The smart phone is going to save the world. Medical apps, diagnostic apps, wellness apps, self-testing, the quantified self….. This is the way of the future, we’re told. And it is true; personalized, mobile sensing technologies are entering our lives in a very real way.
Many of the issues central to the performance of remote sensing and diagnostic applications have been solved. The technology related to data collection, transmission and interpretation has moved extremely rapidly in the past 5 years, both in the developed and developing world.
Sensing technology for biophysical parameters such as blood pressure, temperature and cardiac monitoring has streaked ahead.
New regulation is coming - however slowly – to regulate and monitor the adoption of new paradigms in remote testing, and new insurance models are driving a lot of testing down to the consumer.
New business models, such as that of Theranos, are threatening the status quo for point of care medical diagnostic testing and central laboratory testing.
Big money is being spent on generating revolutionary diagnostic technology, through efforts such as the Qualcomm Tricorder X-prize.
So there’s a lot going on that makes it feel like revolution. But why does it feel like something is still missing in all of this? Like a new immuno-sensor, for instance? Even Dr Spock’s Tricorder had a sensor…
A lot of time and effort have gone into pursuing advances in technologies that can replace many of the elements of a lateral flow device. Microfluidics to replace sample pads and membranes, to add mixing and wash steps; capillary technologies to replace wick materials; integrated reader systems to replace external readers. Why these component technologies have not been brought together into a technology platform that can compete with a lateral flow assay is, arguably, because the economics don’t work. The market is too fragmented, and the value to support the translation of a truly revolutionary design into a broad based manufacturable technology platform doesn’t exist. That may change based on the push to consumer based diagnostics, particularly in the US market, but it does not seem that likely that in the short term a new immuno-sensor platform that has the diverse utility of the lateral flow platform will emerge. As a result, lateral flow remains the only broadly applicable, rapid, sensitive point of need immuno-sensor that can be applied in virtually any environment.
So, if Revolution is not imminent, what of Evolution?
There is certainly evolution occurring in the marketplace. The consumer segment, long promised in this industry, is finally starting to emerge in developed world markets. Wellness applications, allergen testing, food testing, nutritional testing, and consumer focused infectious disease testing are all showing signs of emergent growth. Companion diagnostics, an area that has largely been under-served, is finally showing signs of life as business models are evolved that work for both the pharma and diagnostic companies.
Application wise, in the past 5 years, there has been a growing shift in development activity in lateral flow towards more complex, quantitative, multiplexed assay systems, requiring readers, focused on more difficult diagnostic challenges including cardiac, kidney and brain diagnostics. Assays are faster. Sensitivity requirements are higher. Quantification is expected. So as an industry we have been forced into incremental improvement, and that means we have had to look at these technologies with fresh eyes. As an industry we have had to be prepared to take a step back and ask how we can do it better. As a result, there has been a need for a serious evolution in capabilities, performance, efficiency and, importantly, in design.
Test performance has been improved in many cases through a focus on materials, reagents, signal generation reagents (labels) and manufacturing process. Many of the dedicated suppliers of key materials such as nitrocellulose, glass fibers and specialist filtration media for sample processing, have achieved significant improvements in reproducibility and material performance. In terms of labels, a significant increase in the utilization of novel labels such as fluorescent dyes and particles, up-converting phosphors, and novel visual labels such as cellulose nanobeads, has led to significant improvements in sensitivity and quantification ability. Manufacturing processes have evolved to the point where control of key parameters is possible to very high fidelity, and an appreciation of what those key parameters are has become more commonplace. The emergence of contract manufacturers with significant experience from other related industries has made a significant impact on the quality of many available lateral flow assays. Reader systems are now more commonplace. In regulated markets, these reader systems still tend to be small benchtop units that are fully validated, while in less regulated markets there has been significant interest in smart phone and app-based solutions.
However among all of these evolutionary steps is one that is potentially the most important to the long term viability of this technology – a growth in the understanding of the importance of user-centric design in lateral flow devices. Not only is the design of a lateral flow cartridge and sample collection device critical to the function of the overall assay, it is also central to the value proposition of the product. Particularly as markets shift into areas where users have potentially less technical expertise, testing devices need to be designed for the user, their environment and their application. A focus on better design can lead to the ability to obtain certain regulatory approvals, such as CLIA waiver, but it can also improve user experience, add value to the product, and distinguish the product from the competition. These are all lessons that have been well learned in consumer markets for other technologies, and this industry is now starting to take them on board.
Lateral flow remains a strong and relevant technology, and will for the foreseeable future. Simply put, currently there is no other technology that can do what we ask of lateral flow. As an industry we have developed tests that are used in saving lives through testing of cardiac markers and kidney disease markers, and through the detection of flu, HIV infection, malaria and dengue. We have produced tests that improve crop yield, help in the identification of GMO organisms, and improve pest control. We have developed tests that help to diagnose and treat our pets, make sure our cattle are disease free, our milk is free from contaminants and our food is free of infectious agents. We have tested blood, sweat and tears – literally! We have also tested CSF, stool, soil, beans, bread, meat, wine, and milk. We have developed tests to keep our populations safe from terrorist attacks, and for detection of exposure to radiation and cyanide. We are helping law enforcement with drug testing.
There’s nothing else out there that can do what lateral flow can do, but there is enough momentum behind the changes that are coming in this marketplace to represent a substantial threat in the medium to long term in many application areas. As a result, evolution in performance, quality, efficiency and design remain the keys to the ongoing relevance and continued adoption of this technology.
