One day soon, maybe: Mobile health apps that are actually useful

Future of Wireless You don't have to stick sensors inside people to see what's killing them - but just how much can you find out with nothing more than a breath of air and a teardrop or two?

Quite far, according to Professor Chris Lowe, of Cambridge University, who has been using glucose-detecting contact lenses to demonstrate how our tears show our health as well as our happiness - though what he'd really like to do is use piezoelectrics to analyse more-integral fluids or maybe catch a breath of unfresh air.

Presenting at the Future of Wireless conference in Cambridge last week the good professor spent a while justifying the electrification of health monitoring (pdf, slide deck), the benefits of which are far from obvious. There are dozens of "medical" smartphone applications, the market for which is driven by the "worried well", or "a bunch of attention seeking old-style hypochondriacs and neurotics" as a speaker at a previous conference styled them, but like that speaker Lowe also expressed concern at the number of (unregulated) apps getting installed onto the iPhones of medical professionals.

Despite that, Lowe argued, the change in what kills us means we have to change the way we diagnose and treat those conditions. When premature death could largely be attributed to bad water and infected wounds then microscopes, detergents and penicillin were the order of the day, but now it's cancer, diabetes and heart failure so a different approach is necessary.

The problem with most monitoring tech, the stuff that doesn't require a scalpel and a sure hand to install, is that it grabs data only occasionally while the things which need monitoring change awfully quickly - the gas content of blood in a matter of minutes, other chemicals in hours. Only a handful of useful markers can be usefully measured on a daily basis. The other problem is that we have very little information on the variation present in healthy people as intensive (implant) monitoring is usually reserved for the sick, so doctors would like to gather a load more data, ideally without having to plant sensors in too many people.

This is where the contact lenses developed by Professor Lowe's team come in: they change colour based on the glucose level in tears, which is proportionate to (though lower than) the glucose level in the blood. The colour change is detectable by a web cam or similar, so a diabetic could be monitored by their computer, but the technology could also help build up a baseline of what's normal.

Diabetics are something of a focus for Lowe, who points out that six per cent of the UK population falls into that category, and 11 per cent of the Chinese are diabetic too. So cheap and effective monitoring is more than an academic concern as responding quickly to variations in glucose levels will make those 150 million or so people cheaper to look after, and more productive too.

But it's not just tears that the team is looking at, they've worked out how variations in a piezoelectrically-resonating plate can reveal the constituents of the liquid resting on it, creating a tiny and cheap chemical analysis kit. The first applications of that kit will need to be in contact with liquid we normally keep internally so not a perfect solution though a lot smaller than existing implants.

Another approach being explored by the team is to take a careful look at the air we breathe, which apparently has the potential to diagnose conditions ranging from asthma to renal failure, covering liver dysfunction and some forms of cancer in between, enough to be worthy of greater analysis.

Professor Lowes contends that we've moved beyond a time when checking for leaking blood would diagnose most life-threatening conditions, to at time when diagnosis will only be possible with reference to data gathered by mobile technology over a period of time - here's hoping we can all afford to do just that.