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Figure 1. low power siliconlabs
sensors would be used to monitor
vital signs such as heart rate, blood
pressure and respiratory rate, in the
case of patients who have suffered
congestive heart failure or are
considered high risk for a heart attack.
If a patient has had a stroke or is
suffering from mobility issues either
leading up to or post hip-replacement
surgery, accelerometers and similar
motion sensors can be deployed
around the body to ensure they
are moving well and also to alert
emergency services if they suffer a
fall. Researchers have also found that
in the case of rehabilitation, they get
a better sense of the effective mobility
of a patient if they can determine how
well a patient climbs and descends
stairs and gets out of a chair rather
than simply walking across a doctor’s
surgery.
Wearable IoT goes far beyond
treatment of medical conditions. It
can help reduce injury and boost
wellness. People who wear simple
exercise-monitoring wristbands find
that working out how many steps
they have taken that day changes
their behaviour. GPS-enabled sports
watches are already in widespread
use by athletes, amateur and
professional alike. The same IoT
technology proposed for medical
sensors can be used to prevent injury,
such as damage to knees caused by
bad running posture, through the use
of accelerometers worn on the legs,
perhaps sewn into a pair of leggings.
Similar sensors incorporated in a vest
could help prevent the poor posture
that leads to back pain. In these cases,
exercise programs in a smartphone or
tablet would advise interactively on
better ways to run or sit and warn the
user that they are slipping into bad
habits when they lose concentration.
The sensors used for wellness
need not be entirely wearable. For
people suffering from debilitating
conditions such as dementia that
threaten to remove their ability to live
independently, sensors and displays
placed around the home can help
them. The sensors detect what kinds
of activities the occupant is trying to
perform and can present reminders
and help on the displays as they move
around their home.
The unifying theme behind these
different applications is that of
intelligent sensor fusion. Smart
sensors wirelessly relay data about
changes in circumstance to a
monitoring unit which assimilates
the incoming information and makes
decisions on what to do next. For
example, a sudden change in heart
rate flagged by one sensor may simply
be through additional exertion. But if
accompanied by difficulty breathing
picked up by another sensor may
trigger the monitoring unit to send an
alarm to a nearby medical specialist
over the cellular connection of a
mobile phone.
The key component technologies
therefore
are
low-power
microcontrollers and sensors that
either have built-in wireless support
or can communicate with low-power
RF devices that are able to fit in a
compact package. The key wireless
technologies for wearable and smart-
home applications are Bluetooth
Low Energy (BLE) and ZigBee.
Both are designed for low-energy
36 l New-Tech Magazine Europe