An interdisciplinary team of engineers at the University of Arkansas
has developed a wireless health-monitoring system that gathers critical patient
information, regardless of the patient’s location, and communicates that
information in real time to a physician, hospital, or the patient herself.
The system includes a series of nanostructured, textile sensors integrated
into a conventional sports bra for women and vest for men. Via a lightweight
and wireless module that snaps onto these garments, the sensors communicate
with system software that relies on a smart phone to collect information,
compress it and send it over a variety of wireless networks.
“Our e-bra enables continuous, real-time monitoring to identify any
pathophysiological changes,” said Vijay Varadan, Distinguished Professor of
electrical engineering. “It is a platform on which various sensors for
cardiac-health monitoring are integrated into the fabric. The garment collects
and transmits vital health signals to any desired location in the world.”
The system monitors blood pressure, body temperature, respiratory rate,
oxygen consumption, some neural activity, and all the readings provided by a
conventional electrocardiograph (ECG), including the ability to display
inverted T waves, which indicate the onset of cardiac arrest. The system does
not require a cuff or any extra accessories to measure blood pressure and could
therefore replace conventional blood-pressure monitors. It could also replace
the cumbersome combination of ECG sensors and wires attached to patients while
they walk on treadmills.
The sensors, which are smaller than a dime, include gold nanowires, as well
as flexible, conducting textile nanosensors. The sensors are made of arrays of
gold nanoelectrodes fabricated on a flexible substrate. The textile sensors are
woven into the bra material. These sensors do not require conventional sticky
electrodes or the use of gel.
Electrical signals and other physiological data gathered by the sensors are
sent to the snap-on wireless module, the contents of which are housed in a
plastic box that is slightly smaller than a ring box. As the critical wireless
component, the module is essentially a low-powered laptop computer that
includes an amplifier, an antenna, a printed circuit board, a microprocessor, a
Bluetooth module, a battery and various sensors. The size of the module depends
heavily on power consumption and minimum battery size. Varadan said that
anticipated battery and Bluetooth upgrades will allow the researchers to build
a smaller—1.5 in long, 0.75 in wide, and 0.25 in deep—lighter and flexible
module that will replace the rigid box.
Data from the sensors then stream to commercially available cell phones and
handheld devices, which expand the use of the system beyond health care. By
carrying a cell phone, athletes can monitor all signs mentioned above and other
metrics, such as number of calories burned during a workout. To render clean
data, the software includes filtering algorithms to mitigate problems due to motion
of the hand-held device during exercise.
Whether on a computer or cell phone, the software is set up so that users
can view all data on one screen or window, or they can view each measurement on
its own unique window. The software also includes a global positioning system
that tracks the exact latitude and longitude of the patient or athlete. The
geographic information is transferred to a cloud cluster and stored in a
secured database that doctors or other health-care personnel can access to view
location of the patient as well as historic or real-time ECG data. The system
can also be programmed to send emergency messages, via voice or text messaging,
if it detects extreme or abnormal conditions.
