An overview of wearable sensors and their implications on health monitoring
As wearable sensors become more common, they are becoming more sophisticated and able to do more than just track activity levels. The data generated by sensors can provide tremendous value to healthcare services and is capable of providing insights into the well-being of an individual. This article will explore the types of sensors used in health monitoring, and how they will transform the healthcare industry.
Wearable technology, such as the APPLE WATCH or Fitbit’s fitness trackers, has been one of the most popular new technologies in recent years. The market has been booming: According to a study from ROCK HEALTH, more than 40% of US consumers now have a wearable device. Recent advances in wearable sensors have fueled the growth, leaving a huge potential for health monitoring applications.
In recent years, the term “wearable” has been used to refer to a wide variety of devices that can be worn ON DIFFERENT PARTS OF THE BODY. Typical data points tracked by off-the-shelf wearables include vital data (resting heart rate, ECG voltage, SPO2), sleep patterns (length, interruptions, intensity), and physical activity (type, duration, levels). All of those digital biomarkers are derived from mostly passively collected data of different sensors.
What types of sensors are used in wearables?
There are four main types of wearable sensors: chemical, electromechanical, optical, and electrical sensors.
Chemical sensors measure the concentration levels of chemicals in sweat or other bodily fluids. Examples include glucose monitors for diabetics and lactate level measurements, as well as sensors to measure stress hormones in sweat. Chemical sensors are not very common in consumer wearables due to their often invasive nature and the difficulty to miniaturize.
The most popular wearable device relying mainly on chemical sensors is the Freestyle Libre by Abbot Diabetes Care. This device is worn on the back of the upper arm and uses an invasive sensor (needle) to measure glucose levels in the interstitial fluid between cells. The recent advances have been pushing Freestyle Libre closer to a “true” wearable, making it more discreet and easy for users to wear the device continuously.
Electromechanical sensors use electrical measurements to track mechanical movements. A good example of this is the use of an accelerometer to measure physical activity. This is the most common type of sensor in current wearable devices and is built-in in every smartphone. Other examples of electromechanical sensors are inertial measurement units, which measure angular changes and linear acceleration for rotational velocity and position tracking.
Optical sensors are very common in wearable devices and provide tremendous value for health monitoring. They are small, non-invasive, and can be worn on the body for long periods of time without causing any irritation. Optical sensors use light to detect various biological signals like heart rate, oxygen saturation, or more recently blood pressure.
Light sources like LED’s are used to emit light into the body. Sensors then measure how much of that is absorbed, reflected back out, or passed through for spectroscopy analysis. This way blood flow is measured to derive (resting) heart rate data through the sensor.
Other optical sensors that are being developed include temperature, galvanic skin response, and stress sensors.
Electrical sensors primarily use electrical signals to measure heart rate or brain activity. One example of an electrical sensor is the electrocardiogram (ECG or heart rate monitor). This records the electrical activity of your heart and can be used to detect abnormalities like arrhythmias.
Electrical sensors are also used to measure brain waves using an EEG (electroencephalogram). This records the electrical activity of your brain through electrodes that attach to the scalp. This kind of technology is typically used in research environments.
Other electrical sensors include electromyography (EMG) which measures muscle movement and electrode dermal patches used for measuring sweat levels in perspiration monitoring.
How do wearable sensors advance health monitoring?
Traditionally health has been measured in the doctor’s office or the hospital. The recent advances in health monitoring technologies have revolutionized things. Wearables allow for continuous 24/7 observation of a patient’s health, whether it be at home or on the road.
Thousands of data points are passively collected every day allowing for constant monitoring, early identification of abnormalities, and ultimately data-driven decisions. This is a big step forward in the health care industry.
Examples of remote health monitoring applications are mHealth apps that help manage chronic conditions or cardiac rehabilitation. Sensor-based devices are also being used to measure stress levels in pregnant women for early detection of preterm labor and delivery. In recent years, wearable health monitoring technology has been introduced as a new method to monitor the effects of certain treatments such as chemotherapy on patients undergoing cancer treatment.
How recent advances in wearable sensors for health monitoring will affect the industry
Wearable technology has not only changed how we think about healthcare but also how it should be delivered. Sensor-based devices are continuously becoming smaller, more accurate, and cheaper to produce allowing mass adoption by consumers. Wearable data is increasingly being used in clinical decision-making, with recent studies showing that wearable devices can accurately measure heart rate, activity, and sleep.
Wearables allow the healthcare industry to get a continuous stream of data on their patients’ health to gain insights about their current state of health and ultimately trends over time.
Wearable technology could be used to detect the early stages of chronic diseases, monitor the effects of certain treatments, and even help you get a better night of sleep.
It is important to note that there are multiple types of wearables available on the market today. Each one has different features, but they all have a few things in common: they are unobtrusive, collect data passively, and every third patient already owns one.