates and improves their prosthetic designs to fulfill their mission of delivering highly functional but ultra low-cost prosthetics. Over the years, LIMBS has fostered productive relationships between engineers, prosthetists, and students to ensure the high quality of prosthetic designs that amputees depend on in their daily lives.

We’re proud to say that one of those engineering relationships is with Andrews Cooper.

prosthetic engineering

As it happens, one of AC’s Program Directors and one of LIMBS Executive Board members met at a training event for guide dogs for the blind and visually impaired. It wasn’t long before their shared interests and values turned into an opportunity to collaborate between their organizations.

At that time, AC’s Bothell office in Washington state had expanded to offer new capabilities in custom automation design and testing. We could see that a volunteer partnership would perfectly couple our relevant MedTech engineering expertise and resources with our cultural values to be a force for good in the world.

Mechanical Engineer, Danielle Kuyltjes, was the AC engineering lead for LIMBS prosthetic engineering hardware testing at the outset of the partnership. She describes the opportunity:

image provided by limbs

“We were excited to support such a great cause – the work LIMBS is doing is so meaningful. As engineers, we could really make a difference by supporting them. Our initial effort was to improve the consistency of the bend and swing movement of their ultra low-cost prosthetic LIMBS Knee. As our teams worked together over the course of the first year, we were able to identify design improvements, but then a secondary objective began to surface: the need for a better way to perform repeated cycle testing with the changes we were developing together.”

LIMBS Director, Lucas Galey M.S., recalls the emerging need for a test device:

“We explored many ideas with Andrews Cooper and they helped us improve the new LIMBS Knee prototype by making friction more consistent throughout the range of movement and over time. We are able to perform certain types of tests at LIMBS, but ultimately we realized we didn’t have a lot of ways to properly test the prototypes the way we wanted. That’s when we explored the need and requirements for a Cycle Tester.”

High Performance, Adaptable Cycle Tester for Prosthetic Knee Development

Working from her knowledge of designing of medical devices, Danielle brought in senior AC mechanical and controls engineers to help define the overarching requirements of a first generation LIMBS Knee prosthetic tester.

LIMBS primary objective was a prosthetic development of a high level of adaptability and low cost. At a high level, the LIMBS Knee Cycle Tester needed to accommodate:

> Repeatable testing at ≥6M cycles
> Adjustability to accommodate different prototype measurements
> Measuring of changes in friction over time

prosthetics testing
prosthetic test

With quality assurance at the center of their design and testing approach, Lucas describes the importance of the collaboration:

“It’s important that LIMBS technology evolves from a rigorous design approach and adequate testing before we release new generations into real-world situations that directly impact the daily lives of amputees around the world. AC’s engineers helped us develop an adaptable way to rigorously test current and future design prototypes.”

Team Collaboration: Performance Objectives & Prosthetic Development Solutions

During the development phase, as more engineers joined the effort, our collaboration achieved a number of performance objectives to improve prosthetic testing while keeping manufacturing costs low:

prosthetic engineering and hardware testing
prosthetic development and hardware testing

As a result of our collaboration, the first generation LIMBS Knee Cycle Tester was deployed earlier this year:

Over the months and years, our cumulative effort helps LIMBS product development team leverage current technologies, materials, and methods that meet their commitment to drive affordable and sustainable prosthetics. Working together, LIMBS ensures quality is maintained through all stages of product creation, testing, and training.

As Lucas reflects:

prosthetic knee engineering

“Our partnership with Andrews Cooper bolsters LIMBS own continuous improvement process within our product development team. Most of our design work has been on our own, but we also seek out highly-skilled experts like AC to ensure that our analysis and testing is thorough and process-driven. This approach is highly effective and enables us to measure and ensure the performance of our designs as they evolve over time. We want to see better and better performance and maintain ultra low-cost impacts for the patient with each new generation.”

LIMBS International Logo

Check out Lucas’s blog: Building a Bionic Knee on a Budget, published in AMPLITUDE online.

Shared Values

AC celebrates LIMBS and recognizes their unique blend of proactive compassion in the world through innvotive engineering. Our shared values run deep. AC’s founders, Neal Andrews and Steve Cooper, not only envisioned an engineering community founded on respect for excellence and dedication to teamwork, but also for positive contribution to the betterment of the world and our communities. And as engineers, we understand the meaningful product design work of LIMBS International.

Engineering for a Better WorldAC continues to support our engineer volunteers through charitable PTO hours and contribution opportunities. Contact your manager to join the AC LIMBS team.Our thanks to AC engineers who shared their expertise and time to support LIMBS through this rewarding partnership! We want to recognize: Levi Haupt, Danielle Kuyltjes, Peter Van Tamlen, Steve Frankovich, Scott Britt, Shawn Daniel, Cody Severson, and everyone in our Product Development and Automation teams who lent a hand in this effort.

Through the months and years of working together, AC’s volunteer engineers continue share their knowledge of R&D Automation and Hardware Testing toward the quality improvement of LIMBS prosthetics.

Remember you don’t have to be an engineer to partner with LIMBS. Anyone can donate to support their work.

Want to Learn More?

> Check out their web site: LIMBS International.
> Learn about their technology and rehabilitation successes.
> Open your heart through patient stories and see how their charitable work is bringing true hope to amputees.

Want to Get Involved?

> Start by donating your birthday!
> Volunteer your time and expertise!
> Share this blog on social media with the links below to spread the word and encourage support of LIMBS transformative work across the globe!

Check back with us for future blogs about the next generation of LIMBS Knee Cycle Tester currently in development.



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