Skills Developed:

• 🔨 Computer-Aided Mechanical Design
• 🧪 Materials and Biomechanics
• 📌 Team Workflow Documentation

Overview:

Plain radiograph of Art’s pelvic region (frontal view)

Our patient in DP-2 was Art Vandelay (Psuedonym). Art was suffering from a Trendelenburg gait as well as limited mobility. This was accompanied by pain as he walked. After considering the given X-ray, as well as other measures, we swiftly diagnosed Art Vandelay with a deformed right femur as a result of his early hip dysplasia as a child. With a deformed acetabulum and femoral head/neck, we had to do a full hip replacement, replace the acetabular cap, and create a bone graft to attach the implant. We designed a 3D model of the implant, as well as a computer program to calculate stress and strain levels on the implant when subjected to bodily forces.

Design Process:

As usual, the first step of any design project is to create ideas for how the design should function. After creating an appropriate list of objectives, functions, and constraints. To create the best design possible, we each made our own design to compare. Each of us tried to cover a different aspect of the design (form, forces, materials, etc).

Final Concept Design:

We worked together to compare all of our designs while comparing with the need statement that we drafted up for Art, and created a final, refined sketch: Refined and final sketch of the implant As you might have noticed, the implant materials were also added to the final sketch. This was done after extensive research. When considering materials, we all broke off and compared different materials for each implant component, considering biomedical properties and calculating the stress and strain each material would experience.

🦴 Femoral Stem, and Femoral Neck:

Nickel Titanium Alloy (Nitinol): A highly elastic shape memory alloy that can resist deformations. Beneficial for the client as it is long-lasting and can withstand extra friction and wear associated with extensive movement.

💎 Femoral Head (Coating):

Polycrystalline Diamond: Used as a coating to increase biocompatibility and prevent the release of nickel ions. Promotes osteoblast adhesion and thus bone growth. This was our novel material.

🦴 Acetabular Cup:

Ultra-high Molecular Weight Polyethylene (UHMWPE): a polymer with high biocompatibility, wear resistance, and reduced friction between bone and material. Optimal for the patient as it will increase the longevity of the implant despite movement.

Computer-Aided Design and Prototyping:

As a member of the CAD sub-team, the majority of my technical skills were applied in a 3D modeling setting. The work of modeling the implant was divided into two sections: the femur replacement and the acetabular cup replacement. I chose to design the femur replacement (femoral head, stem, and neck).

The final design of the femoral implant, coloured to represent different materials that are used

I used the given measurements and took other necessary measurements from a 3D render of Art’s healthy left femur created using medical imaging. I found important details, such as femoral head diameter, shape, medullary canal diameter, and the femoral neck offset. This was all crucial to the fit of the implant and the strength of the implant against loads

The culmination of this project took place at the 2023 iBiomed Design showcase, where we had the opportunity to show peers, professors, and colleagues our designs. A short presentation “script” was conceived, and we were ready to show the world all of our hard work. We were accompanied by our poster board that showcased our design.

Project Reflection:

This project was one of the first biomedical engineering projects I had ever been tasked with (courtesy of the iBiomed Program at McMaster 😄). That being said, it’s important to look back and think about what could have gone better, and what we learned during the project. The two main takeaways I received from working on DP-2 were the power of an effective team and the importance of readiness.

Working as a team revolves around much more than “divide and conquer”: teams operate best when the dynamic benefits all, and you understand each other strengths, weaknesses, and skills. In DP-2, our team learned to truly trust each other. As the project progressed, we learned more about how we work as a unit and became one cohesive group. The earlier you reach that level of trust and understanding, the better the final deliverables of the project will become.

Secondly, I learned how important it was to show up ready for meetings rather than spending the first minutes of valuable time where everyone was present setting things up, or downloading documents. Time as a group can be scarce and should be utilized to the fullest extent. I will take this habit into future design projects.

For further reading, please consult the additional documentation included at: Old Notion Blog