The Rise of 3D Printed Prosthetic Eyes

Recently there’s been quite a lot of attention on the use of 3D printing to manufacture artificial eyes (aka. ocular prostheses). This has largely been due to an announcement out of the UK that the world’s first 3D printed artificial eye was implanted in a patient.

Quite a cool milestone and application of 3D printing, and also happens to be a field I’ve been investigating for the past 6 months with some of my colleagues at the Herston Biofabrication Institute. We’ve just published a review of all research into the use of 3D printing for orbital and ocular prostheses, and you can access the full article for free here.

The graph above does a nice job of showing the overall trend for research on this topic, with the first ever paper dating back to 2004. Early studies like this certainly weren’t 3D printing eyes and implanting them in patients, but instead used 3D printing as part of the process, creating moulds and similar devices. The first time a 3D printed part was directly used as part of a prosthesis was in 2014.

Perhaps one of the best ways to demonstrate what is possible now using full-colour 3D print methods (material jetting) is the below video from Weta Workshop. While these may be eyes for monsters, the same principle is being used for human prosthetic eyes. One of the key differences between what Weta Workshop have achieved, and what is being done for patients, is the need for biocompatible materials, as well as the need for a patient’s eye to perfectly match their existing “good” eye.

While it’s early days in the clinical trial phase of implementing 3D printing for prosthetic eyes, there are many benefits which we summarised from our research, including:

  • Manual steps in prosthesis fabrication can be replaced by digital methods, potentially saving time
  • Less discomfort to patients through use of medical imaging or 3D scanning techniques
  • Weight reduction compared to traditional methods
  • Improved accuracy and fitting of prosthesis
  • Minimised need for gluing a prosthesis to the skin
  • Good realism of eye
  • Ability to easily re-print the same components in the future

Of course, there are currently some limitations as well, such as:

  • End-use 3D printed parts are typically not biocompatible and require coating with PMMA or used as a mould to cast with biocompatible material (although the UK trial shows that direct 3D printing of multi-colour biocompatible materials may be possible)
  • Experience in computer-aided design (CAD) technology is required, which is not part of traditional skillset for prosthetist
  • AM times are slow (although they can also happen overnight or while a specialist does other things)
  • Rough surface quality of parts requires additional post-processing e.g. polishing
  • Challenges associated with using 3D scanners e.g. patient movement or scanning anatomy with hair
  • Expert manual skills are still required for some steps of the workflow
  • Use of CT scanning for the purposes of creating a prosthetic increases patient exposure to potentially harmful radiation

Research to-date has been limited to small case studies and engineering experiments, making it difficult to understand whether outcomes will translate to the clinical context. It will be great to see how the UK clinical trial progresses, and hopefully provides improved outcomes for patients. Let’s watch this space!

– Posted by James Novak

3D Printing and COVID-19 in Data

Figure 2 Timeline

Following my previous post discussing some of the opportunities and challenges of using 3D printing to fill supply chain holes during COVID-19, I’m pleased to share the more detailed research I’ve been working on that supported my article in The Conversation.

Published here in an open access journal is an analysis of all 3D printing projects that were initiated during the first months of the pandemic. As a summary, the image above shows the timeline of these projects, and the types of products that were being produced. In total, 91 projects were documented in my research, with only 7 of these occurring before the World Health Organization (WHO) declaration of a pandemic on March 11. Most of these were based in Asia. The remaining 84 projects (92%) followed the declaration as the pandemic spread around the world and health systems rapidly struggled to meet the demand.

The figure above also shows that 60% of projects were for personal protective equipment (PPE) such as face shields and goggles, while 20% were for ventilator components, and a further 20% were for miscellaneous projects such as hands-free door openers.

200523 3D Print COVID-19 Data

Of the PPE projects, 62% were for face shields as shown above in the left chart. This includes the popular Prusa RC3 face shield pictured in my previous post, although the first documented face shield actually occurred on February 25 from The Hong Kong Polytechnic University. Obviously face shields are a relatively low risk product compared to components for a ventilators, and makers could easily 3D print these on desktop 3D printers.

The chart on the right above documents the types of 3D printing technologies used for each of the 91 projects. Perhaps it is no surprise that fused filament fabrication (FFF) was the most used, accounting for 62% of projects. Resin printing with stereolithography (SLA) or digital light processing (DLP) was the next most popular for 10% of projects, followed by multi jet fusion (MJF=9%), selective laser sintering (SLS=8%), continuous liquid interface production (CLIP=2%), and concrete was used in one project in China to 3D print concrete isolation houses for Xianning Central Hospital in Hubei. Interestingly, 8% of projects did not specify the 3D printing technology being utilised, suggesting that some projects lacked documentation or were reported by the media simply as “3D printing.”

While this review provides an overview of the broad trends related to the 3D printing of health and medical products during the first months of the COVID-19 pandemic, ongoing research is needed to continue monitoring 3D printed products throughout the pandemic to understand longitudinal trends. For example, does the initial hype from March subside and a more stable pattern of research and collaboration continue through April and the following months? Do projects consolidate and merge, with others ending as regulations tighten, or traditional supply chains stabilise?

It will also be necessary to analyse 3D printed products and validate them, particularly as the health crisis continues for months or even years. Initial 3D printing projects, while well intentioned, were largely unregulated and a reflexive response to direct and immediate needs. As supplies stabilise, and the infection curve flattens, more time and resources can be devoted to research, building upon the NIH 3D Print Exchange database of approved designs, perhaps developing an approved FDA or TGA database of designs as well as 3D print technologies and materials. These may be necessary for any future outbreaks of the virus, as well as allowing for better preparation for future health, humanitarian and natural disaster crises that may require a similarly rapid response to equipment shortages.

If you want to find more of the data and read the detailed analysis, please read the article here. Additionally, you can freely access all of the data I collected for this research, and continue building off it, by accessing it on Figshare. I hope it is useful for building our understanding of how 3D printing can be deployed during a health crisis.

– Posted by James Novak

Millions of products have been 3D printed for the coronavirus pandemic – but they bring risks

Header Image High Res

** Please note: this is a copy of an article I wrote for The Conversation, published on 5th May, 2020, and is shared under a CC-BY-ND license. You can access the original article by clicking here.**

With the COVID-19 pandemic, an urgent need has risen worldwide for specialised health and medical products. In a scramble to meet demand, “makers” in Australia and internationally have turned to 3D printing to address shortfalls.

These days 3D printers aren’t uncommon. In 2016, an estimated 3% of Australian households owned one – not to mention those available in schools, universities, libraries, community makerspaces and businesses.

3DEC Lab

A collection of desktop 3D printers in the Deakin University 3DEC lab. James Novak

Across Europe and the United States, access to essential personal protective equipment (PPE) remains a concern, with nearly half of all doctors in the UK reportedly forced to source their own PPE.

In Australia, reports from March and early April showed hospital staff reusing PPE, and health-care workers sourcing PPE at hardware stores due to shortages.

The global supply chain for these vital products has been disrupted by widespread lockdowns and reduced travel. Now, 3D printing is proving more nimble and adaptable manufacturing methods. Unfortunately, it’s also less suited for producing large numbers of items, and there are unanswered questions about safety and quality control.

Sharing is caring

One of the earliest examples of 3D printing being used for pandemic-related purposes is from mid-February. One Chinese manufacturer made 3D-printed protective goggles for medics in Wuhan. With 50 3D printers working around the clock, they were producing about 300 pairs daily.

Designers, engineers, students, manufacturers, doctors and charities have used 3D printing to produce a variety of products including face shields, masks, ventilator components, hands-free door openers and nasal swabs.

Many designs are freely shared online through platforms such as the NIH 3D Print Exchange. This US-based 3D printing community recently partnered with the Food and Drug Administration (FDA) and the Department of Veterans Affairs, to assist with validating designs uploaded by the community. So far, 18 3D-printable products have been approved for clinical use (although this is not the same as FDA approval).

Such online platforms allow makers around the world not only to print products based on uploaded designs, but also to propose improvements and share them with others.

Just because you can, doesn’t mean you should

In a public health crisis of COVID-19’s magnitude, you may think having any PPE or medical equipment is better than none.

However, Australia’s Therapeutic Goods Administration (TGA) – our regulatory body for medical products – has not yet endorsed specific 3D-printed products for emergency use during COVID-19. Applications for this can be made by manufacturers registered with the TGA.

However, the TGA is providing guidelines which designers, engineers and manufacturers are working with. For example, Australian group COVID SOS aims to respond to direct requests by frontline medical workers for equipment they or their hospital need. So, local designers and manufacturers are directly connected to those in need.

3D printing provides a means to manufacture unique and specialised products on demand, in a process known as “distributed manufacturing”.

Unfortunately, compared with mass production methods, 3D printing is extremely slow. Certain types of 3D-printed face shields and masks take more than an hour to print on a standard desktop 3D printer. In comparison, the process of “injection moudling” in factory mass production takes mere seconds.

That said, 3D printing is flexible. Makers can print depending on what’s needed in their community. It also allows designers to improve over time and products can get better with each update. The popular Prusa face shield developed in the Czech Republic has already been 3D printed more than 100,000 times. It’s now on its third iteration, which is twice as fast to print as the previous version.

Prusa RC3 Face Shield

A Prusa RC3 face shield 3D printed on a desktop 3D printer. James Novak

Opportunity vs risk

But despite the good intent behind most 3D printing, there are complications.

Do these opportunities outweigh the risks of unregulated, untested product used for critical health care situations? For instance, if the SARS-CoV-2 virus can survive two to three days on plastic surfaces, it’s theoretically possible for an infected maker to transfer the virus to someone else via a 3D-printed product.

Medical products must be sterilised, but who will ensure this is done if traditional supply chains are bypassed? Also, some of the common materials makers use to 3D print, such as PLA, aren’t durable enough to withstand the high heat and chemicals used for sterilisation.

And if 3D-printed products are donated to hospitals in large batches, identifying and treating different materials accordingly would be challenging.

For my research, I’ve been tracking 3D-printed products produced for the pandemic. In a soon-to-be-published study, I identify 34 different designs for face shields shared online prior to April 1. So, how do medical practitioners know which design to trust?

If a patient or worker is injured while wearing one, or becomes infected with COVID-19, who is responsible? The original designer? The person who printed the product? The website hosting the design?

These complex issues will likely take years to resolve with health regulators. And with this comes a chance for Australia – as a figurehead in 3D printing education – to lead the creation of validated, open source databases for emergency 3D printing.

– Posted by James Novak

Read more: Can 3D printing rebuild manufacturing in Australia?