Domestic Mobility Aid
September - November 2019
The Problem
My role
User interviews, engineering design, manufacturing
My skills
User-centered design
Product Research
User testing
Technical writing
Public Speaking
The Shirley Ryan Ability lab is a groundbreaking not-for-profit rehabilitation and physical medicine research hospital located in downtown Chicago. Upon meeting a patient at Shirley Ryan who had limited mobility in her legs, my team of Northwestern engineers was tasked with designing and manufacturing a device for her that would help her get through everyday activities such as getting into bed or into a car. Traditional "leg loops" existed on the market, but our client found them difficult to carry around and often unable to support the weight of her leg without breaking.
The engineering design process led us to two solutions, each of which uniquely tackles the user's described problems and requirements. Further, design choices were made based on feedback that the team received during user testing and observations of product performance during testing.
Solution 1: The Pusher
Our first solution tackled the problem of stability when transferring from a wheelchair onto a soft surface without one's use of their legs. The user grips the handle of the pusher and presses down onto the soft surface, creating contact with the surface that not only covers a much larger surface area than a hand or fist, but also reduces the amount of slipping at the point of contact due to the rubber-lined bottom.
The foundation is made of a 1/4" thick, 10" x 12" slab of rigid HDPE plastic with rounded corners, lined with a sheet of neoprene attacked to the bottom with adhesive. Grip tape wrapped on the handle makes for a more comfortable hold for the user. The heads of the screws used to attack the handle are hidden underneath the neoprene sheet.
Two prototypes with differing handle materials and orientations (top) and the final design (bottom)
Solution 2: The Portable Leg Loop
Since the Pusher was meant for in-home use, we aimed to satisfy the user's desire for a more portable and stable version of her "leg loop" by creating one that is easily foldable into a purse or other bag.
The user will start in a seated position, pulling the hammock underneath the back of their knee and wrapping the velcro straps around their thigh and upper calf. They can then grab both handles and lift their leg onto the surface, at which point they can remove the leg loop.
A 6.5" x 9" nylon hammock coated in silicone provides a lightweight support for the user's leg, weighing only 0.6 oz. Straps are made of velcro for its ease of use and versatility, and large amounts of overlap between the hook and loop sides of the velcro ensure that the device will be able to support the weight of a leg. Polypropylene handles are on each side of the user's leg in locations that are convenient to grab. Using polypropylene to make the handles, which often takes up considerable space in existing devices, also allows our leg loop to fold down into a 5" x 2" x 3" space.
Design concept (top), prototype and design description (bottom)
