| 摘要 |
<p>A system for providing an input signal, comprises an element (M, 1) controllable by a user by means of interaction with a user's limb, which system comprises a sensor (5, 6) capable of detecting the presence of a limb placed over at least part of the element (M, 1), timing means (2) for determining the length of a time during which the limb is present and means (11, 9, 7, 8) of generating an alarm signal if the length of time exceeds a threshold value. The alarm signal can be used to effect discontinuation of the presence of the limb.</p> |
