3D Printing and Medicine: Developing Technology

3D printing is making leaps and bounds in its advancement, and through its journey forwards, this technology is taking many other technologies and applications forward along the way. As part of a series of articles, in this particular instalment, we look at the development of 3D printing technology as it has become suitable for more and more areas of the medical industry.

 

Rapid Tooling- A dusty venture (1980s to 1990s)

This process is a means of creating a functional model, or parts of one by combining both Rapid Prototyping and conventional tooling processes. One way of doing this would be by using a CNC milling machine to create a model from a CAD file. This method is still used in other applications, though it has mostly been replaced in the field of medicine. One upside of this method is that the doctor would have access to a model version of a part of a patient that is hard or impossible to properly look at and touch. However, the choice of materials is limited, making it hard to mimic the properties of some body parts that may be modelled, so it doesn’t provide a a completely accurate reconstruction.

Additive Manufacturing – Printing in plastic (2000s to 2010s)

At this point in the development of 3D printing, this technology was more commonly known as Additive Manufacturing. This name is still used, though the alternate term ‘3D printing’ is also common. By this point more and more places were being introduced to the idea of models being built up layer by layer in various materials, though the choice of different printing medium wasn’t as diverse as it is today. Models could be more geometrically complex than before and the idea of customisation was a lot easier to implement. The speed of the process was also beginning to improve too, so its use in the fast-paced medical field was beginning to become even more important.

Multi-functional Additive Manufacturing – Exploring new horizons (2010s)

More materials, techniques and ways to actually 3D print have opened more and more doors into different areas of the medical industry. Nowadays, printers are going as far as printing actual cells as part of a print medium. Biofabrication is being used to create 3D printed structures that stimulate tissue repair and regrowth. Internal and external implants and prostheses are becoming more and more of a norm as this technology progresses and things can only move up and beyond from there.

Traditional Techniques versus 3D Printing

One example of how 3D printing has sped up the process of helping patients, is the process of making soft tissue external prostheses. Traditionally, the steps would run as so:

1. Take impression of the injury area
2. Prosthetic is hand carved (a lengthy process which requires a highly skilled worker)
3. Silicone version of the prosthetic is produced by wax loss process

However, with the use of 3D printing, the steps run like this:

1. 3D scan the patient
2. Mirroring used to create a 3D model of the prosthetic using existing parts of the patient as a guide
3. The prosthetic is then printed
4. Silicone version of the prosthetic is produced by wax loss process

Despite there being an extra step, the process by which 3D printing is used can take only 3 hours, in comparison to the 12 months that the traditional method can take. This is a massive improvement in time scale.

The importance of medical models

Now that medical models an be produced far more easily in a range of materials that can mimic the features of various tissues in the body, these accurate medical models are incredibly useful in many areas. They can be used as training resources, providing a means of hands on learning. They can also be used for the rehearsal of specialised, high risk procedures such as sinus surgery.

Dedicated software has also been developed by Loughborough University, which allows clinicians to create their training cases. This software has been developed with the idea of making it easier to use for clinicians by avoiding the need for CAD training.

Trusting 3D Printing

As much as there are many upsides to this technology, such as the ratio of expenditure to the value of what is produced as well as the speeding up of current processes, the further expansion of this technology is particularly dependant on the exposure of it between clinician to clinician. In the UK certainly, the spread of the application of 3D printing in the medical profession is largely peer driven. With this in mind, the different areas of research this technology can unlock is hoped to not only push forward the development of medical techniques, but also persuade  clinicians to recommend it within treatment as well as part of research and training.

 

With Special Thanks to Russell Harris, Professor of Medical Engineering and Advanced Manufacturing, University of Leeds and EPSRC Loughborough University