Abstract: In a valve-equipped hand switch and a chemical liquid introduction system, a contrast medium in a syringe is delivered to a patient line through a first port, a main passage around a spacer portion, and a second port. Furthermore, a pressure (about 300 psi) of the contrast medium delivered by a chemical liquid introduction device is transmitted as a reaction force through a third plunger from a handle portion of an operation piston held by an operator. As such, the operator can directly feel the pressure of the introduced contrast medium, which gives a sense of ease to the operator during operation.

Abstract: In a valve-equipped hand switch and a chemical liquid introduction system, a contrast medium in a syringe is delivered to a patient line through a first port, a main passage around a spacer portion, and a second port. Furthermore, a pressure (about 300 psi) of the contrast medium delivered by a chemical liquid introduction device is transmitted as a reaction force through a third plunger from a handle portion of an operation piston held by an operator. As such, the operator can directly feel the pressure of the introduced contrast medium, which gives a sense of ease to the operator during operation.

Abstract: This channel switching apparatus comprises a first channel switching device (303) for switching a first main channel and a second main channel, a second channel switching device (305) for switching a third main channel and a fourth main channel, a third channel switching device (307) for switching a fifth main channel and a sixth main channel, and a fourth channel switching device (308) for switching a seventh main channel and an eighth main channel. Thus, a channel switching apparatus which can readily and correctly perform even by touch can be provided.