Dave Sandbach is Thrive’s co-founder and Director of Innovation. With a broad career history developing smart fabrics, green tech and assistive technologies, Dave has worked extensively with high-impact, user-centred technology and is currently very active in the arena of stress detection and management. With technology in this field now starting to make an impact in the mainstream, Dave shared his views on the current state of play and the future of technology that measures and reports on stress markers and then intervenes to improve the user’s long-term health by altering their condition – including some applications that Thrive is currently working on.

Stress

Is stress always a bad thing?

The autonomic nervous system (ANS) manages our stress response, as it’s the part of our nervous system that responds to threat or instigates relaxation. The ANS comprises the sympathetic and parasympathetic nervous systems, which activate several of the body’s responses to external stimuli. Of course, these aren’t simply two disparate systems that operate independently of each other, and they influence many aspects of our physical and mental state through a complex interplay that controls the release of hormones that can significantly impact our mood and physical health in the longer term when there’s a sustained imbalance.

More often than not, people think of stress as an unpleasant experience with only negative health consequences. However, this notion is over-simplified, as Dave explains:

“When we talk about stress, we’re normally talking about the negative consequences of stress, and this makes sense to some extent – for example, if a person’s cortisol levels are elevated for a prolonged period due to overstimulation of the sympathetic nervous system, this will have a damaging effect on their body. But only having our parasympathetic nervous system active has been shown to have negative effects of its own. To prevent health issues from arising in the long term, a balance must be found between the two. Short spikes in stress hormones through activation of the sympathetic system can help to keep us healthy.”

How well can stress be measured?

There are various ways to measure stress markers on the body using biometric sensors. With the right design for example, optical sensors can measure heart rate variability (HRV), which can give some indication of stress by calculating how much variation there is in the intervals between heartbeats. Having some elasticity in this measurement is a healthy sign, and in particular the intervals between heartbeats when inhaling should be different from those during exhalation.

Alongside HRV measured through photoplethysmography (PPG) sensors, a range of other biosensors can be used, usually in combination, to give us a clearer picture of stress levels, including electrocardiogram (ECG) and electrodermal activity (EDA), as well as other technologies for detecting respiration rhythms, but because metrics vary from device to device, with no universally applied interpretations in wearable tech, it’s hard for users to build a coherent picture of their stress levels.

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How can we manage stress?

While stress management technology is a fast-evolving market, historically the most common ways to manage stress have involved certain regular practices or exercises.

Understanding how these techniques work can give us some clues as to how technology may enact interventions to help with stress management. Examples of active stress management include ancient practices such as meditation and yoga, alongside modern derivatives like the Wim Hof Method, which is gaining popularity around the world.

“Wim Hof has made techniques that have existed for centuries accessible to anyone, which is impressive given the shorter attention spans and time constraints that many people struggle with in the modern world,” Dave points out. “What’s intriguing is that his method involves deliberately activating the sympathetic nervous system by placing the body under stress using breathing techniques or cold-water immersion, combined with meditation to exit the stressed state. This is an example of the positive impact of stress. What it shows is that we have the capacity to take control of our own bodies, intervening to manage our stress through these techniques.”

The Wim Hof method is an example of how briefly heightened stress can be healthy – occasional spikes in cortisol levels at certain times of the day can be beneficial, as long as the hormone mostly remains at a low residual level. Although we can point to a so-called ideal stress profile, in reality there are a number of factors involved and each individual is different; in any case, we should only be seeing heightened cortisol release in response to healthy stressors such as exercise.

“We’re working on systems that will help users to understand how they can tailor their approach to ascertaining and achieving a pattern that’s healthy for them as individuals,” Dave says, adding: “To give a simple example, an athlete’s journey towards an optimised stress profile, and the management system they need to achieve this, might be vastly different to that of someone who suffers from clinical anxiety or is being treated for a health condition.”

What’s possible with stress management technology?

Although methods such as those outlined above can help people to stay healthier by regulating their stress, there are also treatments and technologies that can intervene to produce change in the body. These present obvious advantages in that they reduce the effort required by the individual and provide an immediate impact rather than requiring training over a period of time. In terms of wearable products in this area, there is plenty of space for development. Because stress is such a personal experience, we need to establish solutions that are tailored for individuals’ needs. These can vary depending on both a person’s condition and their stress management goals. Dave believes that we will see more wearable technology designed to help with stress coming to the market very soon:

“At Thrive, we’re working on combining technology building blocks to focus on what we see as the future of stress detection and management: tailored applications aimed at specific user needs.”

An example of technology already on the market, Fitbit Sense is a smartwatch that uses PPG and other sensors to help users identify and manage their stress levels. One of the sensors Fitbit Sense uses for this is EDA, a repurposing of tech historically used in lie detectors, that measures electrical signals in the skin to identify changes in stress via the sweat response. This is the first time we’ve seen this technology used in this way in a mainstream wearable product, and although it has some useful applications in terms of understanding the body’s response to stimuli and making incremental improvements, there are also some serious limitations.

One of the main challenges in the space is a “one-size-fits-all” approach from bigger players, who often prioritise selling large numbers of devices in order to compete in the market. Because of this, they often converge to lowest-common-denominator offerings that operate with closed data and limited APIs, preventing some more innovative and niche applications. While Thrive develops similar platforms, we’re able to keep these options open and support the ecosystem to be rapidly configured to enable new applications and opportunities. A product that has already shown success in actively helping users manage their stress through direct intervention is Sensate, which Thrive developed for technology start-up BioSelf. You can find out more about this from our case study here.

Where do we go from here?

The next step in the development of stress management technology is to establish what metrics need to be analysed and how interventions can be implemented effectively to change the user’s state at the right times, and in the right ways.

“We’re working on a detailed mapping of how the array of available technologies can be applied to give specific, actionable insights that are relevant for particular users,” Dave reveals. “Bringing together technologies that measure and present stress data in a consistent way will give meaningful insights that allow users to identify triggers for undesirable stress responses by mapping spikes during the day against stimuli that occurred at the same times and then respond accordingly. This technology has the potential to be really helpful for understanding conditions like bipolar disorder, and we’re now actively talking to users and therapists with the aim of delivering something that will work alongside CBT to deliver substantial results. This is something that’s not currently available with mainstream wearable devices, so it’s a really exciting development.”

What seems clear is that we are on the cusp of some big steps in the development of stress management wearable technology.

“Stress management will involve different solutions for different users, because they have such a variety of goals – so the future lies in providing a whole range of applications that are tailored for different sets of needs,” comments Dave, who concludes: “With the advancements that we’ve seen, we can expect to see a range of stress management wearable products entering the market in the near future, and our role as a leader in this area sees us increasingly contributing our experience to support initiatives looking to address these diverse needs.”

wimhof
sensate
Sensate product

Sensate

fitbit

Fit Bit Sense

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About Thrive

Thrive are a team of designers, developers and engineers with a mission to solve global health challenges with the power of technology innovation, connected devices and data processing. We are the leading wearable technology design and development consultancy and we work with global companies, academic partners, charities and individuals to turn great ideas into world changing wearables. Read more about Thrive. 

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