A state detecting device can efficiently remove air bubbles from a liquid no matter whether the liquid flows forwards or backwards. The latch further includes a rotatable claw, a pawl resiliently biased into contact with the claw, and an intermediate release lever. The SIPSS7 gateway extracts a called party number from the INVITE message and determines whether a telecommunications service is required and a type of service required for the INVITE message based on the called party number. The fiber end provides one intermittent axis of rotation and the friction cam provides another intermittent axis of rotation. The system and method may also be used for removing fluid from a negative pressure device. The encode amount predicting unit 207 calculates predicted encode amounts.