Welcome to Sentivia

Okay, let me tell you a bit about myself and what I'm passionate about. My name is Amos Winter, and I'm a mechanical engineer, and I work as an academic researcher, primarily at MIT. I'm really interested in design and engineering solutions that can make a real difference in people's lives, particularly for those living with disabilities in developing countries.

It all started back in 2005 when I spent a summer in Tanzania assessing the state of technology. I was particularly struck by the challenges faced by wheelchair users in rural areas. While we might take for granted things like elevators, sidewalk cutouts, and accessible transportation in places like the U.S., these are often absent in many developing countries. I saw firsthand how the lack of appropriate mobility devices was a major barrier to community, employment, and education. People were having to travel long distances over rough terrain, often with devices not designed for the conditions and that broke down constantly. There are 40 million people who need a wheelchair that don't have one, and the vast majority of them are in rural areas where they are desperately needed for survival, and those who do have one have a poorly made device.

I realized that the wheelchairs typically available to them just weren't cutting it. They weren't designed for the rough terrain, they broke easily, and they were difficult to repair. As a mechanical engineer, it felt like a problem I could address and something that I had the resources to deal with. My initial idea was to try and adapt a mountain bike concept to a wheelchair, since mountain bikes are designed for diverse terrain and use gears to adjust speed and torque. The problem was that the available products using mountain bike parts were too expensive and complicated to transfer to the developing world, and they just would not work, so we had to start from scratch.

So, I was looking for a way to create a system that was both simple and offered a big mechanical advantage. It was like the answer was right in front of me: levers. Levers are simple, and they are everywhere. They are in tools, doorknobs, bike parts, and a simple lever that someone could manipulate seemed like the answer. The key invention moment came when I was thinking about someone grabbing a lever and realizing that you could change the amount of force and speed by changing the position on the lever. I realized that sliding your hand up and down a lever would essentially create a gear system, and you could have a low-gear, high-torque mode or a high-gear, high-speed mode, and you could do this simply with a lever.

That’s what led to the Leveraged Freedom Chair, or LFC. The core of the LFC is the levers. The user moves the levers back and forth to propel the chair and changes their hand positions on the lever to adjust their speed and power. It works like a person bench-pressing themselves through tough terrain, but it has a great deal of flexibility to travel far and fast. What's exciting about it is that the mechanism is simple and it can be made from parts that are readily available anywhere in the world. We used bicycle parts that are produced by the gazillions in China and India, which makes them cheap, and it means that the chair can be built anywhere and repaired using local resources, tools, and knowledge.

We have designed the LFC to be as versatile as possible. When you’re done with your rough terrain and are trying to go indoors, it can easily convert to a standard wheelchair. You just pull the levers out and stow them in the frame, and now it operates like a normal wheelchair which can fit through standard doorways and other tight places. It’s low enough to fit under tables and small enough to get into bathrooms so the user can have more independence.

One of the biggest lessons I've learned through this project is the importance of combining rigorous engineering science with user-centered design. We initially went to Tanzania, Kenya, and Vietnam with a prototype that didn’t work that well, but once we got actual users involved in the design process, it really became something special. They gave us really critical feedback. They weren’t just telling us about the problems, they were suggesting solutions, and the LFC is a direct result of this feedback loop between me, my team, and the users. The people who are going to be using this have to define what it has to do, and they have to give it the thumbs-up and say that it actually works and meets their needs.

We also tested the LFC in a field trial in Guatemala, where we measured the performance of users with it compared to a standard wheelchair and were able to quantify the performance benefits. It's about 80 percent faster and 40 percent more efficient, and it allows people to generate 50 percent more torque to get through rough terrain.

The project also proves that design constraints can push innovation. We needed to hit a low price point, we needed to design a device that could work on diverse terrain, but still be practical indoors, and repairable in remote areas. All of these challenges resulted in a completely new product that has really revolutionized the wheelchair industry in a way that hasn’t been seen in over a hundred years. We even decided to team up with a design firm to create a high-end version of the chair for sale in the US and Europe, proving that the features that make the LFC good for the developing world are good features everywhere.

I also believe this project has worked because we engaged every stakeholder in the cycle of inception to implementation. The end-user is central to this. I, as an academic engineer, can make prototypes, analyze data, and test ideas in the lab. But I need collaborators who can get those bench prototypes to market. We need gap-fillers like the design firm and NGOs, and we need manufacturers who can mass produce these devices. And then, finally, there are the distributors who can get the products to the people who need them.

We had a field trial in India where there was a 90% adoption rate, and to me, that is the most important thing. There was a man, Ashok, who was injured and unable to get to his job after the injury. After he got an LFC, he was back at work and supporting his family, and that is where you see the real impact of this project. The key to our success was bringing together stakeholders from every point in the design and manufacturing chain to combine their knowledge to create a product that neither of us could have made alone. That is the real magic of engineering and collaboration.