Abstract:
There is described a continuous process for the manufacture of ethylenediamine from the products of the reaction of ethylene oxide and ammonia, provision of a continuous recycle stream of monoethanolamine to the products of the reaction of ethylene oxide and ammonia, the amination of such products of the reaction of ethylene oxide and ammonia combined with the monoethanolamine recycle in which the feed stream to the amination reaction zone contains at least 70 weight percent monoethanolamine as well as diethanolamine and triethanolamine, the moles of ammonia provided to the amination reaction exceeds the molar concentration of alcoholic hydroxyl groups present in the amination feed, and the feed to the amination reactor contains at least a 5% increase in the concentration of monoethanolamine over the concentration of monoethanolamine in the reaction product stream from the reaction of ethylene oxide and ammonia.
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:
Methods and apparatuses for manipulating an elongated flexible shaft of a catheter provide case and reliability of positioning electrodes against or near tissue. Dual-bend flexible distal tips (30) may be used in combination with flat wires. In some embodiments, flat wires which are free to rotate upon initial bending of shaft segments are employed. In some embodiments, one or more transition segments (48) are used to relocate the satellite lumen-to-main lumen transition of pull wires (42, 40) away from a change in shaft stiffness.
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:
A medical device is disclosed which includes a displaceable electrode slidably mounted over the device. An electrode displacement mechanism is connected to the electrode, and may be actuated to displace the electrode relative to the medical device. The medical device may be used for therapeutic, diagnostic, or other medical procedures.
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 50 to about 90 mole % AEEA,(b) less than about 3 mole % EDA but more than 0.01 mole % EDA,(c) less than about 2 mole % DETA but more than 0.01 mole % DETA,(d) about 5 to about 18 mole % of the combination of PIP, AEP and HEP,(e) about 5 to about 20 mole % of one or more of TETAs and TEPAs,(f) less than about 1 mole % of other polyalkylene polyamines,(g) a mole ratio of AEEA to the combination of PIP, AEP, HEP, DETA and EDA is greater than about 2.5,(h) an AEEA to EDA mole ratio greater than about 22 and(i) an AEEA to PIP mole ratio greater than about 7;and a process of manufacturing the same, which comprises feeding hydrogen and MEA to a reaction zone containing a fixed bed of a reductive amination catalyst, wherein the hydrogen comprises about 20 to about 80 mole percent of the feed in the reaction zone, the temperature of the reaction zone is about 120.degree. C. to about 300.degree. C., the pressure of the reaction zone is about 200 to about 1200 psig, the conversion of MEA is about 15 to about 42 weight percent, and recovering said producers composition from the reaction zone.
Abstract:
Embodiments described herein relate to methods of using a catheter having a braided conductive member. One embodiment relates to a method for treating a condition of a patient that involves contacting an exterior wall of a blood vessel with the braided conductive member. Another embodiment relates to a method that involves contacting a wall of a blood vessel with the braided conductive member and controlling energy delivery to the braided conductive member based on at least one sensed temperature.
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:
A catheter includes a pull wire which extends through two different lumen and attaches to the distal end of the catheter at an off-axis location. By tensioning the pull wire, the catheter can assume various complex curves, depending on the respective lumen through which the pull wire passes.
Abstract:
Color-containing alkanolamines or alkyleneamines, having color numbers of up to 100 PtCo or higher, can be treated with inorganic solid acidic catalysts. Inorganic support materials having bonded inorganic acid functionalities may be used as the inorganic solid acidic catalysts. In the presence of water, these inorganic solid acidic catalysts produce decolorized alkanolamines or alkyleneamines having color numbers of 20 PtCo or less. The process of decolorization can be carried out in batch or continuous mode processes thus providing low cost, high quality and high purity end products.