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 stent for prostatic urethra expansion which does not generate bladder stones, is removable without causing injury on a urethra, and does not generate atrophy of a prostatic urethra even after removal. The stent for prostatic urethra expansion include a stent unit including a cylindrical body with space parts formed by knotting or crossing shape memory alloy wires and bending terminals formed at both ends of the cylindrical body, a pair of hook wires passing through the space parts and knotted to the shape memory alloy wires, both ends thereof being wound on the bending terminals and then being bent upwardly to produce hooks, and a pair of hanging strings arranged in opposite directions to form a hanging knot. The stent for prostatic urethra expansion does not move into the bladder, and expands and maintains a lumen of the stenosed prostatic urethra, thereby reducing post-operative recovery time.

Abstract: A balloon type stent system for treatment of obesity is disclosed. An injection expansion unit and a plurality of distribution expansion units extend in a longitudinal direction of a stent unit body formed by coupling two sheets of synthetic vinyl in the shape of a cylinder. The injection expansion unit has an expansion agent injection port, and the distribution expansion units each have a distribution injection port communicating with a distribution channel. Connection ends are partially cut in the longitudinal direction such that the expansion units are divided into an integrated expansion unit and a separated expansion unit. The injection expansion unit and the distribution expansion units constituting the separated expansion unit are bent outward to form a balloon type stent unit. A tube has a length corresponding to a lumen length of the duodenum, and the tube is connected to the stent unit body by a connection wire.

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 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.

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 balloon catheter for the respiratory tract, which serves to widen the lumen of the respiratory tract when stricture or stenosis of the lumen occurs and is configured to enable a patient to breathe even during catheterization. The catheter includes a tube unit having a double structure consisting of an inner tube and an outer tube spaced apart from the inner tube to surround the inner tube, and a cylindrical balloon integrally connected to facing distal ends of the inner and outer tubes. The balloon is inflated to have a hollow cylindrical shape as inflation gas is supplied into the outer tube, thereby acting to widen the stenosed or narrowed lumen of the respiratory tract, and simultaneously, oxygen is supplied into the inner tube to pass through the cylindrical balloon, thereby enabling a patient to breathe and resulting in stability in catheterization.

Abstract: If smooth transportation of bile toward the duodenum is difficult due to cancerous cells growing in the bile duct or due to stricture of the bile duct, a cylindrical stent may be implanted into the stenosed site of the bile duct to enable smooth supply of bile. Conventional stents have no risk of slippage at an implanted position thereof, but suffer from invasively growing cancerous cells. Although a covered stent having a coating has been proposed to solve invasion of the growing cancerous cells, the covered stent may have a risk of slippage at an implanted position thereof and also, may cause pancreatitis and cholelithiasis. To solve the above described problems, disclosed herein is a stent to prevent backflow of food from the duodenum to the bile duct while assuring smooth transportation of bile without a risk of unwanted displacement caused by the transported bile.

Abstract: Disclosed herein is a drawstring for removal of a stent. The drawstring includes a circumferential string which is made of soft material and is formed in an end of the stent body in an annular shape. A hook loop is formed by tying opposite ends of the circumferential string to each other. The hook loop protrudes a relatively long distance from the stent body. A marking wire made of radiopaque material is wound around the hook loop. Therefore, when X-rays or endoscope are applied to a relative portion of a patient's body, the position of the hook loop can be easily detected. Furthermore, because the hook loop is made of flexible and soft material, even though it comes into contact with an internal organ of the patient's body, the organ is prevented from being damaged by the hook loop.

Abstract: Disclosed herein is a drawstring for removal of a 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: A wavily deformable stent includes a hollow cylindrical net body formed of elastically deformable wires interlaced with each other. The net body extends in a longitudinal direction and terminates at open opposite ends. The net body has at least one high-rigidity section and at least one low-rigidity section less rigid than the high-rigidity section. The high-rigidity section and the low-rigidity section are arranged continuously and alternately along the longitudinal direction. The stent is wavily deformed and held in place against unwanted displacement when situated inside a stenosed part of a bodily organ. Also provided is a method for producing the wavily deformable stent.

Abstract: A partially biodegradable stent includes a main net body of hollow cylindrical shape formed of elastically deformable wires interlaced with each other, the net body extending in a longitudinal direction and terminating at open opposite ends, and an auxiliary net portion provided at one of the open opposite ends of the main net body, the auxiliary net portion formed of a biodegradable wire which can be degraded and removed by a bodily fluid. The auxiliary net portion is formed by interlacing the biodegradable wire into a cylindrical shape independently of the main net body or by interlacing the biodegradable wire with the elastically deformable wires at one of the open opposite ends of the main net 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: The object of this invention is to provide a stent for high frequency thermotherapy, which is fabricated by knitting first superlastic shape-memory alloy wires as a way to allow the first superelastic shape-memory alloy wires to cross each other at different positions to make a hollow cylindrical stent body having a net structure with a plurality of meshes. The stent body is covered with an insulating substance. A hollow cylindrical conductive body surrounds a waist part of the stent body while any one end or both ends of the conductive body is attached to the waist part of the stent body. At this time, the conductive body is fabricated by knitting second superelastic shape-memory alloy wires as a way to allow the second superelastic shape-memory alloy wires to cross each other at different positions.

Abstract: A biodegradable double stent is used for various organs such as a biliary tract, an esophagus, an airway and a ureter. A biodegradable stent having a hollow cylindrical body woven out of a separate wire made of biodegradable polymer so as to have a plurality of rhombic spaces is fixed to an intermediate portion of a primary stent having a cylindrical body. When administered into the organ, the biodegradable stent has its original function of expanding the organ, and is firmly supported in the inner wall of a narrowed passage of the organ by pressurizing the inner wall of the narrowed passage of the organ. After a predetermined time period has elapsed, the biodegradable stent is gradually degraded away by bodily fluids, thereby enabling the primary stent to be easily removed from the organ.

Abstract: A double-tube type stent is inserted into a hollow tubular organ such as a bile duct so as to relieve narrowing of the bile duct on, for instance, an anastomotic area of the intrahepatic bile duct of a liver transplant patient. A hollow cylindrical body has a plurality of rhombic spaces formed by weaving a superelastic shape-memory-alloy wire so as to be crossed. A silicon coating layer is coated on an outer surface of the cylindrical body using a silicon solution. A polytetrafluoroethylene (PTFE) tube is fixedly fitted around the cylindrical body having the silicon coating layer leaving a gap therebetween.

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 comprises a biologically active material and a coating material selected from among pullulan acetate, represented by the following Chemical Formula 1, and a polyurethane-surfactant mixture.

Abstract: A stent inserting device is used in inserting a self-expandable stent with leading and trailing ends into a tubular organ of a living body. The stent inserting device includes a grip body, an external tube attached to a front end of the grip body, a push member movably inserted into the external tube from a rear end of the grip body, and a tubular cap for removably receiving the stent in a compressed state. The tubular cap has a front end operatively connected to the push member and a rear end slidably fitted to a front end of the external tube. The stent inserting device is designed to hold the stent within the tubular cap in such a manner that the stent is first expanded at the trailing end and then gradually expanded toward the leading end when the tubular cap is pushed away from the external tube.

Abstract: The object of the present invention is to provide an electrode device for high frequency thermotherapy, including a main casing, an electrode needle, a first engaging part, and a guide unit coupled to the engaging part to be longitudinally moved relative to the electrode needle. The guide unit has a guide tube to receive therein the electrode needle to expose a tip of the electrode needle to the outside of an end of the guide tube. Thus, the exposed length of the tip of the electrode needle is varied according to a position that the guide unit is coupled to the engaging part. The electrode device may further include a three-way valve -provided between the main casing and the guide unit to supply a liquid medicine or water t a desired part of a patient body.

Abstract: A multi-channel radio frequency generator for high-frequency thermal treatment is used in combination with a plurality of electrodes. The multi-channel radio frequency generator includes an oscillator for producing a high-frequency, a waveform modulator part for modulating an waveform of the high-frequency generated by the oscillator, first to third amplifying channels for amplifying the high-frequency outputted from the waveform modulator part to have a root mean square output of 30-200 Watts and then supplying the root mean square output to the electrodes, a channel selection part for allowing a user to select one or more of the first to third amplifying channels, a key part for enabling the user to set a voltage, a current and an impedance for the first to third amplifying channels, and a microcontroller unit for controlling a power, a time and a phase of the high-frequency outputted from each of the first to third amplifying channels.