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Respisense™ was conceived early in 2003 when the inventor's triplets
were born. Because they were born prematurely (raising the probability
of apnoea) and the little girl had suffered apnoea episodes while in
the neonatal unit, their parents appreciated the advantages of using
breathing monitors. Because of the inherent advantages the triplets'
parents had them sharing a cot for their first six months and wanted a
breathing monitor that could work in such a set-up. Nothing of the
sort was available at the time, so their father designed the unique
Respisense™. Over the following two and a half years he developed the
design with his newfound colleague and friend, Greg Gallagher.
A mother's wish
list found on the Internet provided a useful reference and the
motivation for the TummyTickle™ breathing stimulator:
-
It should not cost much more than
a regular baby monitor. Poor babies get SIDS, too.
-
It should be small enough and
comfortable enough to wear that it does not wake up the baby, or
make the baby hot/sweaty/sticky/itchy. No one is going to want to
use a baby monitor that keeps the baby from sleeping. They will use
it if they know their baby has an apnea problem, but ideally,
this should be something all babies could wear easily. Because none
of us can be sure our baby doesn't have an apnea problem.
-
It also needs to be highly
portable (and battery operated). I like the mat idea mentioned in
prior posts, but what if the baby falls asleep in the car-seat,
stroller, baby-carrier or your arms?
-
Piercing alarms are scary. If
apnea is a somewhat common occurrence in infants, with only a
limited number of occurrences leading to SIDS, we could be dealing
with a lot of loud, terrifying alarms. It would be nice if after,
say 5 or 10 seconds of missing motion, a warning buzz would go off -
something just loud enough to disturb the baby into breathing
without waking him/her up completely."
-
S.G. Lueck, 6 May 2002
A working
proof-of-concept prototype was completed by October 2003, and between
then and early 2005 the model was refined and miniaturised to produce
the world's first and only perfectly portable, ultra-safe baby monitor
with proactive TummyTickle™ breathing stimulation; the only monitor of
its kind to satisfy all the requirements stated above.
Today the
triplets are healthy and growing up fast, and Respisense™ monitors are
being made available to other parents across the globe to help raise
their children safely.
Intrinsic
safety
The principle operation of the Respisense™ is similar to that used by
the traditional mattress-type monitors, although the implementation of
the principles into a more functional form is radically different and
the source of its numerous advantages over older designs.
The electronic
circuitry was shrunk dramatically by using "micro amp" technology;
circuit components that are very small and use exceptionally little
electrical current. Doing so enabled the developers not only to make
the unit about 30 times smaller and 20 times lighter than a monitor of
traditional design, but to increase its safety by eliminating all
wires and giving it a permanently sealed life-time battery. This
removed all hazards of limbs or necks caught in cables or straps,
batteries being swallowed or choked on, and babies being electrocuted
by mains connections. It also eliminated bad plug connections, the
source of many false alarms, and extended the usefulness of such
monitors by being able to accompany baby when he/she leaves the cot.
Mothers are no longer reminded too late to switch off the alarm when
they pick baby up, which often results in the whole household being
awakened in the dead of night just because she wanted to breastfeed,
and if mother should want to breastfeed in her bed, she no longer has
to worry that she might fall asleep during the process and so leave
her baby unprotected.
Making the
monitor smaller and placing it in contact with the baby also allows a
Respisense™ Buzz to stimulate breathing through gentle tactile
vibrations, and being so small and light (weighing a mere 30g, or 1oz)
allows the monitor to be used wherever baby may fall asleep. This
perfect portability, safety and proactive stimulation are unsurpassed
in the world of baby monitoring today.
Advanced
plastics
Respisense™ took the sensing design a step further by utilising piezo-electric
plastic rather than the traditional piezo-electric ceramic or crystal
elements, which are brittle. The material used is so sensitive that it
can measure a spider walking on it, yet so strong that it is used to
measure the forces expended on surfaces by explosions. The signals
generated by the sensor can be amplified a thousand times or more, but
because Respisense™ detects movements directly off a baby's tummy it
only needs to amplify the signal a few times to get a dependable
signal. This makes the unit less susceptible to extraneous noises,
such as those often picked up by traditional movement monitors from
ceiling fans and air conditioners. During the amplification stage the
circuit also filters the signals to those expected from breathing
movements, further eliminating extraneous noise. Finally, hooking a
Respisense™ onto a baby's nappy further isolates it from external
movements such as those caused by siblings sharing a bed. The design
has therefore also managed to eliminate most external sources of
erroneous operation (false negatives, which are dangerous). The shell
of a Respisense™ was made more durable than other monitors by using
safe but exceedingly strong plastics, the same kind of material used
for blast screens in the television programme "Mythbusters".
Further
improvements and extended safety
The amplified and filtered signal is continuously analysed by a
microcontroller, an integrated microcomputer circuit with built-in
memory, and various outputs (indicators, alarm and vibration motor)
switched on and off as needed. The batteries use environmentally
friendly Lithium Manganese Dioxide chemistry and are known for their
excellent power density and exceptionally long shelf life. These
specialised batteries can be replaced by Infantrust, and a
refurbishment service is available at a small cost to parents wishing
to extend the life of their Respisense™ monitors.
The idea of
using a little motor, the TummyTickle™ feature, came to the inventor
when he realised just how little effort is used to stimulate babies in
neonatal wards that suffer apnoea episodes: a nurse would usually
simply tickle the baby's feet or tummy. During our extensive patent
searches we did stumble upon a design patent that uses electrical
shock to stimulate a baby but realised that such a crude method would
not be acceptable to parents. Adding a little motor, like those used
to make cell phones vibrate, to do the tickling was a more
contemporary, and far more acceptable, solution. It is also more
effective than simple sound stimulation.
Even though
much of the Respisense™ technology is similar to that used by
traditional designs, apart from the additional features like the
TummyTickle™ stimulator it also contains some noticeable improvements.
In many traditional monitors for example the user needs to remember to
test the battery (also wasting battery power) and can often only know
that the reserves are depleted by a decreased alarm sound. In the
Respisense™ design the battery is periodically checked by the on-board
microcontroller, and when the battery nears the end of its useful life
the user will be warned in advance. Each monitor also runs a self-test
routine every time it is switched on, and has different alarms for
different situations. Such features make Respisense™ monitors more
sophisticated than traditional designs while still being very
affordable.
Testing
From our prototype that we had working in October 2003, every version
and model has been tested night after night on the inventor's own
triplets. When the final model was ready in early 2005 the developers
also tested these monitors on various babies from pre-term (26 weeks
gestational age) to 2-year olds. Testing was done to determine how
sensitive the units should be, how safe they are, what stimulation was
necessary to stir a baby, what delays (for example, between suspension
of breathing and stimulation) were practical and how loud the alarm
should be. Once we had the design finalised we supplied a number of
mothers and paediatricians with units and incorporated their feedback
into the design and the user manual - a strategy we'll be doing
continuously in the future. The design we now have has therefore been
through a test period of more than 2 years, although the most
important testing was done during 2005.
Respisense™ monitors were also tested in laboratories to determine the
toxic
safety and flammability of the plastics used, the susceptibility of
the monitors to external electrical noise, and the amount of radiation
they generate during operation. As was expected, all tests were passed
and the device earned the CE mark of safety accreditation from TUV
Rheinland Quality Services (www.tuv.com).
Throughout the
design and testing phases we were fortunate to be guided by a
prominent neonatalogist and head of one of South Africa's busiest
neonatal units, where babies with birth weights of little over 700g
routinely survive. He and his colleagues will also be involved in the
testing we have planned for the future, which includes further
clinical trials and the development of additional features.
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