摘要:
A guidewire and a method for its manufacture, wherein at least the distal portion of the guidewire comprises an element made of a precursor of a superelastic alloy such as a Ni--Ti linear elastic alloy. The element exhibits a stress strain curve with a linear stress-strain relationship and a yield point. At room temperature to body temperature the precursor is in the martensitic phase. The distal portion of the guidewire is deformable beyond the yield point by the physician in the field to a desired set shape and exhibits resistance to kinking during insertion into the body as a result of its elasticity.
摘要:
The invention features a catheter and methods for delivering drug to tissue at a desired location of the wall of a body lumen. The catheter is constructed for insertion in a body lumen and has a catheter shaft and an expandable portion mounted on the catheter shaft. The expandable portion is expandable to a controlled pressure to fill the cross-section of the body lumen and press against the wall of the body lumen. In one embodiment, at least a portion of the exterior surface of the expandable portion is defined by a coating of a tenaciously adhered swellable hydrogel polymer. Incorporated in the hydrogel polymer is an aqueous solution of a preselected drug to be delivered to the tissue or plaque. The hydrogel polymer and drug are selected to allow rapid release of a desired dosage of the drug from the hydrogel polymer coating during compression of the hydrogel polymer coating against the wall of the lumen when the expandable portion is expanded. In other embodiments the polymer is released from the expandable portion in response to pressure, to coat the wall of the body lumen.
摘要:
Device and method for heating tissue, the device having a catheter shaft for insertion into a patient's body, a chamber formed by a collapsible balloon mounted on the catheter shaft and filled with an electrically conductive fluid, two or more electrical contacts enclosed within the chamber, a power supply for applying an electrical potential to the contacts, and a two or more conductors for connecting each of the contacts to the power supply. The fluid is heated on the basis of I.sup.2 R losses by a radio frequency electric current flowing between the electrodes, and the fluid in turn heats the surrounding tissue by heat transfer through the wall of the chamber. According to the method, the apparatus is inserted into the patient's body, the chamber is filled with an electrically conductive fluid, and an electrical potential is applied to the contacts. The apparatus functions as a temperature source. A thermister sensor in the balloon or in contact with tissue responds to the heating effect to control the application of the current. Advantageously, by periodic sensing of temperature, and application of controlled rf power, a preset constant temperature is maintained at the selected sensing point, either at the internal body site or the liquid within the balloon. In this way carefully controlled therapy can be conducted at constant temperature.
摘要:
Stabilizing an object in the body of a patient involves the injection of a lower critical solution temperature (LCST) material or other flowable material into the body of the patient so that the material contacts the object. The LCST material or other flowable material then forms a gel in the body such that the object is contained at least partially within the gel and thereby stabilized by the gel such that the object can then be easily fragmented within the body and/or retrieved from the body.
摘要:
Stabilizing an object in the body of a patient involves the injection of a lower critical solution temperature (LCST) material or other flowable material into the body of the patient so that the material contacts the object. The LCST material or other flowable material then forms a gel in the body such that the object is contained at least partially within the gel and thereby stabilized by the gel such that the object can then be easily fragmented within the body and/or retrieved from the body.
摘要:
Stabilizing an object in the body of a patient involves the injection of a lower critical solution temperature (LCST) material or other flowable material into the body of the patient so that the material contacts the object. The LCST material or other flowable material then forms a gel in the body such that the object is contained at least partially within the gel and thereby stabilized by the gel such that the object can then be easily fragmented within the body and/or retrieved from the body.
摘要:
The present invention generally relates to the field of insertable or implantable medical devices, such as balloon catheters, stents and other similar diagnostic or therapeutic devices which may be provided within the body for treatment and/or diagnosis of diseases and conditions. In particular, the present invention relates to devices whose surfaces are electrically actuatable between a hydrophobic state and a less hydrophobic state or a hydrophilic state. Such devices include drug-eluting devices such as balloon catheters and stents which release therapeutic agents upon the application of an electric field. Such devices further include devices such as balloon catheters and stents whose lubricity may be modulated in situ by the application of an electric field.
摘要:
Disclosed is an implantable or insertable medical device comprising (a) a substrate and (b) a hydrogel polymer coating at a least a portion of the surface of the substrate, wherein the hydrogel polymer is adapted to render the medical device visible under magnetic resonance imaging (MRI) upon insertion or implantation of the medical device into a patient. Also disclosed is the use of such a hydrogel coated implantable or insertable medical device in a medical procedure, wherein during or after insertion or implantation of the medical device in a patient, the position of the medical device is viewed under MRI. The use of a hydrogel polymer for coating a medical device wherein the hydrogel polymer is adapted to render a medical device coated with the hydrogel polymer visible under MRI and a hydrogel polymer adapted to render a medical device coated therewith visible under MRI are also disclosed.
摘要:
In one aspect, the present invention is a medical device that reduces the likelihood of an operator improperly reusing it. The medical device includes (a) a device body; (b) a substrate comprising a contrast material that covers at least a portion of the device body; and (c) an outer layer comprising a hydrophilic material that covers at least a portion of the substrate. The outer layer comprising hydrophilic material is capable of absorbing water-soluble contaminants during clinical use that, once absorbed, are visible against the background of the substrate comprising the contrast material. In another aspect, the device includes (a) a device body and (b) an outer layer comprising a usage indicator reagent. In another aspect, the invention provides methods of preventing re-use of a single use medical device.
摘要:
An elongate polymer member having molecular helical orientation formed by rotation immediately after passing through the extrusion head. The elongate polymer member is rotated downstream of the extrusion head in the molten state prior to solidification in order to impart the molecular helical orientation. Rotating the polymer member in the molten state allows the helical orientation to be imparted at the molecular level, and allows for more rotations per lineal foot of extrusion.