The AR Workbench: A Complete Co-located Reach-in Mirror-Based ...

5.5 Lexical Design
Marlon Richert, Master’s Thesis, Friday, 23 February, 2007
Figure 10 shows the design of the exact dimensions of the workbench. The two
faces drawn in the picture (not to scale) represent the eye height of a 95 th -percentile
male and a 5 th -percentile female when seated as high as possible. It evaluates
several design options with the use of the anthropometric data mentioned in chapter
4. For the 5 th -percentile female, it shows her nose height above the surface (44 cm),
the height above the work surface of her maximum horizontal reach (25 cm), her
maximum horizontal reach (42 cm) and her eye height above the work surface (48
cm). For the 95 th -percentile male, it shows his eye height above the seat, which is
positioned for the 5 th -percentile human thigh clearance. Some of the values listed,
such minimum mirror and screen depth, ended up discarded because they were the
result of assumptions that prototyping later showed to be invalid.
Most of the resulting dimensions—though not all—then functioned as guidelines
for the virtual prototype of the workbench. One of the nonfunctional requirements,
however, is that the workbench should fit into an office environment, so constraints
relating to that were also taken into account. For example, the workbench is 75 cm
deep because the standard issue desks in the MedICLab are also 75 cm deep.
Further, because only limited accuracy was possible in the construction of the
wooden frame, all dimensions were rounded to multiples of 5 cm.
Figure 10 Lexical design of the workbench, showing the field of view of a
95 th -percentile male and a 5 th -percentile female, as seen from the side.
Figure 11 and Figure 12 then show the virtual prototype based on the lexical design.
At the top, it contains support strips for the projection screen. There is nothing
located above the projection screen; this way, it can be easily removed and
replaced. In the center of the frame are two crossbars that uphold the transmitter of
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