A New Era of Wearable Tech

Jon Gabay for Mouser Electronics

When considering wearable technology, our minds often gravitate toward watch-like gadgets. Yet, numerous other tech tools satisfy the criteria for wearables.

Historically, technology has often been employed to safeguard individuals, amplify sensory capabilities, and compensate for limitations. However, modern wearables are broadening the horizons of human betterment, wellness, and fitness. Presently, there is a proliferation of wearable technologies that focus on health management and data accessibility. Yet, the next phase of wearable tech will move beyond essential medical monitoring to embrace human augmentation.

Let’s explore wearables technology, starting with the early days of wearables.

Earliest Wearables

While many of today's wearables aim for style and comfort through watches, rings, pendants, wristbands, and implants, earlier iterations did not place comfort and convenience as the primary factor in technology that humans wear. Millennia ago, a soldier's helmet was considered a high-technology device that, for the first time, let soldiers survive head blows that would otherwise hinder an unprotected soldier. Even eyeglasses were once the wearables of the times, improving the ability to learn and contribute to society.

While armor and eyeglasses can be thought of as passive wearable technology, mechanized wearables have also advanced society. Mechanized wearable technology arose in the early 1500s with the birth of the pocket watch, providing industry and ordinary humans easy and accurate access to time measurement—access that was (and still is) important for scheduling and manufacturing. Through the new technology, processes from smelting metals to baking bread could be refined more accurately. The introduction of the wristwatch did the same for even more of the population. Modern technology has built on these advancements and taken wearable technologies to new levels.

Let’s see how far we’ve come.

Today’s Wearables

Unlike the examples of static armor or mechanized technology, today’s wearables are electronic. Because of the widespread and low-cost manufacturing of devices like microprocessors, displays, and sensors, more people now have relatively low-cost and easy access to the benefits of these devices.

Many modern wearable devices are used for health and fitness, but some provide seamless access to information technology and communications. Both uses are actively marketed, and the once-mechanized wristwatches have been made more aesthetically appealing via modern displays and touchscreens.

Watches made famous by leading electronics manufacturers provide easy-to-read and customizable displays of time, date, calendar alerts, and message alerts, along with audio and video and much more. As technology improves, wearable devices will significantly affect how we interact with machines. But to most, health is still the driving factor.

Health and Fitness Monitoring

Advances in accelerometer technology are primarily driving the use of health and fitness monitoring devices. Accelerometers enable step counters to track steps; they’re also implemented in watches, bands, pendants, rings, and all other wearables we can think of today.

While rings traditionally have not offered as much functionality as watches and bands, wireless communications allow them to monitor the perfusion index (how well blood circulates), heart rate variability, sleep times and levels, blood oxygen levels, and even stress (Figure 1). With an integrated accelerometer, they can also be used as step counters.

Figure 1: While watches and wristbands are mostly used for wearable technologies, rings are becoming more popular, especially as display technology makes their information more accessible. (Source: P.S/stock.adobe.com)

While a good indication of motion, step counters cannot accurately relay exercise intensity and burned calories. A step counter will count steps but will not differentiate walking or jogging on a flat surface as opposed to stairs, hills, and inclines. This accuracy issue could be overcome when combined with GPS technology, but current GPS technology is not accurate enough to detect altitude with any degree of certainty.

Smartwatches and fitness trackers are the most widely used wearables. Fitness trackers often lack displays but can count steps, track calories, and record sleep patterns, as well as measure heart rate, blood pressure, and skin resistance (sweat, stress, and exertion levels).

Sleep patterns are the most critical monitoring function for many people, especially those with sleep apnea. For the first time, people can monitor and track sleep patterns without costly and inconvenient sleep study facilities. Sleep monitoring can also be critical for young babies since a wearable wrist device can detect if a baby stops breathing.

Another useful application of accelerometer-based fitness trackers is to measure when and if someone has fallen. This is particularly important with older people and the aging population. While the older wireless buttons that can be activated after a fall have saved many lives, these will not alert help if the user is unconscious. However, the wireless communications between watches, pendants, rings, and even pocket wearable devices can alert emergency contacts when a fall occurs. The technology can also help track patients with Alzheimer's or other forms of dementia, helping facility staff ensure their safety while moving around the building.

More sophisticated medical devices are also positioned to help save and extend lives. While more expensive than the $20 to $100 wearable devices, wearable medical devices go beyond monitoring heart rate, detecting and logging cardiac events. With wireless access to global networks, remote doctors, or even cloud-based services, these devices can upload data periodically or even in real time to alert monitoring staff of any incidents.

Another widely used wearable medical technology is the patch. While, for the most part, patches dispense medications at a pre-determined rate, many embed active electronics that monitor physiological conditions through the skin to control the introduction of drugs. Similarly, wearable electrostimulation technology has been used for years. Here, peel-and-stick disposable electrodes can attach around muscles and painful areas, delivering minor, periodic electric surface shocks that can override deeper internal pain mechanisms to provide relief.

The next big trend in medical wearables will likely be implanted sensors. Embedded technology can more accurately dispense medication as needed with smart patches, wearable watches, rings, pendants, and wristbands. Implanted sensors can communicate with active patches that dispense precise amounts of medication on command.
Subdural and Implantable Wearable Technology
Some may consider medical implants a futuristic technology, but medically implantable devices have been around for decades. The first pacemaker was implanted in 1958, and since then, the technology has steadily improved, including defibrillators that can restart the heart.

As with wearable sensors, implanted sensors have steadily increased in popularity. Modern implantable sensor technology can monitor blood sugar levels, tissue and bone regeneration, hypertension, arrhythmias, nerve stimulation (like cochlear implants and intraocular lenses), and even dispense insulin, intrauterine contraceptives, and other medications as needed.

While devices like insulin pumps and pacemakers are surgically inserted, new technology makes injectable medical implantable devices possible. These injectable sensors can communicate wirelessly outside the body. A technology called Quantum Dots can even store personal medical information.

A big market for these injectable sensors is monitoring prosthetic devices to improve functional myoelectric control. Motor neuroprosthetics are expected to increase as knee, hip, and other replacement joints become more widespread (Figure 2). Feedback sensors detect joint angles, skin contact pressures, and tissue strain.

Figure 2: Implanted sensors can aid in the use of prosthetic limbs for both control and sensory feedback. (Source: Gorodenkoff/stock.adobe.com)

Implants are also being used for non-medical applications, such as inserting RFID technologies under the skin. The RFID technology can operate entirely from RF energy supplied by an external reader, allowing nonvolatile storage of information that could be used as medical alerts. Some people have even implanted RFID devices that allow them to unlock their cars and homes. With subdural RFID technology, people can become credit cards to help combat identity theft.

Brain Implants Overcome Shortcomings
Brain implants, also called neural implants, connect directly to the brain and other nerve cells (Figure 3) and can be used for applications such as alleviating the conditions of Parkinson's disease or stimulating the vagus nerve to help control digestion and heart rate.

Figure 3: Brain implants have already been performed and can monitor neural firing, stimulate nerves, and provide sensory information directly to the brain. (Source: ktsdesign/stock.adobe.com)

Several of these types of medical implants have helped countless numbers of people gain improved hearing and vision. There have even been cases where integrated circuit technology has been successfully implanted to allow those with color vision deficiencies to see and differentiate colors.

The range of human sensory organs can also be extended using these implants—for example, extending the field of vision into the infrared and ultraviolet spectrums is now possible. Hearing implants can also extend the hearing range and apply specific filters that allow users to hear stimuli that fall outside of the typical range of human detection. This can be done using wearable hearing aids as well.

More recently, more sophisticated implants have demonstrated the ability to use computers and compose text from brainwave decoding. These technologies can be life changers as motorized artificial limbs and joints can be controlled using thought patterns.

And with the advent of implantable AI processors that can learn complex brain-firing patterns, it is possible to communicate with prosthetic and bionic limbs by thinking of shapes and colors. With enough processing and DSP functionality, implanted processors could pass neural messages across severed nerves, allowing the sensory nerve messaging (e.g., hot and cold sensations, touch) to pass.

Optimizing Processor Cores and Peripherals for Advanced Wearable Technology

Despite space limitations, external wearable technology can incorporate a wide array of processors, depending on the preferences of design engineers. With numerous powerful and multicore processors available, selecting the optimal combination of processor cores and peripherals is crucial for matching the ideal processor to the appropriate wearable device.

Meeting that need are the i.MX RT5000 crossover microcontrollers from NXP Semiconductors, a world leader in secure connectivity solutions for embedded applications. These microcontrollers feature a blend of processor cores and peripheral interfaces specifically tailored for wearable designs, offering a comprehensive solution for a variety of applications.

The i.MX RT5000 is equipped with a 2D graphics engine GPU that boasts vector graphics acceleration using a high-speed parallel interface. A MIPI Serial Display Interface (MIPI DSI®) is also integrated into the chip for seamless interfacing with serial display modules. The on-chip LCD interface allows for swift customization of wearables to leverage TFT, OLED, micro-LED, and even emerging quantum dot display technologies.

The i.MX RT5000 series also incorporates a robust 200MHz Arm® Cortex®-M33 processor core designed to provide real-time responsiveness. This feature works with the 5MB on-chip zero wait state SRAM, ensuring that critical code remains readily accessible while minimizing lag time from data movements.

Furthermore, a Cadence Tensilica Fusion F1 DSP core operating at 200MHz can manage signal processing data from various external sensors. These sensors can detect chemical levels, such as sugar or hormone concentrations, or monitor nerve activity for sensation transmission or pain mitigation.

To implement functions like direct muscle stimulation and electrical pulses, multiple interfaces are required to facilitate communication with sensors and actuators. These interfaces enable mechanized prosthetics to interact with muscles, restoring control and mobility. The i.MX RT5000 includes high-speed USB 2.0, SPI, I²C, UART, and I²S interfaces, which can connect sensors and stimulators and wireless communications modules. This adaptability allows wearables to evolve alongside wireless protocols.

The i.MX RT5000 also features multiple flash interfaces, cryptography, and math accelerators for implementing complex dynamic security algorithms. Ensuring the security of medical data and body interfaces is paramount to prevent unauthorized access to devices like pacemakers. Advanced security support enables secure communication with external phones or networks, including asymmetric cryptography, AES 256, and SHA2-256 (ECC and RSA). Secure boot and physically unclonable function (PUF)-based key storage are also integrated. Advanced energy management minimizes energy consumption, and a fusible link protects root key storage.

Conclusions

In under 60 years, we have gone from extensive, surgically inserted technology to subdural and injectable medical monitoring and administration technology. Not only have these innovations saved and extended lives, but they have also improved the quality of life and made caregivers and medical practitioners able to care for more people at reduced costs.

The reduced size of integrated circuits and lower-power semiconductor technologies have permitted more sophisticated and safe technologies to be worn and implanted. While this article did not discuss clothing as wearable technology, clothes can also benefit the population but with challenges such as maintaining functionality after washing and drying.

The NXP i.MX RT5000 is an ideal processor for next-generation wearables. A mature development environment is ready to use, and several application notes help guide you through AES encryption, DSP examples and usages, power management, and implementing secure I/O.

Looking forward, expect to see more active wearable and injectable devices. Smart patches will simplify the automated dispensing of medications, especially when coupled with implanted sensors. The ability to use RFID to identify and verify may help curb identity theft, too. We talk a lot about the medical benefits of wearables, but once we become part of the machine, the possibilities are limitless.