SyriSter

The design process began by interviewing paramedics, SES, and SAR personnel to gain insight into processes and systems that are causing inefficiencies in their jobs. These interviews identified a need for safe re-use of critical and commonly used medical supplies, particularly in crisis zones where re-use is unavoidable.

Alongside interviews, research was conducted to look at potential methods of sterilisation. The biggest challenge was overcoming the resource constraints, as the device could not rely on water, gas, or consumable supply. Ideation led to several concepts that were evaluated by the interviewees, alongside medical device design experts. Eventually, the method of using UV-C light to sterilise syringes was found to be the most viable option. UV-C sterilisation posed a few issues in efficacy due to light paths and dosage, as well as potential degradation of the syringe material. Calculations, dosage mapping, iterative design and testing revealed that the dosages received would be enough to eradicate HIV in 60 seconds. The degradation testing also revealed no signs of material failure after 12 hours of continuous dosage.

In parallel, iterative prototypes and custom PCBs were created to complement the testing, as well as narrow down robust design for manufacture and assembly. As the product would be needed for crisis zones/low socio-economic areas, low cost was essential. Work was put into making the chassis injection mouldable, as well as using LEDs to keep PCB costs down, totalling a cost per unit of $655 AUD. Usability research showed a need for storage of the syringes after sterilisation, so that users would not prematurely dispose of the syringes and be left with a short supply to resterilise. These findings led to the additions of an o-ring seal and intuitive lighting indicators to show the user the chamber status.

The entire product was designed with the end user in mind. The severe resource constraints and requirement for a low price drove the technology, size, and manufacturing of the product. As consumable supplies are not an option for a disrupted supply chain, the use of UV-C light to sterilise the syringes means that the only resource requirement for the SyriSter is power. The device also contains a rechargeable battery for extra help if power supply is cut off.

The sizing of the product makes it portable, and fits into a standard SAR supply crate. In terms of usability, the user’s journey was well thought out to inform aspects of the design. Each chamber features a large button that can be easily pressed with a thumb to comfortably position your hand to lift the lid. The back wall of the chamber lid hinges upwards when opened to allow for simple loading of the syringe onto 2 mounting points. When closed, the lid physically clicks shut, with a green light as a visual indicator that the lid is secure.

The indicator lights on the front panel shine amber, green, and blue for unlocked, locked, and sterilising respectively. The icons were also selected to be universally readable by users of any language background due to the nature of the product being used in crisis response settings. The chambers also include a poka-yoke design where needles cannot be inserted along with the syringe, as the back hinging wall will jam and prevent the lid from closing.

To make the product AS61010 compliant for the users safety, a hardwired interlocking system was incorporated into each chamber. This prevents the UV-C light turning on while the chamber is open and unlocked. As soon as the chamber opens the light will immediately switch off.

Innovation in this product comes from the use of UV-C light to sterilise. UV-C has historically been implemented as an effective disinfectant, but is yet to emerge commercially for sterilisation as dosage requirements are much higher and products are harder to make viable when highly specified. The SyriSter utilises this innovation to become a competing sterilisation product at a price point 7x cheaper than benchmarked autoclaves and chemical sterilisers.

The device features 6 chambers that can be used simultaneously. All chambers have a hinging back wall to allow for easier user loading, as well as an o-ring seal to store the syringes once sterilised. Inside each chamber, vacuum metalised aluminium is used to assist in reflecting the UV-C radiation around the syringe for a higher dosage. The hinging back wall, as well as physical dimensions and features of the chamber make it impossible to load a syringe with a needle, as needles can never be effectively sterilised.

The design has no need for external consumables, water, gas or mains power, allowing for a portable and self-sufficient device that can be easily implemented into low socio-economic hospitals or disaster zones. Usability was also taken into account through design language and safety features, so a user from any background could comfortably use the device.

Design and engineering efforts were made to cost down the manufacturing of a sterilisation device to make it more affordable. The device’s use of LEDs lowers the costs, where the unit cost is approx $655AUD to manufacture. Current competing disinfection devices start at $900AUD, while sterilisation devices start at $7000AUD. The entire design cost down makes the product more accessible to lower socio-economic regions, with no additional consumable or running costs.

Reliable UV-C sterilisation through the SyriSter allows for syringes to be safely re-used on hundreds of patients without risk of pathogen transmission. This takes massive amounts of pressure off the hospital to supply new syringes, whether it be from a supply chain disruption or financial burden.  Re-use practices in developing countries are often due to lack of education on the risks of disease transmission. Implementing the device in areas like this can promote safer and healthier sterilisation practices in areas where this knowledge is not common.

The innovative use of UV-C LEDs as a steriliser allows SyriSter to become a significantly cheaper and more accessible alternative to current sterilisation devices on the market. This makes the device more accessible to lower socio-economic regions where it is needed most.

While the device components themselves may not contribute to sustainable practice, the product service system could potentially prevent millions of single use plastic syringes from ending up in landfill and contributing to biohazardous waste. During the design process, testing found that the syringe can withstand up to 120 sterilisation cycles before degradation and failure of the syringe gasket occur.

This design builds on Victorias design and creative culture by creating new technological innovations that could potentially be utilised for many new devices, not just for sterilising syringes. UV-C LEDs when configured correctly can be highly effective in sterilisation. Further development of this product and other implementations of the technology could open up a whole new range of cost effective medical sterilisation products out of Victoria.