Advanced design technology, used to develop components for the aerospace and automotive industry, has been harnessed in the production of custom medical devices.
Researchers at the University of Birmingham, working in partnership with design software specialists Autodesk, the Center for Manufacturing Technology (British National Center for Additive Manufacturing), and Birmingham University Hospitals, have used a technique called generative design to produce a knee implant that can be used to treat osteoarthritis.
A proof-of-concept paper describing the overall workflow for the detailed design and advanced manufacturing processes of a patient-specific orthopedic stabilizer designed generally in Progress for Additive Manufacturing has been published.
Generative design uses artificial intelligence (AI) and machine learning to design parts that can be manufactured to be absolutely perfect for their intended use. For an airplane or car, for example, this might be a lighter and stronger component, resulting in greater fuel efficiency and reduced carbon dioxide.2 emissions. This study is the first known application of the obstetric design to an implantable biomedical device.
There are many advantages to being able to use this technology in medical applications. For example, current knee implants for knee osteoarthritis are manufactured in a limited number of shapes and sizes. Although new 3D printing technologies are beginning to be used to make implants tailored to an individual patient’s shape, this does not take into account the limitations imposed by surgical planning, as well as the patient’s weight or activity levels. These are important elements of understanding how the patient’s anatomy and the knee implant interact and are essential to implant design and postoperative rehabilitation.
The obstetric design allows the implants to be biomechanically specific, so the implant is designed according to the load it will withstand. This also allows the end product to be lighter, less prominent and less invasive, which means the patient will heal more quickly and are less likely to need revision surgery.
In the new study, the researchers outline how a design produced by Autodesk software can be fabricated and processed into a functional prototype, including how much of the process can be automated.
“The ‘one size fits all’ approach used in knee surgery to treat osteoarthritis can lead to significant complications, primarily due to over-engineered implant designs and thus limiting reliance,” said Sanjivan Kanagalingam, alumnus and principal investigator, from the University of Birmingham. Surgical and Patient Outcomes.The AI-integrated design interface allows us to configure tailor-made surgical planning parameters and take personal biomechanical information into account, synergistically integrating it with embedded manufacturing intelligence to model each patient’s specific medical titanium implants.
Principal Investigator and Senior Lecturer, Dr Lauren Thomas Seal, also at the University of Birmingham, added: “The combination of the academic, industry and clinical knowledge of the team working on this project, and the extensive design space provided by Generative Design, has resulted in more implant designs than anything that has been done. Seen before. Such an approach, which indicates the diversity of the project team, has enabled the development of a design process that can take into account the many differences between patients, for example the variance between male and female body mass.”
The next steps will be to mechanically test the devices for how well they bend and flex under loads. If successful, the team will eventually move to clinical testing.
“This obstetric design approach not only increases patient specificity in orthopedic fixations but also serves as a new and versatile framework in the design of patient-specific implants bearing the hips, shoulders, and maxillofacial implants,” Kanagallingam concluded.