Design Process for the Fortrus
The main challenge was to design a structure that could be very compact but still as rigid as possible when fully deployed. While the design team came across several examples of foldable litters on the market that split apart in separate pieces in its compact mode, we felt that a single structure would be best in terms of rigidity and stability.
In place of independent collets or snap-locks, we use integrated sliding collet locks that automatically lock into place once the structure is fully deployed. The design also allowed us to put in colored indicators such that users can easily tell when any of the locks are not appropriately engaged.
In order to justify the use of Aluminum piping in place of more expensive (Ti) or heavier (Steel) materials, we use a truss design for the sides in order to best distribute the weight of the patient throughout the structure.
All parts used were designed for manufacturing and take advantage of fast and inexpensive machining processes such as waterjetting. This design greatly minimizes the need for welding and pipe-bending, a consideration that should decrease the production costs and errors.
Though a lot of progress was made for the initial prototype, we did not fail to neglect the areas where the Fortrus can be improved. More work needs to be done to ensure that the sliding locks do not jam after the structure has been used in the dirty and dusty outdoors for extended periods of time. Also, the current spring-loaded locks will need to be well-protected to ensure that they will not accidentally unlock caught on anything in the wilderness.
Also, although limited testing has shown that the Fortrus is compatible with existing litter attachments (such as wheels and backboards), more research needs to be done to optimize the usability of the device (gripping points and tie points in particular).
The Fortrus team sees this product as the first step in many that will help mountain rescue operations decrease the manpower required for each rescue. We hope that the innovations made through this project will encourage the continued development of other add-ons or features that will also help the rescue process.