Devices and methods for selectively deploying catheter instruments

Abstract

To provide devices and methods for controlling the position of a deployable catheter instrument.SOLUTION: A catheter can include: an instrument slidably disposed within an inner lumen of the catheter and coupled to at least one protrusion 118; and a retraction stop 120 coupled to the catheter. The catheter can further include: a biasing element 122 coupled to the instrument that can proximally push out the instrument such that the at least one protrusion abuts against the retraction stop; and an advancing mechanism 124 to selectively engage and distally push out the instrument. In some embodiments, the biasing element can be omitted and a deployment stop can be included distally to the retraction stop. These configurations can prevent unintentional instrument deployment and provide greater positioning precision during instrument deployment.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims priority to U.S. Patent Application No. 15 / 970,543, filed on May 3, 2018, entitled "Devices and Methods for Selectively Deploying Catheter Instruments". The entire content of this application is incorporated herein by reference.

[0002] The present disclosure generally relates to surgical instruments, and more specifically to catheters having deployable instruments for use in surgical procedures.

Background Art

[0003] Catheters are widely used in surgical procedures for delivering instruments and pharmaceuticals to specific locations within a patient's body. For example, a catheter can be introduced into a patient's circulatory system and guided through the patient's blood vessels to various regions of the body (e.g., the heart). By using a catheter, a procedure can be provided that is less invasive than the procedures required in other methods for accessing the interior of a patient's body.

[0004] Catheters can be provided with components that can be manipulated from outside the patient's body when advancing the catheter towards the surgical site, for example, to be able to guide the often tortuous path of the patient's circulatory system. There are various known mechanisms for manipulating a catheter, most of which involve using one or more steering cables that pass longitudinally through the sidewall of the catheter from the distal portion of the catheter to a handle or other control assembly outside the patient's body. By pushing or pulling on one or more steering cables, the catheter can be bent in one direction or another.

[0005] Catheters can be used to deliver various surgical instruments during surgery. One common example is a deployable, elongated body, such as a needle, which can be configured to penetrate tissue at the treatment site and deliver therapeutic fluids, energy, etc. The deployable needle can be slidably positioned within the lumen of the catheter and can be retracted distally to the catheter during delivery to the surgical site. Then, after the catheter is positioned at the surgical site, the deployable needle can be selectively deployed.

[0006] Selective retraction and deployment of a needle, other elongated body, or other surgical instrument is typically enabled by connecting the needle to a handle or other control assembly located outside the patient's body (via a connecting member, e.g., a flexible and substantially incompressible tube). The user can control the position of the needle at the distal end of the catheter by manipulating an accessible portion of the needle (or connecting member) within the handle or control assembly. As a result, the needle's position relative to the catheter is set at the proximal end of the device.

[0007] One of the problems encountered with these devices is that the shortening of the catheter during manipulation can inadvertently expose the needle, other elongated body, or other surgical instrument. As described above, the manipulation of the catheter is achieved by pushing or pulling one or more wires extending through the side walls of the catheter. This operation causes a portion of the catheter to retract or compress and change direction, thereby shortening the overall length of the catheter. This shortening occurs along the distal portion of the catheter, but as described above, the position of the needle or other elongated body relative to the catheter is set at the proximal end of the device. As a result, when the distal portion of the catheter is compressed and bent, the floating distal tip of the needle within the lumen of the catheter may be exposed.

[0008] Complications during surgical procedures can occur if needles, other elongated bodies, or other instruments configured to penetrate tissue are accidentally exposed. For example, an exposed needle may unintentionally damage tissue when a catheter is maneuvered to a predetermined position at the surgical site.

[0009] Furthermore, during manipulation, the relative movement between the catheter and the needle makes it difficult for the user to know precisely how far the needle or other elongated body has extended from the distal end of the catheter when the catheter is positioned at the surgical site. This is because the needle's position relative to the catheter is set at the proximal end of the device, which is outside the patient's body. While this position can be initially set to retract the needle a certain amount into the catheter lumen before any manipulation is performed, the user cannot know how the needle has moved relative to the distal end of the catheter while advancing the needle while the catheter is being manipulated. Therefore, the user cannot precisely control the advancement of the needle at the surgical site (for example, to extend the needle a specific distance from the distal end of the catheter).

[0010] Previous attempts to address these problems have focused on further retracting the needle or other elongated body into the catheter lumen to prevent accidental exposure of the needle tip during manipulation. However, this is problematic because it is distal to any maneuvering mechanism, and the distal portion of the catheter housing the elongated body or other instrument becomes longer, reducing the catheter's maneuverability. Furthermore, nothing addresses the problem of accurately deploying the needle after it has been positioned at the surgical site. Other attempts to address these problems involve adding a rigid support wire to the catheter to reduce its compressibility, but this also reduces the catheter's maneuverability.

[0011] Therefore, improved devices and methods are needed for the selective deployment of catheter needles or other surgical instruments. In particular, improved devices and methods are needed to prevent accidental exposure of such instruments during catheter manipulation and to allow for more precise extension of such instruments when the catheter is positioned at the surgical site. [Overview of the project]

[0012] This disclosure provides devices and methods for selectively deploying catheter needles or other surgical instruments, generally addressing, and in particular, the above-mentioned needs in the art. The devices and methods described herein generally involve biasing a deployable needle or other surgical instrument proximally so that a portion of the needle or instrument is held against a retraction stop to which it is coupled to a catheter. The retraction stop may be formed at a predetermined position near the distal end of the catheter, thereby enabling the precise positioning of the needle or other instrument relative to the distal end of the catheter, even when the catheter is difficult to manipulate. The devices and methods described herein may further comprise a forwarding mechanism capable of selectively pushing the needle or other instrument distally against the biasing force in order to forcibly deploy the instrument from the distal end of the catheter. As a result, the devices and methods described herein can prevent accidental deployment of the instrument held within the catheter during maneuvering operations, and enable precise deployment of the instrument once the catheter is positioned at the surgical site.

[0013] In one embodiment, a catheter is provided that includes an instrument slidably disposed within the lumen of the catheter, the instrument being coupled to at least one projection. The catheter may further include a retraction stop coupled to the catheter proximal to at least one projection. There may also be a biasing element coupled to the instrument and configured to push the instrument proximally so that at least one projection abuts the retraction stop. The catheter may further include a forwarding mechanism configured to selectively engage the instrument and push the instrument distally relative to the catheter.

[0014] The catheter described above may have various modifications and / or additional features within the scope of this disclosure. For example, in some embodiments, the catheter may be maneuverable using one or more control cables extending through the catheter. In some embodiments, one or more control cables may be terminated at a predetermined position proximal to the retraction stop. This prevents deformation of the distal portion of the catheter beyond the retraction stop during maneuvering, thereby preventing shortening of the distal portion during catheter maneuvering.

[0015] In some embodiments, the advancement mechanism may include a tab or other user-operated handle coupled to the proximal portion of the instrument. In some embodiments, the tab or handle may be firmly coupled to the instrument. In other embodiments, the advancement mechanism may include a clutch for selectively engaging the instrument. For example, in the case of a needle, if the user wishes to deploy the needle from the lumen of the catheter, the clutch may engage with the needle or an intermediate component coupled to the needle. If deployment is not desired, the clutch may be disengaged from the needle or intermediate component, thereby allowing a biasing element to pull the needle proximal to the retraction stop. In certain embodiments, the clutch may be positioned in the proximal portion of the catheter within a handle assembly. Furthermore, in some embodiments, the advancement mechanism may include one or more predetermined distance increments that can be selected to push the instrument distally by a predetermined distance.

[0016] In certain embodiments, the catheter may include at least one indicator light configured to activate when the advancement mechanism engages with the instrument, thereby warning the user that the instrument may extend from the distal end of the catheter or unfold accidentally, as the position of the instrument within the catheter is no longer controlled by the biasing element. The indicator light may be used when the clutch is activated, the tab or handle is moved, or when any other type of advancement mechanism is activated.

[0017] In some embodiments, the biasing element may be located in the proximal portion of the catheter within the handle assembly. However, in other embodiments, the biasing element may be located at the distal end of the catheter. The biasing element can take various forms and may be configured to push or pull the instrument, or an intermediate component attached to the instrument, toward the proximal end of the catheter.

[0018] In certain embodiments, the retraction stop can be positioned so that the distal tip of the instrument is proximal to the distal tip of the catheter when at least one projection is in contact with the retraction stop. In other embodiments, the retraction stop can be positioned so that the distal tip of the instrument is uniform with the distal tip of the catheter when at least one projection is in contact with the retraction stop. Such positioning ensures that the distal end of the instrument does not damage tissue when the catheter is manipulated or moved through the body. Furthermore, the advancement mechanism can be configured to advance the instrument distally so that the distal tip of the instrument is distal to the distal tip of the catheter. In other words, the biasing element allows the advancement mechanism to be used to reliably retract the instrument into the lumen of the catheter until the instrument is extended from the catheter.

[0019] In some embodiments, at least one projection may include one or more fluid channels formed internally to allow fluid to flow through it. This allows for the clean flushing of body fluids or other contaminants from the catheter lumen during use. The fluid passages can have a variety of shapes and sizes, ranging from a single channel to multiple channels extending across at least one projection.

[0020] In another embodiment, an ablation device is provided that includes a catheter having a lumen extending through the interior, the lumen including a retraction stop formed in its distal portion. The ablation device may further include a needle slidably disposed within the lumen of the catheter, the needle including a lumen, at least one exit port formed in its distal portion, and at least one projection formed on its outer surface that is proximal to the at least one exit port and distal to the retraction stop of the catheter lumen. The ablation device may also include an ablation element disposed in the distal portion of the needle and configured to cauterize tissue, as well as a biasing element coupled to the needle and configured to push the needle proximal so that at least one projection on the needle abuts the retraction stop of the catheter lumen. Furthermore, the ablation device may include a forward mechanism configured to selectively push the needle distal to the catheter.

[0021] Similar to the catheters described above, ablation devices may have various modifications and / or additional features, all of which are considered to be within the scope of this disclosure. For example, in certain embodiments, the catheter of the ablation device may be maneuverable using one or more cables extending through the catheter. In other embodiments, a biasing element may be located in the proximal portion of the catheter within a handle assembly.

[0022] In other embodiments, the advancement mechanism may include a clutch for selective coupling to a needle or an intermediate component coupled to the needle. In certain embodiments, the clutch may be located in the proximal portion of the catheter within the handle assembly.

[0023] In yet another embodiment, the retraction stop can be positioned such that the distal tip of the needle is proximal to the distal tip of the catheter when at least one projection is in contact with the retraction stop. In yet another embodiment, the retraction stop can be positioned such that the distal tip of the needle is uniform with the distal tip of the catheter when at least one projection is in contact with the retraction stop. Furthermore, in some embodiments, the advancement mechanism can be configured to advance the needle so that the distal tip of the needle is distal to the distal tip of the catheter. Furthermore, in some embodiments, at least one projection on the needle may include one or more fluid channels formed internally to allow fluid to flow through its interior.

[0024] In certain embodiments, the ablation device may further include at least one heating element disposed within the lumen of the needle and positioned within its distal portion, which is proximal to at least one exit port. The at least one heating element may be configured to heat the fluid flowing through the lumen of the needle.

[0025] In another embodiment, a method is provided for selectively deploying an instrument from a catheter, the method comprising the step of pushing an instrument slidably disposed within the lumen of a catheter toward the proximal end of the catheter, so that at least one projection attached to the instrument abuts against a retraction stop attached to the distal portion of the catheter. The method further comprises the steps of attaching a forward mechanism to an instrument to control the movement of the instrument within the catheter, and activating the forward mechanism to push the instrument distally relative to the catheter.

[0026] In some embodiments, the step of pushing the device distally relative to the catheter can include advancing the device from a first position to a second position, where at the first position, the distal tip of the device is proximal to the distal tip of the catheter, and at the second position, the distal tip of the device is distal to the distal tip of the catheter. In other embodiments, the step of pushing the device distally relative to the catheter can include advancing the device from a first position to a second position, where at the first position, the distal tip of the device is flush with the distal tip of the catheter, and at the second position, the distal tip of the device is distal to the distal tip of the catheter. Note also that any number of additional positions can be included such that the device extends distally from the catheter at various distances.

[0027] In certain embodiments, the method can further include maneuvering the catheter to a predetermined position within the patient's body. This step can be performed, for example, using one or more of the control cables described above.

[0028] In still other embodiments, the device can be a needle, and the method can further include delivering fluid to tissue through the lumen of the needle and at least one outlet port formed within the distal portion of the needle. In still other embodiments, the method can further include heating the fluid delivered to the tissue using a heating element positioned within the lumen of the needle proximal to at least one outlet port. The method can also include delivering ablation energy to the tissue from an ablation element disposed at the distal portion of the needle.

[0029] In certain embodiments, the method can further include activating at least one indicator light when the advancement mechanism is coupled to the device. Such an indicator light can provide feedback to the user that the device may extend from the distal end of the catheter or may deploy inadvertently, such as during manipulation of the catheter.

[0030] In another aspect, a catheter can be provided that includes an instrument slidably disposed within the lumen of the catheter, the instrument being coupled to at least one protrusion. The catheter can further include a retraction stop coupled to the catheter and a deployment stop coupled to the catheter and disposed distal to the retraction stop. The catheter can further include an advancement mechanism configured to move the instrument relative to the catheter between a first position and a second position, wherein in the first position, the at least one protrusion contacts the retraction stop and in the second position, the at least one protrusion contacts the deployment stop.

[0031] Similar to the above aspects and embodiments, multiple variations and / or substitutions are possible. In some embodiments, for example, the deployment stop can be the distal end of a groove formed in the sidewall of the catheter and configured to receive the at least one protrusion. In certain embodiments, the catheter can further include a second deployment stop at the distal end of a second groove formed in the sidewall of the catheter. In such embodiments, the groove for receiving the at least one protrusion can be selected by rotating the instrument about its longitudinal axis. In some embodiments, the groove can be serpentine or can include a plurality of longitudinally extending portions connected by at least one transition portion. In such embodiments, either proximal or distal translation of the instrument can move the at least one protrusion through one of the plurality of longitudinally extending portions, and rotation of the instrument can move the at least one protrusion through the at least one transition portion.

[0032] In some embodiments, the deployment stop can be a partition having a through-hole formed therein for receiving the at least one protrusion. Further, the at least one protrusion and the through-hole can have complementary shapes such that the at least one protrusion can pass through the through-hole in a first orientation and passage of the at least one protrusion through the through-hole in a second orientation is prevented.

[0033] In certain embodiments, the position of the deployment stop relative to the retraction stop can be adjusted. For example, in some embodiments, the deployment stop can be coupled to an intermediate shaft located within the lumen of the catheter, with the instrument as the center. The position of the deployment stop relative to the retraction stop can be adjusted by moving the intermediate shaft relative to the catheter, for example, by a screw-type coupling.

[0034] In yet another embodiment, the deployment stop may be a return stop formed on the side wall of the catheter, and at least one projection may be biased to extend into the return stop when aligned with the stop. In some embodiments, the catheter may include additional deployment stops to allow the instrument to advance or retract relative to the catheter at different distances.

[0035] In some embodiments, the catheter may further include a biasing element coupled to the instrument. Such an element may be used optionally, but is not necessary, for example, when both a retraction stop and an extension stop are used to control the movement of the instrument relative to the catheter.

[0036] Any of the above features or variations may be applied to any particular aspect or embodiment of this disclosure in several different combinations. The absence of explicit reference to any particular combination is solely to avoid repetition in the summary of the invention. [Brief explanation of the drawing]

[0037] The aspects and embodiments of this disclosure described above will be better understood from the following detailed description, which is made in conjunction with the accompanying drawings.

[0038] [Figure 1] This figure shows one embodiment of a catheter device having a selectively deployable instrument.

[0039] [Figure 2]This is a perspective view showing another embodiment of a catheter device having a selectively deployable instrument.

[0040] [Figure 3] Figure 2 is a front view of the catheter device.

[0041] [Figure 4] Figure 2 is an exploded view of the catheter device.

[0042] [Figure 5A] Figure 2 is a perspective view of the catheter device with its distal end retracted.

[0043] [Figure 5B] Figure 5A is a cross-section of the distal end of the catheter.

[0044] [Figure 5C] Figure 5A is a cross-sectional view of the distal end of the catheter.

[0045] [Figure 6A] Figure 2 is an oblique cross-section of the distal end of the catheter device in a partially unfolded configuration.

[0046] [Figure 6B] Figure 6A is a cross-sectional view of the distal end of the catheter.

[0047] [Figure 7A] Figure 2 is a perspective view of the distal end of the catheter device in its fully deployed configuration.

[0048] [Figure 7B] Figure 7A is a cross-section of the distal end of the catheter.

[0049] [Figure 7C] Figure 7A is a cross-sectional view of the distal end of the catheter.

[0050] [Figure 8A]This is an alternative cutaway diagram of the distal end of the catheter device in the retracted configuration shown in Figure 2.

[0051] [Figure 8B] Figure 8A is a detailed cross-section of the distal end of the catheter.

[0052] [Figure 9] Figure 2 is a partial view of the proximal end of the catheter device.

[0053] [Figure 10] This is an alternative partial view of the proximal end of the catheter device shown in Figure 2.

[0054] [Figure 10A] Figure 10 is a detailed view of the proximal end of the catheter.

[0055] [Figure 11] Figure 2 is an alternative diagram of the proximal portion of the catheter device.

[0056] [Figure 12] This is a perspective view of one embodiment of a forward movement mechanism.

[0057] [Figure 13A] Figure 12 is a front view of the forward mechanism of the engagement / disengagement configuration.

[0058] [Figure 13B] Figure 12 is a front view of the forward mechanism of the engagement configuration.

[0059] [Figure 14A] Figure 12 is a front view of the forward mechanism, which has an engagement / disengagement configuration within the device shown in Figure 2.

[0060] [Figure 14B] Figure 12 is a front view of the forward mechanism, which is an engaging configuration within the device shown in Figure 2.

[0061] [Figure 15]Figure 12 is an exploded view of the forward movement mechanism.

[0062] [Figure 16] This is a perspective view of one embodiment of a clutch mechanism that can be used in a forward drive mechanism.

[0063] [Figure 17A] Figure 16 is a front view of the clutch mechanism in its engagement / disengagement configuration.

[0064] [Figure 17B] Figure 16 is a front view of the clutch mechanism in its engagement configuration.

[0065] [Figure 18] Figure 16 is an exploded view of the clutch mechanism.

[0066] [Figure 19A] This is a perspective view of one embodiment of a bearing assembly.

[0067] [Figure 19B] Figure 19A is a cross-sectional view of the bearing assembly.

[0068] [Figure 20A] Figure 2 is a perspective view of the proximal portion of the catheter device in the engagement / disengagement configuration.

[0069] [Figure 20B] Figure 20A is a perspective view of the catheter device with its engagement configuration.

[0070] [Figure 20C] Figure 20A shows a perspective view of the catheter device in its deployed configuration.

[0071] [Figure 20D] This is an alternative diagram of the catheter device shown in Figure 20A of the deployed configuration.

[0072] [Figure 21A] Figure 20A is a cutaway view of the catheter device.

[0073] [Figure 21B] Figure 20B is a cross-section diagram of the catheter device.

[0074] [Figure 21C] Figure 20C is a cross-section diagram of the catheter device.

[0075] [Figure 22A] Figure 20A is a cross-sectional view of the catheter device.

[0076] [Figure 22B] Figure 20B is a cross-sectional view of the catheter device.

[0077] [Figure 22C] Figure 20C is a cross-sectional view of the catheter device.

[0078] [Figure 23] This is a partial view showing the proximal end of another embodiment of a catheter device having a selectively deployable instrument.

[0079] [Figure 24] Figure 23 is a perspective view of the catheter device's advancement mechanism.

[0080] [Figure 25] Figure 24 is an exploded view of the forward movement mechanism.

[0081] [Figure 26] Figure 25 is an exploded view of the clutch mechanism.

[0082] [Figure 27A] Figure 24 is a front view of the forward mechanism of the engagement / disengagement configuration.

[0083] [Figure 27B] Figure 24 is a front view of the forward mechanism of the engagement configuration.

[0084] [Figure 28] Figure 24 is a front view of the forward mechanism of the engagement / disengagement configuration within the catheter device housing.

[0085] [Figure 29] This is a partial perspective view of one embodiment of a catheter device having a selective deployment type instrument including multiple deployment stop sections.

[0086] [Figure 30] This is a partial perspective view of another embodiment of a catheter device having a selectively deployable instrument including multiple deployment stop sections.

[0087] [Figure 31] This is a partial perspective view of another embodiment of a catheter device having a selectively deployable instrument including multiple deployment stop sections.

[0088] [Figure 32] This is a partial perspective view of another embodiment of a catheter device having a selectively deployable instrument including multiple deployment stop sections.

[0089] [Figure 33] This is a cross-sectional view of another embodiment of a catheter device having a selectively deployable instrument including an adjustable deployment stop section.

[0090] [Figure 34] This is a cross-sectional view of another embodiment of a catheter device having a selectively deployable instrument that includes multiple deployment stop sections. [Modes for carrying out the invention]

[0091] Here, specific exemplary embodiments are described to provide an overall understanding of the principles of the devices and methods disclosed herein. One or more examples of these embodiments are shown in the accompanying drawings. Those skilled in the art will understand that the devices and methods specifically described herein and shown in the accompanying drawings are non-limiting exemplary embodiments and that the scope of this disclosure is defined solely by the claims. Features illustrated or described in relation to one exemplary embodiment may be combined with features of other embodiments. Such modifications and variations are intended to be included within the scope of this disclosure.

[0092] As described above, catheters with selectively deployable surgical instruments (e.g., elongated bodies such as needles) are commonly used in current medicine. Furthermore, catheters holding these instruments are often maneuverable using one or more wires extending through the sidewall of the catheter, and these wires can be pushed or pulled to change the direction of the catheter. However, this maneuvering action shortens the length of the catheter, but there is a risk that the needle or other instrument may inadvertently protrude from the distal end of the catheter. This is because the needle or other instrument only references the catheter body at the proximal end of the device, typically outside the patient's body. Along the distal portion of the catheter where shortening occurs due to bending and compression, the needle floats freely and often does not experience the same shortening as the sidewall of the catheter. Inadvertent protrusion of the tip of a needle or other instrument from the distal end of the catheter can cause damage to surrounding tissue.

[0093] Furthermore, when the catheter is in place, it can be difficult to accurately determine the position of the needle or other instrument relative to the distal end of the catheter. This is also because the relative position of the instrument and the catheter is set only at the proximal end of the device outside the patient's body. While this setting allows for the precise positioning of the needle or other instrument relative to the distal end of the catheter in an unmaneuvered configuration, their relative positions can be altered by moving the distal portions of the catheter and needle during manipulation. As a result, by extending the needle or other instrument by a certain distance (e.g., 5 mm) at the proximal end of the device, the surgeon or other user cannot be certain that the instrument will actually extend that distance from the distal end of the catheter. Insufficient precision and accuracy in extending the needle or other instrument from the distal end of the catheter can also lead to complications, as the tissue at the surgical site may be extremely thin.

[0094] The devices and methods described herein address these and other shortcomings of previous designs by providing a reference point for a needle or other surgical instrument positioned along the distal portion of a catheter. The needle or other instrument may include features configured to connect with a retraction stop formed along the distal portion of the catheter, thereby providing a reference position where the relationship between the needle or other instrument and the distal tip of the catheter is known. This reference position can be positioned distal to any maneuvering mechanism such that any flexibility (i.e., the ability to shorten by maneuvering) within the catheter body occurs proximal to the reference position. Thus, whenever the needle or other instrument is pulled relative to the retraction stop of the catheter at the reference position, the relative position of the needle or other instrument and the catheter along the most distal portion of the catheter is reliably known.

[0095] To ensure that the relative positions of the needle or other surgical instrument and the catheter do not change during operation, the needle or other surgical instrument may be biased proximal. When the catheter is in a predetermined position at the surgical site, the needle or other surgical instrument can be selectively advanced distally against the biasing force using an advancement mechanism that can selectively engage with the needle, for example, using a clutch mechanism.

[0096] Figure 1 illustrates one embodiment of a catheter device 100 having a selectively deployable instrument (in this embodiment, a needle) as taught in this disclosure. The device 100 can generally be divided into a distal portion 102 located inside the patient's body and a proximal portion 104 placed outside the patient's body and manipulated by a surgeon or other user. The catheter device 100 includes a side wall 106 and a lumen 108. The distal portion 102 may be maneuverable using cables 110, 112 extending through the side wall 106. For example, the distal portion 102 may be oriented towards the bottom of the figure by pulling it proximal on the lower cable 112.

[0097] An elongated body, such as a needle 114, can be positioned within the lumen 108 of the distal portion 102 of the catheter. The needle 114 may extend along the entire length of the catheter device 100, or it may be coupled to a connecting member 116 extending between the needle 114 and the proximal portion 104 of the device. The needle 114 may also have one or more projections 118 formed on the needle (or on part of the connecting member 116), such as flanges, ribs, shelves, or shoulders. The projections 118 may be positioned distal to the retraction stop 120, such as corresponding flanges, ribs, shelves, shoulders, or other features formed on the sidewall of the catheter lumen 108. The projections 118 and the retraction stop 120 may be configured so that the projections cannot pass proximal through the retraction stop, but instead abut against it. Furthermore, the reversal stop unit 120 can be positioned distal to the distal ends of the control cables 110 and 112, thereby ensuring that any bending of the distal portion 102 during operation occurs proximal to the reversal stop unit 120.

[0098] Assuming that the projection 118 is formed on the needle 114 (or, for example, on the connecting member 116 and thus coupled to the needle), the retraction stop 120 is formed on the side wall of the lumen 108 at a specific location (or, for example, on another component and coupled to the catheter), and the relative position of the distal end of the needle 114 and the distal end of the device 100 is recognized whenever the projection 118 is pulled against the retraction stop 120 at the reference position 121 located distally. The biasing element 122 can push the needle 114 and the connecting member 116 toward the proximal end of the device 100. This ensures that the projection 118 remains firmly pressed against the retraction stop 120 at the reference position 121, even if the overall length of the catheter device 100 is reduced by manipulation during use.

[0099] The catheter device 100 also includes a forwarding mechanism 124 that can be used to selectively push the needle 114 or other instrument distally to the catheter. The forwarding mechanism 124 can have various forms, but in some embodiments it may include a clutch mechanism that selectively engages with the needle 114 or the connecting member 116 coupled to it only when needle deployment is desired. For example, Figure 1 shows the forwarding mechanism 124 as including an upper clutch member 126 and a lower clutch member 128. During maneuvering or at other times when needle deployment is undesirable, the clutch members 126, 128 may be separated and not in contact with the needle 114 or the connecting member 116 (if present). As a result, the biasing element 122 can push the needle 114 proximal so that the projection 118 abuts against the retraction stop 120.

[0100] If deployment of the needle 114 from the distal end of the catheter device 100 is desired, the advancement mechanism 124 can be operated such that the clutch members 126 and 128 move toward each other to contact the needle 114 or the connecting member 116 (if present) and securely grasp them. The clutch members 126 and 128 can then be translated distally while grasping the needle 114 or the connecting member 116, thereby pushing the needle 114 distally against the force of the biasing element 122. The advancement mechanism 124 engages with the needle 114 or the connecting member 116 while the projection 118 is in contact with the retraction stop 120 (i.e., at the reference position 121 located distally), so that the position of the needle relative to the distal tip of the catheter is always accurately known.

[0101] In some cases, it may be desirable to position the projection 118 along the needle 114 and / or connecting member 116 such that, when fully retracted, the distal tip of the needle is uniform with the distal end of the distal portion 102. In other embodiments, it may be desirable to position the projection 118 such that, when fully retracted, the distal tip of the needle is retracted into the lumen 108 by a distance D1 min. When utilizing the gap distance D1, the user may be informed that the advancement mechanism 124 must be moved by the desired extension distance plus the gap distance. Alternatively, a gradient marked on the outer surface of the proximal portion 104 of the device, or other indication of the needle extension distance, may be calibrated to include the gap distance D1, as well as any extension of the connecting member 116 and compression of the catheter sidewall 106.

[0102] After the use of the needle 114 or other surgical instrument is complete, the advancement mechanism can be retracted proximal to pull the needle 114 back into the lumen 108 of the catheter. Alternatively, the clutch members 126 and 128 can be engaged and disengaged (i.e., moved away from each other), and the force of the biasing element 122 can retract the needle 114 to a reference position 121 where the projection 118 abuts against the retraction stop 120.

[0103] The catheter device shown in Figure 1 may offer several advantages. For example, it solves the problem associated with referencing the relative positions of the catheter and deployable needle or other instrument from a position near the proximal end of the device. Instead, a reference position near the distal end of the device (i.e., distal to any part of the device that bends or articulates during manipulation) is utilized, and the deployable needle or instrument is biased proximal to ensure it is positioned at the reference position. This eliminates uncertainty regarding the needle's position and allows for accurate deployment once the catheter is positioned at the surgical site.

[0104] Furthermore, by using a forward mechanism with a selectively engageable clutch, it is ensured that the needle or other instrument does not move unintentionally when the clutch is engaged or disengaged. Moreover, the clutch can be configured to securely grip any part of it when activated, so there is no need to form a special interface function on a portion of the needle body extending from the proximal part of the connecting member or device. Such a device can be made safe and secure so that the needle or other instrument does not unintentionally deploy even during the most difficult maneuvers, and after the catheter has been led into place, it can also provide precise deployment control from outside the patient's body. However, in certain embodiments, interface features can be used to facilitate the coupling of the connecting member with a forward mechanism such as a selectively engageable clutch.

[0105] Naturally, the catheter device shown in Figure 1 is one of many possible configurations considered within the scope of this disclosure. For example, the projection 118 and the retraction stop 120 may have any of various complementary forms, such as a full-circumferential flange, shoulder, or shelf, and one or more bumps, ribs, or other formations that can abut against each other to stop further proximal movement of the needle 114 beyond a reference position. Similarly, the biasing element 122 used to push the needle 114 proximal could be a coil or other type of tension spring positioned along the proximal or distal portion of the device, or a compression spring similarly positioned along the proximal or distal portion of the device. Other known forms of biasing elements, such as electromagnetic biasing assemblies, may also be available.

[0106] The advancement mechanism can similarly have any of several different configurations. For example, the advancement mechanism may be a very simple mechanism, such as a protruding tab or handle formed on the connecting member 116 (or the needle body if the needle extends along the entire length of the device) and simply translating along the needle 114 in the proximal or distal direction. In such a configuration, the advancement mechanism should have sufficient clearance so that the needle 114 does not reach the proximal stop (e.g., the proximal end of a slot formed in the device housing from which the tab or handle extends) before reaching the reference position 121 in response to the force from the biasing element 122. This is because it could interfere with determining the precise position of the needle relative to the distal end of the catheter.

[0107] In yet another embodiment, the forward mechanism may include any of the various different clutch mechanisms known in the art to facilitate selective engagement with the connecting member 116 or the needle 114. These include a mechanical clutch mechanism that physically grips the connecting member 116 or the needle 114, an electromagnetic clutch mechanism that applies force to the connecting member or the needle without physical contact, or any other mechanism known in the art.

[0108] Furthermore, any of the various known mechanisms can be used to push the needle 114 distally in response to the force of the biasing element 122. These can range from simply applying a translational distal force by the user, as described in relation to Figure 1, to using various gear, belt, or rack drive systems, or using an electric solenoid.

[0109] Figures 2 and 3 show alternative embodiments of the catheter device 200 having a selectively deployable instrument at its distal end. The devices and methods described herein can be used with any of the various surgical catheter devices, but device 200 is configured, for example, to deliver a fluid-assisted ablation therapy to the user's heart. Fluid-assisted ablation therapy involves the delivery of therapeutic energy (e.g., radiofrequency electrical energy) simultaneously with the delivery of therapeutically heated saline (e.g., saline above approximately 40°C) or other fluid to selectively destroy tissue. This therapy can be used to treat various conditions, for example, cardiac arrhythmias such as ventricular tachycardia. Further information on fluid-assisted ablation therapy can be found in U.S. Patent No. 6,328,735, “Thermal Ablation System,” U.S. Patent No. 8,702,697, “Devices and Methods for Shaping Therapy in Fluid Enhanced Ablation,” and U.S. Patent Publication No. 2012 / 0265199, “Methods and Devices for Use of Degassed Fluids with Fluid Enhanced Ablation Devices.” The entire contents of these publications are incorporated herein by reference, as reproduced herein.

[0110] The device 200 generally includes a catheter 201 having a distal portion 202 and a flexible portion 204. The proximal portion 206 of the device includes a handle 208, a steering control unit 210, a steering tension knob 211, and a forward mechanism 212. Extending from the proximal end of the device are tubes 214, 216 that receive fluids for delivery during treatment and while the instrument is being flushed, respectively. An additional inlet 218 at the proximal end of the device can accept any number of power and control cables.

[0111] The device 200 may have a variety of different sizes depending on its intended use. For example, in some embodiments, the catheter 201 may have a length of about 120 cm and a diameter of about 8 Frenchs ("French" is a unit of measurement used in the catheter industry to describe the size of a catheter, and is equal to three times the diameter of the catheter (in millimeters)). Such a catheter may be very suitable for introduction into a patient's heart via the circulatory system. The catheter may be formed from any of the various materials known in the art, such as polyurethane, nylon, and polyetheramides such as PEBAX®. The catheter 201 may be flexible so that it can be maneuvered through a meandering path in the body using one or more maneuvering cables, as will be described in more detail below.

[0112] The proximal portion 206 of the device 200 can also have a variety of different shapes and sizes. For example, in some embodiments, the total length of the proximal portion 206 may be about 25 cm, and both the width and height may be about 5 cm (given the various dimensions described above, it will be clear that the figures are not necessarily to scale, particularly with respect to the length of the catheter 201). The various components of the proximal portion 206 can be formed from a variety of materials known in the art, such as various metals and polymers.

[0113] Figure 4 shows an exploded view of the proximal portion 206 of the device 200. Visible in this figure are the lower housing 402 of the handle 208, the upper housing 404, the printed circuit board 406, the catheter maneuvering control unit 210, and the advancement mechanism 212. The figure also shows a connecting member 408 (which may be an embodiment of the connecting member 116 described above) extending through the proximal portion 206 of the device and connecting the deployable needle (described below) to the advancement mechanism 212. The connecting member can be formed from any of a variety of materials and, in some embodiments, can be omitted in place of the needle body extending from the distal tip of the catheter 201 to the proximal portion 206 of the device. In some embodiments, the connecting member 408 can be formed from a polyimide tube and may include a lumen that communicates with the therapeutic fluid line 214 and the lumen of the deployable needle (described below).

[0114] Figures 5A to 5C show the distal portion 202 of the device 200 in a fully retracted (i.e., undeployed) configuration. The distal portion 202 of the device includes an end 502 coupled to a flexible portion 204 extending to the proximal portion 206 of the device. Because the end 502 is positioned distal to any maneuvering component of the device 200, its dimensions do not change due to tension or compression experienced during maneuvering. The end 502 can have a variety of different lengths and diameters depending on the length of any deployable instrument held internally. The end 502 can also include any of a variety of other features or devices to assist the operation of the device. For example, the illustrated end 502 includes a mapping ring electrode 506 disposed around the outer surface of the end. The ring electrode 506 can be used to help guide the catheter to a predetermined location, for example, within the patient's heart. The distal tip 508 covers the end 502 and includes an opening 510 formed on the distal surface of the tip that connects to the lumen 511 of the catheter 201.

[0115] The cutaway and cross-sectional views in Figures 5B and 5C show the position of the surgical instrument in a fully retracted configuration. In the illustrated embodiment, the surgical instrument is a needle 512 configured to penetrate tissue and deliver fluid-assisted ablation therapy. As described above, fluid-assisted ablation therapy involves delivering radio frequency (RF) electricity or other therapeutic energy in combination with a therapeutically heated fluid such as saline. Thus, the needle 512 may include one or more outlet ports 514 arranged along its distal portion, thereby allowing the fluid flowing through the lumen of the needle to be delivered to adjacent tissue. The needle 512 can be coupled to a connecting member 408 extending through the flexible portion 204 of the catheter 201 to the proximal portion 206 of the device. The lumen of the needle can communicate with the lumen of the connecting member 408 and then with a therapeutic fluid line 214 to receive fluid from a reservoir or other external source.

[0116] The needle 512 can be formed from a variety of different materials and can have many different diameters, lengths, sidewall thicknesses, etc. In some embodiments, the needle 512 may be a 25-gauge thin-walled stainless steel needle having a lumen diameter of about 0.4 mm. The needle may have at least one ablation element disposed on it, configured to deliver therapeutic electrical or other energy to the surrounding tissue. The ablation element may be a separate element coupled to the needle 512, or in some embodiments, all or part of the needle itself may be used as the ablation element. For example, a conductive needle 512 may be electrically coupled to a power source or other control component, for example, via a cable extending through an inlet 218, to facilitate the delivery of RF energy to tissue after the needle has been deployed, for example, in the wall of the heart. The needle 512 may also include a heating element 520 disposed within its lumen to heat saline (e.g., normal or concentrated saline), Ringer's solution, or any other fluid used in this treatment to a therapeutic level before being delivered to adjacent tissue via one or more outlet ports 514. The heating element 520 may be, for example, one or more wires suspended within the lumen of the needle 512 that allow RF electrical energy to pass through the fluid as it flows through the needle. For example, in some embodiments, the heating element 520 may be a single wire suspended within the lumen of the needle 512, and the fluid flowing through the lumen may be heated by the electrical energy passing between the wire and the needle body. In other embodiments, the heating element 520 may include two wires suspended within the lumen of the needle 512, between which electrical energy can pass, and which may heat the fluid flowing through the lumen. In any of such embodiments, one or more wires may be routed through one or more spacers to prevent accidental contact between the wires and the needle 512.Further information relating to heating assemblies for use in fluid-assisted ablation therapy can be found in U.S. Patent Publication No. 2012 / 0265190, entitled "Methods and Devices for Heating Fluid in Fluid Enhanced Ablation Therapy," which is incorporated herein by reference as it is reproduced herein.

[0117] The needle 512 may have one or more protrusions or other features formed on it, configured to abut against a retraction stop formed on the lumen 511 of the catheter and define the nearest position of the needle (referred to above as the reference position). The protrusions or other features formed on the needle, and the retraction stop formed on the side wall of the catheter lumen, may have any of a variety of configurations. For example, one or more ribs, shoulders, flanges, or other features may be positioned around the periphery of the needle and the side wall of the catheter lumen so that they interfere with each other. Furthermore, the protrusions or other features on the needle 512, and the retraction stop formed on the lumen 511, may be positioned such that the distal end 513 of the needle 512 is uniform with or proximal to the distal end 515 of the catheter end 502 (i.e., the distal end of the catheter 201) when the two components are in contact with each other. In such a configuration, the needle 512 can be retracted into the catheter lumen 511. Furthermore, in certain embodiments, the position of projections or other features and the retracted lumen can be selected such that a gap of distance D1 exists between the distal end 513 of the needle and the distal end 515 of the catheter 201.

[0118] In the illustrated embodiment, the needle 512 includes a full-circumferential flange 516 formed thereon, having an outer diameter substantially similar to the diameter of the lumen 511. Proximal to the flange 516 is a retraction stop 518 formed from a collar coupled to the inner sidewall of the catheter lumen 511. The flange 516 can be translated within the lumen 511 when the needle 512 is deployed or retracted, but the retraction stop 518 does not translate relative to the end 502 and thus forms a proximal stop of the needle 512. As seen in Figure 5C, the proximal surface of the flange 516 abuts against the distal surface of the retraction stop 518 when the needle is in a fully retracted (i.e., undeployed) configuration.

[0119] Figures 6A and 6B show the distal portion 202 of the device 200 in a partially deployed configuration. In this configuration, the user begins to advance the needle distally from the proximal portion 206 of the device using the advancement mechanism 212 (described in more detail below). By translating the connecting member 408 distally at the proximal end of the device, the needle 512 is also translated distally, thereby exposing the distal tissue puncture tip 513 of the needle and separating the flange 516 from the retraction stop 518. In other words, the needle 512 is advanced distally so that the distal tip 513 of the needle is distal to the distal end 515 of the catheter 201.

[0120] Figure 6A also shows that the collar of the retraction stop 518 surrounds the connecting member 408 with some clearance so that the connecting member 408 can slide through the collar. It may also be necessary to flush the lumen 511 of the catheter with fluid to remove air, coagulant, or other foreign matter from the device. The clearance between the inner diameter of the retraction stop 518 and the outer diameter of the connecting member 408 allows such fluid to flow. The flange 516 can be sized to extend across the diameter of the lumen 511 and may include one or more fluid channels 602 formed internally to allow fluid to flow through the flange 516. In the illustrated embodiment, the fluid channels include a plurality of circular passages extending around the periphery of the flange 516. In other embodiments, the fluid passages can be formed in various numbers, shapes, sizes, etc. For example, one or more slot and / or groove-shaped passages can be formed at various locations extending around the periphery such as the flange 516.

[0121] The fluid channel 602 allows fluid to be introduced from the proximal end of the device and exit from the distal end of the device to flush into the patient's body. Flushing the device in this manner prevents blood from entering the device from the distal end, forming a thrombus in the lumen, and returning from the distal end to cause a stroke or other complications. Filling the lumen of the device with fluid also prevents any air from exiting from the distal end of the device, which could cause similar problems as thrombosis. In fact, in some embodiments, anticoagulants such as heparin can be included in the fluid that flushes through the lumen to further reduce the likelihood of coagulation.

[0122] Figures 7A, 7B, and 7C show the distal portion 202 of the device 20 when it is in a fully extended configuration. In such a configuration, the advancement mechanism 212 is extended distally by its maximum amount such that the distal surface of the flange 516 abuts the proximal surface of the distal tip 508 of the catheter. Naturally, the needle 512 or other surgical instrument does not need to extend to this fully extended configuration to deliver the treatment. Rather, the needle 512 can be extended to any distance necessary to perform the desired treatment. For example, in some embodiments, the needle may have a total length of several millimeters, but the tissue to be treated may be substantially thinner than this total length. In such embodiments, the user may extend the needle only by a portion of its total length to ensure that the needle does not pass completely through the tissue. As a further example, in some embodiments, the needle 512 may have a total length of about 13 mm and may be configured to extend about 8 mm from the distal end of the catheter when fully extended. However, in other embodiments, only a maximum extension of about 4 mm may be desired. Alternatively, the maximum extension may be much longer, for example, about 20 mm, as is the case when treating thicker tissue. Furthermore, in some embodiments, it may be desirable to increase the length of the needle within the catheter without increasing the maximum extension length of the needle beyond the distal end of the catheter, as lengthening a portion of the needle within the catheter lumen can help reinforce the portion of the needle extending beyond the distal end of the catheter. Thus, various needle lengths and extension lengths are possible in various embodiments.

[0123] Figures 8A and 8B illustrate cutaway diagrams of the interaction between the needle 512, the flange 516, and the retraction stop 518. As shown, the proximal end of the needle 512 is coupled to the distal end of the connecting member 408, which then extends proximal to the distal end 802 of the proximal portion 206 of the device 200. The connecting member 408, which may be a single component or a combination of several intervening components, transmits the force applied by the user to the needle 512. The retraction stop 518, having a longitudinal position fixed along the catheter 201, provides a proximal stop for the needle 512 and defines a reference position near the distal end of the device, where the relative position of the needle 512 and the catheter 201 is known.

[0124] The figure also shows a control ring 804 and a control cable 806 that control the maneuvering of the catheter 201. Specifically, the control ring 804 is connected to the catheter 201, and the control cable 806 is connected to the control ring 804. By pushing or pulling the control cable 806 from the proximal end of the device 200 (i.e., using the control control unit 210), the flexible portion 204 can be bent to change the orientation of the end 502.

[0125] The bending of the flexible portion 204 as described above may shorten the length of the catheter 201, which in conventional devices could cause accidental exposure of the distal tip of the needle or other surgical instrument. In the illustrated embodiment, the reference position defined by the interface between the flange 516 and the retraction stop 518 is located distal to the termination points of the control ring 804 and the control cable 806. Therefore, all bending or flexing occurs proximal to the reference position. As long as the flange 516 remains pressed against the retraction stop 518, the relative positions of the needle 512 and the end 502 of the catheter 201 are known.

[0126] To maintain this position regardless of distortion of the flexible portion 204, the needle 512 can be biased proximal. Whenever distal advancement of the needle is undesirable, this biasing force ensures that the flange 516 is securely pressed against the retraction stop 518. As will be described in more detail below, the advancement mechanism 212 can be used to selectively overcome the biasing force and advance the needle distally after leading the catheter to the surgical site.

[0127] Figure 9 illustrates a partial view of the proximal portion 206 of the device 200. The biasing element 902 can be seen in this figure as being distal to the forward mechanism 212. The biasing element 902 can have various different forms, but in some embodiments it may be a coil or other compression spring compressed between a portion of the connecting member 408 and a reference structure such as the lower housing 402 or upper housing 404. As will be described in more detail below, the biasing element 902 in the illustrated embodiment is a coil spring compressed between a flange 1006 (shown in Figure 10A) firmly coupled to the connecting member 408 and a stop portion 1102 (shown in Figure 11) formed on the lower housing 402. In such embodiments, the spring can push the connecting member 408 proximal to the lower housing 402, and the forward mechanism 212 may be configured to grip the connecting member 408 and push it distally, thereby further compressing the spring. However, in other embodiments, different biasing elements can be used, for example, including tension springs, electromagnetic biasing assemblies, and the like. Furthermore, in certain embodiments, the position of the biasing elements can be changed; for example, a compression spring or other biasing element can be positioned at the distal end of the device between the flange 516 of the needle 512 and the distal tip 508 of the catheter 201. Alternatively, a tension spring or other biasing element can be positioned at the proximal end of the device, as in the configuration illustrated in Figure 1 and above.

[0128] Figure 9 also shows an indicator lens 904 at the distal end of the proximal portion 206. The indicator lens 904 can be formed from a transparent or translucent material and can cover one or more indicator lights 1104 (see Figure 11) that can be used to provide feedback to the user. For example, in some embodiments, one or more indicator lights can be activated whenever the advancement mechanism 212 is engaged with the connecting member 408. This can serve as an indicator to show the user that the catheter 201 should be handled carefully because the needle 512 or other instrument may advance from the distal end of the device. One or more indicator lights 1104 may be, for example, light-emitting diodes, incandescent bulbs, etc.

[0129] Figure 10 shows an alternative subdivision of the proximal portion 206 of device 200. This figure more clearly shows the pathways of the treatment line and instrument flushing fluid line 214, 216, as well as the biasing element 902. A branching base 1002 is also visible, which directs the fluid flow from the instrument flushing line 216 into the annular space surrounding the connecting member 408 within the catheter lumen 511. The branching base 1002 may also function as a mounting location for one or more indicator lights 1104 (see Figure 11).

[0130] Figure 10A shows the biasing element 902 and the proximal portion of the connecting member 408 in more detail. As seen in the figure, the connecting member 408 includes a sleeve 1004 to which it is coupled at its distal end. The sleeve 1004 can be formed from a variety of materials, but in some embodiments it may be formed from a rigid conductive material such as stainless steel or another metal. The sleeve 1004 can be bonded to the connecting member 408 so that it cannot move relative to the sleeve, for example, using epoxy or other binders. The sleeve 1004 can provide greater rigidity for the forward mechanism 212 to grip the connecting member 408 (this may be formed from a material that can deform when clamped by, for example, the clutch mechanism 1301 described below in some embodiments). The conductive properties of the material can also assist in constructing an electrical circuit for activating one or more indicator lights 1104 (see Figure 11), as will be described in more detail below.

[0131] The sleeve 1004 may include a flange 1006 or other features configured to abut against the proximal end of the biasing element 902. The flange 1006 can provide a surface for the biasing element 902 that acts when biasing the connecting member 408 in the proximal direction. As shown in Figure 11, the distal end of the biasing element 902 can abut against a spring retainer 1102 formed on the lower housing 402 of the device 200. As a result, the connecting member 408 can be biased proximal to the device housings 402, 404 and the catheter 201.

[0132] Figures 12 to 19 illustrate the advance mechanism 212 in more detail. As described above, the advance mechanism 212 selectively engages with the connecting member 408 to bring about distal movement of the needle 512 or other surgical instrument when desired by the user. The advance mechanism 212 can have a variety of different forms, ranging from simple tabs or other features formed on the connecting member 408 to which the user can apply force, to more complex assemblies such as clutch mechanisms that selectively engage with the connecting member 408 when activated.

[0133] The illustrated forward mechanism 212 includes a clutch housing 1202 having upper and lower operating projections 1204, 1206 that can be operated by a user, as described below. The clutch cap 1208 forms the distal end of the forward mechanism 212 surrounding the connecting member 408. The distal and proximal anti-rotation stop sections 1210, 1212 include posts 1211, 1213, respectively, which are coupled to the clutch cap 1208 and the clutch housing 1202 and are configured to ride within a track formed in the lower housing 402 (not shown). The track formed in the lower housing 402 extends along the longitudinal axis of the device so that the anti-rotation stop sections 1210, 1212 can translate in the proximal and distal directions relative to the lower housing 402, but cannot move across it. The figure shows a bearing assembly 1214 that facilitates the rotational motion of the forward mechanism 212 relative to the lower and upper housings 402, 404.

[0134] Figures 13A and 13B show the engaged and disengaged configurations of the forward mechanism 212, respectively. These figures also show the clutch mechanism 1301 within the clutch housing 1202. The clutch mechanism 1301 includes a first clutch member 1302 and a second clutch member 1304, which are pivotally coupled to each other by a clutch shaft 1306. The first and second clutch members 1302 and 1304 are biased toward the disengaged configuration, as shown in Figure 13A, and the outer surfaces of the first and second clutch members 1302 and 1304 each abut against the bearing assembly 1214. The connecting member 408 is positioned in the space between the clutch members 1302 and 1304.

[0135] In the engaged and disengaged configuration of Figure 13A, the clutch members 1302 and 1304 do not contact the connecting member 408. Therefore, the forward mechanism 212 exerts no force on the connecting member 408, and only the biasing element 902 acts on the connecting member. However, in the engaged configuration of Figure 13B, the clutch members 1302 and 1304 are pivoted toward each other by a force applied by the bearing assembly 1214. In this configuration, the clutch members 1302 and 1304 contact and grip the connecting member 408 (not shown in Figure 13B), thereby coupling the forward mechanism 212 to the connecting member 408. The forward mechanism 212 can then be used (for example, via a force applied to the operating projections 1204 and 1206) to push the connecting member 408 (and therefore the needle 512 or other device) distally against the force of the biasing element 902.

[0136] Figures 14A and 14B show the forward mechanism 212 in the engaged and disengaged configurations of Figures 13A and 13B, respectively, but also show the forward mechanism associated with the lower and upper housings 402 and 404 of the device 200. In particular, Figures 14A and 14B illustrate that when the forward mechanism rotates relative to the housing, portions of the lower and upper housings 402 and 404 are used to move the forward mechanism 212 between the engaged and disengaged configurations.

[0137] In Figure 14A, for example, the forward mechanism 212 is positioned within the lower and upper housings 402, 404 of the device 200 such that bearing assemblies 1214 extending from opposing sides of the clutch housing 1202 are located within recesses 1402 formed in the lower and upper housings. The recesses 1402 allow the bearing assemblies 1214 to extend radially outward, thereby allowing the first and second clutch members 1302, 1304 to pivot away from each other around the clutch shaft 1306 (for example, due to a biasing force exerted by the spring 1602 shown in Figure 16). As described above, in such a configuration, the clutch members 1302, 1304 do not contact the connecting member 408 or exert any force on the connecting member 408. The connecting member 408 can freely translate in the proximal or distal direction relative to the forward mechanism 212.

[0138] To move the forward mechanism 212 into the engagement configuration shown in Figure 14B, the user can rotate the forward mechanism by applying force to the operating projections 1204 and 1206 (for example, in the illustrated embodiment, by rotating the forward mechanism counterclockwise from the viewpoint shown in the figure). When the forward mechanism 212 is rotated counterclockwise, the bearing assemblies 1214 extending from opposing sides of the clutch housing 1202 move from the recess 1402 to the flat portions 1404 of the lower and upper housings 402 and 404. This movement presses the bearing assemblies 1214 radially inward, causing the first and second clutch members 1302 and 1304 to pivot toward each other around the clutch shaft 1306. In this engagement configuration, the first and second clutch members 1302 and 1304 can be coupled to the connecting member 408, thereby preventing the connecting member from translating relative to the forward mechanism 212. In other words, when the forward movement mechanism 212 is in the engagement configuration shown in Figure 14B, it can control the proximal / distal position of the connecting member relative to the device.

[0139] Figure 15 illustrates an exploded view of the forward mechanism 212, showing the various components more clearly. In particular, the figure shows the first and second biasing springs 1502 and 1504 that bias the forward mechanism toward the engaged and disengaged configurations of Figures 13A and 14A. The first biasing spring 1502 is positioned between the distal anti-rotation stop 1210 and the clutch cap 1208 and can abut against them. Similarly, the second biasing spring 1504 is positioned between the clutch housing 1202 and the proximal anti-rotation stop 1212 and can abut against them. Posts 1211 and 1213 extending from the anti-rotation stop 1210 and 1212 and riding within tracks (not shown) formed in the lower housing 402 prevent the anti-rotation stop from rotating relative to the lower housing 402 (but can still translate longitudinally). As a result, the first and second biasing springs 1502 and 1504 can provide a rotational biasing force to the forward mechanism 212.

[0140] Figure 16 illustrates the clutch mechanism 1301 in more detail. As described above, the first and second clutch members 1302 and 1304 are pivotally coupled to each other by the clutch shaft 1306. Furthermore, the first and second clutch members 1302 and 1304 are biased toward the open configuration by one or more biasing springs 1602 disposed around the clutch shaft 1306. The first and second clutch members 1302 and 1304 can have various different shapes and sizes depending on the size of other components in the device, the size of the connecting member 408, etc. Furthermore, the first and second clutch members 1302 and 1304 can be formed from a variety of materials, including, for example, stainless steel, acrylonitrile butadiene styrene (ABS) plastic or other suitable polymers, and even softer, more conformable materials, such as rubber (e.g., 65A durometer rubber), silicone or silicone blends. Furthermore, the first and second clutch members 1302 and 1304 may include mechanical teeth or other features to assist in gripping the connecting member 408. For example, coil-shaped (i.e., threaded) mechanical teeth may be formed on each member to assist in gripping the connecting member.

[0141] The first and second clutch members 1302, 1304 are also configured to form part of an electrical circuit that activates one or more indicator lights 1104 when the forward mechanism 212 is in an engaged configuration. In particular, each clutch member includes a first distal electrical connector 1604A and a second distal electrical connector 1604B, as well as a first proximal electrical connector 1606A and a second proximal electrical connector 1606B. In each clutch member, the first and second distal electrical connectors 1604A, 1604B are electrically coupled to each other, and the first and second proximal electrical connectors 1606A, 1606B are electrically coupled to each other, but the sets of distal and proximal electrical connectors (i.e., 1604A, 1604B and 1606A, 1606B) are electrically isolated from each other. Furthermore, the second distal electrical connector 1604B and the second proximal electrical connector 1606B are configured to contact the connecting member 408 when the clutch member is in contact with the connecting member.

[0142] To create an electrical circuit that activates one or more indicator lights 1104 only when the forward mechanism 212 is in an engaged configuration, one or more indicator lights 1104 can be electrically coupled to a first distal electrical connector 1604A, and a power supply (not shown) can be electrically coupled to a first proximal electrical connector 1606A. When the clutch members 1302 and 1304 are in a disengaged configuration (i.e., not in contact with the connecting member 408), one or more indicator lights 1104 are not connected to the power supply. However, when the clutch members 1302 and 1304 are engaged and in contact with the connecting member 408, the connecting member makes contact with both the second distal electrical connector 1604B and the second proximal electrical connector 1606B, completing the circuit and conducting electricity to one or more indicator lights 1104. For such a circuit to operate, the connecting element 408 must be able to conduct electricity between the two electrical connectors 1604B, 1606B, although in some embodiments, a non-conductive material (e.g., polymer) is used to form the connecting member. In such embodiments, a sleeve 1004, disposed around the connecting member 408 and formed from stainless steel or another conductive material, may extend along any portion of the connecting member that can contact the clutch members 1302, 1304.

[0143] The completion of the electrical circuitry when the forward mechanism 212 is in operation can be utilized to provide feedback to the user in several different ways. One possible option is to activate one or more indicator lights 1104 to visually remind the user that the forward mechanism is engaged. In other embodiments, the circuitry may be located within the device 200 as described in the above-mentioned patents and patent publications incorporated by reference, or coupled to a controller or other component of the system, incorporated into an external controller, such as a fluid replacement ablation treatment controller. Such a controller, or other external interface device, can provide similar feedback to the user visually, audibly, tactilely, or otherwise. Furthermore, feedback from the electrical circuitry can be used to control the delivery of the treatment (e.g., delivery of RF electrical energy from the needle 512). However, in the illustrated embodiment, the indicator lights 1104 may at least serve to remind the user that the forward mechanism is engaged, and since the needle 512 or other instrument may extend from the distal end of the device, the catheter manipulation should be performed with care.

[0144] Figures 17A and 17B show the disengaged and engaged configurations of the clutch mechanism 1301 and the bearing assembly 1214 separately. The first distal electrical connector 1604A of each clutch member is shown, while the second distal electrical connector 1604B is not shown in this figure. Figure 18 illustrates the components shown in the exploded views of Figures 17A and 17B. Figure 18 shows that the clutch members 1302 and 1304 may each include an insert 1802 having a shape configured to securely grip the connecting member 408 (or a sleeve 1004 disposed around it) in some embodiments. The insert 1802 may be formed from the same or different material as the clutch members 1302 and 1304 and may have a variety of shapes and sizes. In some embodiments, for example, the insert 1802 may be formed from stainless steel, acrylonitrile butadiene styrene (ABS) plastic or other suitable polymers, as well as softer and more conformable materials, such as rubber (e.g., 65A durometer rubber), silicone, or a silicone blend. Furthermore, when using inserts, they may include the mechanical teeth or other features described above that can assist in gripping the connecting member 408. For example, coil-shaped (i.e., threaded) mechanical teeth may be formed on each member to assist in gripping the connecting member.

[0145] Figures 19A and 19B illustrate the bearing assemblies 1214 in more detail. Each bearing assembly 1214 includes a base 1902 configured to abut against the outer surface of one of the clutch members 1302, 1304. The base also includes one or more raised portions 1904 on which a ball bearing 1906 can be seated, and one or more caps 1908 extending around each ball bearing 1906 and the raised portion 1904. The caps 1908 may include openings on which the ball bearing 1906 can partially extend. As a result, the ball bearing 1906 can abut against, for example, a recess 1402 or flat portion 1404 of the upper or lower housing 402, 404, and the bearing facilitates smooth movement along these portions of the housing when the forward mechanism 212 rotates or translates about the longitudinal axis of the device.

[0146] Figures 20, 21, and 22 illustrate various views of the proximal portion 206 of the device 200 as the forward movement mechanism 212 is moved from the engagement / disengagement configuration to the engagement configuration, and this mechanism is used to advance the needle 512 from the configuration shown in Figure 5 to the configuration shown in Figure 7. These figures are accompanied by a description of how to use the device 200 provided below.

[0147] At the start of a surgical procedure in which device 200 is used, for example, a fluid-enhanced ablation therapy procedure to treat ventricular tachycardia, the forward mechanism 212 may be positioned as shown in Figures 20A, 21A, and 22A. That is, the forward mechanism 212 can be positioned in its most proximal position so that the actuation projection 1204 abuts against the proximal end of the opening 2001 in the upper housing 404 (as can be seen from Figures 3, 4, and 14, the actuation projection 1206 may similarly extend from the opening in the lower housing 402). The opening 2001 may include a notch 2002 at its proximal end, which prevents the forward mechanism 212 from translating proximal or distal to the device. The notch 2002 can be positioned such that the first and second biasing springs 1502 and 1504 push the forward mechanism into the notch and into an engagement / disengagement configuration in which the clutch members 1302 and 1304 are not in contact with the connecting member 408.

[0148] In the configurations shown in Figures 20A, 21A, and 22A, the biasing element 902 can push the connecting member 408 proximal until the flange 516 abuts against the retraction stop 518, as shown in Figures 5A to 5C. As described above, the positions of the flange 516 along the needle 512 and the retraction stop 518 within the lumen 511 of the catheter 201 are selected so that when the flange abuts against the retraction stop (i.e., in the reference position), the distal tip 513 of the needle is uniform with or close to the distal tip 515 of the catheter 201. In certain embodiments, the positions of these components can be selected to maintain a desired gap D1 between the distal tip 513 of the needle 512 and the distal tip 515 of the catheter 201 when in this configuration. Any desired gap distance can be utilized, and in some embodiments, the distance may be about 2 mm.

[0149] In this configuration, the catheter 201 can be maneuvered to a predetermined position within the patient's body. In particular, the catheter can be introduced, for example, into the patient's circulatory system, and the maneuver control unit 210 can be used to maneuver the catheter through the patient's body to a surgical site, for example, the patient's heart. By biasing the needle 512 proximal and positioning the flange / retract stop interface distal to the termination point of the maneuver cable 806, the needle is securely placed within the catheter lumen 511. Thus, the user can ensure that the needle 512 does not accidentally extend from the distal end of the catheter, even if the flexible portion 204 of the catheter 201 bends sharply when maneuvered into a predetermined position.

[0150] Once the catheter 201 is led to a predetermined position at the surgical site, the user can move the forward mechanism 212 from the engagement / disengagement configuration shown in Figures 13A, 14A, 20A, 21A, and 22A to the engagement configuration shown in Figures 13B, 14B, 20B, 21B, and 22B. This is achieved by rotating the forward mechanism 212 to move the actuation projection 1204 (and similarly, the actuation projection 1206 on the opposite side of the device) out of the notch 2002. The rotation of the forward mechanism 212 moves the bearing assembly from the recess 1402 in the housing to the flat portion 1404, thereby pressing the clutch members 1302 and 1304 together to securely grip the connecting member 408. Furthermore, the sleeve 1004 contacts the electrical connectors 1604B and 1606B on the clutch member, activating one or more indicator lights 1104 that illuminate through the indicator lens 904 to notify the user that the forward mechanism 212 has engaged with the needle 512.

[0151] To deploy the needle 512 from the distal end of the catheter 201, the user can translate the advancement mechanism 212 distally, as shown in Figures 20C, 21C, and 22C. This translation of the advancement mechanism 212 also advances the needle 512 distally, passing through the positions shown in Figures 6A and 6B, and ultimately to the positions shown in Figures 7A and 7C. In such a configuration, the biasing element 902 is compressed as shown in Figure 22C, and the advancement mechanism 212 is positioned near the distal end of the opening 2001.

[0152] The needle 512 can be precisely controlled because it always begins to advance distally from a reference position where the flange 516 abuts against the retraction stop 518. By using a biasing element, some compressive strain may be applied to the catheter body and some tension to the connecting member 408 (these need to be relieved before the needle begins to move relative to the retraction stop 518), but this can be characterized and compensated for, for example, by setting the position of the notch 2004 described below. The final result is that moving the advancement mechanism 212 distally, for example by 5 mm (and further, the distance necessary to compensate for the strain of the biasing element described above), moves the needle 512 5 mm distally from the reference position. Such precision is not possible with conventional devices that do not guarantee the starting position of the needle or other instrument relative to the distal tip of the catheter.

[0153] To allow the user's hands to be free when the needle is deployed, the opening 2001 may include one or more additional notches 2004 formed at specific deployment distances. For example, in some embodiments, the notches 2004 may be provided at needle deployment distances of 2 mm, 5 mm, and 8 mm, as shown in Figure 20D. The notches can be positioned so that the forward mechanism 212 is pushed into a predetermined position within the notch by the first and second biasing springs 1502, 1504. However, unlike the notches 2002, the notches 2004 can be positioned so that the connecting member 408 is securely gripped and held in place against the force of the biasing element 902 so that the forward mechanism remains in the engaged configuration when seated. Furthermore, any distance represented by the notch 2004 can represent the distance the needle 512 extends from the distal tip of the catheter 201, and can take into account any gap distance D1 maintained between the distal tip of the needle and the distal tip of the catheter when fully retracted, as well as any additional forward distance necessary to relieve the compression within the catheter body imparted by the tension and biasing elements of the connecting member 408. Any number of notches can be provided at any various distances, and in some embodiments, the notch 2004 may not be used in place of several other known mechanisms for maintaining the translational and rotational positions of the forward mechanism 212, such as set screws and locking pins.

[0154] Once the needle 512 is deployed from the end of the catheter 201 and inserted into the tissue, the user can initiate the delivery of fluid replacement ablation therapy. This may include the step of delivering fluid from a reservoir or other source to the tissue by supplying fluid through the therapeutic fluid delivery line 214, as well as through the lumen of the connecting member 408 and the needle 512. The fluid can be delivered to the tissue through one or more outlet ports 514 of the needle 512. Furthermore, the fluid can be heated before being delivered to the surrounding tissue using a heating element 520 (see Figure 5C) disposed within the lumen of the needle 512. As described above, the length of the heating element 520 may be, for example, the length of an exposed wire that allows RF electrical energy to pass through the fluid to the sidewall of the needle 512, thereby heating the fluid flowing through the lumen of the needle due to its inherent resistivity. Further details regarding heating elements suitable for use with the deployable needle 512 are available in the patents and published applications incorporated by reference above.

[0155] Fluid-assisted ablation therapy may also include a step of delivering RF electricity or other energy to tissue using ablation elements disposed on the outer surface of a needle 512. In the illustrated embodiment, for example, the needle 512 may be formed from a conductive material such as stainless steel, and its entire surface may be used as an electrode. However, in other embodiments, only a portion of the needle 512 may be used as an ablation element (for example, by covering the rest of the needle with an insulating material), or individual ablation elements may be coupled to the needle. Further details of the ablation elements are described in the patents and published applications incorporated by reference above.

[0156] If the catheter 201 needs to be repositioned during surgery, the user can retract the needle 512 by reversing the deployment step detailed above. That is, the advance mechanism 212 can rotate out of notch 2004, translate proximal, rotate again, and enter a new notch, for example, notch 2002. The needle can be moved by any desired amount, proximal or distal, and catheter manipulation is always possible. However, the indicator light 1104 may remain activated until the clutch members 1302, 1304 of the advance mechanism 212 disengage from the connecting member 408 to remind the user that the needle 512 is in the deployed state. As described above, in certain embodiments, the signal activating the indicator light 1104 can be used to control other aspects of the device, such as locking the maneuvering control until the needle is retracted, preventing the start of treatment until the needle is deployed, etc.

[0157] The foregoing description provides details of specific embodiments of the present disclosure. Specific features described in relation to these embodiments do not limit the scope of the present disclosure. For example, the device 200 described above includes a hollow needle 512 configured to deliver fluid and ablation energy to tissue. However, the present disclosure may be applicable to any surgical instrument (needle or other) that is delivered to a surgical site within a catheter and can be selectively deployed for use. Furthermore, specific biasing elements disclosed herein are not intended to be limiting. As an example, a compression coil spring 902 can be placed at various locations within the device 200, such as the distal portion 202 of the catheter 201 rather than the proximal portion 206 of the device. Additionally, different types of biasing elements, such as tension springs and electromagnetic biasing assemblies, may be used.

[0158] Furthermore, the forward mechanism 212 can have a variety of different configurations. For example, the clutch mechanism 1301 can be replaced with several different possible mechanical, electromechanical, or electromagnetic clutch mechanisms. In some embodiments, the pivot clutch members 1302, 1304 can be replaced with silicone or other compliant members that extend around the connecting member 408 and are pressed against the connecting member by the rotation of the forward mechanism 212. When in contact with the connecting member, friction prevents movement between the compliant member and the connecting member 408, thereby allowing the forward mechanism to be used to translate the needle 512 distally with respect to the force of the biasing element 902.

[0159] Figures 23–28 show the proximal portion of another embodiment of the catheter device 2300, including an alternative advancement mechanism 2312. Device 2300 is substantially the same as device 200 shown in Figure 9, and the advancement mechanism 2312 functions similarly to selectively grasp the connecting member 408 and result in distal advancement of the needle or other surgical instrument. However, the advancement mechanism 2312 includes an alternative mechanical design, which is shown in detail in Figures 24 and 25.

[0160] The forward mechanism 2312 includes an upper clutch housing 2314 and a lower clutch housing 2316 that cooperatively enclose the other components of the mechanism. The upper and lower clutch housings 2314, 2316 each include operating projections 2318, 2320 (each) that can be operated by a user to actuate the mechanism and bring about distal motion of the connecting member 408. The distal and proximal anti-rotation stop units 2322, 2324 are coupled to the upper and lower clutch housings 2314, 2316 and posts 2326, 2328, which are configured to ride within tracks formed in the lower housing 402 (not shown) of the device. The tracks formed in the lower housing 402 can be extended along the longitudinal axis of the device so that the anti-rotation stop units 2322, 2324 can translate proximal and distal relative to the lower housing 402, but cannot move laterally relative to the lower housing. The distal and proximal biasing springs 2330 and 2332 are coupled to one of the anti-rotation stop units 2322 and 2324 (via posts 2329 and 2331, respectively), and to one of the upper and lower clutch housings 2314 and 2316, thereby biasing the clutch housing by rotation to the engagement / disengagement configuration, similar to the forward mechanism 212 described above.

[0161] The exploded view in Figure 25 illustrates the various components housed between the clutch housings 2314 and 2316. In particular, the clutch mechanism 2501 is located between the upper clutch housing 2314 and the lower clutch housing 2316, and between the distal anti-rotation stop 2322 and the proximal anti-rotation stop 2324. The clutch mechanism 2501, which will be discussed in more detail below, includes first and second clutch members pivotably coupled to each other by a clutch shaft extending between the distal and proximal anti-rotation stop 2322 and 2324. Furthermore, a pair of bearing shafts 2503 are mounted in slots formed within the distal and proximal anti-rotation stop 2322 and 2324 and are positioned radially outward from the first and second clutch members of the clutch mechanism 2501. The bearing shafts 2503 can rotate and move radially within the slots of the anti-rotation stop 2322 and 2324. One or more stabilizing shafts 2505 also extend between distal and proximal anti-rotation stop sections 2322, 2324 to improve the rigidity of the forward mechanism 2312.

[0162] Figure 26 illustrates the clutch mechanism 2501 in more detail. Similar to the clutch mechanism 1301 shown in Figure 18, the clutch mechanism 2501 includes first and second clutch members 2602, 2604 that are pivotally coupled to each other by a clutch shaft 2606. Furthermore, the first and second clutch members 2602, 2604 are biased toward the open configuration by one or more biasing springs 2608 disposed around the clutch shaft 2606. Similar to the clutch mechanism 1301 described above, the first and second clutch members 2602, 2604 can have a variety of different shapes and sizes and may include alternative arrangements of the biasing components. Furthermore, each of the first and second clutch members 2602, 2604 may include an insert 2610 configured to contact a connecting member 408 when the clutch mechanism 2501 is in operation. The insert 2610 can have various shapes and sizes and can be formed from the same or different materials as those used to form the first and second clutch members 2602, 2604. The insert 2610 can be selectively separated from the corresponding clutch member to facilitate replacement, for example, when the insert inevitably wears out or when a connecting member 408 of a different size is used.

[0163] Furthermore, similar to the clutch mechanism 1301 described above, the clutch mechanism 2501 may be configured to form part of an electrical circuit that activates one or more user feedback mechanisms (e.g., indicator lights 1104) when the forward mechanism 2312 is in an engaged configuration. In particular, the first clutch member 2602 may include a first electrical connector 2612, and the second clutch member 2604 may include a second electrical connector 2614. Lead wires (not shown) may be electrically coupled to the first and second electrical connectors via posts 2616, 2618 (respectively) and extend to one or more indicator lights 1104 and a power supply (not shown). This allows the first and second electrical connectors 2612, 2614 to form a switch in the circuit connecting the power supply to one or more indicator lights 1104. When the clutch mechanism 2501 is activated and the first and second clutch members 2602, 2604 contact the connecting member 408, the first and second electrical connectors 2612, 2614 also contact the connecting member 408, for example, closing the switch via the conductive material of the connecting member 408 as described above. As a result, one or more indicator lights 1104 can be powered on only when the clutch mechanism 2501 is in contact with the connecting member 408. Powering on one or more indicator lights 1104 as described above is an example of the feedback that can be provided by such a switch. In other embodiments, the open or closed position of the switch can be communicated to a controller or other components of the system. Such a controller can provide feedback to the user visually, audibly, tactilely, or otherwise, or can control the delivery of a treatment (e.g., delivery of RF electrical energy from the needle 512 or other instrument).

[0164] Figures 27A and 27B show the engagement and disengagement configurations of the clutch mechanism 2501, along with the interactions between the clutch mechanism and other components of the forward mechanism 2312. The movement shown in Figures 27A and 27B is the rotation of the clutch housings 2314, 2316 around the anti-rotation stop 2324, because the proximal anti-rotation stop 2324 is prevented from rotating by a post 2328 (see Figures 24 and 25) that extends into a track formed on the lower housing 402 (not shown). The stabilizing shaft 2505 and the clutch shaft 2606 do not move in the plane of the figure for the same reason, as they extend between recesses formed in the distal and proximal anti-rotation stop 2322, 2324. However, the shaft 704 can move radially inward or outward. This is because the bearing shaft 2503 is received in a slot formed in the anti-rotation stop 2322, 2324 that allows such movement.

[0165] In the engagement / disengagement configuration of Figure 27A, the clutch housings 2314 and 2316 are positioned such that the recesses 2702 are aligned with each bearing shaft 2503, thereby allowing the bearing shafts to move radially outward. In this configuration, the force of the clutch mechanism 2501 causes the biasing spring 2608 (see Figure 26) to separate the first and second clutch members 2602 and 2604, pushing the bearing shafts 2503 to their outermost positions. Furthermore, the clutch members 2602 and 2604 maintain a state where they are not in contact with the device's connecting member 408 (not shown).

[0166] To engage with the forward mechanism 2312, the user can rotate the clutch housings 2314, 2316, for example, by operating the operating projections 2318, 2320, to the configuration shown in Figure 27B. As the clutch housings 2314, 2316 rotate, the recess 2702 moves, becoming misaligned with the bearing shaft 2503, and the flat (or protruding) portion 2704 of the clutch housing can be repositioned with the bearing shaft. Such rotational motion of the clutch housings 2314, 2316 causes the bearing shaft 2503 to move radially inward, thereby overriding the force of the biasing spring 2608 and moving the first and second clutch members 2602, 2604 toward each other. In the configuration shown in Figure 27B, a connecting member (not shown) disposed between the first and second clutch members 2602, 2604 is securely gripped. Next, the user can translate the forward mechanism 2312 in the proximal or distal direction to bring about similar movement of the needle or other surgical instrument connected to the connecting member as described above.

[0167] Figure 28 illustrates the forward mechanism 2312 relative to the lower housing 402, the upper housing 404, and the connecting member 408. The forward mechanism in a disengaged configuration is shown in Figure 27A and does not come into contact with the connecting member 408. As can be seen by comparing Figure 28 with Figures 14A and 14B, the forward mechanism 2312 is entirely contained within the clutch housings 2314, 2316 and does not rely on interaction between the lower and upper housings 402, 404 and the bearing assembly 1214 to bring about the movement of the clutch members 2602, 2604.

[0168] The forward mechanisms 212 and 2312 described above are merely two possible embodiments. Furthermore, both embodiments utilize clutch members that move toward or away from each other via pivot connections. In other embodiments, the clutch members 1302, 1304 (or 2602, 2604) can be linearly separated from each other. For example, tapered surfaces on the clutch members 1302, 1304 and the clutch housing 1202 can press the clutch members toward each other as the forward mechanism 212 rotates or translates. In yet another embodiment, the forward mechanism 212 may include separate mechanisms for controlling the engagement of the mechanism with the connecting member 408 and the translation of the mechanism relative to the device, or the forward mechanism 212 may be configured such that a single movement (e.g., distal translation) causes both engagement with the connecting member 408 and distal forward movement. Furthermore, the device according to the teachings of this disclosure may utilize any method of gearing systems (e.g., worm gears, etc.) and actuators (e.g., solenoids, etc.) to assist or fully power-drive the forward mechanism.

[0169] Figures 29-34 illustrate additional embodiments of a forwarding mechanism that can restrict the distal advancement of a needle or other surgical instrument positioned within the distal portion of a catheter using a known reference position. Thus, the position of the needle or other instrument within the catheter can be reliably determined not only when retracted proximal to the retraction stop described above, but also when deployed distally to the deployment stop, as described below. The known positioning of the deployment stop relative to the distal end of the catheter ensures that a certain length of needle or instrument is deployed beyond the distal end of the catheter when a projection or other positional feature formed on the instrument is in contact with the deployment stop. Furthermore, a series of deployment stops can be used to achieve deployment of instruments of various lengths, e.g., 2 mm, 5 mm, 8 mm, etc. Moreover, such embodiments may optionally utilize biasing elements. In certain embodiments, the absence of biasing elements may eliminate the need to compensate for the tension in the connecting members and the compression of the catheter that biasing elements may impart.

[0170] In the first embodiment shown in Figure 29, a series of tracks 2902, 2904, and 2906 may be formed on the sidewall of the lumen 2908 of the catheter 2910. An elongated body 2912, for example, a needle or another surgical instrument, may be positioned within the lumen 2908 and configured to translate and rotate relative to any of its tracks. The elongated body 2912 may include projections 2914 formed on its outer surface. The projections 2914 may have a shape complementary to the tracks 2902, 2904, and 2906, so that the tracks can receive the projections and guiding motion of the elongated body 2912 relative to the catheter 2910. For example, at a proximal position, the elongated body 2912 can be rotated around a longitudinal axis L to align the projections 2914 with one of the tracks 2902, 2904, and 2906. Next, the elongated body 2912 can be advanced relative to the catheter so that the projection 2914 enters one of the tracks 2902, 2904, or 2906. The elongated body 2912 can be advanced until the projection reaches a deployment stop formed by the distal end of the deployed track. At that point, interference between the projection 2914 and the distal end of the track can prevent further advancement of the elongated body 2912 relative to the catheter 2910. By terminating the tracks 2902, 2904, or 2906 at a specific distance from the distal end of the catheter 2910, the deployment of the elongated body can be restricted at a specific distance from the distal end of the catheter 2910.

[0171] For example, as shown in Figure 29, the first track 2902 can be shorter than the second track 2904 and shorter than the third track 2906. By rotating the elongated body 2912 in a proximal position so that the projection 2914 is aligned with the first track 2902, and then advancing the elongated body distally, the length of the first track can limit the distance the elongated body can advance relative to the catheter. If a longer distance is desired, the elongated body 2912 can be retracted to a proximal position, rotated to align with one of the longer tracks 2904, 2906, and then advanced distally to the end of the selected track.

[0172] With such a configuration, as described above, when the elongated body is retracted proximal to the retraction stop, and in various deployment positions, the user can be reliably given the relative position of the elongated body located within the catheter. Here, the elongated body advances toward one of the distal ends of tracks 2902, 2904, and 2906. Furthermore, since tracks 2902, 2904, and 2906 are formed along the side wall of catheter 2910 along a portion of the catheter distal to any maneuvering mechanism, the user can ensure any proximal deformation of the catheter due to maneuvering, etc., and the distance the elongated body extends from the distal end of the catheter does not affect it.

[0173] Figure 29 illustrates three tracks 2902, 2904, and 2906 of different lengths. However, in other embodiments, any number of tracks can be used to bring about advancement or deployment of the elongated body by various distances. By controlling the rotation of the elongated body 2912 relative to the catheter 2910, one of the various tracks can be selected at the proximal end of the device. For example, in some embodiments, a knob or other operating feature can be coupled to the elongated body along its proximal portion and used to rotate the elongated body 2912. For example, a marking, stopper, or other identifying feature on the housing positioned around the elongated body 2912 can indicate to the user which track the projection 2914 is aligned with, for example, by indicating the distal advancement possible by that track (e.g., 2 mm, 5 mm, 8 mm, etc.).

[0174] Figure 30 illustrates a second embodiment in which a flange 3002 or other feature formed on the elongated body 3004 is utilized in combination with a complementary through-hole 3006 formed in the catheter 3008, allowing for selective advancement of the elongated body 3004 when rotated to a correctly keyed orientation. For example, as shown in Figure 30, the elongated body 3004 is shown rotated to a position where the flange 3002 is positioned to advance through the hole 3006 or to a keyed position. However, in this rotated position, the elongated body is prevented from advancing beyond the more distal through-hole 3010. To achieve such further distal advancement, the elongated body 3004 needs to be rotated 90° after passing through the through-hole 3006.

[0175] In such a system of key-shaped flanges and through-holes located in different rotational directions around a longitudinal axis L, a known selectively restricted advance of the elongated body 3004 relative to the catheter 3008 can be obtained in the same manner as the various tracks described above. For example, if the position of the through-hole 3006 is known relative to the distal end of the catheter 3008 and the position of the flange 3002 is known relative to the distal end of the elongated body 3004, then the known relative positions of the elongated body 3004 and the distal ends of the catheter 3008 can always be determined when the elongated body advances so as to abut the through-hole 3006 but not pass through it (for example, by rotating the elongated body around axis L so as not to pass through the hole 3006). Furthermore, the position of the hole 3006 may be distal to any maneuvering mechanism of the catheter 3008, and any proximal deformation or movement of the catheter 3008 and / or elongated body 3004 caused by maneuvering the catheter along its distal portion will not affect the relative positioning of the catheter and the distal end of the elongated body, as described above.

[0176] Furthermore, by arranging a series of through-holes (e.g., holes 3006, 3010, etc.) along the length of the catheter at various distances relative to the distal end of the catheter, the elongated body 3004 can be selectively advanced by rotation, allowing the flange 3002 to be selectively positioned with various through-holes. If misaligned with a particular through-hole, the distal advance of the elongated body will press the flange 3002 against the partition surrounding the through-hole (e.g., partition 3007 surrounding through-hole 3006 or partition 3009 surrounding through-hole 3010), thereby forming an deployment stop and preventing any unintended further advancement.

[0177] It should be noted that in some embodiments, the above configuration can be used in combination with proximal biasing of the elongated body 3004 to maintain the elongated body in a desired position relative to the catheter. For example, after the flange of the elongated body has passed through the hole, the elongated body can be rotated to prevent it from being pulled out of the hole, and then pushed proximally so that the flange is pressed against the septum it has just passed through. For example, the elongated body 3004 can be advanced distally from the position shown in Figure 30 so that the flange passes through the hole 3006, and then the elongated body can be rotated 90° to adjust its position so that it passes through the hole 3010, but can be pulled proximal by a biasing mechanism, for example. By pulling it proximal in this way, the flange 3002 can be kept in contact with the septum 3007, and the position of the elongated body relative to the catheter can be maintained. Such a configuration effectively provides a series of retraction stops (such as the stop 518 described above) along the length of the distal portion of the catheter.

[0178] One embodiment of the flange 3002 and through holes 3006, 3010 is shown in Figure 30, and any of a variety of different configurations are possible. For example, the flange 3002 may be in the form of one or more radially extending projections of various shapes and sizes, and the through holes 3006, 3010 may be complementary and positioned at any of a variety of rotational positions. The actuator described above can be used to control rotation and distal advance or proximal retraction from the proximal portion of the elongated body.

[0179] Figure 31 illustrates yet another embodiment of a forward movement mechanism in which a single meandering or labyrinthine track 3102 is formed on the sidewall of the catheter 3104 to guide the movement of an elongated body 3106 relative to the catheter. As described above, a projection 3108 formed on the elongated body 3106 can be configured to be received within the track 3102. When the projection 3108 is received within the first portion 3110 of the track 3102, the elongated body 3106 can be prevented from rotating relative to the catheter 3104 and its distal advancement can be restricted only until the projection 3108 abuts against the distal end of the first portion of the track, thereby reaching a first deployment stop. As described above, the distal end of the first portion 3110 of the track 3102 can be positioned at a known distance from the distal end of the catheter. These fixed distances can be used in combination with a fixed distance between the projection 3108 and the distal end of the elongated body 3106 to determine the relative position between the distal end of the catheter and the elongated body.

[0180] To further advance the elongated body 3106 relative to the catheter 3104, the elongated body can be rotated so that the projection 3108 passes through the first transition section 3112 of the track 3102. Once the projection 3108 is aligned with the second section 3114 of the track 3102, the elongated body 3106 can advance distally until the projection abuts the distal end of the second section of the track, thereby reaching the second deployment stop. If further distal advancement is desired, the elongated body 3106 can be rotated to move the projection 3108 through the second transition section 3116 and align it with the third section 3118 of the track 3102. In various embodiments, any number of track sections and transition sections can be used to provide various stepwise advances of the elongated body relative to the catheter.

[0181] Furthermore, the elongated body 3106 can advance relative to the distal end of each section of the track 3102, or be pulled out proximal to the proximal end of each section to control the positioning of the elongated body relative to the catheter 3104. This is conceptually analogous to advancing the flange 3002 distally to the partition or pulling it out proximal to the partition in the embodiment shown in Figure 31. Otherwise, there may ultimately be a series of effective retraction or deployment stops for either proximal retraction or distal advancement, which can be used to verifiably achieve and maintain the position of the elongated body relative to the catheter, regardless of the relative movement between these components along the more proximal section, for example, due to deformation from catheter manipulation.

[0182] Figure 32 illustrates yet another embodiment in which a series of tracks 3202, 3204 are formed on the sidewall of catheter 3206 at different angular positions about the longitudinal axis L of the catheter. An elongated body 3208 disposed within the lumen of catheter 3206 may include projections, keys, or other features 3210 formed on the outer surface of the elongated body that can be received within tracks 3202, 3204 to guide the movement of the elongated body relative to the catheter. By positioning tracks 3202, 3204 at different angular positions about the longitudinal axis L, it may be necessary to rotate the elongated body 3208 to some extent to move the keys 3210 from, for example, a position aligned with the first track 3202 to, for example, a position aligned with the second track 3204. This means that, prior to such rotation, when the key 3210 contacts the distal end of a track disposed within the catheter, the distal advance of the elongated body 3208 relative to the catheter 3206 can reach the positive deployment stop. As described above, tracks 3202, 3204 can be formed on the distal portion of the catheter 3206, which is located distally to any maneuvering portion. Thus, the distance between the most distal end of any track and the distal end of the catheter can be known and does not change. The key 3210 or other feature can similarly be fixed to the distal end of the elongated body 3208, so that the relative position between the distal end of the elongated body 3208 and the distal end of the catheter 3206 (e.g., how far the distal end of the elongated body extends beyond the distal end of the catheter) can be known when the key 3210 contacts the distal end of the track.

[0183] The transition of key 3210 between tracks 3202 and 3204 can be achieved in various ways. For example, a transition track section (e.g., transition sections 3112 and 3116 above) can be used to bridge the gap between different tracks. Alternatively, a 360° rotation of the elongated body can be made possible, providing annular transition sections that intersect each of tracks 3202 and 3204. Although only two tracks are shown in the figure, any number can be used along the length of the catheter. Furthermore, in some embodiments, it may be possible to enter multiple tracks from a given transition region. For example, using a configuration similar to that shown in Figure 29, multiple tracks (e.g., having different lengths) can be selected based on the rotation of the elongated body to position key 3210 on a desired track.

[0184] Figure 33 illustrates an embodiment in which the intermediate shaft 3302 is disposed within the catheter 3304 on the elongated body 3306 and serves as an active stopper for advancing the elongated body 3306 distally relative to the catheter. Similar to the above configuration, the elongated body 3306 may include a flange 3308 or other features formed thereon, which, when used in conjunction with a fixed retraction stopper 3310, can ensure that the elongated body is held securely in a known location within the catheter 3304 and prevent the elongated body from unintentionally extending beyond the distal end of the catheter, such as during catheter placement. The intermediate shaft 3302 may be disposed around the elongated body 3306 and the retraction stopper 3310 and may be movable relative to them to adjust its position along the longitudinal axis L of the catheter. The intermediate shaft 3302 may include a distal end 3312 having a lumen with a reduced diameter so that the elongated body 3306 can pass through the distal end of the shaft 3302 but the flange 3308 cannot.

[0185] As a result of this configuration, when the flange 3308 contacts the distal end 3312 of the intermediate shaft 3302, it reliably stops the elongated body from advancing distally relative to the catheter 3304. Furthermore, when the flange 3308 of the elongated body 3306 is retracted relative to the stop and the distal end of the elongated body is aligned with the distal end of the catheter 3304 (for example, as shown in Figure 33), by setting the distance X between the distal end 3312 of the intermediate shaft 3302 and the retraction stop 3310, when the elongated body is advanced distally so that the flange 3308 contacts the distal end 3312 of the shaft 3302, the user can reliably extend the elongated body by the same distance X from the distal end of the catheter. Naturally, in other embodiments, the configuration shown in Figure 33 may be adjusted to accommodate any substantial thickness of the flange 3308 and, for example, the desired safe return of the elongated body 3306 within the catheter 3304 when it is retracted.

[0186] The position of the intermediate shaft 3302 relative to the catheter 3304 and the retraction stop 3310 can be adjusted in several ways. For example, in some embodiments, the intermediate shaft 3302 can be screw-engaged with the catheter 3304 so that its position can be adjusted along the longitudinal axis L of the catheter by rotating the shaft 3302. In other embodiments, the shaft 3302 can be marked relative to the catheter 3304 using a series of return stops with spring-loaded or fixed claw-like features, or using any other known configuration. In some embodiments, the shaft 3302 can be marked relative to the catheter 3304 at a predetermined position distal to any maneuverable portion of the catheter, thereby avoiding any accidental movement between the shaft 3302 and the catheter 3304, which may result in variations in the distance X between the distal end 3312 of the shaft and the fixed retraction stop 3310.

[0187] A further configuration is shown in Figure 34, where the position of the elongated body 3402 relative to the catheter 3404 is controlled using a series of return stoppers 3406, 3408, 3410, and 3412 formed on the side wall of the catheter lumen. The elongated body 3402 may include projections 3414 formed on its outer surface, which can be joined with the return stoppers 3406, 3408, 3410, and 3412 to maintain the position of the elongated body relative to the catheter. Since the positions of the return stoppers 3406, 3408, 3410, and 3412 are known with respect to the distal end of the catheter 3404, and the position of the projections 3414 is known with respect to the distal end of the elongated body 3402, the relative position of the elongated body and the distal end of the catheter can be known for each of the return stoppers. Furthermore, the projection 3414 can be coupled to each stopper in such a manner that it prevents both proximal and distal movement of the elongated body 3402 relative to the catheter 3404 until sufficient force is applied to push the projection against the adjacent stopper.

[0188] The projections 3414 may have various configurations to allow them to move between adjacent stoppers after sufficient force has been applied. For example, the projections 3414 may be formed from a single deformable material (e.g., one of several polymers) that is stiff enough to resist deformation until sufficient force is applied. In another embodiment, the projections 3414 may be a spring ball mechanism. In yet another embodiment, the projections 3414 may be formed from a rigid material, and the stoppers 3406, 3408, 3410, and 3412 may be formed from a material that is deformable enough to allow selective movement of the elongated bodies.

[0189] The projection 3414 can be formed on one side of the elongated body 3402, or on the opposite side of the elongated body 3402, as shown in Figure 34. In yet another embodiment, multiple projections and retainers can be spaced apart around the periphery of the elongated body 3402, or a single feature can be extended annularly around its periphery to connect with an annular retainer formed within the catheter 3404. Furthermore, in some embodiments, the illustrated arrangements can be reversed so that projections formed on the catheter 3404 can connect with retainers formed on the elongated body 3402, or so that a single retainer formed on either the elongated body or the catheter can be configured to connect with one of a series of projections formed along the length of the other component.

[0190] The devices disclosed herein may be designed to be discarded after a single use or may be designed for multiple uses. However, in either case, the devices may be refurbished for reuse after at least one use. The refurbishment steps may include any combination of the steps of disassembling the device, cleaning or replacing specific parts thereafter, and reassembling it. In particular, the device may be disassembled and any number of specific pieces or parts of the device may be selectively replaced or removed in any combination. After cleaning and / or replacing specific parts, the device may be reassembled in a refurbishment facility or immediately before surgery by a surgical team for later use. Those skilled in the art will understand that various techniques for disassembly, cleaning / replacement, and reassembly are available for the refurbishment of devices. The use of such techniques and the resulting refurbished devices are all within the scope of this disclosure.

[0191] The devices described herein can be treated before use in surgical procedures. First, new or used instruments can be obtained and cleaned as necessary. Then, the instruments can be sterilized. In one sterilization technique, the instruments can be placed in a sealed container, such as a plastic or TYVEK bag. The container and its contents can then be placed in a field of radiation that can penetrate the container, such as gamma rays, X-rays, or high-energy electrons. The radiation can kill bacteria in the instruments and container. The sterilized instruments can then be stored in a sterile container. The sealed container can keep the instruments sterile until they are unpacked in a medical facility. Other forms of sterilization known in the art are also possible. These may include beta or other forms of radiation, ethylene oxide, steam, or liquid baths (e.g., cryoimmersion). Certain forms of sterilization may be more suitable for use in different parts of a device, depending on the materials used, the presence of electrical components, etc.

[0192] All papers and publications cited herein are incorporated herein in their entirety by reference. Those skilled in the art will understand the further features and advantages of the present disclosure based on the embodiments described above. Therefore, the present disclosure should not be limited by what is specifically shown or described, except as indicated by the appended claims.

Claims

1. It is an ablation device, A catheter having a lumen extending through the catheter and being controllable using one or more control cables extending through the catheter, wherein the lumen includes a retraction stop portion formed distally to the distal end of the one or more control cables, A needle slidably disposed within the lumen of the catheter, wherein the needle includes the lumen, at least one exit port formed in the distal portion of the needle, and at least one projection formed on the outer surface of the needle proximal to the at least one exit port and distal to the retraction stop portion of the lumen of the catheter, the distal portion of the needle being configured to cauterize tissue, A biasing element is connected to the needle and configured to push the needle proximal so that at least one projection on the needle contacts the retraction stop portion of the lumen of the catheter, An ablation device comprising a forward-moving mechanism configured to push the needle distally to the catheter.

2. The ablation device according to claim 1, wherein the forward mechanism includes a clutch for coupling with the needle.

3. The ablation device according to claim 2, wherein the clutch is positioned in the proximal portion of the catheter within the handle assembly.

4. The ablation device according to any one of claims 1 to 3, wherein the biasing element is located in the proximal portion of the catheter within the handle assembly.

5. The ablation device according to any one of claims 1 to 4, wherein the retraction stop portion is positioned such that when the at least one projection is in contact with the retraction stop portion, the distal tip of the needle is proximal to the distal tip of the catheter.

6. The ablation device according to claim 5, wherein the advancement mechanism is configured to advance the needle distally such that the distal tip of the needle is distal to the distal tip of the catheter.

7. The ablation device according to any one of claims 1 to 6, wherein the at least one projection on the needle includes one or more fluid channels formed internally to allow fluid to flow through the at least one projection.

8. The ablation device according to any one of claims 1 to 7, further comprising at least one heating element disposed within the lumen of the needle and positioned within the distal portion of the needle proximal to the at least one exit port, wherein the at least one heating element is configured to heat a fluid flowing through the lumen of the needle.

9. The ablation device according to any one of claims 1 to 8, wherein the retraction stop portion has a longitudinal position fixed to the catheter.

10. The ablation device according to claim 2, wherein the clutch is configured to be separated from and not in contact with the needle until the needle is biased distally to the catheter.

11. The ablation device according to any one of claims 1 to 9, wherein the forward movement mechanism is configured to move the needle distally relative to the catheter and includes one or more notches corresponding to the distance the needle extends from the distal end of the catheter.

12. The ablation device according to claim 11, wherein the forward movement mechanism is configured to lock with respect to one or more notches to maintain the position of the needle relative to the distal end of the catheter.

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