Smart wearable technology that changes colour, heats up, squeezes or vibrates as your emotions are heightened has the potential to help people with affective disorders better control their feelings.
Researchers from Lancaster University’s School of Computing and Communications have worked with smart materials on wrist-worn prototypes that can aid people diagnosed with depression, anxiety, and bi-polar disorders in monitoring their emotions.
Wrist bands that change colour depending upon the level of emotional arousal allow users to easily see or feel what is happening without having to refer to mobile or desktop devices.
“Knowing our emotions and how we can control them are complex skills that many people find difficult to master,” said co-author Muhammad Umair, who will present the research at DIS 19 in San Diego.
“We wanted to create low-cost, simple prototypes to support understanding and engagement with real-time changes in arousal.
The idea is to develop self-help technologies that people can use in their everyday life and be able to see what they are going through. Wrist-worn private affective wearables can serve as a bridge between mind and body and can really help people connect to their feelings.
“Previous work on this technologies has focused on graphs and abstract visualisations of biosignals, on traditions mobile and desktop interfaces. But we have focused on devices that are wearable and provide not only visual signals but also can be felt through vibration, a tightening feeling or heat sensation without the need to access other programmes—as a result we believe the prototype devices provide real-time rather than historic data.”

The researchers worked with thermochromic materials that change colour when heated up, as well as devices that vibrate or squeeze the wrist.
Tests of the devices saw participants wearing the prototypes over the course of between eight and 16 hours, reporting between four and eight occasions each when it activated – during events such as playing games, working, having conversations, watching movies, laughing, relaxing and becoming scared.
A skin response sensor picked up changes in arousal – through galvanic skin response, which measures the electrical conductivity of the skin – and represented it through the various prototype designs.
Those smart materials which were both instant and constant and which had a physical rather than visual output, were most effective.
Muhammad added: “Participants started to pay attention to their in-the-moment emotional responses, realising that their moods had changed quickly and understanding what it was that was causing the device to activate.
It was not always an emotional response, but sometimes other activities – such as taking part in exercise – could cause a reaction.
“One of the most striking findings was that the devices helped participants started to identify emotional responses which they had been unable to beforehand, even after only two days.
“We believes that a better understanding of the materials we employed and their qualities could open up new design opportunities for representing heightened emotions and allowing people a better sense of sense and emotional understanding.”
Wearable Health Devices (WHDs) are an emerging technology that enables continuous ambulatory monitoring of human vital signs during daily life (during work, at home, during sport activities, etc.) or in a clinical environment, with the advantage of minimizing discomfort and interference with normal human activities [1].
WHDs are part of personal health systems, a concept introduced in the late 1990s, with the purpose of placing the individual citizen in the center of the healthcare delivery process, managing its own health and interacting with care providers – a concept that is commonly referred to as “patient empowerment.
The aim was to raise people interest about their health status, improving the quality of care and making use of the new technology capabilities.
These devices create a synergy between multiple science domains such as biomedical technologies, micro and nanotechnologies, materials engineering, electronic engineering and information and communication technologies [2,3].
The use of WHDs allows the ambulatory acquisition of vital signs and health status monitoring over extended periods (days/weeks) and outside clinical environments.
This feature allows acquiring vital data during different daily activities, ensuring a better support in medical diagnosis and/or helping in a better and faster recovering from a medical intervention or body injury.
WHDs are also very useful in sport activities/fitness to monitor athlete’s performance or even in first responders or military personnel to evaluate and monitor their body response in different hazardous situations and to better manage their effort and occupational health.
These devices can be for both medical and/or activities/fitness/wellness purposes, always targeting the human body monitoring. Taking this in account, the best terminology is “health”, leading to WHDs.
WHDs denomination can be more specific referring to which areas they are applied to. Independently of WHDs purpose, there are four main requirements on their design: low power consumption, reliability and security, comfort and ergonomics [4,5].
According to Statista [6], the wearable devices market is currently having a worldwide revenue of around $26 billion, and is expected to reach almost $34 billion in 2019. Regarding healthcare and medical environments, it is expected to grow almost to $15 billion worldwide value in 2019 [7].
This review aims to gather recent information on WHDs and better evaluate the current situation of such devices, foreseeing their evolution in the coming years. The main focus will be in vital signs and in textile embedded WHDs.
The document is organized in seven sections.
In Section 2 we discuss what really are the most needed measurements to be acquired concerning medical, personal healthcare, fitness/wellness and sport activities areas.
The signs where a higher technological development effort is being made is also covered. Then, Section 3 presents recent technologies used to acquire each identified vital sign.
In Section 4, a generic system architecture is presented to better understand WHDs components, workflow and the differences between existing devices.
Section 5 reviews some types of WHD with a main focus on heart activity monitoring devices.
A focus on commercialized WHDs t-shirts is made to compare devices and discuss properties. Some prototypes are also briefly presented.
To foresee possible future trends in this area, this review is complemented with a market analysis in Section 6.
Finally, Section 7 concludes this review referring to some future challenges and perspectives in the WHDs area.
This review differs in several aspects from other publications with similar topics, correlating different areas and aspects related with WHDs that are sometimes not combined nor analysed.
For example, in recent publications (e.g., [8,9]) there is a very good description of the technical aspects related with the physiologic signs description, acquisition methods, some devices and fabrication methods, but few information about the concerns and needs of those signs on the human health or about the WHDs system architecture. On the other hand, some other publications are strongly focused on the WHDs architecture and technical aspects of it, such as in [10].
There are still other publications that focus on other aspects, but here we present a concatenation of the main aspects related with WHDs.
This review also addresses two topics that are not very much explored in WHDs technology publications which are the understanding of the most important vital signs, where some medical aspects are included, and also a market trend analysis to understand what can be the future of these type of devices. A unique characteristic of this review is the heart activity monitoring focus that is performed to understand the state-the-art of one of the largest area of WHDs.
Provided by Lancaster University