A differential pressure sensor positioned adjacent a pressure chambers separated by a nozzle. The signal is transmitting off the pad through non-contact couplings such inductive coupling or optical couplings after being converted into signal formats enabling non-contact transmission. The plurality of coil drives may include a first inductive coil drive comprising a first pair of opposing poles; and a second inductive coil drive comprising a second pair of opposing poles, where the second pair of opposing poles are offset from the first pair of opposing poles in at least two dimensions. Both patient line presenceabsence and fill state can be determined using an optical system, e. The harmful information blocking code module is automatically transmitted to and installed in the client system only by online connecting to the harmful information management server, so that the harmful information detected on the client system can be actively blocked in real time without requiring a manual installation process. A correction sensor TFT is disposed adjacent to the photosensor TFT, to thereby eliminating noise caused by the temperature distribution, stray light, or the like, and erroneous operation of the photosensoris prevented.