Initial Concept


Once it was decided that an alarm/tracker device would be designed, the next decision to be made was in what form this unit would take to best fit the brief criteria.

Many ideas were discussed. The Wrist Band and Control Unit was one of the first ideas to be considered along with broaches, belts, lapel pins and shoes.  The shoe idea came a close second to our final choice, but it was thought that the amount of wear and tear a shoe takes in its lifetime would be far too great for the survival of the precision electronics contained within.  Another aspect of the shoe design concept which eventually ruled it out as a contender was the fact that children wear shoes out very quickly and also grow out of them at almost the same rate.

We finally decided on a Wrist Band containing the relevant electronics to facilitate an alarm system and a GPS tracker.  This would be combined with a hand held Control Unit which would not be dissimilar to a mobile phone.


Wrist Band / Control unit


Preliminary Design Concept


The design of the Wrist Band will be of the greatest importance due to the ergonomic factors of the human wrist. The hand held Control Unit is of less importance as a design concept because it will probably be loosely based on a Motorola Pebble mobile phone.

In order to fit the necessary electronics into the Wrist Band, a portion of its circumference would have to be flatter than the rest of the band.  A means of recharging the internal battery will be needed also.  It was decided a rechargeable battery would be preferable to a throw away lithium type, for environmental reasons.

The system would be multi-functional or could be ordered as a basic unit with basic functions. The simplest of models would consist of an alarm system only with a preset distance range (set in factory during manufacture). The next model up would also be an alarm system only but the user can set distance range via the hand held Control Unit. Other models would grow in sophistication up to an ultimate model which would incorporate all functions, including, alarm, and health status of the wearer, tracking system and GPS (Global Positioning System) over a wide distance range. If the IC’s (Integrated Circuits) are produced small enough to fit the Wrist Band, then a communications system can be incorporated. This would allow the Control Unit user to communicate with the Wrist Band wearer at any time, over any distance and visa-versa.

The design as a whole produced a great deal of useful information with respect to research.  We found that the proposed design concept was already in production but lacked certain technological design features which are now possible with today’s advances in microchip technology.  The amount of circuit information that can now be installed in a microchip measuring no more than 7mm by 7mm is such that the space required, including external surface mounted components, is minimal, and a Wrist Band could be designed which would be very small.  Therefore the amount of information transferable between Wrist Band and Control Unit need not be limited to one function only but could include all functions; GPS, alarm, and wearers health status.

When all our initial design concepts were complete and we came to the point of deciding which design was the most acceptable, by using a concept matrix in making that decision, the results were interesting.  The Wrist Band concept which received the most points was one depicting a small teddy bear with a flip up lid, under which is a watch.  The design in itself is very good but it would only appeal to young children and predominantly female, therefore the Wrist Band must be available in more than one design so as to cater for a larger cross section of users rather than a limited age group.  This would be more costly in the design and production stages but would obviously be offset by the increase in sales.

The Control unit design chosen by using the concept matrix is a hand held unit with integral key ring.  The ergonomic shape of the unit is such that it would fit in the palm of the hand very comfortably.  The design concept includes all the functions necessary for the tracking of a Wrist Band wearer and probably could include a mobile phone function, or at least a communications function between Control Unit and Wrist Band.