Table 4 Measures of efficiency for each device

N. attempts before achieving a proper actuation

2.0 ± 1.1

2.6 ± 1.1

1.6 ± 0.8

1.6 ± 1.0

<0.0001

Successful at 1st attempt (%)

42.6 %

18.0 %

55.7 %

62.4 %

<0.0001

N. attempts before achieving proper actuation (after failure of the first attempt)

2.8 ± 0.8

3.0 ± 0.8

2.4 ± 0.6

2.7 ± 1.0

<0.0001

Total time needed for a proper actuation^a (sec)

343 ± 308

615 ± 301

150 ± 95

170 ± 137

<0.0001