News from SME
AM sparkles for making one-of-a-kind parts and products with complex, organic shapes. This imitates nature’s method of making every human body part unique.
Medical device producers found this years prior, applying the technology to the production of in-the-ear hearing aids, most of which are customized. Today, the shells for these hearing aid products are made using AM. The hearing instrument industry was the first to adopt AM across most major manufacturers, including Phonak, ReSound, Singia (formerly Siemens), Starkey, and Widex. This shows how AM can become a go-to production method when the application is a perfect fit for the technology.
AM for medical implants is additionally significant. They require complex textures, trabecular surfaces, to integrate with the surrounding tissue. AM is the most capable method for these structures in infinitely variable patterns. Stryker has used AM to produce more than 300,000 orthopaedic devices for patients, many with trabecular surfaces.
Implant production utilizing AM is already a maturing and growing industry, yet generally for standard items and sizes. Examples: acetabular hip cups, spinal implants, and knee replacements. Custom implants are used but are more expensive. Each implant must be modelled from scan data, built and checked. It is believed that custom implants will become more common in the future.
The Central University of Technology’s Centre for Rapid Prototyping and Manufacturing (CRPM) in South Africa has used titanium facial implants to successfully treat cancer patients for years. Lately, CRPM designed cages into the implant to hold proteins that stimulate jawbone ingrowth. After treatment and bone growth, the patient can receive dental implants.
Creating Complex Designs
3D printing makes possible the design freedom for complex casts. Unlike injection moulding, urethane casting allows for varying wall thickness and does not require a draft. Production with a 3D printed master pattern allows designers to incorporate organic shapes, embossed text and consolidated part designs into a cast. Due to the soft silicone moulding process, it is now able to produce very large parts quickly. Production of medical cart housings and large panels are possible for bigger products. Full finishing and post-processing of casts are also available, including production painting and texture, EMI/RFI shielding and co-moulding inserts.
Eliminating Hard Tooling Costs
Due to the quick production of silicone moulds, cast urethanes have low overhead tooling costs; parts can be delivered in as little as seven days. Frequently, engineers will use cast urethanes when they need to develop lower quantities of parts quickly and are unsure about long-term quantities for the market and therefore cannot make significant capital investments in production tooling. Cast urethanes allow the production of parts quarter by quarter, with the added benefit of easy design changes. Speed to market continues to be key for the medical industry, and the improved production time possible with urethane casting allows for early revenue.
To push standardization initiatives, more AM medical case data need distributing, indicating that AM-based treatments are safe and effective. Fortunately, the number of AM-related articles published in peer-reviewed medical journals dramatically increased from 2014 to 2018.
Influential groups are being framed to help advance the adoption of AM in the medical industry. Hospitals without on-site AM capabilities can find support from gatherings. Professor Deon de Beer and Dr Gerrie Booysen pointed out that surgery time—including ICU access, high-care facilities, and dedicated medical staff time—is cut in half when AM is used. Patient recovery is also faster and outcomes are more successful.
Today, what we see of AM in the medical field is the tip of the iceberg. Different subjects such as regenerative medicine, 3D bioprinting, stem-cell research, 3D-printed drugs, and custom medical devices highlight a future where AM could benefit every human being’s quality of life!