The Evolution of Medical Wearables
Image Source:
sitthiphong/Stock.adobe.com
By Jon Gabay for Mouser Electronics
Published December 28, 2022
When we think of wearable technology, our minds tend to race toward watch-type devices. However, there are many
other technological devices that fit the “wearable bill.”
In the past, technology was used to protect people, enhance sensory abilities, and overcome shortcomings.
Newly-introduced devices are expanding the scope of human enhancements, health, and wellness. The most recent flurry
of wearable technologies involves health maintenance and information access; as for the future, we will be moving
beyond mere medical monitoring and toward human augmentation.
Let’s explore by taking a brief walk through the early days of wearables.
Earliest Wearables
While many of today’s wearables aim for style and comfort in the form of watches, rings, pendants,
wristbands, and implants, earlier iterations (really, really old) have not placed comfort and convenience as the
primary factor in technology that humans wear. Many years ago, a soldier’s helmet was considered a high
technology device that for the first time let soldiers survive head blows that would otherwise incapacitate 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 also advanced
society. Mechanized wearable technology arose in the 1600s with the birth of the pocket watch, providing industry
and ordinary humans easy and accurate access to time measurement. This access is still important for scheduling and
manufacturing. Processes could be refined more accurately for anything from smelting metals to baking bread. The
wristwatch did the same for even more people, but 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 static armor or mechanized technology, today’s wearables are electronic. Because of the widespread and
low-cost manufacturing of devices like microprocessors and sensors, more and more of the population now have
relatively low-cost and easy access to these devices' benefits.
Many of these wearable devices are used for health and fitness. However, others can 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. 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
Accelerometer advances are primarily driving health and fitness monitoring devices. Step counters use
accelerometers to track steps. They’re also implemented in watches, bands, pendants, rings, and all other
wearables we can think of today.
While rings have traditionally not offered as much functionality as watches and bands, wireless communications
allow them to monitor the perfusion index (how well blood circulates), heart rate, 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. (Image Source:
P.S/stock.adobe.com)
While a good indication of motion, step counters are not accurate regarding exercise intensity and calories burned.
A step counter will count steps but will not differentiate walking or jogging on a flat surface as opposed to
stairs, hills, and inclines. When combined with GPS technology this accuracy issue could be overcome, but modern-day
GPS is still not accurate enough to detect altitude with any degree of certainty.
Smartwatches and fit bands are the most widely used. Fit bands have no or limited displays, count steps, track
calories, measure sleep patterns, and measure heart rate, blood pressure, and skin resistance (sweat, stress, and
exertion levels). But there are also some sleep benefits to these wearables.
Sleep patterns are the most important monitoring function for many people, especially those with sleep apnea. Links
to heart conditions and decreased health have been attributed to sleep apnea, and for the first time, people can
monitor and track sleep patterns without the 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. Sudden Infant
Death Syndrome (SIDS) can be eliminated with the use of this technology.
Another useful application of accelerometer-based fitness trackers is to measure when and if someone has fallen.
This is particularly important with the elderly and with an aging population. While the older wireless buttons that
can be activated after a fall have saved many lives, if someone is unconscious, these will not alert anyone.
However, the wireless communications between watches, pendants, rings, and even pocket wearable devices can alert
emergency contacts when a fall occurs. The same technology can be used to detect if someone is in a car crash.
Related to this is the ability to track wandering patients with Alzheimer's or other forms of dementia. Logging
movement within a building like an assisted living facility can alert staff when someone who is mentally impaired is
in a location they should not be at, at least unsupervised. This can be even more important when a mentally impaired
person wanders into a stairwell that is not traversed as often as other corridors or passages.
While more expensive than the $20 to $100 wearable devices, more sophisticated medical devices are also positioned
to help save and extend lives. Instead of just monitoring heart rate, wearable medical devices have been used to
detect and log cardiac events. These cardiac events don't typically happen in a doctor's office and are often missed
and not diagnosed because accurate EKG waveforms are unavailable. Now they are. With wireless access to global
networks, remote doctors, or even cloud-based services, these devises can upload data periodically or even in
real-time to alert that an incident is happening.
Patches can be considered wearable medical technology, too. While for the most part, patches just dispense
medications at a pre-determined rate, active electronics embedded into patches monitor physiological conditions
through the skin to control the introduction of medications like pain relief.
Wearable electrostimulation technology has also been used for years. Here, 'peel and stick' disposable electrodes
can attach around muscles and painful areas. Little periodic electric surface shocks can override deeper internal
pain mechanisms and provide relief.
The next big wave will be implanted sensors. Combined with smart patches, wearable watches, rings, pendants, and
wristbands, implanted technology can more accurately dispense medication as needed. Implanted sensors can
communicate with active patches that dispense precise amounts of medication on command. What's more, it is much
easier to replace a patch than to refill an implanted insulin pump, for example.
Subdural and Implantable Wearable Technology
Most people consider medical implants a more 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-day 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 in monitoring prosthetic devices to improve functional myoelectric
control. Motor neuro-prosthetics 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. Multipoint topologies are becoming the dominant technology for this as wired star topologies are phasing
out. This delves into bionics, which can enhance normal human strength and reflexes.
Figure 2: Implanted sensors can aid in the use of prosthetic limbs for both
control and sensory
feedback. (Image Source: Gorodenkoff/stock.adobe.com)
Implanted hormonal and brain chemistry sensors are also emerging to help those with mental conditions remain
medicated. It's possible for those who stop taking their medications to become more agitated and violent. Automated
medication dispensing reduces the number of mentally unstable people.
Implants are also being used for non-medical applications. For example, people have been implanting RFID
technologies under their skin. The RFID technology, like generation II, can operate entirely from RF energy supplied
by an external reader, allowing nonvolatile storage of information that could be used as medical alerts. Or even to
unlock their cars and houses.
Brain Implants Overcome Shortcomings
Brain implants, also called neural implants, connect directly to brain and other nerve cells and can be used for
various applications (Figure 3). Some of these are beneficial, like alleviating the conditions of
Parkinson's disease or Vagus nerve stimulation 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 hearing or vision-impaired people.
There have even been cases where integrated circuit technology has been successfully implanted to allow those who
are otherwise color-blind to see and differentiate colors.
The range of human sensory organs can also be extended using these types of 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 implanted people to hear things ordinary people cannot hear.
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, allowing amputees to live more traditional, unassisted lives.
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. Visualizing a yellow triangle, for
example, can command a prosthetic arm to move.
Conclusions
In under 60 years, we have gone from large, surgically-inserted technology to subdural and injectable technology
for medical monitoring and administration. Not only have these innovations saved and extended lives, but they have
also improved quality of life and made caretakers and medical practitioners able to care for more people at reduced
costs.
The reduced size of integrated circuits, coupled with lower-power semiconductor technologies, has permitted more
sophisticated and safe technologies to be worn and implanted. While we did not discuss clothing as wearable
technology, clothes can also benefit the population, but these come with other challenges like surviving washing and
drying.
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. As chemical sensors advance,
overcoming mental disabilities may even help curb the violent tendencies of those who commit violent actions.
Combine this with RFID to identify and verify, maybe we can 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.
Author Bio
Jon Gabay is a
contributing writer for Mouser Electronics. Jon Gabay is a mad scientist with no hostility. He doesn't want to rule
or blow up the world. He wants to make it a better place. Studying electrical engineering, he has worked with
defense, commercial, industrial, consumer, energy, and medical companies as a design engineer, firmware coder,
system designer, research scientist, and product developer. As an alternative energy researcher and inventor, he has
been involved with automation technology since he founded and ran Dedicated Devices Corp. up until 2004. Since then,
he has been doing research and development, writing articles, and developing "Gizmo Blocks" for next-generation
engineers and students.
