Elevate
Mechanical seat lift retrofit for manual wheelchair users providing up to 20cm of added height
Many wheelchair users face not only physical challenges in seeing and reaching high up objects, but also social challenges in speaking and connecting with others eye to eye.
Elevate is a mechanical seat lift retrofit that can attach to manual wheelchairs. It provides up to 20cm of assisted elevation to address the physical and social challenges that come with living at a seated height.
Extensive research was conducted via interviews with manual wheelchair users at the Spaulding Rehabilitation Hospital in Boston to better understand the challenges they face and inform key use cases.
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USER EXPERIENCE
Elevate transforms the user’s experience by elongating their reach, extending their line of sight, and bridging the gap when speaking eye to eye with others.
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User squeezes the lever and pushes off the armrests to raise the seat
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The gas spring locks at any height up to 20cm operating just like a desk chair
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User can attach their choice of cushion to the rigid seat and back rest
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A gas spring provides a lifting force of 30 - 50% of the target user's weight aiding them as they push their body up
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Four clamps secure the retrofit in place attaching to bars common to rigid lightweight wheelchair models most popular among our target users
USER RESEARCH
Extensive research was conducted via interviews with manual wheelchair users at the Spaulding Rehabilitation Hospital in Boston to better understand the challenges they face and inform key use cases.
Users described to us the many situations where they were physically limited by their seated height. Anything as simple as reaching for a high shelf to transferring themselves to a chair taller than their wheelchair. However, beyond the physical limitations, users expressed that it can take an immense emotional toll when socialising with others. Not being able to talk to people at standing eye level often feels like a social disadvantage.
PROTOTYPE I
During the mechanical design, I led a group of four members focused on researching lifting mechanisms to find a safe and feasible option. A scissor lift and gas spring combo was found to be optimal. The scissor lift provided stability and the gas spring provided the lifting and locking mechanisms similar those found in a desk chair.
Several models were built to prototype individual parts of the design. My unit of five members built a conceptual prototype to test the lifting mechanism.
We disassembled a desk chair and integrated the gas spring lifting mechanism into the frame of a manual wheelchair with a bike handle attached to trigger the lifting mechanism (seen left). We tested this model ourselves to check the feasibility of this lifting mechanism.
PROTOTYPE II
Next, a working prototype was built by the whole team to test the feasibility of attaching a scissor lift and handle bars to a wheelchair frame and the feasibility of lifting a person via this mechanism. I helped to design and manufacture the four clamps that attach the seat lift to the wheelchair.
I led several rounds of testing with manual wheelchair users to better understand the pros and cons of our design.
ALPHA PROTOTYPE
The final prototype our team created was manufactured from steel, aluminium, high density foam, and thermoformed plastic. The device is designed to be compact, stable, and easy to use. I mainly worked on manufacturing the scissor lift.
LIGHTWEIGHT
Manufacturing at scale would use titanium and carbon fibre composites weighing < 5 lbs, comparable to a text book.
STABLE
Testing and tipping calculations ensure that the user is still safe going up standardised accessibility ramps inclined at 5 ̊.
COMPACT
The gas spring is placed behind the backrest, keeping it above the wheelchair axle and preventing it from catching on rough terrain.
EASY TO USE
A purely mechanical system with no motors or batteries. The lifting mechanism is smooth, easy to use and changes height quickly.
