A guiding catheter has incorporated toward its distal end, a flexible member capable of non-uniform elongation to cause the distal end portion to bend and straighten as desired so that it can be maneuvered through and accurately positioned in a tortuous, non-linear conduit containing branches, for example blood vessels. The flexible member comprises interconnected, and preferably braided, filaments with gaps between the filaments. The member has a first configuration that is axially lengthened and a second configuration that is axially shortened. Means are provided to move the member between its first and second configurations. Biasing means are provided to restrict axial lengthening along one side of the flexible member resulting in bending of the catheter tip.
This application is a continuation-in-part of application Ser. No. 880,107 filed June 30, 1986 which in turn is a continuation of application Ser. No. 778,575, filed Sept. 20, 1985, both now abandoned, the disclosure of which is incorporated herein by reference.
A bending sheath for a probe being inserted in a channel of a forceps of an endoscope inserted in a body cavity of a patient for observing the diseased part thereof is disclosed. The bending sheath comprises a hollow sheath, at least one extended portion extending in the sheath axis direction from the sheath tip portion, and a tip holding member for holding detachably the inserted tip portion of the probe inserted in the sheath.
In accordance with the present invention there is provided a catheter having a tubular body with a proximal end, a distal end and at least one lumen extending therethrough. A predetermined length of the distal end of the body has varying bending stiffness in both the circumferential and longitudinal directions of the tubular body. The catheter further includes a pull wire extending through the lumen. The pull wire has a proximal end and a distal end. the distal end of the pull wire is attached to the distal end of the tubular body. Preferably the catheter has at least two strips of material extending longitudinally along the body. The strips of material are offset from each other in both the circumferential and longitudinal directions. These strips of material have a greater bending stiffness than the tubular body so that the distal end of the body has varying bending stiffness in both the circumferential and longitudinal directions.
A steerable device, such as a catheter or a guidewire, adapted for insertion into a patient is provided with a means for controllably varying the curvature at the distal end of the device. The arrangement includes a conduit, at least a portion of which is formed from a material that contracts when contacted by a first liquid and expands when contacted with a second liquid. The liquids preferably are immiscible and are disposed in the conduit. Means are provided for shifting the position of the liquid column in the conduit. The portion of the conduit formed from said material is formed into a configuration that will cause that portion of the conduit to change shape depending on the position of the liquid column in the conduit.
This invention comprises a guidewire with a tenacious lubricious coating on its surface comprising a finely divided lubricious particulate. The coatings of this invention have a thickness of not more than about 0.00002 inch, a coefficient of friction of not more than about 0.030 and a hardness not less than about 1.0 Mohs. Preferably, the surface coating comprises a monomolecular layer of particulate tungsten disulfide. The guidewire of this invention incorporates an improved distal tip configuration comprising a flexible elongate core member which has at least one tapered section at its distal extremity and a flattened distal portion. The distal portion has two or more flattened regions having cross-sectional areas which decrease in the distal direction. A flexible helical coil is attached to the core member and comprises three or more distinct regions, each having increasing coil spacing in the distal direction. Preferably, the entire length of the guidewire proximal to the helical coil has the lubricious particulate surface coating of the invention.
A dilating device for use in obtaining access to a body organ of a patient comprises, in accordance with the present invention, a plurality of elongate rigid members extending substantially parallel to one another, and an elastic membrane connected to the rigid members for defining a transversely expandable longitudinally extending channel. The rigid members take the form of elongate, substantially cylindrical or conical segments. A needle is inserted through the channel defined by the membrane and the rigid segments. Alternatively, the dilating device is inserted through the needle. Upon expansion of the dilating device, an instrument such as a catheter or endoscope is inserted to implement a surgical or diagnostic procedure.
