Deflectable medical probe

A medical probe includes a shaft for navigation in a patient body, and first and second deflection mechanisms. The shaft ends with a flexible section and a spring, followed by a rigid distal tip having one or more medical devices coupled thereto. The first deflection mechanism is configured to deflect the flexible section relative to the shaft. The second deflection mechanism is configured to deflect the distal tip relative to the first flexible section by using the spring.

FIELD OF THE INVENTION

The present invention relates generally to medical probes, and particularly to methods and systems for deflecting medical probe distal ends.

BACKGROUND OF THE INVENTION

Medical probes, such as deflectable catheters, are used in some medical applications. Various types of deflectable catheters are known in the art.

For example, U.S. Pat. No. 5,431,168 describes a steerable catheter comprising an elongated catheter body and a tip portion. First and second lumens extend through the catheter body and tip portion. The first lumen is open at the distal end of the catheter. The second lumen is off-axis.

U.S. Pat. No. 5,242,441 describes a cardiac arrhythmia ablation catheter that has a highly flexible tubular distal segment particularly adapted for navigating and exploring a ventridular cardiac chamber.

U.S. Patent Application Publication 2002/0077590 describes a deflectable catheter comprising a catheter body, a tip section, and a control handle for affecting deflection of the tip section. The tip section comprises a flexible tubing having proximal and distal ends and at least two lumens extending therethrough.

SUMMARY OF THE INVENTION

An embodiment of the present invention that is described herein provides a medical probe including a shaft for navigation in a patient body, and first and second deflection mechanisms. The shaft ends with a flexible section and a spring, followed by a rigid distal tip having one or more medical devices coupled thereto. The first deflection mechanism is configured to deflect the flexible section relative to the shaft. The second deflection mechanism is configured to deflect the distal tip relative to the first flexible section by using the spring.

In some embodiments, the first deflection mechanism includes one or more wires coupled to the flexible section. In other embodiments, the medical probe includes a device external to the patient body, the wires extend between the flexible section and the device, and the device is configured to deflect the flexible section relative to the shaft by applying a force to at least one of the wires. In yet other embodiments, the force includes a pulling force.

In an embodiment, the second deflection mechanism includes one or more other wires coupled to the distal tip. In another embodiment, the medical probe includes a device external to the patient body, the other wires extend between the distal tip and the device, and the device is configured to deflect the distal tip relative to the flexible section by applying a force to at least one of the other wires.

In some embodiments, the force includes a pulling force. In other embodiments, the medical probe includes a handle, which is coupled to at least one of the first and second deflection mechanism, and which is configured to deflect at least one of the distal tip and the flexible section, using, respectively, one or more of the first and second deflection mechanisms.

There is additionally provided, in accordance with an embodiment of the present invention, a method for producing a medical probe, the method includes assembling a shaft ending with a flexible section and a spring, followed by a rigid distal tip having one or more medical devices coupled thereto. First and second deflection mechanisms are connected to the medical probe, the first deflection mechanism deflects the flexible section relative to the shaft, and the second deflection mechanism deflects the distal tip relative to the first flexible section.

DETAILED DESCRIPTION OF EMBODIMENTS

Overview

Some medical procedures, such as cardiac electrophysiology (EP) and sinuplasty, may involve navigating a medical probe to a target location in an organ of a patient. In some cases, a physician that carries out the procedure may face challenges in navigating the probe into the organ in question and in setting the probe at the target location. For example, forcing the catheter into the patient body may cause damage to the organ tissue. Furthermore, in some procedures it is important to approach the tissue with the probe from a desired angle and to make a proper physical contact between the probe and tissue at the target location.

Embodiments of the present invention address these challenges, by providing a medical probe having a flexible distal end assembly that comprises multiple deflectable sections coupled along a longitudinal axis of the probe, each section is configured to deflect independently of the other section or sections using a different deflection mechanism.

In some embodiments, the probe comprises a rigid distal tip having one or more medical devices, such as sensing electrodes, coupled to an external surface of the distal tip. In an embodiment, the distal tip may have a hollow profile so as to enable passage of leads coupled to the electrodes. The leads are configured to conduct electrical signals between the electrodes and a computer coupled to the proximal end of the probes.

In some embodiments, the probe comprises a shaft for navigating the probe in a patient body. The shaft ends with a hollow flexible section and a spring, followed by the distal tip. The flexible section has some inherent level of flexibility that allows some deflection in response to bending forces applied to the flexible section, for example, using a manipulator device located at the proximal end of the probe.

In some embodiments, the spring connects between the distal tip and the flexible section, along the longitudinal axis of the medical probe. In response to bending forces applied to the flexible section, the spring is configured to deflect the distal tip relative to the flexible section of the probe.

In some embodiments, the medical probe comprises one or more pulling wires coupled, at respective coupling locations, to the inner surfaces of the hollow distal tip and flexible section. The pulling wires are adapted, when pulled by the physician, to apply bending forces that induce deflection of the flexible section relative to shaft, and deflection of the distal tip relative to the flexible section. The physician may control the degree of deflection by controlling the pulling force applied to each of the pulling wires.

Note that typically the distal tip is coupled to one set of one or more pulling wires, and the flexible section is coupled to another set of one or more pulling wires, so that the distal tip and flexible section can be deflected independently of one another.

In some embodiments, the pulling wires may be coupled to a manipulator device, also referred to herein as a handle, which is coupled to the proximal end of the medical probe, so as to control the levels of deflection caused to the distal tip and the flexible section using a single manipulator device.

In some embodiments, the probe may comprise any suitable number of pulling wires coupled to the inner surface at any suitable configuration, so as to control the angles and levels of deflection of the distal tip and the flexible section.

The disclosed techniques increase the maneuverability and functionality of medical catheters by enabling improved flexibility of the distal end assembly, and independent manipulation of multiple sections along the longitudinal axis of the probe.

System Description

FIG.1is a schematic, pictorial illustration of a catheterization system20, in accordance with an embodiment of the present invention. System20comprises a probe, in the present example a cardiac catheter22, and a control console24.

In the embodiment described herein, catheter22may be used for any suitable therapeutic and/or diagnostic purposes, such as for sensing electro-potential signals or for ablating tissue in a heart26of a patient28.

In some embodiments, console24comprises a processor34, typically a general-purpose computer, with suitable front end and interface circuits for receiving signals from catheter22and for controlling the other components of system20described herein.

In some embodiments, console24further comprises a memory48, and a display46, which is configured to display data, such as an image44of at least part of heart26of patient28. In some embodiments, image44may be acquired using any suitable anatomical imaging system, such as computerized tomography (CT) or fluoroscopic imaging.

A physician30, inserts catheter22through the vascular system of patient28lying on a table29.

Reference is now made to an inset38. In some embodiments, catheter22comprises a shaft23for navigation the catheter in a patient body. In some embodiments, shaft23, or any other suitable component of catheter22, is coupled to a distal-end assembly40, depicted in detail inFIG.2below. Physician30moves assembly40in the vicinity of the target region in heart by manipulating shaft23of catheter22using a manipulator32coupled near the proximal end of catheter22. The proximal end of catheter22is connected to interface circuitry of processor34.

In some embodiments, the position of distal-end assembly40in the heart cavity is typically measured using position sensing techniques. This method of position sensing is implemented, for example, in the CARTO™ system, produced by Biosense Webster Inc. (Irvine, Calif.) and is described in detail in U.S. Pat. Nos. 5,391,199, 6,690,963, 6,484,118, 6,239,724, 6,618,612 and 6,332,089, in PCT Patent Publication WO 96/05768, and in U.S. Patent Application Publications 2002/0065455 A1, 2003/0120150 A1 and 2004/0068178 A1, whose disclosures are all incorporated herein by reference.

In some embodiments, console24comprises a driver circuit42, which drives magnetic field generators36placed at known positions external to patient28, e.g., below the patient's torso.

Deflecting the Distal End Assembly of the Medical Probe

FIG.2is a schematic, pictorial illustration of distal end assembly40, in accordance with an embodiment of the present invention. In some embodiments, distal end assembly40comprises a rigid distal tip50made from any suitable rigid material such as metal or plastic.

In some embodiments, distal tip50comprises one or more electrodes (not shown), coupled to the outer surface of distal tip50and configured to exchange, via catheter22, electrical signals between console24and the tissue of heart26. The electrodes may be used for sensing signals from heart26, and/or for applying ablation signals for ablating the tissue of heart26.

In some embodiments, distal tip50may be hollow, so as to enable passage of electrical leads configured to conduct the electrical signals between console24and the electrodes. In other embodiments, distal tip50may comprise a flexible substrate, e.g., a flexible printed circuit board (PCB), wrapped around a solid profile of tip50. In these embodiments, the PCB may comprise the leads formed thereon, and the electrodes formed and/or mounted thereon.

In some embodiments, distal tip50may have a tubular shape as shown inFIG.2, or any other suitable shape, such as a balloon shape, a lasso, or a basket catheter.

In some embodiments, distal end assembly40comprises a hollow flexible section66, which is coupled to shaft23of catheter22along a longitudinal axis55of assembly40, and is configured to deflect relative to shaft23in response to a bending force, as will be described below. Note that in a non-deflected position (e.g., when assembly is inserted into the body of patient28,) flexible section66is typically aligned with distal tip50and with shaft23, along longitudinal axis55.

In some embodiments, distal end assembly40comprises a spring60, which is coupled to distal tip50at one end of the spring and to flexible section66at the opposite end of the spring, along longitudinal axis55.

In some embodiments, spring60is configured to enable deflection of distal tip50relative to flexible section66. In some embodiments, flexible section66and spring60are hollow, so as to allow passage of the electrical leads between catheter22and distal tip50.

In some embodiments, distal end assembly40comprises a pair of pulling wires53and54, and a pair of pulling wires63and64. Each pair serves as a, typically independent, deflection mechanism. In these embodiments, wires53and54are adapted to deflect distal tip50relative to flexible section66, thereby serving as one deflection mechanism, whereas wires63and64are adapted to deflect flexible section66relative to shaft23, thereby serving a different deflection mechanism. In the example ofFIG.2, wires53and63are coupled to one section (referred to herein as the “right section”) of the inner surface of assembly40, and wires54and64are coupled to an opposite section (referred to herein as the “left section”) of the inner surface of assembly40.

In some embodiments, system20may comprise one or more mechanical-based and/or electrical-based control assemblies (not shown) that are respectively coupled, together or separately, to pulling wires53,54,63and64.

In some embodiments, the control assemblies may be coupled to manipulator32, e.g., as two separate control knobs, one for distal tip50and the other for flexible section66. In these embodiments, physician30may use the control knobs to control the respective directions and levels of deflection of distal tip50and flexible section66. In other embodiments, manipulator32may comprise any other suitable configuration of controlling features. Additionally or alternatively, the control assemblies may be controlled, using a suitable software, executed, for example, by processor34in control console24.

In some embodiments, wire53is coupled to the inner surface of the right section of distal tip50, at a coupling point51. Similarly, wire54is coupled to the inner surface of the left section of distal tip50, at a coupling point52facing coupling point51.

In some embodiments, physician30may deflect distal tip50to a desired side by pulling a selected wire among wires53and54. In the example ofFIG.2, physician30applied the respective control knob to pull wire53, so as to apply bending force on distal tip50, thereby to deflect assembly40to a desired spatial angle.

Reference is now made to an inset58showing a sectional top view AA of distal tip50.

In the configuration ofFIG.2, distal tip50is deflectable in two dimensions indicated by the directions of arrows59A and59B. In some embodiments, physician30may deflect assembly40in other directions, relative to axis55, by a combined operation that comprises both rotating distal end assembly40about axis55, shown by an arrow69, and pulling wire53or54.

In other embodiments, assembly40may comprise any additional wires coupled to the inner surface of tip50at respective locations. For example, distal end assembly40may comprise two additional pulling wires (not shown) coupled to the inner surface of distal tip50at coupling points56and57, thereby allowing deflection in directions indicated by respective arrows67A and67B.

In this configuration, physician30may pull, for example, two or more wires coupled to distal tip50at coupling points52and51, so as to deflect the distal tip in a different direction indicated by an arrow68, which is a sum of vectors of forces indicated by arrows59A and67B.

In alternative embodiments, any other suitable number of wires may be coupled to the inner surface of distal tip50at any suitable configuration. For example, the probe may comprise a single pulling wire and a rotation capability about axis55. Note that the pulling wires may be coupled at the same sectional slice (e.g., section AA) or at different distance from the distal edge of assembly40.

In some embodiments, distal end assembly40further comprises additional pulling wires, such as wires63and64, coupled to flexible section66at respective coupling points61and62. By pulling wire63or64, physician can deflect flexible section66to the directions indicated by arrows59B and59A, respectively.

Note that flexible section66is typically less flexible than spring60, so that the deflection level of flexible section66is lower compared to the deflection level of distal tip50.

In other embodiments, any suitable number of pulling wires may be coupled at any other suitable location and angle to the inner surface of flexible section66, instead of or in addition to wires63and64.

In alternative embodiments, wires53and54, and wires63and64may be coupled to the outer surfaces of distal tip50and flexible section66, respectively, or at any other suitable locations.

In other embodiments, distal end assembly40may comprise one or more rigid wires in addition to, or instead of, some of the pulling wires. The rigid wires may be used for deflecting distal tip50relative to flexible section66, and flexible section66relative to shaft23, by applying, for example, a pushing force instead of, or in addition to, the pulling force described above.

The configuration of distal end assembly40shown inFIG.2is an example configuration, which is chosen purely for the sake of conceptual clarity. In alternative embodiments, any other suitable configuration can also be used.

For example, assembly40may comprise any suitable number of sections, such as distal tip50and flexible section66, coupled along the longitudinal axis of catheter at any suitable configuration. The sections may be coupled to one another using any suitable number and type of flexible elements, having any suitable degree of flexibility.

Although the embodiments described herein mainly address cardiac procedures, the methods and systems described herein can also be used in other applications, such as in sinuplasty, surgery, endoscopy, otolaryngology and neurology.