Capstone Spotlight BME 104 - Patellar (Knee) Decompression Brace

Jon-Michael Duley, Greyson Hesch, Matthew Macaluso and Lokesh Narayanan
Top to bottom, left to right: Jon-Michael Duley, Greyson Hesch, Matthew Macaluso, Lokesh Narayanan




Jon-Michael Duley
Greyson Hesch
Matthew Macaluso
Lokesh Narayanan

Jennifer Puetzer, Ph.D., assistant professor

Ashley Harwood, D.P.T., VCU Health

Project title: Patellar (Knee) Decompression Brace

What it is, in a nutshell
A device to alleviate knee pain from the wearing away of cartilage.

What it is, in a slightly bigger shell
It is an attachment that can fit onto existing anterior cruciate ligament (ACL) and knee braces that helps to very slightly lift the kneecap to reduce pain caused by bone-on-bone rubbing from the wearing away of cartilage in the knee.

A prototype of the knee brace attachment designed by the team
A prototype of the knee brace attachment designed by the team.

How it will help people
By helping to reduce discomfort at the patellofemoral joint between the kneecap (patella) and thighbone (femur), people can live more enjoyable and pain-free lives without having to worry about knee aches. The adaptable design fits multiple types of existing knee braces.

How they’re building it
The team’s prototype consists of two C-shaped Acrylonitrile Butadiene Styrene (ABS) plastic wedges that are coated in polyurethane foam and silicone. These wedges fit together to wrap around the patella so that they can be brought closer together or further apart depending on how much patellar lift a person needs. The wedges are held together by a pair of removable pins. Both wedges are then held to the hinges of pre-existing ACL or unloading knee brace hinges by straps similar to the straps that adjust a backpack.

What they’re working on right now
The team is conducting force analysis tests in SolidWorks to best understand the forces that are being applied on the patella and the patellofemoral joint by the wedges.

The biggest challenge so far
The biggest challenge has been making it as comfortable as possible while having as little bulkiness as possible. To make the device more comfortable, the team is coating the wedges with a layer of polyurethane foam coated in silicone to create a soft but effective wedge.

How it has changed since they started
The team originally worked on a design that used suction generated at the kneecap to generate lift, but they soon realized that suction applied to the skin for many hours may result in bruising and bleeding. They decided to instead go with movable wedges to generate lift.