Abstract:
Apparatus for irrigating an electrode of a catheter are disclosed. Among other things, a catheter is disclosed that comprises a shaft portion including a fluid passage to conduct fluid, an electrode coupled to a distal end of the shaft portion, and a handle portion coupled to a proximal end of the shaft portion. A portion of the fluid passage defines an opening in the shaft portion. The opening is constructed and arranged such that when fluid is conducted through the fluid passage, at least some of the fluid will contact the electrode after passing through the opening in the shaft portion.
Abstract:
The present invention encompasses apparatus and methods for mapping electrical activity within the heart. The present invention also encompasses methods and apparatus for creating lesions in the heart tissue (ablating) to create a region of necrotic tissue which serves to disable the propagation of errant electrical impulses caused by an arrhythmia.
Abstract:
An electrophysiology catheter and method of use for mapping and ablation procedures. The catheter includes a braided conductive member at its distal end that can be radially expanded. The catheter can be used in endocardial and epicardial mapping and ablation procedures.
Abstract:
An ablation catheter comprises a shaft and at least one ablation electrode which may be fixed or movable relative to the shaft. An insulating cap is placed over portions of the electrode which are susceptible to high current concentrations when RF energy is applied to the electrode. Typically, such portions occur in the region of abrupt surface transitions such as the edges of the electrode.
Abstract:
A medical device including an elongated shaft that is twisted through a predetermined angle. One or more lumen are formed in the shaft and twist through the predetermined angle as well. A pull wire extends through one of the lumen and attaches to a distal portion of the elongated shaft at an off-axis location. By tensioning the pull wire, the medical device can assume various complex curves, depending on the degree of twist imparted to the shaft.
Abstract:
A steerable catheter includes control handle having a generally tubular housing with a longitudinal slot therein in which an axially or longitudinally movable two-part slideblock resides, and a generally cylindrical, rotatably mounted thumbwheel surrounding a distal portion of the tubular housing, for controlling the axial translation of the slideblock. The pullwire passes into the distal end of the control handle and is only secured to the proximal part of the two-part slideblock so as to prevent the user from placing the pullwire under compression. A tip radius adjusting wire is attached to and extends distally from a slide actuator in the control handle into and through the main catheter shaft portion. The free distal end of the tip radius adjusting wire is selectably locatable at different positions. The radius of curvature of the tip portion, when deflected, depends upon how far distally into the deflectable tip portion the radius adjusting wire has been advanced by the user. The electrode catheter thus has a deflectable tip whose radius of curvature is adjustable over a relatively wide range.
Abstract:
A continuously generated alkyleneamines producers composition comprising, based on 100% of the moles of the composition and exclusive of any MEA and water present,(a) about 15 to about 50 mole % AEEA,(b) about 15 to about 55 mole % EDA,(c) about 10 to about 20 mole % DETA,(d) about 5 to about 20 mole % of the combination of PIP, AEP and HEP,(e) about 3 to about 10 mole % of one or more of TETAs and TEPAs,(f) less than about 1 mole % of other polyalkylene polyamines,(g) an DETA to AEEA mole ratio less than 0.77, and(h) an EDA to AEEA mole ratio less than 8;and a process of manufacturing the same, which comprises feeding hydrogen, ammonia and MEA to a reaction zone containing a fixed bed of a reductive amination catalyst, wherein the hydrogen comprises about 20 to about 60 mole percent of the feed in the reaction zone and the mole ratio of ammonia to MEA is about 1 to about 5, the temperature of the reaction zone is about 120.degree. C. to about 300.degree. C., the pressure of the reaction zone is about 400 to about 1400 psig., the conversion of MEA is about 20 to about 45 weight percent, and recovering said producers composition from the reaction zone.
Abstract:
A process is provided for preparing alkanolamines having a high yield of monoalkanolamine which comprises reacting in a reaction mixture an alkylene oxide having from two to four carbon atoms with ammonia in a molar ratio of ammonia to alkylene oxide within the range from about 15.1 to about 50.1 at temperatures above the critical temperature of the reaction mixture and at pressures above the critical pressure of the reaction mixture and high enough to maintain the reaction mixture at sufficiently high fluid densities.
Abstract:
A process is provided which may be run continuously for producing polyethylene polyamines having improved color characteristics which comprises treating discolored polyethylene polyamines with polyethylene polyamine hydrochloride in the presence of water at elevated temperatures for the time necessary to reduce the color of said polyethylene polyamines and then flash evaporating the decolorized polyethylene polyamines from the treating mixture.