Home/Case study: Scoliosis orthosis
Case study: Scoliosis orthosis 2017-05-19T11:11:43+00:00

Case study: Scoliosis orthosis

Idiopathic scoliosis is a complex deformity of the spine and rib cage that usually starts during the childhood (around 11-12 years) and could worsen until a surgery is needed to stop the progression. Unfortunately the cause of the development of scoliosis is not known and therefore all treatments are focused on minimizing the effects of the disease. Within the University of Twente a research program is running that addresses scoliosis correction and within that program a new brace concept has been developed to stop progression of scoliosis. Our task in this project was to develop a commercial product that can be manufactured in series and that should maintain the original working principle.  A clinical trial performed with this product can be found here.

Nordic Orthopedica
Meridian Medical

Stage 1: Explore

The new brace concept is based on “force controlling” which means that a set of correction forces and reaction forces should always work on the patient, independent of the patient’s body movement. The consequence of this working principle is that a flexible coupling is required between the thoracal- and lumbar part of the body that is able to transfer forces while providing the required body motion. After several attempts we managed to design a coupling that consists of a simple envelope connected to a thoracal bandage structure.

Stage 2: Design

In this stage several models where developed with a focus on the functionality of the design. Key issue was to find a configuration of the coupling that was able to withstand the high forces and that was able to provide the body motion that was required. The solution was to use a specific material combination. Another key issue was to find a reliable manufacturing process for the lumbar part that consists of spring-steel strips. We design several models an along with every model requirements and specifications where updated.

Stage 3: Engineer

Once the concept is fully developed and tested we started the engineering stage. The focus in this project was on the development manufacturing process which was indicated as the key issue. Especially the step from prototype series to regular production was challenging, expecailly because a lot of manufacturing steps where needed for the realization of the product.

Stage 4: Validate

In the validation stage various mechanical tests where performed for the coupling and the strength of the lumbar part. All thests where performed in house on our test machine. For the coupling testing was focused on the wear of the envelope and for the lumbar part, the focus was on fatigue strength.

Stage 5: Transfer

The first series where manufactured by BAAT, later the customer took over the manufacturing chain and process control. The product is still on the market.

Nordic Orthopedica
Meridian Medical