CATHETER ASSEMBLY LOCK

A medical device for use with a catheter assembly including an elongated catheter coaxially disposed within a sheath is disclosed. The medical device includes a deformable tube having a proximal end, a distal end, an outer wall with an outer diameter, and an inner wall forming an axial lumen. The distal end attaches to the sheath, and the proximal end receives the catheter into the lumen. The medical device also includes a opposing paddles disposed against the outer wall, each of the opposing paddles having a generally planar lock region to be disposed against outer wall at the outer diameter, the lock surface tangential to the deformable tube.

TECHNICAL FIELD

The present disclosure relates generally to medical systems and methods using catheter assemblies. More specifically, the present disclosure relates to medical systems and methods for locking catheter assemblies in position within a patient during procedures.

BACKGROUND

Medical devices in the form of catheter systems are widely used in various medical procedures to access remote anatomical locations or deploy therapeutic devices. For example, electrophysiological procedures involve guiding catheter assemblies into the heart and tracking the location of the catheter assemblies with respect to the heart. Catheter ablation is a minimally invasive electrophysiological procedure to treat a variety of heart conditions such as supraventricular and ventricular arrhythmia. Cardiac mapping via catheters is another minimally invasive electrophysiological procedure to identify temporal and spatial electrical potentials during a heart rhythm. Catheter assemblies, including catheter assemblies in electrophysiological procedures, can include a plurality of catheter elements such as catheters, sheaths, guidewires, and needles. For instance, a catheter assembly can include an elongated catheter within an elongated sheath. Access to the patient's heart can be obtained through a vessel, such as a peripheral artery or vein via a large bore sheath or introducer sheath. Once access to the vessel is obtained, the catheter assembly can be navigated to within the patient's heart, and the catheter can be selectively deployed from within the sheath.

SUMMARY

In Example 1, a medical device for use with a catheter assembly including an elongated catheter coaxially disposed within a sheath. The medical device includes a deformable tube having a proximal end, a distal end, an outer wall with an outer diameter, and an inner wall forming an axial lumen, the distal end configured to attach to the sheath, the proximal end configured to receive the catheter into the lumen. The medical device also includes a plurality of opposing paddles disposed against the outer wall, each of the opposing paddles having a generally planar lock region configured to be disposed against outer wall at the outer diameter, the lock surface disposed tangentially to the deformable tube, the plurality of opposing paddles laterally movable with respect to the deformable tube along the outer diameter. The medical device having a first compressed state wherein the catheter is coaxially disposed within the sheath and the opposing paddles are releasably urged against the deformable tube at the outer diameter to collapse the deformable tube to hold the catheter in place with respect to the sheath and deformable tube, the collapsed deformable tube to form an elongated opening along the inner wall and the catheter. The medical device having a second compressed state wherein the catheter is not coaxially disposed within the sheath and removed from the deformable tube and the opposing paddles are releasably urged against the deformable tube at the outer diameter to collapse the deformable tube and seal the lumen.

In Example 2, the medical device of Example 1, wherein the catheter assembly is incorporated into the medical device.

In Example 3, the medical device of any of Examples 1-2, wherein the catheter assembly is configured to perform an irreversible electroporation.

In Example 4, the medical device of any of Example 1-3, and further comprising a nominal state wherein the catheter is coaxially disposed within the sheath, and the catheter is movable with respect to the sheath and the deformable tube.

In Example 5, the medical device of Example 4, wherein the inner wall includes a circular cross section in the nominal state.

In Example 6, the medical device of Example 5, wherein the lock regions include a height and the inner wall includes a circumference, and wherein the height is at least half the circumference.

In Example 7, the medical device of any of Examples 4-5, wherein the inner wall includes an ovalized cross section in the first compressed state.

In Example 8, the medical device of any of Examples 1-7, wherein the plurality of opposing paddles includes two opposing paddles.

In Example 9, the medical device of Example 8, wherein the lock regions are generally parallel to each other.

In Example 10, the medical device of any of Examples 1-9, wherein lock regions form an overlapping region on the deformable tube.

In Example 11, the medical device of Example 10, wherein the inner wall associated with the overlapping region pinches the catheter in the first compressed state.

In Example 12, the medical device of any of Examples 10-11, wherein the inner wall associated with the overlapping region seals the lumen in the second compressed state.

In Example 13, the medical device of any of Examples 10-12, wherein the proximal end and distal end are spaced apart from the overlapping region.

In Example 14, the medical device of any of Examples 1-13, wherein the proximal end includes a proximal hub configured to guide the catheter into the lumen, and the distal end includes a distal hub configured to attach to the sheath.

In Example 15, the medical device of any of Examples 1-14, and further comprising a drive mechanism operably coupled to the plurality of paddles, the drive mechanism configured to laterally move the plurality of opposing paddles with respect to the deformable tube.

In Example 16, a medical device for use with a catheter assembly including an elongated catheter coaxially disposed within a sheath. The medical device includes a deformable tube having a proximal end, a distal end, an outer wall with an outer diameter, and an inner wall forming an axial lumen, the distal end configured to attach to the sheath, the proximal end configured to receive the catheter into the lumen. The medical device also includes a plurality of opposing paddles disposed against the outer wall, each of the opposing paddles having a generally planar lock region configured to be disposed against outer wall at the outer diameter, the lock surface disposed tangentially to the deformable tube, the plurality of opposing paddles laterally movable with respect to the deformable tube along the outer diameter. The medical device having a first compressed state wherein the catheter is coaxially disposed within the sheath and the opposing paddles are releasably urged against the deformable tube at the outer diameter to collapse the deformable tube to hold the catheter in place with respect to the sheath and deformable tube, the collapsed deformable tube to form an elongated opening along the inner wall and the catheter. The medical device having a second compressed state wherein the catheter is not coaxially disposed within the sheath and removed from the deformable tube and the opposing paddles are releasably urged against the deformable tube at the outer diameter to collapse the deformable tube and seal the lumen.

In Example 17, the medical device of Example 16, and further comprising a nominal state wherein the catheter is coaxially disposed within the sheath, and the catheter is movable with respect to the sheath and the deformable tube.

In Example 18, the medical device of Example 17, wherein the inner wall includes a circular cross section in the nominal state.

In Example 19, the medical device of Example 18, wherein the lock regions include a height and the inner wall includes a circumference, and wherein the height is at least half the circumference.

In Example 20, the medical device of Example 18, wherein the inner wall includes an ovalized cross section in the first compressed state.

In Example 21, the medical device of Example 16, wherein lock regions form an overlapping region on the deformable tube and the proximal end and distal end are spaced apart from the overlapping region.

In Example 22, the medical device of Example 16, and further comprising a drive mechanism operably coupled to the plurality of paddles, the drive mechanism configured to laterally move the plurality of opposing paddles with respect to the deformable tube.

In Example 23, the medical device of Example 16, wherein the proximal end includes a proximal hub configured to guide the catheter into the lumen, and the distal end includes a distal hub configured to attach to the sheath.

In Example 24, the medical device of Example 16, wherein the plurality of opposing paddles includes two opposing paddles, and wherein the lock regions are generally parallel to each other.

In Example 25, a medical system comprising a catheter assembly having an elongated catheter coaxially disposable within a sheath and a locking mechanism. The locking mechanism comprising a deformable tube and a plurality of opposing paddles. The deformable tube having a proximal end, a distal end, an outer wall with an outer diameter, and an inner wall forming an axial lumen, the distal end configured to attach to the sheath, the proximal end configured to receive the catheter into the lumen. The plurality of opposing paddles disposed against the outer wall, each of the opposing paddles having a generally planar lock region configured to be disposed against outer wall at the outer diameter, the lock surface disposed tangentially to the deformable tube, the plurality of opposing paddles laterally movable with respect to the deformable tube along the outer diameter. The medical system having a first compressed state wherein the catheter is coaxially disposed within the sheath and the opposing paddles are releasably urged against the deformable tube at the outer diameter to collapse the deformable tube to hold the catheter in place with respect to the sheath and deformable tube, the collapsed deformable tube to form an elongated opening along the inner wall and the catheter. The medical system having a second compressed state wherein the catheter is not coaxially disposed within the sheath and removed from the deformable tube and the opposing paddles are releasably urged against the deformable tube at the outer diameter to collapse the deformable tube and seal the lumen.

In Example 26, the medical system of Example 25, wherein the catheter assembly is configured to perform an irreversible electroporation.

In Example 27, the medical system of Example 25, and further comprising a nominal state wherein the catheter is coaxially disposed within the sheath, and the catheter is movable with respect to the sheath and the deformable tube.

In Example 28, the medical system of Example 25, and further comprising a drive mechanism operably coupled to the plurality of paddles, the drive mechanism configured to laterally move the plurality of opposing paddles with respect to the deformable tube.

In Example 29, a method for use with catheter assembly having an elongated catheter coaxially disposable within a sheath. A medical device is provided. The medical device includes a deformable tube having a proximal end, a distal end, an outer wall with an outer diameter, and an inner wall forming an axial lumen, the distal end configured to attach to the sheath, the proximal end configured to receive the catheter into the lumen. The medical device also includes a plurality of opposing paddles disposed against the outer wall, each of the opposing paddles having a generally planar lock region configured to be disposed against outer wall at the outer diameter, the lock surface disposed tangentially to the deformable tube, the plurality of opposing paddles laterally movable with respect to the deformable tube along the outer diameter. The catheter is coaxially disposed within the sheath. The opposing paddles are releasably urged against the deformable tube at the outer diameter to collapse the deformable tube to hold the catheter in place with respect to the sheath and deformable tube, the collapsed deformable tube to form an elongated opening along the inner wall and the catheter. The catheter is removed from the deformable tube. The opposing paddles are releasably urged against the deformable tube at the outer diameter to collapse the deformable tube and seal the lumen.

In Example 30, the method of Example 29, and further including flowing a fluid into the elongated opening.

In Example 31, the method of Example 30, wherein providing the medical device includes providing the deformable tube having an inner wall with a circular cross section, and wherein holding the catheter in place with respect to the sheath includes ovalizing the cross section to form the elongated opening.

In Example 32, the method of Example 29, including forming an overlapping region on the deformable tube

In Example 33, the method of Example 32, wherein holding the catheter in place with respect to the sheath includes pinching the catheter with the inner wall associated with the overlapping region.

In Example 34, the method of Example 32, wherein collapsing the deformable tube and sealing the lumen includes collapsing the deformable tube at the overlapping region.

In Example 35, the method of Example 29, wherein providing the medical device includes providing a proximal hub attached to the proximal end, and further including guiding the catheter into lumen via the proximal hub.

DETAILED DESCRIPTION

For purposes of promoting an understanding of the principles of the present disclosure, reference is now made to the examples illustrated in the drawings, which are described below. The illustrated examples disclosed herein are not intended to be exhaustive or to limit the disclosure to the precise form disclosed in the following detailed description. Rather, these exemplary embodiments were chosen and described so that others skilled in the art may use their teachings. It is not beyond the scope of this disclosure to have a number (e.g., all) of the features in an example used across all examples. Thus, no one figure should be interpreted as having any dependency or requirement related to any single component or combination of components illustrated therein. Additionally, various components depicted in a figure may be, in examples, integrated with various ones of the other components depicted therein (or components not illustrated), all of which are considered to be within the ambit of the present disclosure.

Examples of electrophysiological procedures and systems in which electroanatomical mapping systems and cardiac ablation systems that employ catheter assemblies are described in this disclosure with electrophysiological testing and ablation systems for illustration. Ablation procedures are used to treat many different conditions in patients. Ablation can be used to treat cardiac arrhythmias, benign tumors, cancerous tumors, and to control bleeding during surgery. Usually, ablation is accomplished through thermal ablation techniques including radio-frequency (RF) ablation and cryoablation. In RF ablation, a probe is inserted into the patient and radio frequency waves are transmitted through the probe to the surrounding tissue. The radio frequency waves generate heat, which destroys surrounding tissue and cauterizes blood vessels. In cryoablation, a hollow needle or cryoprobe is inserted into the patient and cold, thermally conductive fluid is circulated through the probe to freeze and kill the surrounding tissue. RF ablation and cryoablation techniques can indiscriminately kill tissue through cell necrosis, which may damage or kill otherwise healthy tissue, such as tissue in the esophagus, phrenic nerve cells, and tissue in the coronary arteries.

Another ablation technique uses electroporation. In electroporation, or electro-permeabilization, an electrical field is applied to cells to increase the permeability of the cell membrane. The electroporation can be reversible or irreversible, depending on the strength and duration of the electric field. If the electroporation is reversible, the temporarily increased permeability of the cell membrane can be used to introduce chemicals, drugs, or deoxyribonucleic acid (DNA) into the cell, prior to the cell healing and recovering. Tissue recovery can occur over minutes, hours, or days after the ablation is completed. If the electroporation is irreversible, the affected cells are killed, such as via form of cell death, such as perhaps programmed cell death through apoptosis for example, or such as traumatic cell death through necrosis for example.

Irreversible electroporation can be used as a nonthermal ablation technique. In irreversible electroporation, trains of short, high voltage pulses are used to generate electric fields that are strong enough to kill cells. In ablation of cardiac tissue, irreversible electroporation can be a relatively safe and effective alternative to the indiscriminate killing of thermal ablation techniques, such as RF ablation and cryoablation. Irreversible electroporation can be used to kill targeted tissue, such as myocardium tissue, by using a selected electric field strength and duration that is effective to kill the targeted tissue but is not effective to permanently damage other cells or tissue, such as non-targeted myocardium tissue, red blood cells, vascular smooth muscle tissue, endothelium tissue, and nerve cells.

Such example electrophysiological procedures often involve guiding catheter assemblies into the patient's heart. Access to the patient's heart can be obtained through a vessel via an introducer sheath. Once access to the vessel is obtained, the catheter assembly can be navigated to within the patient's heart. Other examples of procedures involving large bore sheaths are contemplated such as transcatheter aortic valve replacement, endovascular aneurysm repair, and mechanical circulatory support devices employ large bore access for deployment. Current use of large bore sheaths, however, include issues with air ingress during device introduction and removal. To address the issue of air ingress, clinicians employ informal methods such as high flush, aspiration, and water baths to mitigate risks of complications including air embolisms.

FIG.1illustrates an example clinical setting10for treating a patient20, such as for treating a heart30of the patient20, using an electrophysiology system50, in accordance with the disclosure. The electrophysiology system50includes an ablation catheter system60and an electroanatomical mapping (EAM) system70. The example catheter system60includes an elongated catheter assembly100, which, in the example includes a catheter105within a sheath, an introducer sheath110, a lock mechanism120, and a console130. The electroporation console130is configured to control aspects of the electroporation catheter system60. Additionally, the catheter system60includes various connecting elements, such as cables, that operably connect the components of the catheter system60to one another and to the components of the EAM system70. In general, the EAM system70includes a localization field generator80, a mapping and navigation controller90, and a display92. The EAM system70is operable to track the location of the various components of the catheter system60, and to generate high-fidelity three-dimensional electro-anatomical maps of the heart, including portions of the heart such as cardiac chambers of interest or other structures of interest such as the sinoatrial node or atrioventricular node from a catheter or probe equipped with sensing electrodes. In one illustrative example, the EAM system70can include the RHYTHMIA™ HDx mapping system marketed by Boston Scientific Corporation. One exemplary probe is the INTELLAMAP ORION™ mapping catheter marketed by Boston Scientific Corporation. Also, the clinical setting10can include additional equipment such as imaging equipment94(represented by the C-arm) and various controller elements, such as a foot controller96, configured to allow an operator to control various aspects of the electrophysiology system50. The clinical setting10may have other components and arrangements of components that are not shown inFIG.1.

The introducer sheath110is operable to provide a delivery conduit through which the catheter assembly100can be deployed to the specific target sites within the patient's heart30. Access to the patient's heart can be obtained through a vessel, such as a peripheral artery or vein. Once access to the vessel is obtained, the catheter assembly100can be navigated to within the patient's heart, such as within a chamber of the heart. The lock mechanism can be a separate component in the catheter system60or as a feature of another component, such as the introducer sheath110or other component.

The example catheter105includes an elongated catheter shaft and distal end configured to be deployed proximate target tissue, such as within a chamber of the patient's heart. The distal end may include a basket, balloon, spline, configured tip, or other electrode deployment mechanism. The electrode deployment mechanism includes an electrode assembly, or array, comprising of an electrode to effect treatment or to sense an effect within the heart. For example, the electrode assembly can include a plurality of spaced-apart electrodes or multiple spaced-apart sets or groups of spaced-apart electrodes. In some examples, an electrode, such as a plurality of spaced-apart electrodes, can be deployed on the catheter shaft in addition to or instead of an electrode on the electrode deployment mechanism. In one example, the plurality of electrodes can be formed of a conductive, solid-surface, biocompatible material and are spaced-apart across insulators. Each of the plurality of electrodes is electrically coupled to a corresponding elongated lead conductor that extend along the shaft to a catheter proximal end. The lead conductors can be electrically coupled to plug in the proximal region of the catheter105, such as a plug configured to be mechanically and electrically coupled to the console130, for example, either directly or via intermediary electrical conductors such as cabling.

In one example, the console130is configured to provide an electrical signal, such as a plurality of concurrent or space-apart-time electrical signals, to the electrically connected catheter105along lead conductors to the spaced-apart electrodes. In an example of an ablation catheter, the spaced-apart electrodes are configured to generate a selected electrical signal proximate the target tissue, based on the electrical signals from the console130, to effect ablation.

The ablation catheter system60is configured to deliver energy to targeted tissue in the patient's heart30to create cell death in tissue, for example, rendering the tissue incapable of conducting electrical signals. An elongated catheter assembly, such as catheter assembly100, can include a plurality of coaxially disposed catheter elements. For instance, a catheter element such as a sheath or catheter defines a longitudinal axis that passes through a centroid of a cross section of the catheter element, such as the centroid of a cross section of a catheter shaft or a centroid of a cross section of a lumen of a sheath. Coaxial disposed catheter elements include a catheter element disposed within another catheter element such that the longitudinal axes of each catheter element generally follow the same three-dimensional curve or path up to the most distal point that both are present.

The catheter elements can include a first catheter element, such as an elongated sheath, or outer catheter element in catheter assembly100. Addition, the catheter elements can include a second catheter element, such as an elongated catheter, or inner catheter element in catheter assembly100. The first catheter element includes an elongated lumen and the second catheter element is disposed within the lumen. For example, an outer diameter of the catheter is selected to be less than an inner diameter of the lumen in the sheath. The first and second catheter elements are movable with respect to each other along the longitudinal axis. For example, a distal end of the catheter can be manipulated to extend from the distal tip of the sheath, or the distal tip of the sheath can be retracted from the distal end of the catheter such as to expose the deployment mechanism, which can include expanding the basket. Additionally, the distal end of the catheter can be retracted from the distal tip of the sheath in the assembly100such as to contract the deployment mechanism or retract electrodes.

A selected electrical field can be generated with the electrodes to effect electroporation. A first electrode, or first group of electrodes, can be selected to be an anode and a different, second electrode, or second group of electrodes, can be selected to be a cathode, such that electrical fields can be generated between the anode and cathode based on signals, such as pulses, provided to the electrodes from the electroporation console130. The console130provides electric pulses of different lengths and magnitudes to the electrodes on the catheter105. The electric pulses can be provided in a continuous stream of pulses or in multiple, separate trains of pulses. Pulse parameters of interest include the number of pulses, the duty cycle of the pulses, the spacing of pulse trains, the voltage or magnitude of the pulses including the peak voltages, and the duration of the voltages. For example, the console130can select two or more electrodes of the electrode assembly and provides pulses to the selected electrodes to generate electric fields between the selected electrodes to provide pulsed field ablation (PFA). For example, PFA can be performed with monophasic waveforms and biphasic waveforms. Without being bound to a particular theory, electric field strengths in the range of generally 200-250 volts per centimeter (V/cm) with microsecond-scale pulse duration have been demonstrated to provide reversible electroporation in cardiac tissue. Electric field strengths at approximately 400 V/cm have been demonstrated to provide irreversible electroporation in cardiac tissue of interest, such as targeted myocardium tissue and endocardium tissue, with demonstrable sparing of red blood cells, vascular smooth muscle tissue, endothelium tissue, nerves and other non-targeted proximate tissue.

Another issue encountered during cardiac ablation involves catheter electrodes inadvertently migrating back into the elongated sheath during manipulation unbeknownst to the clinician. For instance, bipolar catheters can include shaft electrodes proximal to the electrode deployment mechanism such as a basket, and the shaft electrodes can be rendered inefficient or ineffective if inadvertently positioned within the sheath during ablation, which can lead to extended procedures or unsuccessful therapy.

FIG.2illustrates a catheter assembly lock mechanism200that can be used with the example electrophysiology system50and can correspond with lock mechanism120of the example electroporation catheter system60, which can be used with introducer sheath110. In the example, the lock mechanism200is configured to be operably coupled to an elongated sheath202and configured to receive an elongated catheter204coaxially within the elongated sheath202to form a catheter assembly206. The locking mechanism200includes a deformable tube210and a plurality of opposing paddles230a,230b.The deformable tube210includes an outer wall212and an inner wall214. The inner wall214forms an axial lumen216along axis A. For illustration, the outer wall212includes a line segment of a secant passing through the axis A defined as an outer diameter Dout.

In the illustrated example, the deformable tube210includes an open, proximal end220and an open, distal end222. The distal end222is configured to be operably coupled to the elongated sheath202having a sheath lumen along the axis A. The proximal end220is configured to receive a catheter204along axis A into lumen216and into the sheath lumen of sheath202to form the catheter assembly206.

The plurality of at least partially overlapping opposing paddles230a,230b,which includes two paddles in the illustrated example, are disposed against the outer wall212of the deformable tube210. Each of the paddles230a,230bincludes a generally planar lock region232a,232bconfigured to interface with the outer wall212generally perpendicular to a secant line of the outer diameter Doutsuch that the generally planar lock regions232a,232bare tangential to the outer wall212when in contact with the outer wall212at a point in its nominal, or undeformed, state. For example, the plane of the lock regions232a,232bare perpendicular to the secant line of the outer diameter Dout. In the illustrated example, the generally planar lock regions232a,232bare generally parallel to each other. The plurality of paddles230a,230bare movable with respect to each other. In one example, at least one of the paddles230a,230bis movable with respect to the deformable tube210. In one example, the paddles230a,230bare movable with respect to the deformable tube210along a line of travel generally perpendicular to the axis A. In another example, the paddles230a,230bare movable with respect to the deformable tube210such that the planes of the lock regions232a,232btravel generally parallel to each other perpendicularly along the secant line of the outer diameter Dout. In the illustration, the generally planar lock regions232a,232bof the opposing paddles230a,230boverlap the deformable tube210when in contact with the outer wall212in an overlap region234. The lock regions232a,232binclude a height H and width W. In one example, the height of each lock region232a,232bis the same, and the width of each lock region232a,323bis the same.

A drive mechanism236can be employed to move and selectively position the paddles230a,230bwith respect to the deformable tube210. Several suitable drive mechanisms234are contemplated including hand positioning of the paddles230a,230bwith respect to the deformable tube210. For instance, the drive mechanism236can cause a selective movement of the paddles230a,230bmay be electrically or mechanically actuated such as along rails, as pistons, as a rack and pinion, or other suitable instrument to maintain the line of travel perpendicular to the axis or along the secant line of the outer diameter Dout. In one example, the position of the paddles230a,230bwith respect to the deformable tube210, or the position of the lock regions232a,232balong the secant line of the outer diameter Doutcan be held in place by a suitable stopping mechanism used in connection with the drive mechanism236. The drive mechanism234can be configured to move both paddles230a,230btoward the axis A and with respect to the deformable tube210at the same time or both paddles230a,230baway from the axis A with respect to the deformable tube210at the same time. In another example, the drive mechanism236can be configured to move one paddle toward the axis A and with respect to the deformable tube210and the other paddle or to move one paddle away from the axis A and with respect to the deformable tube210and the other paddle.

FIGS.3A-3Cillustrate various example states of a cross section300of the example catheter assembly lock mechanism200taken along lines3-3ofFIG.2, or in a cross-sectional plane perpendicular to the axis A. As illustrated, the paddles230a,230bare selectively positionable with respect to the deformable tube210to put the lock mechanism in one of a plurality of states based on a compression of the deformable tube as effected by the paddles230a,230b,which deforms the lumen216. For illustration, a bisector line B passes through the axis A and perpendicular to the outer diameter Dout. The axis A and outer diameter Doutlie in a diameter plane, and the axis A and bisector line B line in a bisector plane, which is perpendicular to the diameter plane. Also, the inner wall214includes a line segment of a secant passing through the axis A defined as an inner diameter Din. The catheter204received in the lock mechanism200is selected to have a length of an outer diameter of the catheter is less than a length of the inner diameter Din.

In a first state, or nominal state320, as illustrated inFIG.3A, the paddles230a,230bare not touching the outer wall212of the deformable tube210or lightly touching the outer wall212. A catheter204is received in the lock mechanism200. The length of the outer diameter of the catheter204is less than the length of the inner diameter Din, and the catheter204can freely travel along the axis A with respect to the sheath202. In the nominal state, the paddles230a,230bdo not compress the inner wall214and do not deform the lumen216, or do not compress the inner wall214or deform the lumen216enough, to pinch or apply a force against the catheter204, which allows the catheter204to travel along the axis A with respect to the lock mechanism200and sheath202. Additionally, the fluid, such as saline, can flow between the inner wall214and the catheter204and down the catheter assembly206such as in the lumen of the sheath202between the catheter204and sheath202in the nominal state320.

In a second state, first compressed state, or sheath-lock state330, as illustrated inFIG.3B, the catheter204is received in the lock mechanism200. The paddles230a,230bare releasably urged against the deformable tube210at the outer wall212to deform the inner wall214, which pinches or applies a force along the line of the outer diameter Doutagainst the catheter204in the overlap region234to hold the catheter204in place with respect to the deformable tube210and sheath202. In the sheath-lock state330, the paddles230a,230bcompress the inner wall214and deform the lumen216. In one example, the shape of the lumen216formed by the inner wall214in the cross-sectional plane perpendicular to the axis A of the overlap region234is no longer circular and has become ovalized. The distance of the cross-sectional shape of the lumen216formed by the inner wall214along the line of the outer diameter Doutbecomes the same as the length of the diameter C of the catheter204. The distance of the cross-sectional shape of the lumen216formed by the inner wall214along the bisector line B becomes longer than the length of the diameter C of the catheter204. In one example, the distance of the cross-sectional shape of the lumen216formed by the inner wall214along the bisector line B becomes longer than the length of the diameter of the lumen216in the nominal state. The collapsed deformable tube210pinching the catheter204in the overlap region234along the bisector plane includes openings240between the catheter204and the inner wall214along the bisector plane as illustrated along the bisector line B.

In the sheath lock state330, the catheter204pinched in the lock mechanism200is not movable with respect to the sheath202, but fluid, such as saline, can still flow through the lock mechanism200and down the catheter assembly206.

In a third state, second compressed state, or air lock state340, as illustrated inFIG.3C, the catheter204is removed from the lock mechanism200. The paddles230a,230bare releasably urged against the deformable tube210at the outer wall212to deform the inner wall214such as to collapse the deformable tube210and seal the lumen216. The inner wall214is compressed together in the overlap region234along the diameter plane and the bisector plane as illustrated along the bisector line B. In the air lock state340, fluid, such as saline or air, does not enter the sheath202from the proximal end220. In the illustrated example, the height H of the lock regions is longer than the length of the diameter of the outer wall212. For example, the height H is longer than one-half of the length of a circumference of an inner wall214. For instance, at least one quarter of length of the circumference of the inner wall214is on each side of the diameter plane. In this configuration, the lock regions232a,232bcan apply a force to the deformable tube210to the entire inner wall214along the overlap region234in the air lock state340. Additionally, the width W is effectively at an amount to maintain the seal under the pressures applied within the lock mechanism200.

FIGS.4and5illustrate a catheter lock mechanism400that can be used with the example electrophysiology system50and can correspond with lock mechanism120of the example electroporation catheter system60and with example lock mechanism200. In the example, the lock mechanism400is configured to be operably coupled to an elongated sheath402and configured to receive an elongated catheter404coaxially within the elongated sheath402to form a catheter assembly406. The locking mechanism400includes a deformable tube410and a plurality of opposing paddles430a,430b.The deformable tube410includes an outer wall412. The deformable tube410includes a proximal end420and a distal end422. The lock mechanism400includes a proximal hub424coupled to the proximal end420of the deformable tube410to receive the catheter404. The lock mechanism400also includes a distal hub426coupled to the distal end422of the deformable tube410coupled to the sheath402. In the example, the proximal hub424is a valve hub which can be coupled to a tubing to receive a fluid such as saline into the lock mechanism400. The valve hub can also create a dynamic seal on the catheter404to reduce the likelihood of air ingress or fluid leaks during use even if the catheter is moved or translated. The proximal hub424can be configured in shape to receive and guide the catheter404along an axis AA of the lock mechanism400and the catheter assembly406. The distal hub426is configured to be operably coupled to the elongated sheath402so as to hold the sheath402in place with respect to the lock mechanism400.

The plurality of at least partially overlapping opposing paddles430a,430b,which includes two paddles in the illustrated example, are disposed against the outer wall412of the deformable tube410. Each of the paddles430a,430bincludes a generally planar lock region432a,432bgenerally parallel to each other. The lock regions432a,432bare configured to interface with the outer wall412generally in an overlap region434. The generally planar lock regions432a,432bare tangential to the outer wall412when in contact with the outer wall412at a point in its nominal, or undeformed, state. The plurality of paddles430a,430bare movable with respect to each other and with the deformable tube410, such as via a drive mechanism (not shown). In one example, the paddles430a,430bare coupled to a shaft436a,436, and the shafts436a,436bcan be coupled to the drive mechanism.

The flexible tube410is selected from a material that is soft and resilient to flex through a number of locking and unlocking cycles without tearing or permanently deforming. Additionally, the thickness of the wall of the flexible tube is selected to compress under the force of the paddles430a,430b.Further, the length of the flexible tube is selected such that the portions deformed under force of the paddles do not overly stress the bonds at the ends420,422with the hubs424,426. For example, the ends420and422are spaced-apart from the overlap region434.

FIGS.4A and5Aillustrate the lock mechanism400in the first state, or the nominal state520. The paddles430a,430bare not touching the outer wall412of the deformable tube410or the lock regions432a,432bare lightly touching the outer wall412and the lock regions432a,432bare spaced apart by a first distance. A catheter404is received in the lock mechanism400, and the catheter404can freely travel along the axis AA with respect to the lock mechanism400and the sheath402. In the nominal state, a fluid, such as saline, can flow into the lock mechanism400and down the catheter assembly206such as in the lumen of the sheath202between the catheter204and sheath202in the nominal state520.

FIGS.4B and5Billustrate the lock mechanism400in the second state or sheath lock state530. The catheter404is received within the lock mechanism400in the sheath lock state530. The paddles430a,430bare releasably urged, such as with the drive mechanism, against the deformable tube410in the overlap region434to deform, or flatten, the tube410. The lock regions432a,432bare spaced apart from each other by a second distance that is less than the first distance. The deformable tube is collapsed against the catheter404, and the force of the paddles430a,430bin a direction toward the axis AA is at least enough to hold the catheter404in place with respect to the deformable tube410and the sheath402. A clinician can select the sheath lock state530prior to performing an ablation, such as by electroporation, to lessen the likelihood that the catheter404will migrate via the shaft402and, in particular, that electrodes on the catheter shaft will migrate into the sheath402.

FIGS.4C and5Cillustrate the lock mechanism400in the third state or an air lock state540. The catheter404is removed from the lock mechanism400and is not present in the lock mechanism400in the sheath lock state540. The paddles430a,430bare releasably urged, such as with the drive mechanism, against the deformable tube410in the overlap region434to deform, or flatten, the tube410. The lock regions432a,432bare spaced apart from each other by a third distance that is less than the second distance. The deformable tube is collapsed, and the force of the paddles430a,430bin a direction toward the axis is at least enough to seal an inner lumen within the deformable tube. A clinician can select the air lock state540such as prior to device insertion into the sheath402to reduce the likelihood of air ingress into the sheath402. The paddles430a,430bcan be configured to provide a constant positive pressure against the deformable tube410via the drive mechanism while in the sheath lock state430and air lock state440.

FIGS.6A-6Cillustrate a cross section600of the lock mechanism400taken along lines6-6ofFIGS.5A-5Cin the various states of the lock mechanism400, such as a top cross sectional view. For instance, the cross section can be taken along the diameter plane inFIGS.3A-3C.FIGS.6A-6Cillustrate the proximal hub424configured to guide the catheter404into an inner lumen416of the deformable tube410formed by an inner wall414of the deformable tube410. The distal hub426is configured to attach to the sheath402and hold the sheath404in place with respect to the lock mechanism400. As the view of the lock mechanism400in the diameter plane, the inner wall414includes a line segment of a secant passing through the axis AA defined as an inner diameter Din, and the outer wall412includes a line segment of a secant passing through the axis A defined as an outer diameter Dout.

The generally planar lock regions432a,432bare tangential to the outer wall412when in contact with the outer wall212at a point in its nominal, or undeformed, state inFIG.6A, taken along lines6A-6A ofFIG.5A. Also, the plane of the lock regions432a,432bare perpendicular to the secant line of the outer diameter DoutinFIGS.6A-6C. In the illustrated example, the generally planar lock regions432a,432bare generally parallel to each other. The plurality of paddles430a,430bare movable with respect to each other. In one example, the paddles430a,430bare movable with respect to the deformable tube410along a line of travel generally perpendicular to the axis AA. In another example, the paddles430a,430bare movable with respect to the deformable tube410such that the planes of the lock regions432a,432btravel generally parallel to each other perpendicularly along the secant line of the outer diameter Dout. In the illustration, the generally planar lock regions432a,432bof the opposing paddles430a,430boverlap the deformable tube410when in contact with the outer wall412in an overlap region434. The lock regions432a,432bincludes a width W to provide an overlap region434that is long enough on the axis AA to maintain hold of the catheter in the sheath lock state530ofFIG.6Cand to maintain a seal of the inner wall414under the positive pressure within the lock mechanism400in the air lock state540ofFIG.6C. In one example, the paddles430a,440bare positioned such that the width of each lock region432a,432bare in the overlap region434.

In the first state, or nominal state520, as illustrated inFIG.6A, the paddles430a,430blightly touch the outer wall412. The length of the outer diameter of the catheter404is less than the length of the inner diameter Din, and the catheter404can freely travel along the axis A with respect to the inner wall414and the sheath402.

In the second state, or sheath-lock state530, as illustrated inFIG.6B, taken along lines6B-6B ofFIG.5B, the catheter404is received in the lock mechanism400. The paddles430a,430bare releasably urged against the deformable tube410at the outer wall412to deform the inner wall414, which pinches or applies a force along the line of the outer diameter Doutagainst the catheter404in the overlap region434to hold the catheter404in place with respect to the deformable tube410and sheath402. In the sheath-lock state530, the paddles430a,430bcompress the inner wall414and deform the lumen416.

In the third state, or air lock state540, as illustrated inFIG.6C, taken along lines6C-6C ofFIG.5C, the catheter504is removed from the lock mechanism500. The paddles are releasably urged against the deformable tube510at the outer wall512to deform the inner wall514such as to collapse the deformable tube510and seal the lumen516in the diameter plane. The inner wall414is compressed together in the overlap region434so that fluid, such as saline or air, does not enter the sheath402from the lock mechanism400.

FIGS.7A-7Cillustrate a cross section700of the lock mechanism400taken along lines7-7ofFIGS.4A-4Cin the various states of the lock mechanism400, such as a side cross sectional view. For instance, the cross section can be taken along the bisector plane inFIGS.3A-3C. As the view of the lock mechanism400in the bisector plane, the outer wall412includes a line segment of a secant passing through the axis AA defined as the bisector line B.

In the first state, or nominal state520, as illustrated inFIG.7A, taken along lines7A-7A ofFIG.4A, the catheter404is received in the lock mechanism400. The paddles430a,430bdo not contact the deformable tube in a way to deform the inner wall414enough to prevent the catheter404from moving freely along axis AA. In particular, the inner wall414is not deformed along the bisector line B to prevent the catheter404from freely moving along axis AA.

In the second state, or sheath lock state530, as illustrated inFIG.7B, taken along lines7B-7B ofFIG.4B, the paddles430a,430bare releasably urged against the deformable tube410at the outer wall412to deform the inner wall414, which pinches or applies a force along the line of the outer diameter Doutagainst the catheter404in the overlap region434to hold the catheter404in place with respect to the deformable tube410and sheath402. The paddles430a,430bcompress the inner wall414and deform the lumen416. In one example, the shape of the lumen416formed by the inner wall414in the overlap region434is no longer circular and has become ovalized. The distance of the cross-sectional shape of the lumen416formed by the inner wall414along the bisector line B becomes longer than the length of the diameter C of the catheter404. In one example, the distance of the cross-sectional shape of the lumen416formed by the inner wall414along the bisector line B becomes longer than the length of the diameter of the lumen416in the nominal state. The collapsed deformable tube410, which is pinching the catheter404, in the overlap region434along the bisector plane includes openings440between the catheter404and the inner wall414along the bisector plane as illustrated along the bisector line B. In the sheath lock state530, the catheter404pinched in the lock mechanism400is not movable with respect to the sheath402, but fluid, such as saline, can still flow through the lock mechanism400and down the catheter assembly406. As illustrated inFIG.7B, saline can flow down the catheter assembly406via openings440even though the catheter404is pinched against the inner wall414along the diameter plane, as illustrated inFIG.6B.

In the third state, or air lock state540, as illustrated inFIG.7C, taken along lines7C-7C ofFIG.4C, the catheter404is removed from the lock mechanism400. The paddles430a,430bare releasably urged against the deformable tube410at the outer wall412to deform the inner wall414such as to collapse the deformable tube410and seal the lumen416. The inner wall414is compressed together in the overlap region434along the diameter plane and the bisector plane as illustrated along the bisector line B. In the air lock state540, fluid, such as saline or air, does not enter the sheath402from the proximal end420. In the illustrated example, the height H of the lock regions is longer than the length of the diameter of the outer wall412. In this configuration, the lock regions432a,432bcan apply a force to the deformable tube410to the entire inner wall414along the overlap region434in the air lock state440. Additionally, the width W is effectively at an amount to maintain the seal under the pressures applied within the lock mechanism400.