Note: Descriptions are shown in the official language in which they were submitted.
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Device for Early Detection of Child Abduction or Wandering
FIELD OF THE INVENTION
The present invention relates to the field of personal monitoring and security
devices.
The present invention provides a device, designed to be worn by a child
walking to school or
playing outdoors, that continually monitors its surroundings to determine if
the child has
wandered outside a permissible zone or an abduction is imminent, and if so, to
generate an
alarm at a remote location wirelessly.
There are several commercially-available products that are wearable by a child
for the purpose
of location tracking, such as the AngelSense GPS Tracker and the Trax. These
products, have
several deficiencies. My objective of the present invention is to design a
device that provides
comprehensive real time child monitoring.
The device is not intended for tracking on monitoring while the child is in a
school bus or other
vehicle. It is also not intended for use when the child is far away (more than
a couple of
kilometers from the monitoring location), for example, when on a school trip
or at a summer
camp.
BACKGROUND
Every 40 seconds in the United States, a child goes missing or is abducted. In
80 percent of
abductions by strangers, the first contact between the child and the abductor
occurs within a
quarter mile of the child's home.
In Canada, there were 45,288 reports of missing children in Canada (in 2015)
as reported by
the RCMP. Of these, abduction by a stranger occurred in 24 cases. while there
were about 400
instances of wandering off. In the U.S., the National Center for Missing &
Exploited Children
(NCMEC) collects information about attempted abductions, short term "abduct
and release"
incidents and other types of suspicious incidents involving children.
According to the FBI, in
2015, there were 460,699 missing children reports. In 2016, NCMEC assisted law
enforcement
and families with more than 20,500 cases of missing children ( a small
fraction of the total
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number of missing children), of which about 1% were non-family abductions, and
approximately
90% were runaways.
The above statistics show that abduction by a stranger is a relatively rare
occurrence. A
wandering or runaway child is much more common. However, the parent's
inability to
differentiate between the two possibilities until the child is located
(usually within 24 hours) can
cause increased worry in the interim period. This is the reason why my device
focuses primarily
on abduction, but also tries to differentiate wandering events.
The statistics also show that early detection is key to a favorable outcome,
in both abduction
and runaway cases. This strengthens the case for my device, since it attempts
to generate an
alarm locally as soon as an abduction is detected.
A look at the Canadian abduction statistics over the past fifty years as well
as the statistics for
the U.S over the period from 2005-2015 reveals the following common trends
that can help in
designing the device.
= The abducted children were usually alone and of school-going age
= Their average age was around 10-11 years.
= In most cases, the victim was travelling between home and school, the
mall, a park or a
friend's house.
= Most of the abductions took place within blocks of the child's home or
school.
The above points show that the proposal to design a device for use close to
the home, or when
walking from home to the school, is sensible. Runaway children, on the other
hand, could
escape from any location such as a friend's house or the mall, for example.
Hence this device
can only detect unintentional wandering, such as a small child wandering off a
specified zone.
Its main purpose is to indicate, in the case of a child missing from near
home, whether or not
there is a reason to fear an abduction.
= Most often, the offenders used a vehicle of some kind in the abduction.
This indicates that my device must have some means of telling whether the
child has moved
into a vehicle.
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= Force was the top method used against children
This means that the device should have a means of detecting that the child is
no longer alone
and perhaps struggling or running.
= Children got away from offenders in a variety of ways, including ignoring
or refusing
them, using their cell phones to threaten intervention, fighting,
screaming/making noise,
child or adult intervention and, ultimately, by the offender or child leaving
the area or the
child being voluntarily released. Of these ways, screaming/making noise was
the only
child behavior that increased the likelihood of an offender's arrest because
it specifically
increased the chances of adult intervention
This is an important statistic that tells us that, in addition to sending a
remote alarm, the device
should also sound an alarm locally, so that the abductor would become aware
that an alarm has
been raised and abandon the attempt.
In view of the foregoing, the device should have:
= A way to obtain the child's location (to see whether off track or outside
perimeter) and
speed (to determine if child has entered a vehicle)
= A way to determine whether the child is alone or in proximity to another
person
= A way to determine whether the child is struggling or being dragged.
Based on these characteristics, it was determined that my device should
consist of a monitor
(transmitter) worn by the child, and a listener (receiver) located in the
home. The transmitter
should have the following components:
= A Global Positioning System (GPS) module to obtain location and speed
information
= An infra-red (heat detecting) sensor to obtain proximity information
= A tilt sensor to determine whether the child is upright or not (on being
dragged, the child
will likely be leaning).
= Audio and visual alarm generating modules.
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These components are readily available and are small and inexpensive. The
details of these
components will be described below.
As mentioned above, there are several commercially-available products with
similar
functionalities. These devices track location alone (through a GPS module),
and so cannot
differentiate between wandering and abduction events. The chief distinction
between these
products lies in how they send the tracking information to the parent's
smartphone:
1. Long-range devices
They use cellular service to monitor a child's location with no limitations on
distance from
the monitoring location, and are unaffected by intervening buildings. The
AngelSense
GPS Tracker and the Trax are examples of such devices. These devices require a
cellular data plan and hence can be expensive and time-consuming to setup,
especially
with more than one child or when travelling outside the local carrier zone.
They are also
unusable in remote locations without cellular service. Since the smartphone is
used as a
receiver, the alerts depend on the phone settings (speaker and airplane mode)
and
whether the monitoring app is running on the phone.
2. Short range (measured in feet)
These devices can monitor a child's location within a very short distance
(less than 50
meters) from the parent's smartphone. They use bluetooth or WiFi for
communication
with the monitoring station. The My Buddy Tag is an example of this class of
device.
These devices require no monthly fees and can operate in areas without
cellular service,
but can only operate in very close proximity to the home. Since the smartphone
is used
as a receiver, the alerts depend on the phone settings (speaker and airplane
mode) and
whether the monitoring app is running on the phone.
3. Medium-range (<3 Kms)
These devices can monitor a child's location when walking to school, for
example or
when visiting a park close to the house.They use radio-frequency (RF)
transmission to
transmit data to the monitoring location. They require no monthly fees, and
can operate
in areas without cellular service. They are very easy to setup. As far as I
could
determine, my device Garuda is the only example in this category. Since the
receiver is
proprietary, the audible and visual alarms are independent of any other
devices. Since
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the kidnapping detection happens on the device itself, alarms can be generated
to deter
the abductor. None of the other devices have this important capability.
Table 2 compares the device of the present invention with these other classes
of devices, from
the point of detecting abduction in the vicinity of home.
As mentioned, the monitoring system consists of:
= A mobile "monitor" module that is located on the person of the child, and
= A fixed "listener" module that displays the status of the various sensors
on the monitor
module.
The monitor module transmits information to the listener module wirelessly at
periodic intervals.
On detection of a potential abduction, the monitor module will sound an alarm
locally (in the
vicinity of the child), and when the listener module receives the alarm
information, it will
generate audible and visual alerts to apprise the guardian of the situation.
The specifications of the listener and monitor modules are derived from the
requirements that
they each need to satisfy.
In a broad aspect, then, the present invention relates to a device to be
carried or worn by an
individual to detect abduction or wandering, comprising a portable processor
and sensors to
detect heat, body position, location and/or acceleration, and a visual and/or
auditory alarm.
Drawings and/or photographs illustrating a prototype of the present invention
by way of
example, are attached hereto.
The requirements, and how these requirements are met by the present invention
are set out in
Table 1.
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TABLE 1
Requirement Specification
Must be wearable by child Tiny, portable, light-
weight
and battery-operated
Determine if abductor is Has a front and rear
infra-red
approaching from front or sensor that can detect
rear presence of nearby humans
Determine if child is being Has tilt sensor to
measure
dragged or carried whether the child is
upright
or not
Determine if child is outside Has a GPS sensor to
defined perimeter or far from determne current location
of
configured track child
Allows creation and storage
of custom perimeter or way-
point track using GPS-based
location
Has mechanism for detecting
track deviation and perimeter
violation
Determine if child is stopped, Has GPS sensor that can
walking, running or in vehicle provide speed information
Sound alarm locally with Has speaker to generate
audible and visual alerts to audible alarm
warn off the abductor Has flashing light to
indicate
an alert
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Communicate status Uses radio-frequency
periodically to listener communication to meet the
module located less than two distance requirement
kilometers away Has a radio-frequency
transmitter to send the
information to the remote
location
Receives information from Has radio-frequency
receiver
transmitter on monitor tuned to same frequency as
module transmitter
Sound alarm locally with Has speaker to generate
audible and visual alerts to audible alarm
warn off the abductor Has display to clearly
indicate status to
parent/guardian
TABLE 2
Invention Compared to other Devices
Property Long-range Short-range
Medium-range
Examples AngelSense, Trax MyBuddyTag Invention
Transmitter Proprietary Proprietary Proprietary
Receiver Standard Standard
Proprietary
(smartphone) (smartphone)
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Ability to use Only in areas of Anywhere Anywhere
anywhere cellular service
Cost Medium to high Low Low
Frequency 30 sec - 15 minutes Seconds Seconds
(of location update)
Abduction Detection None None Yes
Alarm None None Yes
(to discourage
abductor)
Alarm SMS/App App Audio/Visual
(to alert guardian) (Phone setting) (Phone setting)
Perimeter Circle Custom (Polygon) Custom
(Polygon)
Way-point deviation Long-term No
Immediate
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The device of the present invention comprises the following elements:
= Monitor module
= 1.5V Battery pack
= Plastic prototype box and printed circuit board (PCB)
= Speaker (audible local alarm)
= Light-emitting diode (LED) for status and visual local alarm
= RF Transmitter
= Programmable micro-controller (for storing way-points and algorithms)
= LCD display for showing status locally
= Power indicator light
= GPS Sensor
= Two infra-red motion detectors (front and rear)
= Tilt sensor
= Push-button for configuring track or perimeter way-points
Procedure
Unit testing
The following tests verify the behavior of the sensors and output devices in
isolation.
Push button
= Check that the LCD displays correctly show the correct speed status
message when
push-button is depressed for different periods
o SHORT press when depressed for less than three seconds
o MEDIUM press when depressed for 7-13 seconds
o LONG press when depressed for 17-24 seconds
o VERY LONG press when depressed for 30-50 seconds
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Perimeter configuration and violation check
= Turn on the power to the monitor and listener
= LONG press of the push-button (around 20 seconds) to clear all stored
locations
= MEDIUM press of the push-button (around 10 seconds) to start
configuration
= Move to the first location in the perimeter
o SHORT press of the push-button (1-2 seconds) to record its co-ordinates
o Verify the LCD displays at monitor and listener show one point stored
currently
= Move to a second location about 40 feet away
o SHORT press of the push-button (1-2 seconds) to record its co-ordinates
o Verify the LCD displays at monitor and listener show two points stored
currently
= Move to a third location about 40 feet away away from both the first and
the second
points so that a perimeter in the shape of a triangle is formed
o SHORT press of the push-button (1-2 seconds) to record its co-ordinates
o Verify the LCD displays at monitor and listener show three points stored
currently
= MEDIUM press of the push-button (around 10 seconds)to complete perimeter
configuration
o Verify that the LED light changes from green to blue
= MEDIUM press of the push-button (around 10 seconds) to start monitoring
location
o Verify that the LCD indicates that monitoring of region has commenced
= Move around inside the triangle for a minute
o check that the LCD displays report no perimeter violation
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o Check that the LCD displays correctly show the identifier of the stored
point
closest to the current position
= Move outside the perimeter by about 40 feet
o Verify that audio alarm sounds
o Verify that LED color changes to red
o Verify that LCD displays indicate perimeter violation
o Check that the LCD displays correctly show the identifier of the stored
point
closest to the current position
Track-point configuration and violation check
= Turn on the power to the monitor and listener
= LONG press of the push-button (around 20 seconds) to clear all stored
locations
= MEDIUM press of the push-button (around 10 seconds) to start
configuration
= Move to the first location on the track
o SHORT press of the push-button (around 1-2 seconds) to record its co-
ordinates
o Verify the LCD displays at monitor and listener show one point stored
currently
= Move to a second location about 40 feet away
o SHORT press of the push-button (around 1-2 seconds)to record its co-
ordinates
o Verify the LCD displays at monitor and listener show two points stored
currently
= Move to a third location about 40 feet away from the previous point, so
that the three
points are roughly in a straight line.
o SHORT press of the push-button (around 1-2 seconds) to record its co-
ordinates
o Verify the LCD displays at monitor and listener show three points stored
currently
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= MEDIUM press of the push-button (around 10 seconds) to complete track
configuration
O Verify that the LED light changes from green to blue
= MEDIUM press of the push-button (around 10 seconds) to start monitoring
location
O Verify that the LCD indicates that monitoring of track has commenced
= Move on the line between the three way-points for a minute
O Check that the LCD displays report no track violation
O Check that the LCD displays correctly show the identifier of the stored
point
closest to the current position
= Move away from the track and note the distance from the track at which
the alarm
sounds on monitor and listening devices.
O Verify that audio alarm sounds
O Verify that LED color changes to red
O Verify that LCD displays indicate track violation
O Check that the LCD displays correctly show the identifier of the stored
point
closest to the current position
Speed detection
= Check that the LCD displays correctly show the correct speed status
message when
O stationary (STOP)
O walking (WALK)
O running (RUN)
O in a vehicle (VEHI)
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Detection of human in front and to the rear
= Check that the LCD displays correctly show the correct motion sensor
status message
when
o a person is in front of the monitor (MOT F)
o a person is in front of the monitor (MOT R)
o no one is in front of the monitor or to the rear (MOT N)
o someone is in front of the monitor as well as to the rear (MOT B)
Tilt sensing
= Check that the LCD displays correctly show the correct tilt sensor status
message when
o the person wearing the monitor is upright (TILT Y)
o the person wearing the monitor leans in any direction (TILT N)
Distance between monitor and listener devices
= Move the monitor device away from the listener device until communication
is lost
o Note the approximate distance at which this happens
o Repeat the test in different terrain and with a variety of intervening
obstacles
such as walls, trees and buildings.
Integration testing
Now, the functionality of the monitor module as a whole, with multiple sensor
inputs activated, is
verified.
Though the system described consists of a monitor and a listener module, for
prototyping and
demonstration purposes, the monitor module alone was constructed. However, the
monitor
module was equipped with an LCD display (which would normally be found on the
listener
module), so that one could see the status and alarms that would normally be
visible at the
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listener end without actually building the radio transmitter and receiver.
Therefore, the tests
described in relation to distance, to verify communication between monitor and
listener
modules, were not carried out.
False alarm avoidance
During testing, the rear motion sensor would always be triggered when one held
the device in
their hand. To avoid false alarms from my own motion, only the signal from the
front motion
sensor was used to detect if anyone else was near, to trigger an alarm. In
actual use, the rear
sensor will be enabled, but the front sensor may not be as useful as it could
be triggered by the
child's hand or head motions.
Instead of using the current tilt and motion sensor readings to decide on the
action to be
performed every 10 seconds, the tilt sensor and the two motion sensor signals
are sampled
every half second and stored in a list of size 120 (i.e the list can store one
minute's worth of
samples). Whenever the actual number of samples in the list exceeds 60 (i.e
the sensor has
been "ON" for at least 30 seconds), the sensor is considered to be active i.e
motion or tilt is
considered to have occurred. Old samples are removed to make way for new
samples in the
list. This way, even when a sensor becomes active, it will not remain active
beyond a minute
unless the sensor activation persists.
Motion sensor sensitivity
The motion sensor was tested to find the maximum distance at which it could
reliably detect
motion. The sensor was placed at a fixed location on a table and then moved a
fixed distance
away. A hand was moved at intervals and watched to see if the sensor reliably
indicated when
motion was occurring. After a few tests at a given distance, subject moved to
a location a few
feet further away and repeated the test. The following table shows the
observations:
Distance from sensor (straight ahead) Accuracy of motion detection
3 feet Reliable
6 feet Reliable
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9 feet Reliable
12 feet Occasional
15 feet Occasional
18 feet No detection
The above table indicates the maximum range for reliable detection is about 9
to 12 feet.
Next, subject moved in a circle of radius apporximately five feet, at various
angles of the clock
with straight ahead from the sensor being 12 o'clock. The following table
shows the accuracy of
the measurements at various angles.
Angle from position directly in front of sensor Accuracy of detection
(Straight ahead position = 12 o'clock)
1 o'clock Reliable
2 o'clock Reliable
3 o'clock Occasional
4 o'clock No detection
The above table shows that the sensor is able to detect motion reliably only
when it occurs in
front of the sensor. Also, it is less reliable when the motion is off to the
side.
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The rear and front sensor motion counts were checked to verify increase in the
display when
motion occurs in the corresponding direction, and that the counts decrease to
zero after a
minute if no further motion occurs.
GPS point resolution
The accuracy of the GPS was measured in this section. From, a change in the
fourth decimal
place of latitude or longitude indicates a distance of approximately 11 meters
(or 33 feet) while a
change in the fifth decimal place of latitude or longitude reflects a distance
of about lm. In this
section, the precision of the GPS module used was determined.
In the first test, the GPS was placed in a fixed location and observed the
latitude and longitude
readings. The change was observed only in the fifth and sixth decimal places,
so it was
concluded that the GPS is accurate to 4 decimal places.
In the second test, the GPS was moved about 30 feet away from the first
location. There was a
corresponding stable change in the fourth decimal place, so it was concluded
that the GPS
module can be used to measure distances greater than about 30 feet accurately.
Tilt sensor sensitivity
The minimum angle of tilt from the vertical that the tilt sensor can
distinguish was determined.
Subject slowly tilted the sensor from the vertical (12 o'clock) and observed
the position at which
the tilt sensor digital signal went from 0 to 1. This happened at about
roughly horizontal position.
This shows that the sensor is adequately sensitive.
The tilt sensor sample count increases in the display when tilted, and that
the counts decrease
to zero a minute after the tilt is removed.
Speed detection
Subject performed the activities of walking and running at different speeds,
and noted down
speed ranges to allow me to correctly identify the activity given the speed.
This led to the
following classification of the GPS speed reading:
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TABLE 3
GPS Speed Range (Km / hour) Activity identified
< 3 Kmph STOPPED
3 to 6 Kmph WALK
More than 20 Kmph VEHICLE
Any other value RUN
Classification with various speeds of walking and running was retested. For
the vehicle
identification, the GPS module in a car driven at a fixed speed of 40
kilometers per hour to see if
the GPS reading would be correct. The following are test results:
TABLE 4
Type of motion Identification (using GPS)
Stationary STOPPED
Very slow walk WALK
Slow walk WALK
Fast walk WALK
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Slow jog WALK
Run RUN
Sprint RUN
Transport VEHICLE
From the results in the above table, it was concluded that one could correctly
identify the activity
based on the GPS reading.
Perimeter violation check
Based on the procedure described above, a region was marked in a neighborhood
of perimeter
around 500 m with about 12 points. Subject then moved inside and outside the
perimeter and
verified that the LCD displayed the IN/OUT status correctly.
Track violation check
Based on the procedure described above, subject marked a track in the selected
neighborhood
of length around 120 m with four points, then moved on and off the track and
verified that the
LCD displayed the ON/OFF status correctly.
Integration Test Results
The tests described above were performed as mentioned above where subject used
the front
motion sensor alone during testing, since the rear motion sensor was triggered
by movement
and body when held in hands.
The test for entering a bus from the last stop (RIDE) did not succeed if the
vehicle accelerated
slowly from the last point (DEST) on the track. Before the RIDE status could
be triggered, the
PURSUIT2 alarm would become active when running speed was reached, and
thereafter RIDE
would never become active since it requires the absence of prior alarms.
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Discussion
Sources of false alarms
In testing, there was an effort to eliminate as many potential false alarms as
possible. For
example:
= Motion detection due to nearby objects
= Tilt detection when bending to tie shoelaces or falling.
= Leaving the track to take the school bus
There was an effort to distinguish between wandering and abduction to make the
alarms during
abduction as reliable as possible.
Considerations for commercial production
For use on a commercial scale, the following aspects must be considered:
= Battery life of the monitor module
= Size and weight
= Location on the body where the monitor module is designed to be placed
= Use of multiple listener and monitor modules in the same area
A central monitoring service that can simultaneously track several children on
their way to
school from home, or vice versa, would be possible at a low-cost using my
device.
Real-world relevance
As mentioned above thousands of children are reported missing each year in
Canada and US.
The percentage of abductions is small, and most of these children return home
safely within a
day or two. The system presented in this report makes contributions on two
fronts:
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= In the case of abductions, studies have found the sounding of an alarm to
be very
important in thwarting the attempt. Also, in the case of successful abduction,
statistics
show that locating the child within a few hours greatly increases the chance
of recovery
without harm. Since the device has a mechanism for constant monitoring of
abduction-
related conditions, it can sound the alarm to foil an attempt, and in a case
where the
abduction occurs, the alarm at the listener module will give an early
indication of its
onset.
= In the case of wandering, this device should significantly reduce the
worry that a parent
of a missing child would undergo in the period before the child returns home,
by showing
that there was no abduction attempt.
The system of the present invention has several other features, in comparison
with
commercially available products (see Table 1 for details), that increase its
scope of application.
= Since it does not require cellular service:
o It can be used in remote areas
o It can be used when travelling internationally without the need to setup
a data
plan
o It does not require monthly fees for the cellular data plan
o It is easy to use without any cellular service setup requirements
= Since it does not use short-range blue-tooth service, it can operate at a
much greater
distance from the listener (kilometers instead of meters)
= Since it has both track and region monitoring algorithms, it can be used
for regular
activities such as travelling from school to home, as well as unscheduled
neighborhood
playtime.
= Rather than attempting to provide city-wide monitoring, it is
specifically designed for the
most common situation for abductions: within a few blocks of the home.
The two-module design also results in increased flexibility and wider
applicability compared to
commercially available products.
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The monitor device only focuses on detecting abduction and wandering: As a
result it has
several positive attributes:
= It can be made small, inexpensive, light-weight and have long battery
life
= It can generate rapid updates (every 10 seconds) without compromising
battery life
= Simple medium-range (upto 2 Km) RF communication with listener module
The listener module, on the other hand, is in a fixed location; for example,
inside a home or
monitoring facility. This makes it easy to extend with powerful features as it
can use A/C instead
of batteries and bulk not an issue. The functionality could be extended
through add-on
interfaces:
= To display location on a connected computer in Google Maps To use phone
line,
satellite service, cable service, cellular service to communicate
= To use multiple formats for communication: text messaging, email
= To send information to multiple recipients (anywhere in the world)
including emergency
services
The listener module can potentially log events for later analysis, and also it
is possible to
monitor multiple devices at the same time.
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References
[1] SafeWise. (2016, September 16). 10 Wearable Safety and GPS Devices for
Kids.
Safewise.com. Retrieved Jan 20, 2017 from http://www.safewise.com/blog/10-
wearable-safety-
gps-devices-kids/
[2] AngelSense. (2017). The Unique Capabilities of AngelSense. AngelSense.com.
Retrieved
Jan 20, 2017 from https://www.angelsense.com/product-tour/
[3] Trax. (2017). Trax Play GPS-Tracker for Kids and Dogs. traxfamily.com.
Retrieved Jan 20,
2017 from https://traxfamily.com/#features
[4] Government of Canada. (2016, May 19). Canada's Missing -2015 Fast Fact
Sheet.
Retrieved Jan 20, 2017 from http://www.canadasmissing.ca/pubs/2015/index-
eng.htm
[5] Cribb, Robert. (2016, May 25). Child abduction and murder data paint
chilling new portrait.
Toronto Star. Retrieved Jan 20, 2017 from
https://www.thestar.com/news/world/2016/05/25/child-abduction-and-murder-data-
paint-chilling-
new-portrait.html
[6] National Center for Missing & Exploited Children. (2016 June). A 10-Year
Analysis of
Attempted Abductions and Related incidents. NCMEC. Retrieved Jan 20, 2017 from
http://vvvvw.missingkids.org/en_US/documents/AttemptedAbductions_10YearAnalysis
_June201
6.pdf
[7] National Center for Missing & Exploited Children. (2016). Missing Children
¨ Key Facts.
NCMEC. Retrieved Jan 20, 2017 from http://www.missingkids.com/KeyFacts
[8] Bilich, Karin. (2016, Feb 15). Child Abduction Facts. Parents.com.
Retrieved Jan 20, 2017
from http://vvww.parents.com/kids/safety/stranger-safety/child-abduction-
facts/
[9] My Buddy Tag FAQ. Child Safety Wristband and Tag. MyBuddyTag.com.
Retrieved Jan 20,
2017 from http://www.mybuddytag.com/faq
[10] Huber, W. (2015, April 9). Measuring accuracy of latitude and longitude.
Retrieved Jan 20,
2017 from http://gis.stackexchange.com/questions/8650/measuring-accuracy-of-
latitude-and-
longitude/8674#8674
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Appendix A - Component
documentation
Component Documentation
Teensy https://www.pjrc.com/teensy/pinout.html
GPS
https://vvww.arduino.cc/documents/datasheets/E000026_gpsShieldv1_PA6B-
Datasheet-A07.pdf
Motion http://www.robotshop.com/ca/en/parallax-pir-motion-
sensor.html
sensor
Tilt sensor http://www.robotshop.com/ca/en/gravity-tilt-sensor.html
LCD https://www.parallax.com/sites/default/files/downloads/27979-
Parallax-Serial-
LCDs-Product-Guide-v3.1.pdf
