The human body constantly generates electricity, and in data science, electricity is information. This flow of electrons defines the body’s health, the evolution of an illness and allows to check on the efficacy of a treatment.
It opens the doors to the world of quantified self in which physicians stay in front of their computers and communicate mostly with their patients via telehealth services. It undoubtedly modifies the patient-doctor relationship, but wearables sensors are slowly becoming part of how we manage our health, hopefully for the better.
Over the years, the progress in medical technology has made it easier to read and interpret medical data while maximizing human health and longevity Measuring this data has been further simplified by the digital revolution and the internet of things, leading to the development of wearable sensors.
This article will describe the different types of wearable sensors depending on the vital signs to monitor. We will touch on their safety, accuracy as well as glance at the future market projections for this industry that ten years ago did not even exist.
What are wearable sensors?
Wearable biosensors are wireless sensors or sensor suites worn on or in the body that provide continuous, non-invasive detection of biosignals, analytes, or any surrounding forces for monitoring human health and performance.
They can be integrated into smartwatches, smart rings, and other wearable technologies and even directly implanted into the body. As a result, they provide continuous real-time clinically relevant data for patient care and researchers or during clinical studies.
The market for wearable sensors and devices is rapidly expanding and is projected to grow by 19.47% in the next five years. With such rapid growth, regulatory bodies such as the Food and Drug Administration will have to adapt the norms to ensure the safe use of this continuous flow of data.
The massive growth in the medical wearable electronics market is mostly explained by its potential, convenience, relatively low associated costs, and benefits in improving the management of chronic diseases. As a result, healthcare applications are virtually limitless.
Examples of wearable tech
We went a long way from the wired electrodes we all saw in standard 12-leads electrocardiograms. In recent years, new technologies took over and now offer numerous ways to quantify physiological parameters without the need for cables anymore.
Health monitoring is becoming wireless, and wearable sensor systems rely on machine learning for analysis. Let’s describe the most common types of sensors a wearable device relies upon.
Photoplethysmography Sensors (PPG)
Photoplethysmography is a novel technique that utilizes infrared light to monitor cardiac functions, especially the heart rate or blood oxygen saturation. PPG is the core technology used by smartwatches. Have you noticed the colorful LED at the back of your Apple Watch? This is a PPG sensor. Despite being new, this wearable technology is nearly as effective as the electrocardiogram in carrying out this function. However, it is more convenient and flexible for patients.
Photoplethysmography sensors have different product designs. However, they all measure the changes in blood-flow changes with comparable results. These sensors use lights of different colors – especially red and green, directed at the human skin to detect the flow of blood through the capillaries to detect heart rate and blood oxygen saturation.
Infrared light has also been used, although it is more susceptible to motion artifacts that ultimately distort the final result. These sensors can be coupled to accelerometers that will detect human motion and reduce motion artifacts.
Stress triggers many cardiovascular diseases and mental health disorders. Monitoring stress effectively is therefore very desirable. This is what an electrodermal sensor does. It detects the electrical changes of the skin that are mostly linked to the production of sweat which is involuntarily controlled by the parasympathetic system in response to stress.
These activities are easily detected on the palm and the feet, making them the preferred location for these sensors. In addition, these sensors have been incorporated in watches such as the Fitbit Sense.
Electroencephalography (EEG) is the measurement of the electrical signal emitted by. It helps evaluate brain activities. Traditionally, Electroencephlograms required numerous electrodes fitted on the equivalent of a bathing cap and all connected to many wires.
Devices such as the Muse developed by the company InterAxon make the most of just a couple of electrodes integrated into a headband to detect the levels of brain activity and guide users during their meditation exercises.
The body temperature is a critical indicator of the current physiological status of the body. For example, fever is the first sign that the body is fighting some form of infection.
Especially when dealing with contagious diseases, wearable temperature sensors are a convenient way to monitor the patients’ temperature while minimizing physical contact. In addition, doctors can even remotely monitor the status of their patients once they are discharged.
Temperature sensors are now integrated into watches, medical patches, and smart clothes, making it possible to record the temperature in real-time conveniently.
Are wearable sensors safe?
Wearable sensors are considered medical devices. Therefore they are subjected to strict regulations before being approved for us. The regulations that guide the approval and use of medical devices differ by region.
In the United States, it is regulated by the Food and Drug Administration (FDA). In Europe, it is regulated by the European regulatory framework of the European Union. Overall, the devices in the market have been deemed safe and are at least as good as the devices of the previous generation. However, they are still subject to the process of quality improvement, and any complaint about their safety should be reported to the appropriate regulatory agency.
With so many types of data to collect, the wearable sensor technology integrated into a medical device needs to be fail-proof or at least very reliable. The main issue is that the data collected will become the foundation of the doctors’ medical decisions. Hence even a simple temperature sensor has to undergo stringent tests before being made available in the market.
The regulatory agencies will assess the reliability and safety of medical devices. One of the main issues is that companies will not market their products as medical devices to avoid potential complaints or even lawsuits in case of technical glitches.
Users should be aware that consumer-oriented devices are valuable in terms of the information they provide but that the results may not always be at a level reliable enough to support medical decisions.
What does the future hold for wearable sensors?
Over the past few years, telemedicine and remote monitoring of patients have gained a lot of popularity. This has been further amplified because of the COVID-19 pandemic.
Wearable products became ubiquitous in a world where social distancing is the norm and medicine is delivered through a computer or smartphone screen.
The future is bright for wearable sensors as there is likely to be more uptake of the technology to reduce hospital visits.
The market forecast for the wearable sensors market also points in this direction. These devices are convenient and have the potential to reduce the cost of care and improve health outcomes. Furthermore, with the growing elderly population, the need for convenient, accurate, continuous patient monitoring will only increase.
Wearable sensors make patient monitoring a comfortable and reliable process. The next challenge is to make them accessible for all those that need them now and as the demand continues to grow in the coming days.
To wrap up
Biosensors are not limited to measuring physical activity anymore. The development of the technology makes them reliable for measuring blood pressure, skin temperature, blood flow, or glucose level.
Fitness trackers have come a long way, are and the progress in printed electronics and artificial intelligence will most certainly change the way healthcare is delivered.
One critical perk to consider is that this data flow needs to be stored and easily accessible for medical professionals to make the most of it. Thus, the main issues of the coming years may be linked to how cybersecurity and the privacy of medical information are being handled.
Amazon recently started to offer the possibility to store the huge amount of data generated in the cloud leveraging on the power of their artificial intelligence powered data lake. Amazon HealthLake aims at not only storing the information but also at discovering new meaningful relationships between them.
Wearable sensors are ready but are the society ready to handle the change in the way healthcare data is being handled is the question that will need to be answered.