It is not the greatest feeling to get a throat swab. Definitely not something you would wish for yourself every day. However, currently it is the most reliable form of testing for COVID-19... Or is it really reliable? Experienced medical personnel can probably carry it out without any problems, but not all personnel are well trained.
As it is not very pleasant, frequent testing of people at risk becomes problematic. Without doubt healthcare personnel are exposed to the greatest risk of not only being infected, but also transmitting it. An increase in testing frequency, say after every shift, could largely reduce the risk of transmission among healthcare professionals, but to achieve this, one would require a method that does not further increase the burden on caretakers while increasing the viral load to allow for increasing accuracy of the detection methods.
The problem we want to solve
Early detection is a prerequisite for efficient fight against COVID-19, but current sampling methods are not perfect either in comfort, nor in sensitivity. One possible cause of false negative tests is the short exposure time of the sampling probe, leading to low viral load.
A solution we propose
These days we wear masks all the time mostly to protect others from our potential asymptomatic infection. However, we are sure that we will be able to detect asymptomatic infective populations as these infective viral particles will accumulate on the surface of the mask. The small airspace combined with a typical usage of a few hours, offers the perfect condition to collect higher amounts of virus particles, enabling higher testing sensitivity. Seamless integration of a reliable sampling method into the PPE also eliminates the discomfort associated with swab testing. Easy handling and disposal would allow for less manipulation related degradation.
As a first step, frequent testing should be offered to healthcare personnel, who typically wear protective masks with a valve (FFP2-like). Thus, we chose to integrate our sample collection device into the valve and offer this “swab-included” valve to mask manufacturers without altering mask functionality.
Our progress during the weekend
After careful assessment of different designs, we have developed an initial plan for a mask valve that contains a removable sample collection chamber. We also conducted a broad survey on advanced materials that could be used as the inner lining of the sample collection chamber. To expedite approval by regulatory agencies, we chose materials that are already approved for swabs and face masks; advanced biomaterials remain in scope as a possible direction for further development.
- As the mask is used typically for hours, our sample collection device would be able to collect more virus particles than a throat or nose swab which typically lasts seconds.
- This will increase sensitivity of current diagnostic methods or allow for using viral-load-dependent antigen-based rapid tests.
- Increases patient safety and comfort
- Less human resources are needed to operate sampling, meaning that skilled personnel can be redirected to other critical areas of care or the same number of personnel could manage a much larger number of tests.
Our impact on the crisis
Higher sensitivity and earlier detection can help break the infection chain before new infection clusters appear. We will diminish infection within the hospitals where the necessary sanitaries are at high risk of home-isolation if suspect, and infective sanitaries extend the virus through the higher-risk hospitalized population. Even if we hope the pandemic is over soon, we shouldn’t let our defenses down until we have a vaccine. Since infectious clusters are to be expected and our solution could contribute to identifying them earlier, it can also help breaking the transmission chain.
What about peaceful times, after we overcome the crisis
As much as we hope to eradicate COVID-19, it is also sure that humanity has to live together with other viruses. Our solution could be generalized to any airborne infection and thus, improve response against future pandemics as well. Our innovative concept could feasibly be introduced in other types of testing beyond viral infections and the novel designed material could be used for other purposes such as checking surface contamination in the food industry.
What is next for COVID-dosimeter
Our very next step is to produce a small number of prototypes, possibly with 3D printing and start testing the efficiency of our device. In the end of the day we would like to apply for CE and PPE certifications as the health and safety of the user remains our no. 1 priority in the fight against Covid-19.