How miniaturised optical sensors could catch infections early and prevent another pandemic
Getting infected and falling sick often do not happen simultaneously. It takes a virus some time to settle within the body of a host and then multiply – at which point we feel sick. It is the same with all viral infections, including COVID-19. This time lag between infection and manifestation of disease – medically known as “incubation period” – varies depending on the virus and the personal immunity power of the host. It is a dangerous period because, without any signs of illness, the person is not aware of the infection and continues with life as usual – silently infecting others in the process. This is how all pandemics spread. The only solution could be a system that keeps constant watch over our internal physiological processes and even the slightest change detected is flagged as an advance warning sign of possible illness. Well, Nokia Bell Labs has come up with just that! They have miniaturised an optical scanning technique to capture 3D images of live human tissue – and any deviation from normal parameters can be flagged off as an early sign of disease.
This almost echoes the sci-fi movie Innerspace produced by Steven Spielberg in the 1980s. The plot involved an astronaut who was miniaturised almost to the size of a virus along with his navigation capsule and injected inside the body of another person. There, he could move around and explore the anatomy – often noticing unusual physiological processes, which he had to normalise or exploit depending on the situation, to fulfil the experiment.
Nokia Bell Labs has not really invented the knowhow that is being applied here. Called Optical Coherence Tomography (OCT) – the technology has been around since the early 1990s. It uses optical imaging procedure to generate 3D visualizations of living tissues and can determine minute internal physiological changes within the anatomy. In fact, it is an excellent non-invasive procedure for early detection of slight incoherencies in the human body. The medical fraternity was quick to realize the possibilities and OCT has been harnessed as a diagnostic technology in different specialities – skin, eye and heart being the most common among them. But why, despite its capability as an early whistle blower, is it not being put to widespread diagnostic use – especially when it is absolutely safe and non-invasive? For one thing, the machine is exorbitantly expensive: over US$ 1,00,000 for a unit. And the other hindrance is its size: nearly as big as a cupboard.
Although a lot of medical diagnostic equipment are huge and costly, in case of the OCT both size and price are deterrents for its optimal use. OCT is intended to monitor minor physiological changes and identify early red flags. This requires keeping constant watch over bodily functions to get continuous feed on the internal processes – which means either hooking up the person to the machine or attaching the machine to the person. In the first case, the person under investigation is immobilised – which is not practical for an early-detection procedure. The second alternative – lugging around a cupboard-sized machine – is obviously out of question! As for the price, preventive diagnosis based on early detection can only be beneficial for public health if it can reach out to all, or at least the majority of, people. For that, we need devices that are cheap, easy to produce on a mass scale and quick to dispose. Only a portable and affordable tool can be used by everyone for continuous health monitoring.
And this is where Nokia Bell Labs has taken the Spielberg approach. Keeping the technology intact, they have simply miniaturized the OCT system through advanced photonic design. Now just about the size of a large – and a bit too thick – cellular phone, it runs on battery and is the first portable swept-source laser OCT system; obviously way cheaper than its mammoth-sized ancestor. It is, in fact, the culmination of expertise gathered by Nokia Bell Labs over the past 30 years, as they conducted extensive research on integrated photonic technologies for telecommunication systems. There, the target was to miniaturize optical links and augment data speed – all at reduced noise, energy consumption and cost. This principal was now applied to develop an abbreviated but fully capable OCT system, and with spectacular results.
Surprises do not end there. The developers have taken it upon themselves to further improve the efficacy of the OCT system to turn it into a more accurate diagnostic tool. Being an imaging technology, OCT can record changes happening but cannot identify the chemicals that circulate and control our biochemistry. However, the developing team, led by Michael Eggleston, Augmented Human Devices Group Leader at Nokia Bell Labs, have come up with specific biosensors that can respond to changes in targeted biochemicals. The OCT device can record these responses and analyse the changes identified to determine whether things are going normal inside the body. This has already been successfully tested on blood glucose and adenosine triphosphate – and more biosensors are on the anvil.
The vision of Nokia Bell Labs is futuristic. Eggleston thinks the future will see more than wearable monitoring devices. He foresees biosensors directly being implanted under the human skin and their reading could be continuously analysed real time by intelligent analytical and diagnostic systems hosted in the Cloud. Such humans will remain connected as one more element on the Internet of Things. Eggleston calls them “homo augmentus”, meaning the “augmented human”. Monitoring health symptoms and preventing the next pandemic will be a cakewalk in that connected world.