Biosensors are rapidly becoming part of our everyday life. As technology advances, we may soon be able to monitor many aspects of our health at home, in real time and without needles. But how close are we to this future and what are its implications?
Traditionally used in medical practice to monitor patient status, biosensors have recently started to be broadly marketed for wellness and fitness applications. These devices are based on the detection of a specific molecule that is linked to a health condition and can offer an actionable insight into what’s happening in our bodies.
The market for biosensors is growing rapidly. It is predicted to reach a massive €22B by 2020, pushed by a wave of new technologies that are making them more accessible both for patients and consumers.
Currently, point-of-care applications constitute the largest use of biosensors. A plethora of biosensors has been developed over the past decades for hospitals. A recent example is a neuromonitoring system, developed by the Swiss company Luciole Medical, designed to measure blood oxygen levels in the brain for intensive care.
However, the fastest growing segment of the biosensor market is home monitoring kits, such as glucose monitors used by diabetics. Medtech companies are trying to develop smaller, cheaper and easier to use biosensor devices that could be used by anyone at home.
Self-monitoring with biosensors has the potential to impact the care of virtually any chronic disease, by changing the paradigm from a monthly appointment at the hospital to daily monitoring, helping anticipate side effects and prevent the progression of the disease.
Home monitoring could also make a big impact in ensuring people comply with the treatments prescribed by their doctor. Studies have consistently shown that approximately 50% of medications for chronic diseases are not taken as prescribed. According to a EU-funded study, almost 200,000 deaths each year are due to patients missing or using the incorrect dose.
An example is Truvada PrEP, a well-known treatment to prevent HIV infections. However, compliance is impacted by side effects and the stigma around HIV. Gilead is currently running a clinical trial using a digital pill that monitors whether it has been ingested and informs the patient through a smartphone. The digital pill is activated by the acid in the stomach, triggering a radiofrequency emitter that sends the information to a cloud server and the patient’s smartphone.
A similar concept is being used in the monitoring of mental illness treatments. A digital pill developed by Otsuka Pharmaceutical to monitor the ingestion of aripiprazole, used in schizophrenia, bipolar disorder and depression, was recently approved by the FDA.
Biosensors could particularly help monitor cancer treatments, which often show a narrow therapeutic range where slightly lower doses make the therapy fail and overdosage causes severe adverse effects. Lucentix, a spin-off of the École Polytechnique Fédérale de Lausanne, is developing a low-cost biosensor technology that could measure the concentration of a drug in a drop of blood or saliva. The technology is based on a molecule that fluoresces in the presence of a target drug, and according to the company it can be adapted to sense a multitude of different drugs that are commonly monitored in patients, including anti-cancer agents.
“A lot of the way we diagnose disease is based on single-moment-in-time markers. But the promise of wearable sensors is real-time health monitoring, You can see a more complex picture of what’s going on in the body. That alone will lead to more diagnostic techniques across a spectrum of diseases,” said Andrew Jajack, researcher at Eccrine Systems.
US-based Profusa is developing biosensors integrated into human tissues for continuous health monitoring, has started selling in Europe a device for the real-time monitoring of tissue oxygen, with applications in peripheral artery disease; chronic wounds, such as diabetic ulcers; sleep apnea; chronic obstructive pulmonary disease; and reconstructive surgery.
The company is also developing a continuous glucose monitor, an area where new biosensor technologies are especially welcomed. Real-time measures can help people with diabetes better control their sugar levels, which can have a big impact in preventing or delaying the appearance of complications such as neuropathy or diabetic ulcers. In this field, multiple companies are developing glucose biosensors that no longer rely on needles, which are one of the main reasons behind poor blood glucose control in diabetics.
The power of real-time monitoring can be enhanced by simultaneously measuring multiple health indicators. Biovotion, a startup based in Switzerland, is developing a wearable monitoring platform that can measure up to 22 health parameters at once.
As technology advances, scientists are coming up with clever yet unusual ideas to monitor our health. In May 2018, a team from the MIT revealed an ingestible sensor containing genetically engineered bacteria that could diagnose gastrointestinal problems such as bleeding. As a proof of concept, they engineered a probiotic strain of E. coli to emit light when in contact with blood. This so-called “bacteria on chip” combines cells with low-power electronics that convert the bacterial response into a wireless signal that can be read by a smartphone.
Another emerging area is tattoo biosensors. Researchers at Harvard and the MIT have developed color-changing digital tattoos within the scope of a project called Dermal Abyss. The biosensitive inks used in the tattoos change colors based on changes in the concentration of glucose, sodium, and the pH in the interstitial fluid found in between skin cells. The researchers have so far created a tattoo responding to dehydration and another to glucose levels.
Another example from a collaboration between the US and China has resulted in the development of a temporary graphene tattoo sensor that lasts a few days and can be used to measure skin temperature and skin hydration, as well as performing electrocardiograms and electroencephalograms.
The future of biosensors
“Isn’t it ridiculous and terrifying at the same time that we bring our cars to the car service at the moment that it indicates a problem, however, we don’t do that with our own signals? We don’t deal with them, or we don’t even know there was a sign,” writes the Medical Futurist.
Biosensors could become a standard path for doctors to diagnose and monitor their patients. With the advent of personalized medicine, biosensors could quickly become unavoidable.
Nonetheless, there is still a long way to go and we are still quite far from seeing augmented patients with a bunch of biosensors monitoring every feature of their disease. Furthermore, the technology comes with concerns of data privacy, as many of these biosensors are monitored remotely and connected to the Internet, making them potentially hackable.
Some of these innovations have already been marketed for a few years and although the field is advancing rapidly, so far we have only a few examples of breakthrough devices. The technology is still in its early stages so it will be several years until it reaches its maximum potential.
Images via Shutterstock; Medicalfuturist; Proteus Health; MIT; Harvard