A Real-Time and Portable Bionic Eye Simulator - Biomedical Engineering Systems and Technologies - page 40

4.2 Chessboard Test

In this test, there were 7 test subjects (6 male, 1 female) and were the same subjects as
used in the previous Maze Test. The task required subjects to sit down at a table with a
chessboard in front of them and 16 chess pieces (8 black, 8 white) placed in a random
pile to the left of the chessboard. The objective was for the subjects to sort and place
any black coloured pieces on any white square in the bottom half of the chessboard, and
the white pieces on black squares in the top half of the chessboard.

Fig. 11. Chessboard Test finished example

For the test, both time to completion and number of mistakes were recorded for
all subjects. For a piece to be considered as correctly placed, at least half of it had
to be over the right square. Another aspect to this experiment was to test for learning
effects that come from repeated usage of the system. As such, the non-control modes
tested were repeated 3 times in this order (all at full frame rate): control (full resolution,
full colour), binary thresholding, 4-level thresholding, binary, 4-level, binary, 4-level.
Before the testing, subjects were asked to attempt the task without wearing the system
in order to familiarise themselves with the task itself. The testing was conducted in a
single session, with a minimum 1 minute break in between each test.

4.3 Ball Interception Test

Once again, the same 7 test subjects (6 male, 1 female) were used. The Ball Interception
Test required subjects to sit down at a modified table tennis table. The table had a
horizontally sliding 'paddle' mounted on the participant's end and at the opposite end
4 fixed half-pipe ramps that balls could be rolled down. The ramps were all the same
length, had the same elevation angle, and had a 'fast' and 'slow' roll point for the balls.
The ramps were partially covered by a cardboard screen so that the participant could
not see which ramp the ball was rolling down until it reached the bottom. The objective
was for the subjects to use the sliding paddle to block/intercept/stop the balls (similar
to the video game 'Pong' or to 'Air Hockey' in an arcade).
The number of successfully intercepted balls was recorded for all subjects. To be
considered as a successful interception, the ball was not allowed to hit the rail that the
paddle was sliding along. In cases where there was ambiguity in the outcome (ie. balls
getting stuck under paddle or between the paddle and side block), a note was made