WO2023114368A2 - Steerable catheters and related methods - Google Patents

Abstract

A steerable dilator (100) or catheter including an elongated shaft (102) with a proximal end (104) and a distal end (106), an end effector (200) disposed at the distal end (106) of the shaft (102), and a handle (300) disposed at the proximal end (104) of the shaft (102). The end effector (200) includes a dilation portion (202) disposed proximate the distal end (106) of the shaft (102), and a distal tip portion (206) disposed distally on the dilation portion (202). The handle (300) includes a steering actuator (500). Moving the steering actuator (500) in a first or second actuator direction moves the tip portion (206) in a first or second direction respectively in a first steering plane. Moving the steering actuator (500) in a third or fourth actuator direction moves the tip portion (206) in a third or fourth direction respectively in a second steering plane.

Description

STEERABLE CATHETERS AND RELATED METHODS

Cross Reference to Related Application

[0001] This application claims priority to U.S. Provisional Patent Application No. 63/291,028 filed December 17, 2021 , the disclosure of which is incorporated herein by reference in its entirety. This application is also related to U.S. Provisional Patent Application No. 63/041,395 filed June 19, 2020, PCT Patent Application No. PCT/US2021/037803 filed June 17, 2021, and US Patent Application No. 18/080,995, filed December 14, 2022, the disclosures of which are incorporated herein by reference in their entirety.

Technical Field

[0002] The present disclosure generally relates to minimally invasive surgical devices and, more particularly, to steerable catheters. More particularly, the disclosure relates to steerable catheters for creating openings in tissues and/or for Photobiomodulation (PBM Therapy), during minimally invasive neurosurgical procedures, and related methods.

Background

[0003] The present disclosure contemplates that treatments for some conditions may include surgically creating openings through tissues (e.g., biological tissue membranes). For example, for patients suffering from non-communicating hydrocephalus, the normal channel for drainage of the cerebral spinal fluid (“CSF”) from the third ventricle to the lower CSF chambers and central canal that leads to the spinal cord is blocked by an occlusion within the cerebral aqueduct. These patients, through the normal production of the CSF, experience a “rise” in the pressure of the lamina and third ventricles, causing these fluid chambers to distend. To relieve the pressure, neurosurgeons have used a procedure called a third ventriculostomy to rupture the lamina terminalis. This procedure requires creating a hole through the patient’s skull and moving brain tissue to allow the introduction and navigation of an endoscope to the desired site for creation of the ventriculostomy. Once the lamina terminalis is visible in the endoscopic image, a balloon catheter (e.g., Fogarty) is advanced up to and through the membrane. Once the balloon portion of the catheter is passed through the membrane, it is inflated and then retracted through the membrane to create the fenestration (e.g., hole) between the CSF chambers. An alternative ventriculostomy procedure uses similar access through the skull and brain, but, instead of the endoscope/balloon catheter combination, a surgical instrument is used that discretely cauterizes the membrane as it is opened. While such procedures have been successfully used on patients, these procedures involve risks and disadvantages associated with surgically penetrating the skull, dura mater, and/or brain tissues.

[0004] The present disclosure further contemplates that treatments for some conditions may include Photobiomodulation (PBM Therapy) which is the application of red and near infra-red light for medical treatment. The light can originate from a laser or a light emitting diode (LED), and can be pulsed and/or continuous. The health benefits of PBM Therapy are well documented with the application of light typically to the exterior of the body of the patient in a non-invasive manor. Generally, transcranial PBM procedures involve the placement of a light source, or multiple light sources, on one or more areas of the patient’s head, with the goal of treating a certain part of the brain. In transcranial PBM, light must pass through layers of tissue including the scalp, periosteum, skull bone, meninges, and dura, before reaching the cortical surface of the brain. Due to the exponential attenuation of light during the journey through the skull and brain tissues, only a small fraction of the incident light may be delivered to the intended tissue. A device and method of delivering PBM therapy more directly to the tissue to be treated, and specifically the brain and/or spinal tissue, may provide unique benefits.

[0005] Accordingly, and despite the various advances already made in this field, there is a need for further improvements related to steerable catheters for many desired uses during surgical procedures.

Summary

[0006] Generally, a steerable catheter is provided and includes an elongated shaft including a proximal end portion and a distal end portion, an end effector disposed at the distal end portion of the shaft, and a handle disposed at the proximal end portion of the shaft. The end effector includes a distal tip portion disposed distally on the end effector. The handle includes a steering actuator disposed on the handle. The tip portion is movable relative to the shaft. The steering actuator enables a user to steer the tip portion by moving the tip portion with the steering actuator. Moving the steering actuator in a first actuator direction moves the tip portion in a first direction in a first steering plane. Moving the steering actuator in a second actuator direction moves the tip portion in a second direction in the first steering plane, moving the steering actuator in a third actuator direction moves the tip portion in a third direction in a second steering plane. Moving the steering actuator in a fourth actuator direction moves the tip portion in a fourth direction in a second steering plane.

[0007] In some embodiments, the second direction may be generally opposite the first direction in the first steering plane. The third direction may be generally opposite the fourth direction in the second steering plane. The second steering plane may be disposed at a steering plane angle relative to the first steering plane, the steering plane angle being greater than zero. The steering plane angle may be about 90 degrees. [0008] In alternate embodiments, the steering actuator may be generally configured as one or more pivoted supports that allow for the rotation of the steering actuator about a first actuator axis of rotation and a second actuator axis of rotation relative to the handle. Moving the steering actuator in a first actuator direction may rotate the steering actuator about the first actuator axis of rotation and moving the steering actuator in a second actuator direction may rotate the steering actuator about the first actuator axis of rotation, the second actuator direction being generally opposite the first actuator direction. Moving the steering actuator in a third actuator direction may rotate the steering actuator about the second actuator axis of rotation and moving the steering actuator in a fourth actuator direction may rotate the steering actuator about the second actuator axis of rotation, the fourth actuator direction being generally opposite the third actuator direction. The second actuator axis of rotation may be disposed at an actuator axis angle relative to the first actuator axis of rotation, the actuator axis angle being greater than zero. The actuator axis angle may be about 90 degrees. [0009] In alternate or additional aspects, the catheter may include a first, second, third, and fourth steering line operatively connecting the tip portion and the steering actuator. The first, second, third, and fourth steering line may be a high strength fiber. The high strength fiber may be Kevlar. The catheter may include a central lumen extending longitudinally through the handle, the shaft, and the end effector. The central lumen may be configured to receive a guidewire therethrough.

[0010] In some embodiments, the shaft may be generally flexible. A stiffness of the shaft may vary over a length of the shaft between the proximal end portion and the distal end portion. The stiffness of the shaft may vary in discrete intervals over the length of the shaft. The stiffness of the shaft may be greater proximate the proximal end portion than proximate the distal end portion. The shaft may include an inner layer, an intermediate layer, and an outer layer. The outer layer may include a high durometer material. The outer layer may include a braided material. The shaft may include an inner layer, and an outer layer. The outer layer may include a high durometer material. The outer layer may include a braided material.

[0011] In alternate embodiments, the catheter may include a tip portion energizing element disposed on the tip portion. The tip portion energizing element may be configured to be operatively connected to a source of electrical energy. The catheter may include a dilation portion disposed on the end effector, the dilation portion including a dilation portion energizing element. The dilation portion energizing element may be configured to be operatively connected to a source of electrical energy.

[0012] In some embodiments, the catheter may include a dilation portion disposed on the end effector, the dilation portion including an expandable element. The dilation portion expandable element may include a radiopaque material. The dilation portion expandable element may include an inflatable element. The dilation portion inflatable element may be generally toroidal when inflated. The dilation portion inflatable element may be generally cylindrical when not inflated. The dilation portion inflatable element may be generally spherical when inflated.

[0013] In alternate embodiments, the catheter may include an expandable element disposed on the tip portion. The tip portion expandable element may include a radiopaque material. The tip portion expandable element may include an inflatable element. The tip portion inflatable element may generally mimic the shape of the tip when not inflated and may be generally teardrop shaped when inflated.

[0014] In some embodiments, the catheter may include a stent portion removably disposed on the end effector. The stent portion may be generally cylindrical. The stent portion may be generally tapered at the distal end of the stent. The stent portion may have a stent diameter and a distal end diameter. The stent diameter may be greater than the tip portion diameter. The stent distal end diameter may be less than the tip portion diameter. The stent portion may be generally flexible. The stent portion may be directed to a location by the catheter. The catheter may be withdrawn from the stent portion leaving the stent portion in said location.

[0015] In some embodiments, the catheter may include a light element disposed on the tip portion. The light element may be configured to be operatively connected to a source of light. The source of light may be configured to deliver light to the light element. [0016] In another embodiment, a steerable dilator is provided and includes an elongated shaft, an end effector disposed at the distal end portion of the shaft, and a handle disposed at the proximal end portion of the shaft. The shaft includes a proximal end portion and a distal end portion. The end effector includes a dilation portion disposed proximate the distal end portion of the shaft and a distal tip portion disposed distally on the dilation portion. The handle includes a steering actuator disposed on the handle. The tip portion is movable relative to the shaft. The steering actuator enables a user to steer the tip portion by moving the tip portion with the steering actuator. Moving the steering actuator in a first actuator direction moves the tip portion in a first direction in a first steering plane. Moving the steering actuator in a second actuator direction moves the tip portion in a second direction in the first steering plane. Moving the steering actuator in a third actuator direction moves the tip portion in a third direction in a second steering plane. Moving the steering actuator in a fourth actuator direction moves the tip portion in a fourth direction in a second steering plane.

[0017] In some embodiments, the second direction may be generally opposite the first direction in the first steering plane. The third direction may be generally opposite the fourth direction in the second steering plane. The second steering plane may be disposed at a steering plane angle relative to the first steering plane, the steering plane angle being greater than zero. The steering plane angle may be about 90 degrees. [0018] In alternate embodiments, the steering actuator may be generally configured as one or more pivoted supports that allow for the rotation of the steering actuator about a first actuator axis of rotation and a second actuator axis of rotation relative to the handle. Moving the steering actuator in a first actuator direction may rotate the steering actuator about the first actuator axis of rotation and moving the steering actuator in a second actuator direction may rotate the steering actuator about the first actuator axis of rotation, the second actuator direction being generally opposite the first actuator direction. Moving the steering actuator in a third actuator direction may rotate the steering actuator about the second actuator axis of rotation and moving the steering actuator in a fourth actuator direction may rotate the steering actuator about the second actuator axis of rotation, the fourth actuator direction being generally opposite the third actuator direction. The second actuator axis of rotation may be disposed at an actuator axis angle relative to the first actuator axis of rotation, the actuator axis angle being greater than zero. The actuator axis angle may be about 90 degrees.

[0019] In some embodiments, the dilator may include a first, second, third, and fourth steering line operatively connecting the tip portion and the steering actuator. The first, second, third, and fourth steering line may include a high strength fiber. The high strength fiber may include Kevlar. The dilator may include a central lumen extending longitudinally through the handle, the shaft, and the end effector. The central lumen may be configured to receive a guidewire therethrough.

[0020] In alternate or additional aspects, the shaft may be generally flexible. A stiffness of the shaft may vary over a length of the shaft between the proximal end portion and the distal end portion. The stiffness of the shaft may vary in discrete intervals over the length of the shaft. The stiffness of the shaft may be greater proximate the proximal end portion than proximate the distal end portion. The shaft may include an inner layer, an intermediate layer, and an outer layer. The outer layer may include a high durometer material. The outer layer may include a braided material. The shaft may include an inner layer, and an outer layer. The outer layer may be a high durometer material. The outer layer may include a braided material. [0021] In some embodiments, the dilator may include a tip portion energizing element disposed on the tip portion. The tip portion energizing element may be configured to be operatively connected to a source of electrical energy. The dilator may include a dilation portion energizing element disposed on the dilation portion. The dilation portion energizing element may be configured to be operatively connected to a source of electrical energy. The dilator may include an expandable element disposed on the dilation portion. The dilation portion expandable element may include a radiopaque material. The dilation portion expandable element may include an inflatable element. The dilation portion inflatable element may be generally toroidal when inflated. The dilation portion inflatable element may be generally cylindrical when not inflated. The dilation portion inflatable element may be generally spherical when inflated.

[0022] In alternate embodiments, the dilator may include an expandable element disposed on the tip portion. The tip portion expandable element may include a radiopaque material. The tip portion expandable element may include an inflatable element. The tip portion inflatable element may generally mimic the shape of the tip when not inflated and may be generally teardrop shaped when inflated.

[0023] In some embodiments, the dilator may include a stent portion removably disposed on the end effector. The stent portion may be generally cylindrical. The stent portion may be generally tapered at the distal end of the stent. The stent portion may have a stent diameter and a distal end diameter. The stent diameter may be greater than the tip portion diameter. The distal end diameter may be less than the tip portion diameter. The stent portion may be generally flexible. The stent portion may be directed to a location by the dilator. The dilator may be withdrawn from the stent portion leaving the stent portion in said location.

[0024] In some embodiments, the dilator may include a light element disposed on the tip portion. The light element may be configured to be operatively connected to a source of light. The source of light may be configured to deliver light to the light element. [0025] Generally, a method of creating an opening in a biological tissue membrane is provided. The method includes advancing an end effector of a dilator to proximate a biological tissue membrane. An initial opening through the membrane is created by advancing a tip portion of the end effector through the membrane. The initial opening is expanded by advancing at least a portion of the end effector through the membrane. The end effector is withdrawn from the expanded opening. Advancing the end effector of the dilator to the biological tissue membrane includes steering the tip portion of the end effector.

[0026] In some embodiments, steering the tip portion includes steering the tip portion in a first and second direction in a first steering plane. Steering the tip portion may include steering the tip portion in a third and fourth direction in a second steering plane. The method may include at least partially expanding an expandable element disposed on the end effector. At least partially expanding the expandable element may include at least partially inflating an inflatable element. At least partially inflating the inflatable element may include injecting a fluid into the inflatable element.

[0027] Generally, a method of applying light to brain and/or spinal cord tissue is provided. The method includes advancing a catheter to proximate the brain and/or spinal cord tissue and applying light to the brain and/or spinal cord tissue. Advancing the catheter to the brain and/or spinal cord tissue includes steering a tip portion of the catheter.

[0028] Steering the tip portion may include steering the tip portion in a first and second direction in a first steering plane. Steering the tip portion may include steering the tip portion in a third and fourth direction in a second steering plane. The method may include energizing a light element disposed on the tip portion. Energizing the light element may include supplying light to the light element.

[0029]

[0030] Generally, a method of placing a stent in a biological tissue is provided. The method includes installing a stent over an end of a catheter, advancing the stent using the catheter to a location in the biological tissue, locating the stent in the biological tissue, and withdrawing the catheter from the stent leaving the stent in the biological tissue. Advancing the stent includes steering a tip portion of the catheter.

[0031] Steering the tip portion may include steering the tip portion in a first and second direction in a first steering plane. Steering the tip portion may include steering the tip portion in a third and fourth direction in a second steering plane. [0032] Additional features and advantages of the inventive aspects will become more apparent upon review of the following detailed description taken together with accompanying drawings of the illustrative and exemplary embodiments.

Brief Description of Drawings

[0033] FIG. 1 is an isometric view of an illustrative steerable dilator.

[0034] FIG. 2 is an isometric sectional view of an illustrative end effector of the steerable dilator of FIG. 1.

[0035] FIG. 2A is an isometric sectional view of the end effector of the FIG. 2. showing an illustrative expandable element.

[0036] FIGS. 3 and 4 are alternate isometric sectional views of the illustrative end effector of FIG. 2.

[0037] FIG. 5A is a cross sectional view of an illustrative shaft proximate a handle of the steerable dilator of FIG. 1.

[0038] FIG. 5B is a cross sectional view of an illustrative shaft proximate the end effector of the steerable dilator of FIG. 1.

[0039] FIGS. 6 through 8 are isometric sectional views of an illustrative handle and steering actuator of the steerable dilator of FIG. 1.

[0040] FIGS. 9 through 11 are isometric sectional views of an alternate illustrative handle and steering actuator of a steerable dilator.

[0041] FIGS. 12A through 12C are detailed isometric views of the steering actuator of FIGS. 9 through 11.

[0042] FIGS 13 and 14 illustrate a stent being placed in a vessel.

Detailed Description

[0043] Illustrative embodiments according to at least some aspects of the present disclosure are described and illustrated below and include devices and methods relating to surgical procedures. Of course, it will be apparent to those of ordinary skill in the art that the embodiments discussed below are examples and may be reconfigured without departing from the scope and spirit of the present disclosure. It is also to be understood that variations of the exemplary embodiments contemplated by one of ordinary skill in the art shall concurrently comprise part of the instant disclosure. However, for clarity and precision, the illustrative embodiments as discussed below may include optional steps, methods, and features that one of ordinary skill should recognize as not being a requisite to fall within the scope of the present disclosure.

[0044] The present disclosure includes, among other things, steerable dilators. As used herein, the term steerable dilator, or simply dilator, includes but is not limited to steerable catheters with a dilation mechanism. It should be understood that some embodiments described herein may comprise steerable catheters that do not necessarily include a dilation mechanism. Some illustrative embodiments according to at least some aspects of the present disclosure may be used in connection with creating openings in tissues during minimally invasive neurosurgical procedures. For example, illustrative apparatus and methods disclosed herein may be utilized in connection with minimally invasive surgical treatment of hydrocephalus involving creation of an opening through the lamina terminalis. While the present detailed description of illustrative embodiments focuses on minimally invasive neurosurgical procedures, it will be appreciated that various embodiments according to at least some aspects of the present disclosure may be utilized in connection with other procedures. Additionally, although some features may be described herein in connection with particular exemplary embodiments, one of skill in the art will appreciate that any features described herein may be used alone or in any combination within and between various embodiments.

[0045] FIG. 1 is an isometric view of an illustrative steerable dilator 100, according to at least some aspects of the present disclosure. The dilator 100 includes an elongated shaft 102 having a proximal end portion 104 and a distal end portion 106. As used herein to describe various embodiments from the perspective of a user of a surgical device, “proximal” may refer to a direction generally towards the user of the device, while “distal” may refer to a direction generally away from the user of the device. Similarly, in the context of a surgical device inserted into a patient’s body and from the perspective of a user of the device, “proximal” may refer to a direction generally away from the center of the patient’s body, and “distal” may refer to a direction generally towards the center of the patient’s body. For reference, arrow 10 points generally proximally and arrow 12 points generally distally. The dilator 100 includes an end effector 200 disposed at the distal end portion 106 of the shaft 102, and a handle 300 disposed at the proximal end portion 104 of the shaft 102. A strain relief portion 108 is fixed generally between the relatively rigid handle 300 and the more flexible shaft 102 to distribute forces more evenly between the handle 300 and the shaft 102. For example, the strain relief portion 108 may be formed of a polymer with a hardness of about Shore 40D to about Shore 60D that flexes with the proximal end portion 104 of the shaft 102. [0046] FIG. 2 is an isometric sectional view of an illustrative end effector 200, FIG. 2A is an isometric sectional view of the end effector 200 showing an illustrative expandable element 204, and FIGS. 3 and 4 are alternate isometric sectional views of the illustrative end effector 200, all according to at least some aspects of the present disclosure. FIG. 5A is a cross sectional view of the shaft 102 proximate the handle 300 (see FIG. 1). FIG. 5B is a cross sectional view of the shaft 102 proximate the end effector 200 (see FIGS. 1 and 2). The illustrative end effector 200 includes a proximal dilation portion 202 disposed proximate the distal end portion 106 of the shaft 102, and a distal tip portion 206 disposed distally on the dilation portion 202. The tip portion 206 has a tip portion diameter 208 and the dilation portion has a dilation portion diameter 210. The dilation portion diameter 210 may be the same as the tip portion diameter 208. In some exemplary embodiments, a shaft diameter 110 may approximately equal the dilation portion diameter 210. The tip portion 206 may be constructed of a radiopaque material, which may facilitate visualization of the dilator 100 using various medical imaging modalities.

[0047] Referring to FIGS. 2 through 5B, the illustrative end effector 200 is configured so that the tip portion 206 is steerable in a horizontal steering plane 14 as shown by arrows 16a, 16b and a vertical steering plane 18 as shown by arrows 20a, 20b. Generally, the tip portion 206 is steerable relative to the dilation portion 202 and/or the shaft 102. The horizontal steering plane 14 is disposed transversely relative to the vertical steering plane 18. As used herein, “transverse” may refer to relative angular orientations that are non-parallel (e.g., perpendicular or oblique). For example, the horizontal steering plane 14 may be disposed at a steering plane angle 22 of about 90 degrees relative to the vertical steering plane 18 as shown in FIG. 4. Such a configuration may be advantageous for some uses in which it may be desirable to utilize 3D steering of the dilator 100 relative to the longitudinal axis of the shaft 102. In other exemplary embodiments, the steering plane angle 22 may be between 0 and 90 degrees, for example.

[0048] The illustrative end effector 200 is steerable through the action of one or more tension elements. The tip portion 206 is steerable in the horizontal steering plane 14 by the selective distal pulling of a first steering line 220 and a second steering line 222. Specifically, pulling distally on the first steering line 220 causes the tip portion 206 to flex in the direction of arrow 16a. Pulling distally on the second steering line 222 causes the tip portion 206 to flex in the direction of arrow 16b. The directions of arrow 16a and the direction of arrow 16b may be generally opposite directions.

[0049] Similarly, the tip portion 206 is steerable in the vertical steering plane 18 by the selective distal pulling of a third steering line 224 and a fourth steering line 226. Specifically, pulling distally on the third steering line 224 causes the tip portion 206 to flex in the direction of arrow 20a. Pulling distally on the fourth steering line 226 causes the tip portion 206 to flex in the direction of arrow 20b. The direction of arrow 20a and the direction of arrow 20b may be generally opposite directions.

[0050] In this illustrative embodiment, the steering lines 220, 222, 224, 226 are secured to the end effector 200 by “hooking” 220a, 222a, 224a, 226a the steering lines 220, 222, 224, 226. In some embodiments, the steering lines 220, 222, 224, 226 may be “hooked” into an adjacent lumen, for example. In some embodiments, the steering lines 220, 222, 224, 226 may be connected to the tip portion 206. In some embodiments, the end effector 200 may include a steering ring and the steering lines 220, 222, 224, 226 may be connected to the steering ring. The steering ring may be constructed of a radiopaque material, which may facilitate visualization of the dilator 100 using various medical imaging modalities.

[0051] In this illustrative embodiment, the shaft 102 may include longitudinal lumens extending from the proximal end portion 104 to the distal end portion 106. Each of the steering lines 220, 222, 224, 226 is slidably disposed within a respective steering line lumen 120, 122, 124, 126. In this exemplary embodiment, the lumens of each respective pair of steering line lumens 120, 122, 124, 126 are positioned substantially diametrically opposite each other (e.g., about 180 degrees relative to each other). [0052] In this illustrative embodiment, a guidewire lumen 128 extends longitudinally through the end effector 200, shaft 102, and handle 300, and is configured to slidably receive a guidewire therethrough. In the illustrative embodiment, the guidewire lumen 128 is substantially centrally located in the shaft 102 and the end effector 200.

[0053] As described below, the tension elements, steering lines 220, 222, 224, 226, are tensioned by an actuator 500 disposed on the handle 300 (see FIG. 1). Generally, the tension elements may be constructed of any materials capable of transmitting a tensile force from the actuator 500 to the distal end of the end effector 200. For example, the steering lines 220, 222, 224, 226 may comprise metal wires and/or various suture materials. Steering lines 220, 222, 224, 226 may be constructed of a high strength fiber, such as Kevlar, for example. High strength fiber may allow for reduced clearance between the steering lines 220, 222, 224, 226 and the lumen 120, 122, 124, 126 thereby allowing for a smaller lumen diameter and increasing the strength of the shaft extrusion. High strength fiber steering lines 220, 222, 224, 226 may reduce friction between the steering lines 220, 222, 224, 226 and the lumen 120, 122, 124, 126 improving steering response. Smaller lumen diameters may allow a greater number of lumens for a given outer diameter of a shaft extrusion. Various cross sectional shapes may be utilized for the steering lines 220, 222, 224, 226. For example, a steering line may have a generally round cross section, or it may have a generally rectangular cross section, such as in devices requiring smaller tip portion 206 outer diameters 208.

[0054] Referring again to FIGS. 2 through 5B, the illustrative end effector 200 includes a dilation portion expandable element 204, such as an inflatable element, coupled to the dilation portion 202. The end effector 200 also includes one or more marker bands 230. The dilation portion expandable element 204 may generally mimic the contour and diameter of the dilation portion 202. The dilation portion expandable element 204 is selectively expandable from approximately the expandable portion diameter 210, see FIG. 2, to a fully expanded diameter 210a, see FIG. 2A. In one exemplary embodiment, the dilation portion expandable element 204 may comprise a generally toroidal inflatable element configured to have an expanded diameter. In other exemplary embodiments, the dilation portion expandable element 204 may comprise an inflatable element of a non-toroidal shape, for example. In some exemplary embodiments, the dilation portion expandable element 204 including an inflatable element may be generally in the form of a compliant balloon having a hardness of about Shore 60A to about Shore 25D. The dilation portion expandable element 204 may be fully inflated or partially expanded, such as by injecting and/or withdrawing fluid (e.g., a liquid or a gas) to achieve a desired partially or fully expanded diameter. Fluid may be injected and/or withdrawn via a coupling 310b, described in more detail herein, at the proximal end of the handle 300, for example. The coupling 310b is operably connected to the expandable element 204 through a lumen in the shaft 102 and end effector 200, for example. In some exemplary embodiments, the dilation portion expandable element 204 may be constructed of radiopaque materials, which may facilitate visualization of the end effector 200 using various medical imaging modalities.

[0055] In this illustrative example, the tip portion 206 includes a flushing port 234. The flushing port 234 is operably connected to the coupling 310c, described in more detail herein, via a lumen 134 that runs from the flushing port 234 in the tip portion 206 through the shaft 102 and through the proximal end of the handle 300. A syringe may be connected to the coupling 310c, for example, to inject fluid (e.g., saline, contrast) through the flushing port 234.

[0056] FIGS. 6 through 8 are isometric sectional views of an illustrative handle 300 including an illustrative actuator 500, all according to at least some aspects of the present disclosure. Referring to FIGS. 1 through 7, the handle 300 comprises a handle body 302 generally configured to be gripped by a user’s hand and the steering actuator 500 is rotatably disposed on the handle 300. The shaft 102 is coupled to the handle 300 and passes through the strain relief portion 108 and a portion of the steering actuator 500. The steering lines 220, 222, 224, 226 are routed through respective steering line lumens 120, 122, 124, 126 from the steering actuator 500 through the shaft 102 and to the end effector 200.

[0057] In this exemplary embodiment, the steering actuator 500 is generally a pair of gimbals or pivoted supports that allow for the rotation of the steering actuator 500 about a first axis of rotation 502 and a second axis of rotation 504 relative to the handle 300. In this illustrative example the second axis of rotation 504 is generally along the length of the shaft 102 and the first axis of rotation 502 is generally perpendicular to the second axis of rotation 504. The steering actuator 500 may be moved by a user in relation to the handle 300 in any and/or all directions indicated by arrows 26a, 26b, 30a, and 30b.

[0058] In this exemplary embodiment, the steering actuator 500 includes an x- axis gimbal 510, a y-axis gimbal 540, an x-axis gimbal pinion 560, and an actuator handle 580. The x-axis gimbal 510 is rotatably mounted to the y-axis gimbal 540. The y-axis gimbal 540 includes a pair of gimbal shafts 542, 544. The gimbal shafts 542, 544 of the y-axis gimbal 540 are rotatably mounted on the handle 300. The x-axis gimbal pinion 560 is rotatably mounted to the x-axis gimbal 510. The actuator handle 580 is coupled to the x-axis gimbal 510. The y-axis gimbal 540 includes a tooth portion 546 arranged to engage an opposed tooth portion 562 on the x-axis gimbal pinion 560. In this illustrative embodiment, the tooth portions 546, 562 act as a matched pair of beveled gears. The steering actuator 500 includes four steering line attachment points 520, 522, 524, 526. The x-axis gimbal 510 includes steering line attachment point 524. The y-axis gimbal 540 includes steering line attachment point 526. The x-axis gimbal pinion 560 includes steering line shafts 564, 566 which include steering line attachment points 520, 522 respectively.

[0059] In this illustrative embodiment, the steering actuator 500 is disposed on the handle 300 such that the actuator handle 580 may be moved by the user about the first and second axes of rotation 502, 504 by moving the actuator handle 580 in the directions defined by the arrows 26a, 26b and 30a, 30b respectively. Moving the actuator handle 580 in the direction of arrows 26a, 26b rotates the steering actuator 500 about the first axis of rotation 502 with the gimbal shafts 542, 544 of the y-axis gimbal 540 rotating relative to the handle 300. Moving the actuator handle 580 in the direction of arrows 30a, 30b rotates the x-axis gimbal 510 about the second axis of rotation 504. Further, moving the actuator handle 580 in the direction of arrows 30a, 30b causes the tooth portion 546 on the y-axis gimbal 540 to apply a force to the tooth portion 562 on the x-axis gimbal pinion 560 causing the x-axis gimbal pinion 560 to rotate in relation to the x-axis gimbal 510 about a third axis of rotation 506.

[0060] Referring to FIGS. 1 through 3, and 6 through 8, the tip portion 206 of the end effector 200 is steerable through the action of steering lines 220, 222, 224, 226 and the steering actuator 500. In this illustrative embodiment, the steering lines 220, 222, 224, 226 are connected to the steering line attachment points 520, 522, 524, 526 respectively. The steering lines 220, 222, 224, 226, may be connected to the attachment points 520, 522, 524, 526 by a weld or solder joint, or a mechanical fastener, for example.

[0061] In this illustrative embodiment, moving the actuator handle 580 in the direction of arrows 26a and 26b rotates the steering actuator 500 about the axis of rotation 502 thereby alternatively creating tension on steering lines 222, 226. By moving the actuator handle 580 in the direction of the arrow 26a the steering actuator 500 creates tension on steering line 224 thereby moving the tip portion 206 in the direction of arrow 20a. By moving the actuator handle 580 in the direction of arrow 26b the steering actuator 500 creates tension on steering line 226 thereby moving the tip portion 206 in the direction of arrow 20b.

[0062] In this illustrative embodiment, moving the actuator handle 580 in the direction of arrows 30a and 30b rotates the steering actuator 500 about the axis of rotation 504 thereby alternatively creating tension on steering lines 220, 222. By moving the actuator handle 580 in the direction of arrow 30a the steering actuator 500 creates tension on steering line 220 thereby moving the tip portion 206 in the direction of arrow 16a. By moving the actuator handle 580 in the direction of arrow 30b the steering actuator 500 creates tension on steering line 122 thereby moving the tip portion 206 in the direction of arrow 16b. A user may grasp the handle 300 with one hand and operate the actuator handle 580 with a thumb of said hand allowing for a single hand operation of the steering actuator 500, for example.

[0063] In this illustrative example, one or more mechanical couplings 310a, 310b, 310c, such as Luer-lock fittings, are provided at the proximal end of the handle 300, see FIG. 1. In this illustrative embodiment, the guidewire lumen 128 runs from the tip portion 206 through the shaft 102 and through the proximal end of the handle 300. The mechanical coupling 310a is coupled to the guidewire lumen 128 to facilitate, for example, attachment of a syringe for injection of fluid (e.g., saline, contrast) through the guidewire lumen 128. The coupling 310a may be used in connection with insertion of a guidewire and/or to attach a sealing device to prevent fluid leakage via the guidewire lumen 128.

[0064] Referring to FIGS. 5A and 5B, the shaft 102 may be constructed from one or more layers. For example, this illustrative embodiment includes an inner layer 130 and an outer layer 132. In some exemplary embodiments, the layers 130, 132 are formed separately and are then joined, such as using a thermal bonding process and/or a chemical bonding process. Alternatively, the layers 130, 132 may be formed together. [0065] In this illustrative embodiment, the inner layer 130 comprises a polymer, such as a polymer extrusion. The inner layer 130 may be substantially uniform over the length of the shaft 102, or some characteristics may vary over the length of the shaft 102. For example, in the illustrative embodiment, the inner layer 130 comprises a plurality of extruded segments facilitating a differing stiffness over the length of the shaft 102. As used herein, “stiffness” may refer to the resistance of an object to deformation under an applied force. In this exemplary embodiment, the stiffness of the inner layer 130 decreases from proximal to distal so that the shaft 102 is generally stiff proximally for pushability (e.g., relatively high buckling strength) and/or is generally softer or more flexible distally for flexibility and atraumatic contact with tissue. In the illustrative embodiment, the inner layer 130 extends substantially from the handle 300 to the tip portion 206 of the end effector 200. The stiffness changes may occur in discrete intervals. The distal portion (e.g., near the tip portion 206) may comprise a polymer having a stiffness of about Shore 80A or less. The proximal portion (e.g., near the handle 300) may comprise a polymer having a stiffness of about Shore 75D or higher, which may approximately match the stiffness of the handle 300 material. In some exemplary embodiments, various intermediate segments (e.g., between a distal-most segment and a proximal-most segment) may vary in stiffness, such as in a stepwise fashion. For example, some intermediate segments may increase in Shore 10D to Shore 15D increments (e.g., 25D, 40D, 55D, 65D) from distal to proximal. In some embodiments, the outer diameter of the inner layer 130 may be about 0.7 mm to about 1.7 mm. Different diameters may be useful when different anatomy will be traversed and/or to accommodate different sized guidewires, for example.

[0066] In this illustrative embodiment, the outer layer 132 comprises a high durometer material (e.g., polyimide, nylon, Pebax 72D). In some embodiments, the outer layer 132 may comprise a composite structure including a braided and/or coiled material. A composite structure on the outer layer 132 may allow a user to better predict the steering at the tip (close to 1 :1 on input to output motion) for example. A composite structure may minimize or eliminate twisting of the shaft 102 enabling a user to maintain the top-dead-center of the device 100 at the end effector 200 by essentially maintaining the handle 300 alignment with the end effector 200. Without this alignment, any twisting of the shaft 102 may result in inputs to the steering actuator 500 not producing the desired outputs at the tip portion 206, i.e. the tip portion 206 may not turn in the desired direction. A braided material may provide a better torque response than a coil or no braid, for example. In the illustrative embodiment, the outer layer 132 is configured to resist kinking of the shaft 102 and/or to increase the torsional strength of the shaft 102. In some exemplary embodiments, some characteristics of the outer layer 132 may vary over the length of the shaft 102. For example, the pitch and/or pick rate of a coil or braided outer layer 132 may vary over the length of the shaft 102. In some embodiments, the braid or coil may be more open (providing better pushability due to the pattern extending more axially) toward the proximal end portion 104 of the shaft 102 and the braid or coil may be more closed (providing better flexibility due to the pattern being positioned more radially) toward the distal end portion 106 of the shaft 102. A coil may be used if a more torturous path requires a greater kink resistance than what may be achieved with a braid, for example. Some illustrative embodiments may not include a structural reinforcing layer (e.g., outer layer 132). For example, a device configured for use where the pathway from the access site to the treatment site is not tortuous may not require the torsional stiffness and/or kink resistance provided by such an outer layer 132. In the illustrative embodiment, the outer layer 132 extends substantially from the distal end portion 106 of the shaft 102 to the proximal end portion 104 of the shaft 102. In some embodiments, the distal end of the outer layer 132 may be 10-15 cm proximal from the tip portion 206. [0067] In some exemplary embodiments, various intermediate segments (e.g., between a distal-most segment and a proximal-most segment) may vary in stiffness, such as in a stepwise fashion. For example, some intermediate segments may increase in Shore 10D to Shore 15D increments (e.g., 40D, 55D, 65D) from distal to proximal. In some embodiments, the segments of the outer layer 132 may be positioned to overlap the segments of the inner layer 130, which may provide generally smoother stiffness transitions over the length of the shaft 102. In some embodiments, the outer diameter of the outer layer 132 may be about 2.3 mm to about 3.0 mm. Different diameters may be useful for creating different opening sizes at the treatment site, for example.

[0068] FIGS. 9 through 11 are isometric views of an alternative illustrative handle 1300 and steering actuator 1500, and FIGS. 12A through 12C are detailed isometric views of the steering actuator 1500, according to at least some aspects of the present disclosure. Generally, the handle 1300 and steering actuator 1500 are similar in construction and operation to the handle 300 and steering actuator 500 described above and any feature(s) of the handle 1300 and steering actuator 1500 may be used in various other exemplary embodiments according to the present disclosure. Like reference numbers refer to like components and attendant function. For brevity, the following description omits redundant description and focuses on the differences between the handle 1300 and steering actuator 1500 and the handle 300 and steering actuator 500.

[0069] In this exemplary embodiment, the steering actuator 1500 is generally a pair of gimbals or pivoted supports that allow for the rotation of the steering actuator 1500 about a first axis of rotation 502 and a second axis of rotation 504 relative to the handle 1300. The steering actuator 1500 may be moved by a user in relation to the handle 1300 in any and/or all directions indicated by arrows 26a, 26b, 30a, and 30b. [0070] In this exemplary embodiment, the steering actuator 1500 includes a yoke 1510, a clevis 1530, a frame 1540, a back bevel gear 1550, a lateral crank 1560, and an actuator handle 1580. The yoke 1510 is rotatably coupled to the clevis 1530. The clevis 1530 is rotatably coupled to the frame 1540. The clevis 1530 is coupled to the back bevel gear 1550. The frame 1540 includes a pair of shafts 1542, 1544. The frame 1540 is rotatably mounted on the handle 1300 by the shafts 1542, 1544. The lateral crank 1560 is rotatably mounted to the frame 1540. The actuator handle 1580 is coupled to the yoke 1510. The back bevel gear 1550 includes a tooth portion 1552 arranged to engage an opposed tooth portion 1562 on the lateral crank 1560. In this illustrative embodiment, the tooth portions 1552, 1562 act as a matched pair of beveled gears. The steering actuator 1500 includes four steering line attachment points 1520, 1522, 1524, 1526. The yoke 1510 includes steering line attachment points 1524, 1526. The lateral crank 1560 includes steering line attachment points 1520, 1522.

[0071] In this illustrative embodiment, the steering actuator 1500 is disposed on the handle 1300 such that the actuator handle 1580 may be moved by the user about the first and second axes of rotation 502, 504 by moving the actuator handle 1580 in the directions defined by the arrows 26a, 26b and 30a, 30b respectively. Moving the actuator handle 1580 in the direction of arrows 26a, 26b rotates the steering actuator 1500 about the first axis of rotation. Moving the actuator handle 1580 in the direction of arrows 30a, 30b rotates the yoke 1510 about the second axis of rotation 504. Further, moving the actuator handle 1580 in the direction of arrows 30a, 30b causes the tooth portion 1552 on the back bevel gear 1550 to apply a force to the tooth portion 1562 on the lateral crank 1560 causing the lateral crank 1560 to rotate in relation to the frame 1510 about a third axis of rotation 1506.

[0072] Referring to FIGS. 1 through 3, and 9 through 12c, the tip portion 206 of the end effector 200 is steerable through the action of steering lines 220, 222, 224, 226 and the steering actuator 1500. In this illustrative embodiment, the steering lines 220, 222, 224, 226 are connected to the steering line attachment points 1520, 1522, 1524, 1526 respectively. The steering lines 220, 222, 224, 226, may be connected to the attachment points 1520, 1522, 1524, 1526 by a weld or solder joint, or a mechanical fastener, for example.

[0073] In this illustrative embodiment, moving the actuator handle 1580 in the direction of arrows 26a and 26b rotates the steering actuator 1500 about the axis of rotation 502 thereby alternatively creating tension on steering lines 222, 226. By moving the actuator handle 1580 in the direction of the arrow 26a the steering actuator 1500 creates tension on steering line 224 thereby moving the tip portion 206 in the direction of arrow 20a. By moving the actuator handle 1580 in the direction of arrow 26b the steering actuator 1500 creates tension on steering line 226 thereby moving the tip portion 206 in the direction of arrow 20b.

[0074] In this illustrative embodiment, moving the actuator handle 1580 in the direction of arrows 30a and 30b rotates the steering actuator 1500 about the axis of rotation 504 thereby alternatively creating tension on steering lines 220, 222. By moving the actuator handle 1580 in the direction of arrow 30a the steering actuator 1500 creates tension on steering line 220 thereby moving the tip portion 206 in the direction of arrow 16a. By moving the actuator handle 1580 in the direction of arrow 30b the steering actuator 500 creates tension on steering line 122 thereby moving the tip portion 206 in the direction of arrow 16b.

[0075] In some embodiments, the end effector 200 may include one or more energizing elements, such as a tip energizing element and/or a dilation portion energizing element. The tip energizing element may form the distal end of the tip portion 106. The energizing element of the distal tip portion 106 may be configured to receive electrical energy via a wiring harness and may be configured to deliver the electrical energy to biological tissues. Depending on the electrosurgical technique that is employed, the wiring harness may comprise one or more separate and/or insulated conductors. The energizing element may be constructed of radiopaque materials, which may facilitate visualization of the dilator using various medical imaging modalities. The distal end of the tip portion may be defined at least partially by the tip energizing element. The tip energizing element may be shaped to facilitate passage of the tip portion 106 through a biological tissue membrane. The tip energizing element 106 may include a beveled shape (e.g., generally beveled) and/or other shapes, such as radiuses and/or tapers (e.g., generally rounded or pointed).

[0076] In some embodiments, the end effector 200 may include one or more light elements, which may form the distal end of the tip portion 106. As described below, the light element of the distal tip portion 106 may be configured to receive light via an optical fiber harness and may be configured to deliver the light to biological tissues. Depending on the surgical technique that is employed, the optical fiber harness may comprise one or more separate optical fibers. In some exemplary embodiments, the light element may be constructed of radiopaque materials. The light element may be shaped to facilitate passage of the tip portion 106 through a biological tissue membrane. The light element may include a beveled shape (e.g., generally beveled) and/or other shapes, such as radiuses and/or tapers (e.g., generally rounded or pointed).

[0077] FIGS 13 and 14 illustrate a stent 600 being placed in a vessel 610. In some embodiments, a stent 600 may be disposed on the end effector 200. The stent 600 may be generally cylindrical and generally mimic the contour and diameter 210 of the end effector 200 to fit over the end effector 200. The stent 600 may be generally tapered at the distal end. The stent may have a stent diameter 602 and a distal end diameter 604. The stent diameter 602 may be greater than the tip portion diameter 208 and the distal end diameter 604 may be less than the tip portion diameter 208. The stent 600 may be generally flexible for steerability with the end effector 200. With the stent on the end effector 200, the stent may be directed to a location by the user utilizing the dilator 100, see FIG. 13. Once in a location determined by the user, the dilator 100 may be withdrawn from the stent 600 leaving the stent 600 in said location, see FIG. 14.

[0078] While the present invention has been illustrated by the description of specific embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features discussed herein may be used alone or in any combination within and between the various embodiments. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of the general inventive concept.

Claims

What is claimed is:

1. A steerable catheter comprising: an elongated shaft comprising a proximal end portion and a distal end portion; an end effector disposed at the distal end portion of the shaft, the end effector including a distal tip portion disposed distally on the end effector; and a handle disposed at the proximal end portion of the shaft, the handle comprising a steering actuator disposed on the handle; wherein the tip portion is movable relative to the shaft, the steering actuator enables a user to steer the tip portion by moving the tip portion with the steering actuator, moving the steering actuator in a first actuator direction moves the tip portion in a first direction in a first steering plane, moving the steering actuator in a second actuator direction moves the tip portion in a second direction in the first steering plane, moving the steering actuator in a third actuator direction moves the tip portion in a third direction in a second steering plane, and moving the steering actuator in a fourth actuator direction moves the tip portion in a fourth direction in a second steering plane.

2. The catheter of claim 1 , wherein the second direction is generally opposite the first direction in the first steering plane.

3. The catheter of claim 1 , wherein the third direction is generally opposite the fourth direction in the second steering plane.

4. The catheter of claim 1 , wherein the second steering plane is disposed at a steering plane angle relative to the first steering plane, the steering plane angle being greater than zero.

5. The catheter of claim 4, wherein the steering plane angle is about 90 degrees.

23

6. The catheter of claim 1 , wherein the steering actuator is generally configured as one or more pivoted supports that allow for the rotation of the steering actuator about a first actuator axis of rotation and a second actuator axis of rotation relative to the handle.

7. The catheter of claim 6, wherein moving the steering actuator in a first actuator direction rotates the steering actuator about the first actuator axis of rotation and moving the steering actuator in a second actuator direction rotates the steering actuator about the first actuator axis of rotation, the second actuator direction being generally opposite the first actuator direction.

8. The catheter of claim 7, wherein moving the steering actuator in a third actuator direction rotates the steering actuator about the second actuator axis of rotation and moving the steering actuator in a fourth actuator direction rotates the steering actuator about the second actuator axis of rotation, the fourth actuator direction being generally opposite the third actuator direction.

9. The catheter of claim 6, wherein the second actuator axis of rotation is disposed at an actuator axis angle relative to the first actuator axis of rotation, the actuator axis angle being greater than zero.

10. The catheter of claim 9, wherein the actuator axis angle is about 90 degrees.

11. The catheter of claim 1 , further comprising a first, second, third, and fourth steering line operatively connecting the tip portion and the steering actuator.

12. The catheter of claim 11 , wherein the first, second, third, and fourth steering lines comprise a high strength fiber.

13. The catheter of claim 12, wherein the high strength fiber comprises Kevlar.

14. The catheter of claim 1 , further comprising a central lumen extending longitudinally through the handle, the shaft, and the end effector.

15. The catheter of claim 14, wherein the central lumen is configured to receive a guidewire therethrough.

16. The catheter of claim 1 , wherein the shaft is generally flexible.

17. The catheter of claim 16, wherein a stiffness of the shaft varies over a length of the shaft between the proximal end portion and the distal end portion.

18. The catheter of claim 17, wherein the stiffness of the shaft varies in discrete intervals over the length of the shaft.

19. The catheter of claim 17, wherein the stiffness of the shaft is greater proximate the proximal end portion than proximate the distal end portion.

20. The catheter of claim 1 , wherein the shaft comprises an inner layer, an intermediate layer, and an outer layer.

21. The catheter of claim 20, wherein the outer layer comprises a high durometer material.

22. The catheter of claim 20, wherein the outer layer comprises a braided material.

23. The catheter of claim 1 , wherein the shaft comprises an inner layer, and an outer layer.

24. The catheter of claim 23, wherein the outer layer comprises a high durometer material.

25. The catheter of claim 23, wherein the outer layer comprises a braided material.

26. The catheter of claim 1 , further comprising a tip portion energizing element disposed on the tip portion; wherein the tip portion energizing element is configured to be operatively connected to a source of electrical energy.

27. The catheter of claim 1 , further comprising a dilation portion disposed on the end effector, the dilation portion including a dilation portion energizing element; wherein the dilation portion energizing element is configured to be operatively connected to a source of electrical energy.

28. The catheter of claim 1 , further comprising a dilation portion disposed on the end effector, the dilation portion including an expandable element.

29. The catheter of claim 28, wherein the dilation portion expandable element comprises a radiopaque material.

30. The catheter of claim 28, wherein the dilation portion expandable element comprises an inflatable element.

31. The catheter of claim 30, wherein the dilation portion inflatable element is generally toroidal when inflated.

32. The catheter of claim 30, wherein the dilation portion inflatable element is generally cylindrical when not inflated.

33. The catheter of claim 30, wherein the dilation portion inflatable element is generally spherical when inflated.

26

34. The catheter of claim 1 , further comprising an expandable element disposed on the tip portion.

35. The catheter of claim 34, wherein the tip portion expandable element comprises a radiopaque material.

36. The catheter of claim 34, wherein the tip portion expandable element comprises an inflatable element.

37. The catheter of claim 36, wherein the tip portion inflatable element generally mimics the shape of the tip when not inflated and is generally teardrop shaped when inflated.

38. The catheter of claim 1 , further comprising a stent portion removably disposed on the end effector.

39. The catheter of claim 38, wherein the stent portion is generally cylindrical.

40. The catheter of claim 39, wherein the stent portion is generally tapered at the distal end of the stent, the stent portion has a stent diameter and a distal end diameter, the stent diameter is greater than the tip portion diameter, and the distal end diameter is less than the tip portion diameter.

41. The catheter of claim 38, wherein the stent portion is generally flexible.

42. The catheter of claim 38 wherein the stent portion may be directed to a location by the catheter.

43. The catheter of claim 42, wherein the catheter may be withdrawn from the stent portion leaving the stent portion in said location.

27

44. The catheter of claim 1 , further comprising a light element disposed on the tip portion; wherein the light element is configured to be operatively connected to a source of light, and the source of light is configured to deliver light to the light element.

45. A steerable dilator comprising: an elongated shaft comprising a proximal end portion and a distal end portion; an end effector disposed at the distal end portion of the shaft, the end effector comprising; a dilation portion disposed proximate the distal end portion of the shaft, a distal tip portion disposed distally on the dilation portion; and a handle disposed at the proximal end portion of the shaft, the handle comprising a steering actuator disposed on the handle; wherein the tip portion is movable relative to the shaft, the steering actuator enables a user to steer the tip portion by moving the tip portion with the steering actuator, moving the steering actuator in a first actuator direction moves the tip portion in a first direction in a first steering plane, moving the steering actuator in a second actuator direction moves the tip portion in a second direction in the first steering plane, moving the steering actuator in a third actuator direction moves the tip portion in a third direction in a second steering plane, and moving the steering actuator in a fourth actuator direction moves the tip portion in a fourth direction in a second steering plane.

46. The dilator of claim 45, wherein the second direction is generally opposite the first direction in the first steering plane.

47. The dilator of claim 45, wherein the third direction is generally opposite the fourth direction in the second steering plane.

28

48. The dilator of claim 45, wherein the second steering plane is disposed at a steering plane angle relative to the first steering plane, the steering plane angle being greater than zero.

49. The dilator of claim 48, wherein the steering plane angle is about 90 degrees.

50. The dilator of claim 45, wherein the steering actuator is generally configured as one or more pivoted supports that allow for the rotation of the steering actuator about a first actuator axis of rotation and a second actuator axis of rotation relative to the handle.

51. The dilator of claim 50, wherein moving the steering actuator in a first actuator direction rotates the steering actuator about the first actuator axis of rotation and moving the steering actuator in a second actuator direction rotates the steering actuator about the first actuator axis of rotation, the second actuator direction being generally opposite the first actuator direction.

52. The dilator of claim 51 , wherein moving the steering actuator in a third actuator direction rotates the steering actuator about the second actuator axis of rotation and moving the steering actuator in a fourth actuator direction rotates the steering actuator about the second actuator axis of rotation, the fourth actuator direction being generally opposite the third actuator direction.

53. The dilator of claim 50, wherein the second actuator axis of rotation is disposed at an actuator axis angle relative to the first actuator axis of rotation, the actuator axis angle being greater than zero.

54. The dilator of claim 53, wherein the actuator axis angle is about 90 degrees.

55. The dilator of claim 45, further comprising a first, second, third, and fourth steering line operatively connecting the tip portion and the steering actuator.

29

56. The dilator of claim 55, wherein the first steering line, the second steering line, the third steering line, and the fourth steering line comprise a high strength fiber.

57. The dilator of claim 56, wherein the high strength fiber comprises Kevlar.

58. The dilator of claim 45, further comprising a central lumen extending longitudinally through the handle, the shaft, and the end effector.

59. The dilator of claim 58, wherein the central lumen is configured to receive a guidewire therethrough.

60. The dilator of claim 45, wherein the shaft is generally flexible.

61. The dilator of claim 60, wherein a stiffness of the shaft varies over a length of the shaft between the proximal end portion and the distal end portion.

62. The dilator of claim 61 , wherein the stiffness of the shaft varies in discrete intervals over the length of the shaft.

63. The dilator of claim 61 , wherein the stiffness of the shaft is greater proximate the proximal end portion than proximate the distal end portion.

64. The dilator of claim 45, wherein the shaft comprises an inner layer, an intermediate layer, and an outer layer.

65. The dilator of claim 64, wherein the outer layer comprises a high durometer material.

66. The dilator of claim 64, wherein the outer layer comprises a braided material.

30

67. The dilator of claim 45, wherein the shaft comprises an inner layer, and an outer layer.

68. The dilator of claim 67, wherein the outer layer comprises a high durometer material.

69. The dilator of claim 67, wherein the outer layer comprises a braided material.

70. The dilator of claim 45, further comprising a tip portion energizing element disposed on the tip portion; wherein the tip portion energizing element is configured to be operatively connected to a source of electrical energy.

71. The dilator of claim 45, further comprising a dilation portion energizing element disposed on the dilation portion; wherein the dilation portion energizing element is configured to be operatively connected to a source of electrical energy.

72. The dilator of claim 45, further comprising an expandable element disposed on the dilation portion.

73. The dilator of claim 72, wherein the dilation portion expandable element comprises a radiopaque material.

74. The dilator of claim 72, wherein the dilation portion expandable element comprises an inflatable element.

75. The dilator of claim 74, wherein the dilation portion inflatable element is generally toroidal when inflated.

31

76. The dilator of claim 74, wherein the dilation portion inflatable element is generally cylindrical when not inflated.

77. The dilator of claim 74, wherein the dilation portion inflatable element is generally spherical when inflated.

78. The dilator of claim 45, further comprising an expandable element disposed on the tip portion.

79. The dilator of claim 78, wherein the tip portion expandable element comprises a radiopaque material.

80. The dilator of claim 78, wherein the tip portion expandable element comprises an inflatable element.

81. The dilator of claim 80, wherein the tip portion inflatable element generally mimics the shape of the tip when not inflated and is generally teardrop shaped when inflated.

82. The dilator of claim 45, further comprising a stent portion removably disposed on the end effector.

83. The dilator of claim 82, wherein the stent portion is generally cylindrical.

84. The dilator of claim 83, wherein the stent portion is generally tapered at the distal end of the stent, the stent portion has a stent diameter and a distal end diameter, the stent diameter is greater than the tip portion diameter, and the distal end diameter is less than the tip portion diameter.

85. The dilator of claim 82, wherein the stent portion is generally flexible.

32

86. The dilator of claim 82 wherein the stent portion may be directed to a location by the dilator.

87. The dilator of claim 86, wherein the dilator may be withdrawn from the stent portion leaving the stent portion in said location.

88. The dilator of claim 45, further comprising a light element disposed on the tip portion; wherein the light element is configured to be operatively connected to a source of light, and the source of light is configured to deliver light to the light element.

89. A method of creating an opening in a biological tissue membrane, the method comprising: advancing an end effector of a dilator to proximate a biological tissue membrane; creating an initial opening through the membrane by advancing a tip portion of the end effector through the membrane; expanding the initial opening to an expanded opening by advancing at least a portion of the end effector through the membrane; and withdrawing the end effector from the expanded opening; wherein advancing the end effector of the dilator to the biological tissue membrane includes steering the tip portion of the end effector.

90. The method of claim 89, wherein steering the tip portion includes steering the tip portion in a first and second direction in a first steering plane.

91. The method of claim 90, wherein steering the tip portion includes steering the tip portion in a third and fourth direction in a second steering plane.

92. The method of claim 89, further comprising at least partially expanding an expandable element disposed on the end effector.

33

93. The method of claim 92, wherein at least partially expanding the expandable element comprises at least partially inflating an inflatable element.

94. The method of claim 93, wherein at least partially inflating the inflatable element comprises injecting a fluid into the inflatable element.

95. A method of applying light to brain and/or spinal cord tissue, the method comprising: advancing a catheter to proximate the brain and/or spinal cord tissue; and applying light to the brain and/or spinal cord tissue; wherein advancing the catheter to the brain and/or spinal cord tissue includes steering a tip portion of the catheter.

96. The method of claim 95, wherein steering the tip portion includes steering the tip portion in a first and second direction in a first steering plane.

97. The method of claim 96, wherein steering the tip portion includes steering the tip portion in a third and fourth direction in a second steering plane.

98. The method of claim 95, wherein the method further comprises energizing a light element disposed on the tip portion.

99. The method of claim 98, wherein energizing the light element comprises supplying light to the light element.

34

100. A method of placing a stent in a biological tissue, the method comprising: installing a stent over an end of a catheter; advancing the stent using the catheter to a location in the biological tissue; locating the stent in the biological tissue; and withdrawing the catheter from the stent leaving the stent in the biological tissue; wherein advancing the stent includes steering a tip portion of the catheter.

101. The method of claim 100, wherein steering the tip portion includes steering the tip portion in a first and second direction in a first steering plane.

102. The method of claim 101, wherein steering the tip portion includes steering the tip portion in a third and fourth direction in a second steering plane.

103. Any apparatus, method, or combination thereof as disclosed herein.

104. Any two or more of the foregoing claims in any combination.

105. Any combination of elements from one or more of the foregoing claims.

106. An apparatus including any combination of elements as disclosed herein.

35