Abstract: A stent system includes a stent and a drawstring for removal of the stent. The drawstring includes an end string, a longitudinal string and a circumferential string. The end string is formed in an end of the stent body in an annular shape in such a way that the end string passes, in a zigzag manner, through mesh arranged in a circumferential direction of the stent body. A hook loop is formed by tying opposite ends of the end string to each other. The longitudinal string extends at a first end thereof from the end string in the longitudinal direction of the stent body. The circumferential string extends from a second end of the longitudinal string and is formed in an annular shape in such a way that the circumferential string passes, in a zigzag manner, through mesh arranged in the circumferential direction of the stent body.

Abstract: Disclosed are a coating agent for drug releasing stents, a method for preparing the same and a drug releasing stent coated therewith. The coating agent for drug releasing stents comprises nanoparticles with a biologically active material entrapped therein, wherein the particles are formed of a polyethyleneimine (PEI)-deoxycholic acid (DOCA) polymer (PDo) in which 1˜8 moles of DOCA are grafted per mole of PEI.

Abstract: Disclosed herein is a common-mode noise filter of an RF generator for radiofrequency ablation. The common-mode noise filter of the RF generator for RFA amplifies an oscillation frequency provided by an oscillator to AC output using amplification means, and providing the amplified oscillation frequency to electrodes. The common-mode noise filter is disposed between the amplification means and the electrodes, thus eliminating harmonic components generated by the electrodes depending on conditions of medical treatment when the electrodes are used. Accordingly, the present invention can prevent the distortion of images or waveforms attributable to harmonic components from occurring in a diagnostic imaging device such as a diagnostic ultrasound system used together with the RF generator for RFA as well as in the RF generator's own display unit.

Abstract: Disclosed herein is the resonant inverter of a radio frequency (RF) generator for radiofrequency ablation (RFA). The resonant inverter of RF generator for RFA amplifies to high power an oscillation frequency output from an oscillator and provides the amplified oscillation frequency to an electrode. The resonant inverter processes the oscillation frequency output from the oscillator as a high-power sine wave having a frequency of 480 kHz and a Root Mean Square (RMS) power of 30 to 200 watts, and transfers the high-power sine wave to the electrode.

Abstract: Disclosed herein is a method and system for controlling radio frequency (RF) output according to the change in impedance of biological cells. In the method of controlling radio frequency (RF) output according to a change in impedance of biological cells, phases of RF voltage and current applied to the electrode are detected and a difference between the phases is obtained. A change in impedance such as a resistance component and a capacitive reactance component (XC) of the biological cells at the time of performing cauterization is obtained. An inductive reactance component (XL) is connected to an RF output terminal so as to cancel the capacitive reactance component (XC) (XC=XL), thus enabling the output impedance to have a resistance component.