Wearable technology: what exactly is it, and why is it so popular?

This article looks at why there is both a need and a desire for wearable technology, and how this demand is being met. It shows how the IoT is the overarching enabler as it makes devices easily visible and controllable by remote users, yet ultimate success depends on the quality and innovation built into the devices themselves. We see how wearable technology is now starting to take various forms, and finish by describing the design approaches currently available to systems developers.

Introduction

Today, the term wearable technology covers a multitude of applications, and even more devices to fulfil them. There are several general factors for this growth, which we can summarise as human need, human want and expectation, the rise of the IoT, and advances in technology that make the wearable devices themselves viable.

Human need relates to medical wearable devices, and has various attributable factors. The first is a steady and continuing rise in the geriatric proportion of the world’s population, which means more people with age-related, complex and sometimes multiple conditions that must be closely monitored and controlled. Another population dynamic feeding this market area’s growth is the ever-increasing incidence of lifestyle-related illnesses. As nations develop, their citizens gravitate to more sedentary activities and richer diets, becoming more susceptible to blood pressure, obesity and diabetes problems.

A third, but related factor is that world governments are recognising these trends, and responding with initiatives for preventative care. Such efforts have increased awareness among consumers of the benefits to be obtained from health monitoring, and prohibitive healthcare costs – for both governments and individuals - have only added to the urgency involved.

So much for human need – but what about human want and expectation? This starts with individuals who are healthy, yet wish to monitor and manage their lifestyle to ensure they remain as fit and as healthy as possible. Such people will spend discretionary income on wearable fitness devices to fulfil this wish. Yet human want extends far beyond the medical sphere; people seek to be informed and entertained as well. This gives rise to opportunities ranging from immersive games to augmented reality headsets that allow users to virtually rearrange or add furniture to their rooms, and compare the results.

Yet another dimension applies not to the individuals wearing the devices, but to third parties instead. For example, electronics in clothing, a lanyard or bracelet can allow managers to track their workers, or hospital to locate patients.

The role of the IoT

The above discussion explains how human needs and wants are driving the various markets for wearable devices. Now let’s look at the ways in which the IoT and device technology are combining to meet this demand. We can start with the IoT, as it is common to all wearable devices that communicate beyond their owners’ bodies.

Take two typical examples of remote patient monitoring (RPM); glucose meters for patients with diabetes and heart or blood pressure monitors for those receiving cardiac care. An IoT infrastructure – sometimes called an Internet of Medical Things or IoMT - provides a route for data from these sensors to reach the doctor’s office, together with the tools to analyse and act on the results. Data from the patient’s sensor can find its way, via a body or local network to a router either directly or through an app on a PC or smartphone and the Internet to a cloud-based server, available for analysis and doctor action. Considering that the people being monitored with this technology are often infirm, the advantages of this IoMT-enabled approach over repeated trips to a surgery become clear.

Devices such as these are often more powerful than sensors alone. Medilync’s Insulync , for example, comprises a glucose meter and an insulin pen reader. It provides near real-time data analysis on blood sugar levels, insulin dosage, pulse and blood pressure. Simultaneously, data collected from the device is combined with meal plan data from partners like MyFitness Pal and exercise information. This data is analysed using machine learning to help understand and identify the best care options for a patient. The device facilitates a complete diabetes healthcare solution for the patient.

Note also that the IoT is a two-way highway; doctors can remotely control wearable medical devices as well as receiving data from them. Infusion pumps, for example, control medicines and fluids delivered to patients.

Wearable device innovation

While wearable technology has been given impetus through the IoT providing remote visibility, controllability and analysis as described, the market’s growth depends just as much on the innovation built into the devices themselves. Users – whether hospitals or commercial enterprises deploying the devices, or patients or customers wearing them – expect high and possibly ground-breaking functionality coupled with ease of use, safety, durability, minimal size and weight, and long battery life.

One effect of innovation is that while we may think of wearable devices as wrist-worn products like Fitbit, the concept is now being extended in many ways, with clothing, jewellery and even tattoos being given intelligence and connectivity. And if we also include virtual reality and augmented reality headsets, a whole further range of opportunities and applications opens up.

Let’s take a look at these various possibilities for wearable technology and how they are being fulfilled in different industries and applications.

Wrist wearables

WristOx2 is a wristwatch-type pulse oximeter that handles tasks like monitoring and measuring users’ heart rates and blood oxygen levels. The device can be used both in the hospital and when the patient goes home to allow remote and extended monitoring of their heart rate and oxygenation.

Applications include cardio-ambulatory monitoring, remote wireless monitoring and overnight studies. The device uses Bluetooth 2.0 wireless technology, with a power-saving feature that automatically adjusts transmission power according to distance from the main unit. It also has an extended transmission range of up to 100 metres.

The device is easy to use, with automatic turn-on upon finger insertion. It is also sufficiently durable to withstand rough handling in home care and ambulatory environments.

One wearable that converts data into information is Final Frontier Device’s DxtER, inspired by Star Trek’s fictional Tricorder. DxtER is an artificial intelligence engine that learns to diagnose medical conditions via data from emergency medicine and analysing patients. Claimed by its developers to be at the intersection of artificial intelligence, the IoT and other key trends, the product is actually a small collection of specialised and smart medical devices that interact with a user’s tablet.

DxtER was designed to prove the concept that illnesses can be diagnosed and monitored in the comfort of one’s own home by consumers without any medical training. The device can run algorithms for diagnosing 34 health conditions, including: diabetes, atrial fibrillation, chronic obstructive pulmonary disease, urinary tract infection, sleep apnoea, leucocytosis, pertussis, stroke, tuberculosis, and pneumonia.

Intelligent clothing

While watch-like devices make convenient platforms for sensors, user displays and wireless transmitters, not everyone is capable of wearing them, and some simply do not like wearing them or making accommodation for them. For these reasons, smart clothing may become an increasingly attractive alternative.

Another reason is accuracy. Fitness bands like Fitbit can be inaccurate when recording step counts, while other metrics such as muscle tension and breathing rate can be difficult to obtain from the wrist. By contrast, smart underwear, by being close to the skin and on the body trunk, can measure breathing, heart rate and muscle tension to determine a number of health and wellness metrics like activity, anxiety and stress levels.

Products like this are already available from companies like OMSignal, which offers ranges of smart sports shirts and sports bras.

A more specialist product for sportspeople is the Hexoskin Smart – a connected shirt laced with sensors that monitor heart rate, breathing and movement. It also has a Bluetooth smart sensor that allows pairing with fitness apps such as MapMyRun, RunKeeper and Strava, and many other third-party accessories. Meanwhile, Yoga students could benefit from the virtual Yoga instructor capabilities of Wearable X’s Nadi X fitness pants. These have built-in haptic vibrations that pulse at the hips, knees and ankles to encourage users to move and/or hold positions. It syncs up via Bluetooth to a smartphone and gives additional feedback through a companion app.

A key enabling technology for smart clothing is provided by Noble Biomaterials Inc., together with Bemis Associates. They offer Circuitex, a fully bonded, conductive material that allows detection, transmission and protection of electronic signals in a soft and flexible format. Designers can use it to design smart garments with integrated stretch and durability using Bemis Sewfree Bonding.

Circuitex is made by permanently bonding pure silver to the surface of a textile fibre or fabric. The bond creates a continuous layer of silver, yet retains the flexibility, comfort and durability of the textile material. Products using Circuitex can provide myriad data streams (ECG, EMG, strain, pressure mapping), as well as allowing for active power delivery (lighting, electro-muscle stimulation, basic power).

Smart Jewellery

Smart jewellery is another wearable alternative for those wishing to look fashionable rather than techie, while enjoying the benefits that technology can bring. One example of this is Senstone , which has the appearance of a gemstone pendant, yet functions as a portable voice recording assistant. It allows users to calendar events, create reminders, take notes or make any other voice recordings. The voice recordings are converted into text and organised for easy access. It allows for more spontaneity than a smartphone or jotter pad, because it can be activated by a touch of a button. This means users can concentrate on what’s being said without being by distracted by setting up a recording device, or by writing. It can also be used to send messages to other team members.

The device can act in standalone mode, recording for up to 2½ hours offline. It automatically syncs when back in range of the user’s smartphone, using BLE wireless. It supports iOS, Android and third-party applications as well as using cloud-based AI systems for analysis. A lithium (LiPo) battery with 80 mAh capacity provides up to four days of average use.

As fashion items, the Senstones are available as pendants, clips or watches. Cases can be clear brass, chrome-plated brass, or white, grey or black anodised aluminium.

Smart tattoos

Wearable technology is now beginning to appear in the form of smart tattoos, or sometimes stickers. One example from Massachusetts-based MC10 is their BioStamp Research Connect , a sticker which attaches directly to skin and provides data to medical researchers. It helps investigations into problems with movement, motor skills and other neurodegenerative disorders. The sticker contains an accelerometer, a gyroscope, a mini ECG, and the ability to measure the electrical signals produced by skeletal muscles.

Smart tattoos can be used for convenience and connectivity as well as medical monitoring. DuoSkin , for example, is a fabrication process that attaches customised functional tattoos directly to skin, using gold metal leaf. Three types of on-skin interfaces are available: sensing touch input, displaying output, and wireless communication. This process draws from the aesthetics found in metallic jewellery-like temporary tattoos to create on-skin devices which resemble jewellery.

DuoSkin devices allow users to control their mobile devices, display information, and store information on their skin while serving as a statement of personal style. DuoSkins can store and share data with a smartphone or other such device via near-field communication (NFC) technology. DuoSkin’s touch input technology converts the skin into a trackpad for activities such as adjusting a smartphone’s volume, turning on lights, or writing text. The tattoo shows information as well, including mood and the weather.

Virtual reality and headsets

The wearable devices we have looked at so far have a common theme. Apart perhaps from making fashion statements, most devices seek to minimise their own impact on their wearers; by being unobtrusive as possible, they maximise their ease of use and the benefits they bring.

However, there is another class of wearable devices, designed with a very different intention; virtual reality systems and the headsets for them. Their entire purpose is to take over the user’s attention and provide them with a totally immersive experience. Gaming provides a primary market for such systems, as they allow players to disconnect from the humdrum realities of everyday life and enter the more exciting worlds engineered by the games’ designers.

Yet VR systems developed for gaming are being employed to great benefit in many other applications as well. We can provide some context for this by discussing one well-known, higher-spec system – the Oculus Rift – in terms of its specification and some of the applications where it can now be found.

The Rift has a Pentile OLED display, 1080×1200 resolution per eye, a 90 Hz refresh rate, and 110° field of view. It has integrated headphones that provide a 3D audio effect and rotational and positional tracking. The positional tracking system, called "Constellation", is performed by a USB stationary infrared sensor that picks up light that is emitted by IR LEDs that are integrated into the head-mounted display. The sensor normally sits on the user's desk. This creates 3D space, allowing for the user to use the Rift while sitting, standing, walking, or even jumping around the same room.

This technology is sometimes called room-scale VR, because it allows users to physically move around within a clear space, rather than remaining seated or standing in a fixed position. This real-world movement makes the virtual environment seem more real.

The Rift system runs on a PC with reasonably modest requirements; an Intel Core i3-6100 or AMD FX4350, Nvidia GTX 960 or Radeon R9 290 and 8GB of RAM.

Fig. 1: Oculus Rift headset – Image via Wikimedia Commons

The Rift provides its gaming experiences through software such as Lone Echo or Robo Recall. Robo Recall is an excellent example of engaging with the world around you, fighting robots and firing at artificial opponents. Lone Echo, though, takes a different tack; it eases players into a life of navigating around a zero-gravity environment for a very pleasant immersive feeling.

However, Oculus also provides an ‘Oculus for Business’ bundle that includes hardware, accessories, dedicated service, and expanded warranty and licensing terms. Oculus believes that the more interactive your customers’ digital experiences are, the more memorable and rewarding they will be.

Clearly, other business developers and designers think so too. The Ford Motor Company employs virtual reality in its Immersion Lab to help understand how customers experience their cars . They use Oculus Rift headsets to look at high-definition renderings of car interiors and exteriors. They've also developed prop-like tools, such as a flashlight, to be used in the VR simulation to create the experience of looking around a car in the dark, for example. All of this allows Ford to move ahead with the product development process without having to wait for physical prototypes.

In a tourism application, Marriott Hotels has created a "teleporter" which lets users step into a booth, wear an Oculus Rift headset and visit downtown London or a beach in Hawaii. The teleporter also caters to other senses, so users can feel wind in their hair and sun on their faces.

The Oculus Rift’s realistic VR capabilities are useful for architecture, as well. It is being exploited by Arch Virtual , specialists in creating 3D environments specifically with virtual and augmented reality in mind. They developed a Virtual Warehouse based on the Oculus Rift headset for Wessels, manufacturer of pressure tanks. The Virtual Warehouse, when used at trade shows, enabled people to feel as if they’re standing in their warehouse – eliminating the need to actually transport tanks that could be two storeys high.

Arch Virtual’s founder, Jon Brouchoud, envisions a VR future where allowing for a unique, bespoke experience not dissimilar to that seen in Christopher Nolan's Inception: "The holy grail is that architects and designers will be able to create in an iterative way, within the building. Making decisions, reaching out and moving walls in real time."

Possibilities for wearable device development

Wearable product designers can initiate a new development project at a couple of distinct levels; they can either buy in a set of chips, passives and other components, and integrate them using hardware design effort, or they can buy in a device that’s more or less complete in terms of hardware, and just needs coding to generate a marketable product.

The spectrum of ‘more or less complete’ devices shades into development kits, as will be evident from the examples currently available from Farnell and shown below.

Ready-integrated product: MBIT-WEARIT

MBIT-WEARIT is a development kit that allows prototyping of a wearable fitness tracking device through coding the ARM Cortex-M0 processor within a BBC micro:bit. The kit includes a micro:bit enclosure, two wrist straps, lanyard, keyring, cable and two AAA batteries as well as the micro:bit. It supports Bluetooth Smart Technology over-the-air programming.

Fig. 2: MBIT-WEARIT development kit

Development Kit, Hexiwear Wearable Device, Kinetis K64 MCU, Advanced NXP Sensors, Blue Top Glass

Hexiwear is a wearable development kit for the Internet of Things; a small and sleek, low-power device packed with sensors to quantify yourself and the world around you. Wirelessly enabled, it can connect both to nearby devices or distant cloud servers.

Although the Hexiwear is described as a development kit – and can be used as one – it is a ready to use device with display, BLE connectivity, sensors, buttons, and battery. However, its functionality can be expanded with ‘Click’ boards, and software development is facilitated with a mikroC PRO for ARM compiler, over 500 libraries, and access to all Hexiwear source code.

Developed in collaboration with NXP Semiconductors, Hexiwear is chiefly aimed at developers who need a complete IoT toolkit – low power yet versatile hardware, compatible smartphone and iOS apps, and cloud connectivity. Hexiwear is completely open source.

Fig.3: Hexiwear wearable device development kit

Reference Design Board, Wearable, Galvanic Skin Response System

GSR measurement detects human skin impedance under different situations. The MAXREFDES73# reference design is a wrist-worn GSR measurement device that monitors both skin impedance and temperature on a user’s wrist. With a mobile device for Android, a user can monitor his or her skin resistance and temperature within 20m through the BLE wireless interface. GSR devices can be used in medical treatment, lie detection, and wellness monitoring.

Fig.4: Wearable, galvanic skin response system

Evaluation Kit, MAX30100 Pulse Oximeter & Heart-Rate Sensor IC, For Wearable Health Devices

The MAX30110 evaluation kit (EV kit) allows for the quick evaluation of the MAX30110 and MAX30112 optical AFE for applications at various sites on the body, particularly the wrist. MAX30110 supports a standard SPI compatible interface, whereas the MAX30112 supports an I2C compatible interface. The EV kit allows flexible configurations to optimize measurement signal quality at minimal power consumption. The EV kit helps the user quickly learn how to configure and use the MAX30110 and MAX30112.

Fig.5: Evaluation Kit, MAX30100 Pulse Oximeter & Heart-Rate Sensor IC

Wireless power transmitter and receiver evaluation boards

The STEVAL-ISB038V1 evaluation board contains a STWLC04 & STWBC-WA Wearable Wireless Power Transmitter & Receiver, while the STEVAL-ISB038V1R Evaluation Board comprises a STWLC04 Wearable Wireless Power Receiver.

Development board: WARP7 Next Generation IoT and wearable platform, Linux and Android OS

WaRP7 speeds and eases development of wearable devices by addressing technology challenges and freeing developers to focus on creating differentiated features. The platform comprises a main board and a daughter card. The main board is based on the NXP i.MX 7Solo applications processor that features an advanced implementation of the ARM® Cortex®-A7 core, as well as the ARM® Cortex®-M4 core. This unique heterogeneous multicore architecture enables low-power modes critical for most wearable designs, but also provides the power to drive a higher-level operating system and a rich user interface. The daughter card is based on a flexible design with sensors to collect a range of data and the MikroBus™ expansion socket opens users to over 200 Click Boards™, allowing rapid prototyping across all potential wearable usage models.

Fig.6: WARP7 IoT and Wearable platform development board

Wearable device component: RSL10 Ultra-low-power multi-protocol Bluetooth 5 radio system-on-chip (SoC)

RSL10 is an ultra-low power, highly flexible multi−protocol 2.4 GHz radio specifically designed for use in high−performance wearable and medical applications. With its ARM® Cortex®−M3 Processor and LPDSP32 DSP core, RSL10 supports BLE technology and 2.4 GHz proprietary protocol stacks, without sacrificing power consumption. It supports Firmware over the air (FOTA) updates.

Fig.7: ON Semiconductor RSL10 RF Transceiver

Conclusion

In this article, we have seen how the general term ‘wearable devices’ has expanded to mean smart clothes, jewellery, tattoos and headsets as well as wristwatch/bracelet type devices. Users range from patients who need the technology to manage and report on their medical conditions, to users who are willing to invest in the equipment to improve their fitness levels. Especially where headsets are involved, many further virtual reality and augmented reality implementations, not only for entertainment, but also for business, training, architecture and other visualisation applications, are increasingly appearing.

Another trend is that, as sensors and the data they generate grow in volume, artificial intelligence strategies are finding a place in analysing the data, spotting trends, learning from them, and presenting summarised, actionable information to the devices’ managers.