Nuno Reis and Ana Ferreira-Barbosa
We have all grown up with the idea that if a woman suspects she is pregnant, she simply can pop into a pharmacy and buy a pregnancy test to use at home.
Conversely, if someone suspects they are suffering from heart disease, cancer or an infection, their first instinct is to contact a GP or call an ambulance. So the obvious question is why easy-to-use self-tests have not yet been developed for life-threatening diseases.
The answer is straightforward for a scientist: it is to do with the level of the biomarker – in this case, the proteins produced by the cells in the body that are specific to the particular condition – that must be measured. Not only that but one has to measure the complexity of the biological sample – the blood or serum in the case of biomarkers.
The impact of those two aspects is huge, as revealed by the very limited technological alternatives to “dipstick” tests currently available to the global health-care market.
The “pregnancy test” is actually a great example of a dipstick test capable of detecting the presence of a pregnancy hormone called human chronic gonadotrophin (hCG) in urine, which is produced by the body after conceiving.
The test uses similar chemistry to the one involved in measuring many other protein biomarkers from blood – but the measurement of protein biomarkers remains limited to bulky clinical pathology labs and companies are still struggling to miniaturise this sophisticated lab equipment.
Clinical diagnostics influences about 70% of health-care decisions, which means they are the foundation of a cost-effective health-care system. Life expectancy has increased massively in recent years due to remarkable developments in clinical diagnostics – these have been extensively reported in scientific literature.
Diagnostic tests provide critical physiological or biochemical information that physicians or patients need for the best health-care decisions.
So in an era when most humans struggle to live without portable computers, tablets, smartphones and the rest – why has a “personal lab” not yet been invented?
Mobile computers only became possible because of major breakthroughs in battery life, transistors, integrated circuits and software development, which allowed incredible levels of miniaturisation. Clinical lab equipment needs to undergo a similar revolution to the one that led to the development of modern computers.
Decentralised diagnostics is fundamental to modern sustainable health-care systems, but miniaturising clinical tests is often regarded as an extremely challenging task.
There has been portable and power-free smartphone diagnostic detection at Loughborough University. Several health conditions – including cancer, cardiac problems and infectious diseases – rely on extremely sensitive quantitation, the ability to actually measure the quantity of a biomarker rather than just providing a yes or no answer to its presence in blood.
Diagnosis through measuring these protein biomarkers requires incredible sensitivity – that is not presently available with existing point-of-care diagnostic tests.
And a microcapillary film (MCF) diagnostic test signal has been detected with a smartphone. Effective testing at the point of care requires miniaturised technologies capable of translating complex laboratory techniques into simple and rapid tests. A number of point-of-care tests have effectively made a difference in improving the health systems.
This includes the glucose test for diabetes monitoring as well as pregnancy and HIV tests. But point-of-care tests for chronic diseases such as cardiovascular diseases and cancer – which according to the World Health Organisation were responsible for 68% of deaths in 2012 worldwide – are generally not available, despite being of key importance to early treatment and survival of patients with these health conditions.
So let’s get our scientific and engineering minds together and revolutionise clinical diagnostics with personal labs accessible to all.
lReis is a lecturer in chemical engineering at Loughborough University.
Ferreira-Barbosa is a PhD researcher at Loughborough University.
This article first appeared in The Conversation.