Patent ID: 8211057

Claim:
A chemical liquid injection system comprising: a liquid syringe having a piston member slidably inserted into a cylinder member having a tubular shape, the cylinder member has a cylinder flange formed on a trailing end of a cylinder body, and the cylinder flange has a pair of flat portions in parallel at opposite positions on its outer circumference; and a chemical liquid injector for injecting a liquid into a patient by pressing the piston member into the cylinder member of the liquid syringe mounted interchangeably thereon, wherein an RFID tag including a tag antenna formed of a loop antenna is positioned on an outer circumference of the cylinder member, and the chemical liquid injector includes a cylinder holding mechanism for holding the cylinder member, a piston driving mechanism for pressing the piston member into the held cylinder member, an RFID reader for receiving data from the RFID tag through electromagnetic induction via a pair of reader antennas formed of loop antennas and connected to each other, a processor configured to permit operation of the piston driving mechanism only when the data is received and an antenna placement portion for placing the paired reader antennas at opposite positions across the axis of the cylinder member and one of the reader antennas at a position opposite to the tag antenna generally in parallel while the cylinder member is appropriately held by the cylinder holding mechanism such that the flat portions of the cylinder flange are located at the top and the bottom.