The innovation behind wearable sensors and smart bandages
Ravinder Dahiya, IEEE fellow and professor of electronics and nanoengineering at University of Glasgow, explains how a smart bandage can be beneficial to both healthcare staff and patients.
Wearable sensors provide an accurate measure of vital physiological parameters. The rich sensor data combined with artificial intelligence (AI) has been an important development over the past few years, not least because of the impact it has had on the healthcare sector. Indeed, wearable sensor technology is significantly improving efficiency in healthcare in the UK. In addition, in other parts of world where health infrastructure is either insufficient or not available, wearable sensor technology will help leapfrog the traditional bottleneck in the way of reaching remote areas.
Robotics and wearable technology are expected to support not only the growing need for remote medical services without spatial and temporal restrictions, but also the increased demand for medical services among senior citizens, who suffer from reduced mobility and a lack of access to professional medical services. The success of these technologies in healthcare applications will eventually be governed by the continuous use intention, not just technology acceptance or adoption rates.
The smart bandage
Patients with an open wound, such as a bedsore or a foot ulcer will often need to be checked frequently, so a healthcare professional can monitor how well the wound is healing. This can require regular and often undesirable trips to a doctor’s surgery. However, smart bandages are a recent innovation, reducing these visits. A smart bandage is essentially a flexible adhesive patch which can be used to apply pressure to help a wound heal. Smart bandages are the first bandage to use sensors that simultaneously measure how much strain is being put on the skin, as well as the patient’s temperature, which can affect the healing process. The readings from the dressing can be sent to a healthcare provider via a smartphone app the researchers developed.
Monitoring wound healing is not the only potential application, as the bandage can also be used to monitor breathing and even detect COVID-19 symptoms. Temperature and strain are two parameters that are rarely combined for wound assessment, making smart bandages one of the most innovative wearable devices to enter the healthcare industry.
A new kind of healing
The bandage uses a variety of techniques to speed up the healing process, including using skin substitutes for wounds that are hard to heal. In addition to this, electroceuticals with piezoelectric materials–based dressings and negative-pressure therapy increase the flow of blood while keeping the wound moist. A compression bandage that applies just the right pressure could make the healing process a lot faster but figuring out the correct pressure and how to monitor body temperature can be challenging. Studies show that wound healing is best at a body temperature between 36° and 38° C.
The 3cm – 6cm, clear adhesive bandage uses two types of sensors and a battery less near-field communication (NFC) tag, which can transmit data from the sensors wirelessly to a smartphone app. One sensor monitors the patient’s temperature, while the other one checks how much strain is being put on the skin. Transparent polydimethylsiloxane (PDMS) is used to make the strain sensor. PDMS is the most widely used silicon-based organic polymer because of its versatility. Strain sensors can determine the right amount of pressure for the compression bandage, and the temperature sensor can detect if a patient is spiking a fever and therefore might have an infection.
Numerous uses
The smart bandage can be used to check the lung functions of those with respiratory conditions such as asthma. The same applies for patients on ventilators, as the patch can be placed on their chest and the strain sensor can detect erratic breathing. The smart app connected to the bandage can immediately notify healthcare professionals, which can speed up testing and potentially stop a sick patient from infecting others. In addition to this, the smart bandage can be used by just about anybody, especially frontline workers.
Despite the benefits, wearable sensors such as smart bandages are incredibly technical devices which require a huge amount of data, and therefore do not always provide conclusive outcomes. AI and data analytics based on the inputs from experienced clinicians can help extract useful information from sensory data. In turn, this can help predict the growth of diseases, improvements with diagnosis or even prevent a disease completely by predicting in advance.