Problem Statement: Considering the presence of stairs in many buildings, whether it is homes, office buildings, or public areas, it is essential that individuals with arthritis or knee pain when walking up stairs have an affordable device that helps them navigate stairs independently, with reduced pain and increased comfort.

Target Audience: Elderly individuals with osteoarthritis. Some individuals who have OA may not use a cane yet, as their pain may not be that high, but certain activities can increase pain, such as navigating stairs. The device will help reduce pain when navigating stairs and provide support for the knee. It will maintain mobility and allow for flexibility and comfort as well.

Design Approach: We brainstormed 3 unique potential designs. Each design was evaluated on a set of criteria using a decision matrix. From there, we ultimately decided to move forward with Design 3. However, during prototyping, we encountered limitations with design 3, which led us to pivot to our current prototype.

Design 1: Pneumatic Knee Brace – The main body of the brace is made of synthetic fabric, providing a breathable, more comfortable user experience. It contains air pockets on both the front, sitting just below the patella, and the back, to support the hamstring. When the user bends their knee to climb a step, the rear pocket inflates, assisting them in raising their leg. The front pocket will then inflate once the user lowers their leg. The brace also includes a tube through which air can flow between both pockets. Some pros include that the brace may be more comfortable to wear, as the brace contains no rigid parts. Some cons include that the brace may be weaker or more fragile than others because it relies entirely on air pockets.

Design 2: Linear Exoskeleton – The Linear Exoskeleton is designed to store and release elastic energy during the gait cycle. The unit consists of a rectangular section that holds a compression coil spring. During the loading phase, a steel piston rod compresses the spring as the user takes a stride (i.e., the knee flexes), storing energy that is released when the user pushes off the ground to provide an upward assistive force. The upper end of the piston rod connects to a strap on the waist that wraps the upper leg. This device can support the user by reducing the effort needed to take an upward stride, using the energy they already exert. This puts the cost in the range of $72-82 and provides an all-around solution for anyone who has difficulty walking up stairs, though it does not directly address knee OA. Some pros include that this design doesn’t

Design 3: Torsion Spring Brace – This brace consists of two metal plates connected by a torsion spring. These plates will be placed behind the leg, one above the knee near the hamstring area, and one below, behind the calf. The spring will be placed behind the knee. The default position of the brace will support the client’s neutral stance. When climbing a step, the brace will bend along with the client’s knee via the torsion spring. The spring will provide torque in the opposite direction, resulting in a slower, less strenuous step climb. Additionally, the brace will apply pressure to the left side of the knee, preventing bones from scraping. Some pros include that this design can help lower the force required to go up stairs and that it is very portable. Cons include the need to acquire a torsion spring and potential discomfort from the rigidity of the design.

Current Prototype: Our device is an adaptive knee brace designed to reduce knee pain while climbing stairs for individuals with knee osteoarthritis (OA). Physically, it consists of two rounded plates, one of which goes under the thigh and the other goes under the shin. Attached to the thigh plate is a housing for the motor, and attached to the shin plate is a block for the motor arm to fasten to, along with a housing for the electronics. The motor is thus attached to both the thigh plate and the shin plate, thereby aiding rotation of the shin plate. The entire brace attaches to the leg with elastic straps and Velcro attachments. The electronics consist of an IMU, an ESP32 board, an 11-volt battery, and a torque motor. This setup, along with our code, allows the IMU to calculate the knee's current angle and adjust the motor's actions accordingly, enabling the brace to adapt to the user’s individual movements. Our adaptive knee brace successfully reduces pain for the client, reduces knee collapse, which is a key factor of pain for individuals with knee OA, and is comfortable.

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