With assistance from the Additive Manufacturing Hub at AMTIL, Melbourne-based Radetec Diagnostics developed an innovative device to facilitate fast and inexpensive testing of various infectious diseases – including COVID-19.

Radetec Diagnostics is a Melbourne-based biotechnology company dedicated to developing a world-leading “platform technology” based on quantum dots – advanced luminescent nanoparticles that can be used as labels for imaging and sensing applications. This has a wide range of clinical applications, particularly in the field of point-of-care rapid diagnostics, portable in-vitro diagnostic (IVDs) devices that are used for fast and inexpensive testing of various infectious diseases such as COVID-19, sexually transmitted infections (STIs) or even cancer and Parkinson’s’ disease biomarkers.

Radetec’s IVD product range consist of point-of-care test strips, and an electronic reader that is able to generate quantifiable readings in the diagnostic process. The test strips are based on a lateral flow assay test methodology, where a reagent deposited on the test strip generates a reaction to a targeted biomarker. In this case, this reaction creates a visible florescence response in the reagent when illuminated with a UV light source.

The project entails the design and manufacture of such a reader to initially assist with the manufacture of the test strips, and later form a complete set of rapid diagnostic products for clinical use.

The challenge

The aim of this project was to develop a multipurpose benchtop reader device that would facilitate the analysis of the point-of-care test strips and other type of samples. During the analysis process, the test strips are illuminated with a UV light source, while being shielded from ambient light. A camera is used to capture the response and allow further analysis within dedicated software

The major challenge for this project was the integration of the main elements of the reader that generated results that were of sufficient accuracy and repeatability. This required successful integration of mechanical hardware design, electronics and software, all of which must work seamlessly to create a device that is intuitive and easy to use for the operator.

The reader has also been designed to offer flexibility in set-up – to allow analysis of a variety of sample types and sizes. It was identified early that offering the ability to analyse samples from a single test strip through to a standard 96-sample well plate would provide a significant benefit for the product over competitor offerings. This demanded more from the camera module, and specifically the relationship of physical position and lens selection.

Time to market was also identified as a major challenge, and this was a major reason why additive manufacturing was selected as a key part of early stage development.

The solution

A first proof of concept of the reader was developed with the help of Professor Dane McCamey (UNSW Sydney and ARC Centre of Excellence in Exciton Science). Cobalt Design was then engaged to improve the design and the sensitivity of the device, as well as manufacturing a series of benchtop reader prototypes to allow extended testing and evaluation of this new device platform. An initial benchtop system prototype was created using an FDM-printed prototype that allowed for variation of position of key elements such as the camera.

This prototype included mounting points for each of the electronics components and an OEM USB camera, and allowed for initial function testing of key elements including:

  • Sample illumination – both with UV and white light sources.
  • Light tightness of the enclosure.
  • Camera optics selection.
  • Camera positioning.
  • OEM hardware including USB camera.
  • Electronics – LED and camera power, communication to control software.
  • Software development – including camera control, lighting control, image capture and image analysis.

This test unit was a critical step in the development process and allowed a number technical risks to be addressed, while also identifying areas for further optimisation and improvement. Filtering of the LED light sources was identified as a definite requirement for the product, which led to a change to the LED configuration along with a hardware change. The test unit was also critical in fast-tracking software development as it provided a working device to test and debug the custom software that was being developed concurrently with the hardware.

After a series of design optimisations, a second round of working prototypes were manufactured and delivered to Radetec to allow extended testing and analysis. Five working units were manufactured using FDM printing, and along with functional changes to improve performance, a number of additional features were included for better integration of components, protection and isolation of the fragile electronics, and improved industrial design.

How the Additive Manufacturing Hub helped

It was predicated that the project would make full use of a $20,000 Build It Better (BIB) voucher co contribution via the Additive Manufacturing Hub. The estimated breakdown amounts for this project were $60,000 to Cobalt Design, with $20,000 to be contributed bia BIB voucher.

In the end, a total of $46,047.60 (ex GST) was spent with two registered providers: Cobalt Design ($44,697.35); and GoProto ($1,350.25). Of this amount, $20,000 was contributed by the BIB voucher and the remaining $26,047.60 was paid by Radetec Diagnostics.

According to Dr John Li, CEO of Radetec Diagnostics: “The Build it Better program allowed Radetec Diagnostics to design, experiment with and ultimately create a sensitive, multipurpose reader that is easy to use and can be utilised to quantify the fluorescence from a variety of solid and liquid substrates. The additive manufacturing capabilities available in Victoria today enabled a rapid development of a superior benchtop system ideal for R&D and medical applications.”

The outcome

The project allowed Radetec to develop the reader just in time for the roll-out of its first product – a COVID-19 antigen point-of-care rapid test. It allowed for a timely delivery of the entire set of diagnostics devices (reader + test strip) to US-based distribution partners for immediate live trial and evaluation. The roll-out of the COVID-10 test was time-critical – the earlier the better.

Another significant outcome from the project is that Radetec has accumulated experience in designing and building a “platform technology reader” that can be used in Radetec’s subsequent products – such as STI tests, cancer biomarker tests, or Parkinson’s disease tests. The reader will only require relatively minor modifications to apply to tests on other diseases.

The AM Hub is an initiative delivered by AMTIL in partnership with the Victorian State Government to promote the adoption of additive manufacturing technology.

For more information, please contact John Croft, AM Hub Manager, on 03 9800 3666 or email amhub@amtil.com.au.