Stable Coronary Catheter Handle

Abstract

The present invention provides a stable coronary sinus catheter system, the stable coronary sinus catheter system having a proximal segment and a distal segment with a shape memory portion, and a tip distal to the shape memory portion. A handle having a body, a tip deflection actuator, a shape memory portion deployment actuator, and an axis. The tip is in line with the axis, and the tip deflection actuator is in a first position. When the tip deflection actuator is in a second position, the tip deflects and is misaligned with the axis. A third position is a delivery configuration in which the shape memory portion and the tip are in line with the axis. The shape memory portion deployment actuator is in a first position. When the shape memory portion deployment actuator is in a second position, the deployment configuration allows the shape memory portion to form a predetermined shape conforming to the shape of the coronary sinus.

Description

Technical Field

[0001] The present disclosure generally relates to control handles for CS catheter systems, and more particularly, to improved handles for maneuverable catheters that can be operated with one hand. Background Art

[0002] During cardiac electrophysiology (EP) procedures, a coronary sinus (CS) catheter may be inserted into the heart to provide a reference for the procedure. The CS catheter has electrodes on its surface, and the signals obtained by the electrodes are used as a reference for other signals obtained during the procedure, such as for EP mapping of cardiac chambers. To serve as a good reference, the CS catheter should not move within its holding chamber (CS), or any movement of it must be permitted.

[0003] While methods for allowing movement are known in the art, it is preferred that the CS holding catheter be fixed in place. Additionally, while it is known to deploy CS catheters with shape memory properties to stabilize the catheter in the CS, the prior art may impose too much stress on both the catheter and the inferior vena cava leading to the right atrium. Additionally, guiding the catheter into the coronary sinus can also be cumbersome.

[0004] Existing catheters, even those with steerable and deflectable controls, typically have limited maneuverability. This is especially true for procedures that require particularly fine movement control. Additionally, existing designs may require two hands to control or be difficult to control. The doctor needs to repeatedly stop looking at his diagnostic tool to see where his hand is and which part of the handle needs to be actuated, which can result in a significant increase in the time of the operating procedure.

[0005] Additionally, electrode catheters are used to stimulate and map electrical activity in the heart, as well as to ablate sites of abnormal electrical activity. In use, the electrode catheter is inserted into a major vein or artery (e.g., the femoral artery) and then guided into the chamber of the heart of interest. Inside the heart, the ability to control the precise position and orientation of the catheter tip is crucial. Thus, any instability of the electrode catheter can affect the outcome of the associated procedure (e.g., unreliable results of cardiac mapping), and is therefore significant for the success of a particular procedure.

[0006] Accordingly, there is a need for improved devices, systems, and methods for control handles that can finely manipulate the control of a catheter while also being able to actuate additional functions, such as the inflation of a sensor anchoring coil. It is also highly preferred that the operation of these functions can be performed with one hand so that the ergonomics of the handle do not fatigue the operator. Summary of the Invention

[0007] To this end, the present disclosure is a stable coronary sinus catheter system having a proximal segment and a distal segment with a shape memory portion, and a distal tip distal to the shape memory portion. A handle may be provided proximal to the proximal segment, having a body, a distal tip deflector actuator, a shape memory portion deployer actuator, and a central axis. The distal tip deflector actuator has a first position in which the distal tip is substantially in line with the central axis. It also has a deflected state when the distal tip deflector actuator is in a second position and the distal tip is deflected and misaligned with the central axis. A third position of the distal tip deflector actuator may have the shape memory portion and the distal tip substantially in line with the central axis, and the shape memory portion deployer actuator is in a first position. Further, when the shape memory portion deployer actuator is in a second position, the shape memory portion may be deployed to form a predetermined shape that generally conforms to the shape of the coronary sinus.

[0008] The stable coronary sinus catheter system may also have a pull wire, wherein a first end of the pull wire is anchored in the distal tip and a second end is fixed in the body. The distal tip deflector actuator may be attached to the pull wire, and the second position displaces the pull wire. The distal tip has a deflection angle between approximately 0° and approximately 180°.

[0009] The coronary sinus catheter also has an intermediate segment distal to the proximal segment, the intermediate segment having an intermediate stiffness, the proximal segment including a proximal stiffness, and the distal tip having a flexibility greater than the proximal stiffness, the intermediate stiffness, and the stiffness of the shape memory portion. A single axis position sensor may be disposed generally at the distal tip.

[0010] In addition, the system has a deflector actuator lock having an unlocked position and a locked position, the unlocked position allowing the distal tip deflector actuator to move between the first position and the second position, the locked position preventing the distal tip deflector actuator from moving between the first position and the second position.

[0011] A shape memory alloy may be disposed along the shape memory portion and have an end fixed in the body. A cover tube may be disposed over a portion of the shape memory alloy and have a shape memory portion deployment end fixed to the shape memory portion deployer actuator. In a delivery configuration, the cover tube constrains the shape memory alloy, and in a deployment configuration, the shape memory alloy is unconstrained by the cover tube.

[0012] When the shape memory portion deployer actuator is in the first position, it holds the cover tube on the shape memory alloy, which prevents the shape memory alloy from returning to the predetermined shape. When the shape memory portion deployer actuator is in the second position, it withdraws the cover tube from the shape memory alloy, thereby allowing the shape memory alloy to return to the predetermined shape.

[0013] In one example, the predetermined shape of the shape memory portion of the stable coronary sinus catheter system is a substantially helical shape. The predetermined shape of the shape memory portion has at least one of the following:

[0014] A proximal segment bending radius between approximately 8.5 mm and approximately 9.5 mm,

[0015] A distal segment bending radius between approximately 7.0 mm and approximately 8.0 mm,

[0016] A proximal segment helical angle between approximately 110° and approximately 120°,

[0017] A distal segment helical angle between approximately 150° and approximately 160°,

[0018] A shape memory portion length between approximately 42.5 mm and approximately 44.5 mm,

[0019] A large diameter of the first helical coil between approximately 14.0 mm and approximately 16.0 mm, and / or

[0020] A taper angle between approximately 3.5° and approximately 5.5°.

[0021] A method of using a coronary sinus catheter to map the electrical activity of the heart, the coronary sinus catheter having a distal segment with a shape memory portion and a distal tip distal to the shape memory portion; the handle may also include a proximal segment disposed proximally having a body, a distal tip deflection actuator, a shape memory portion deployment actuator, a cover tube disposed on a portion of the shape memory portion, and a central axis. The method includes the steps of: delivering the coronary sinus catheter to the coronary sinus in a delivery configuration such that the distal segment of the coronary sinus catheter is substantially in line with the central axis. Then, the coronary sinus catheter is manipulated by actuating the distal tip deflection actuator to deflect the distal tip out of alignment with the central axis. And, subsequently, the shape memory portion of the distal segment of the coronary sinus catheter is deployed in the coronary sinus, having the steps of withdrawing the cover tube from the shape memory portion and causing the shape memory portion to return to a preformed shape. Once deployed, there is a step of applying a lateral force to the coronary sinus using the shape memory portion.

[0022] Various examples of a stable coronary sinus catheter may have a primary sensor probe having a plurality of primary sensors disposed along a first length of the primary sensor probe. Additionally, a plurality of secondary sensor probes each have a second length shorter than the first length and a secondary sensor disposed at a distal location. There may be a sheath having a lumen configured to allow the primary sensor probe and the plurality of secondary sensor probes to pass therethrough. In the sheathed position, the plurality of secondary sensor probes are enclosed within the lumen, and at least a portion of the primary sensor probe is outside the lumen. In the unsheathed position, both the primary sensor probe and the plurality of secondary sensor probes are outside the lumen, and the plurality of secondary sensor probes are angled with respect to the primary sensor probe and exert a lateral force on the coronary sinus.

[0023] The second length has a plurality of sub - lengths, and a portion of each of the plurality of secondary sensor probes has a different sub - length. A midline axis is also included, and the primary sensor probe is disposed generally along the midline axis. The plurality of secondary sensor probes are generally parallel to the midline axis in the sheathed position and form an angle with the midline axis in the unsheathed position.

[0024] The secondary sensor probe angle may be formed between the secondary sensor probe and the midline axis, having an angle between approximately 0° and approximately 90°, and more preferably, the secondary sensor probe angle may be between approximately 0° and approximately 10°. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a side view of an example of a stable coronary sinus catheter of the present disclosure.

[0026] Figure 2A and Figure 2B is a side view of an example of a distal segment of a stable coronary sinus catheter of the present disclosure.

[0027] Figure 3 is a front view of an example of a distal segment of a stable coronary sinus catheter of the present disclosure.

[0028] Figure 4 is Figure 3 a cross - sectional view of a distal end of a stable coronary sinus catheter of

[0029] Figure 5 is an image of a heart identifying the coronary sinus.

[0030] Figure 6 is an image of an example of a stable coronary sinus catheter of the present disclosure fully deployed within the coronary sinus.

[0031] Figures 7A - 7C shows an example of a handle having a deflectable tip and sequentially deployed helical segments.

[0032] Figure 8 This is a cross-section of an example of the handle of the present disclosure, showing elements related to tip deflection.

[0033] Figure 9A and Figure 9B shows the piston movement of the handle for deflecting the tip of the catheter.

[0034] Figure 10 This is a cross-section of an example of the handle of the present disclosure, showing elements related to deploying a helical segment in an undeployed position.

[0035] Figure 11 is Figure 10 an enlarged cross-section A-A of [Figure], showing the shape memory portion deployment actuator in an undeployed position.

[0036] Figure 12 This is a cross-section of an example of the handle of the present disclosure, showing elements related to deploying a helical segment in a deployed position.

[0037] Figure 13 is Figure 12 an enlarged cross-section B-B of [Figure], showing the shape memory portion deployment actuator in a deployed position.

[0038] Figure 14 This is a cross-section of a stable coronary sinus catheter having an additional lumen.

[0039] Figure 15 This is a side view of another example of the stable coronary sinus catheter of the present disclosure.

[0040] Figure 16A and Figure 16B shows a side view of another example of the stable coronary sinus catheter of the present disclosure, and it is deployed in the coronary sinus respectively.

[0041] Figure 17 This is a flowchart showing a method of deploying a stable coronary sinus catheter with an advanced handle. Detailed Description

[0042] As used herein, the term “about” or “approximately” in reference to any numerical value or range indicates a suitable dimensional tolerance that allows a set of components or elements to achieve its intended purpose as described herein. More specifically, “about” or “approximately” can refer to a range of values of ± 10% of the recited value; for example, “about 90%” can refer to a range of values from 81% to 99%.

[0043] As used herein, "subject" or "patient", including blood vessels from a subject or patient, can refer to any applicable human patient as well as any mammalian, veterinary, livestock, or pet animal, etc. For example, the animal can be an experimental animal (e.g., rats, dogs, pigs, rabbits, monkeys, etc.) specifically selected to have certain characteristics similar to humans.

[0044] As used herein, "operator" can include a doctor, surgeon, or any other individual or instrument associated with a medical procedure using the devices of the present disclosure.

[0045] Additionally, the terms "patient", "host", "user", and "subject" refer to any human or animal subject, and are not intended to limit the system or method to human use, but the use of the present disclosure in human patients represents a preferred embodiment.

[0046] As used herein, the term "computing system" is intended to include a stand-alone machine or device and / or a combination of machines, components, modules, systems, servers, processors, memories, detectors, user interfaces, computing device interfaces, network interfaces, hardware elements, software elements, firmware elements, and other computer-related units. By way of example and not limitation, a computing system can include one or more of a general-purpose computer, a special-purpose computer, a processor, a portable electronic device, a portable electronic medical device, a stationary or semi-stationary electronic medical device, or other electronic data processing equipment.

[0047] As used herein, the terms "component", "module", "system", "server", "processor", "memory", etc. are intended to include one or more computer-related units, such as but not limited to hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, an object, an executable file, an execution thread, a program, and / or a computer. By way of example, both an application program running on a computing device and the computing device can be components. One or more components can reside within a process and / or an execution thread, and the components can be located on one computer and / or distributed between two or more computers. In addition, these components can be executed by various computer-readable media on which various data structures are stored.

[0048] Components can communicate via local and / or remote processes, such as according to a signal having one or more data packets, such as data from one component that interacts with a local system, another component in a distributed system, and / or via a network such as the Internet with other systems. The computer-readable medium can be non-transitory. Non-transitory computer-readable media include, but are not limited to, random access memory (RAM), read only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory or other memory technologies, compact disc ROM (CD-ROM), digital versatile disc (DVD) or other optical storage devices, magnetic tape cartridges, magnetic tape, magnetic disk storage devices or other magnetic storage devices, or any other tangible physical medium that can be used to store computer-readable instructions and / or data.

[0049] As used herein, the term "trace" includes a conductive path in a circuit, such as a path integral with a printed circuit, a separate wire, a conductor within a ribbon cable, or other such structures understood and appreciated by one of ordinary skill in the art in light of the teachings of the present disclosure.

[0050] As used herein, the terms "tubular" and "tube" are not limited to structures that are a perfect cylinder or have a completely circular cross-section or a uniform cross-section along their entire length. For example, a tubular structure or system is typically shown as a structure that is substantially a perfect cylinder. However, without departing from the scope of the present disclosure, a tubular system can have a tapered outer surface, a curved outer surface, and / or a partially flat outer surface.

[0051] Turning now to Figure 1 , which shows a stable coronary sinus catheter system that includes a coronary sinus catheter 100 configured to enter the coronary sinus 20 of the heart 10 (see Figure 5 and Figure 6 ). During a cardiac electrophysiology (EP) procedure, a coronary sinus (CS) catheter 100 can be inserted into the heart 10 to provide a reference for the procedure. The CS catheter 100 has a proximal segment 102, an intermediate segment 104, and a distal segment 106. A handle 300 can be disposed proximal to the proximal segment 102 to allow for the movement and deployment of features for controlling the CS catheter 100. The intermediate segment 104 can be located distal to the proximal segment 102 and have an intermediate stiffness. The proximal segment 102 can have a proximal stiffness, and the distal tip 202 can have a flexibility that is greater than the proximal stiffness, the intermediate stiffness, and the stiffness of the shape memory portion 200.

[0052] Although stiffness is a general term, there are multiple ways to form catheter segments 102, 104, 106 with different stiffnesses or, conversely, flexibilities. Each segment can be formed from one or more polymers and / or materials with different rigidities or hardnesses. Additionally, braids or other reinforcements can be used inside or around the catheter segments 102, 104, 106, or the braids or other reinforcements can be directly molded into the catheter segments. Alternatively or in addition, strain relief features such as physical indentations can be added to increase flexibility.

[0053] Figure 2A and Figure 2B The features of the distal segment 106 are shown. The distal segment 106 can have electrodes or sensors 208 along its surface. Signals obtained by the sensors 208 are used as a reference for other signals obtained during a procedure, such as for EP mapping of the heart 10. For use as a good reference, the CS catheter 100 should not move within its holding chamber (CS 20), or any movement thereof must be permitted. To this end, the distal segment 106 also includes a shape memory portion 200 and a distal tip 202 located distal to the shape memory portion 200. Figure 2A and Figure 2B The shape memory portion 200 is shown in a deployed configuration. Here, the shape memory portion 200 forms a predetermined shape that generally conforms to the shape of the coronary sinus 20. The shape can include a helix or a basket. When the shape memory portion 200 assumes the deployed shape (and in this example, a helical shape), the pusher electrode 208 is urged into contact with the wall of the CS 20. The pressure of pressing the shape memory portion 200 into the wall locks the catheter 100 in place. The distal tip 202 can also include a single-axis position sensor 224 to assist in guiding the sensor 208 into the CS 20 prior to deployment.

[0054] To facilitate the locking aspect, the shape memory portion 200 has a proximal end 206 and a distal segment axis 204 extending from the proximal end 206 to the distal tip 202. In Figure 2A , Figure 2B and Figure 3In the example shown in FIGS., the predetermined shape of the shape memory portion 200 has some exemplary measurements when in a tapered helical shape. The proximal segment bend radius 210 can be measured to be between approximately 8.5 mm and approximately 9.5 mm, and the distal segment bend radius 212 can be between approximately 7.0 mm and approximately 8.0 mm. The proximal segment helix angle 214 can be between approximately 110° and approximately 120°. The distal segment helix angle 216 can be between approximately 150° and approximately 160°. The shape memory portion can have a length 218 when deployed between approximately 42.5 mm and approximately 44.5 mm. The major diameter 220 of the first helical coil can be from approximately 14.0 mm to approximately 16.0 mm, and the taper angle 222 is between approximately 3.5° and approximately 5.5°.

[0055] Figure 4 An example of a cross-section of the catheter 100 is shown. In this example, there can be a guidewire lumen 108, which allows the catheter 100 to travel over the guidewire 40 to direct the catheter 100 from an insertion point (typically a groin puncture) to the heart 10. Once near or within the CS 20, the guidewire 40 can be removed to allow the handle 300 to perform other functions, which are described in more detail below. The sensor wire lumen 110 can contain a sensor wire 50 (see Figure 14 ), which connects the sensor 208 back to the system to read data from the sensor and display the data to the user. In one example, there can be at least forty (40) sensors 208 deployed along the distal segment 106. The sensor wire 50 can also transmit signals from a single axis position sensor 224. The movement of the catheter 100 is tracked using at least the single axis position sensor 224 to allow proper placement within the CS 20. Once the catheter 100 is properly placed and the shape memory portion 200 is deployed, the catheter 100 is tracked and the CS chamber is fully presented to the user in the mapping system. Tracking of the catheter 100 can use any known tracking technique, such as

[0056] In an example of the shape memory portion 200 as shown in Figure 5 and Figure 6 , its helical structure also serves as an anchoring mechanism that locks the catheter 100 in place within the CS 20. This also keeps the sensor 208 in continuous contact with the CS 20 chamber wall to provide stable readings unaffected by artifacts such as heartbeat and respiration. These are improvements over existing art CS catheters. Electrocardiogram (ECG) artifacts are created during cardiac systole by the inward movement between the electrode and the CS wall and movement related to respiration-related motion.

[0057] When the shape memory portion 200 anchors the catheter 100, the distal end 202 after the intermediate segment 104 serves as a strain relief. Since it is soft radially, retraction of the guide wire can suspend this segment in the right atrium and apply minimal force to the shape memory portion 200. Because the proximal segment 102 can be rigid, it is pushed slightly forward after complete retraction of the guide wire to build a segment of strain relief. This prevents the cardiac motion caused by breathing and heartbeat from applying force to the shape memory portion 200. This can further prevent the risk of the shape memory portion 200 moving in the CS 20. When the catheter 100 is firmly stabilized in the CS 20, any movement of the catheter 100 is monitored and used to alert the mapping system and the user.

[0058] Having a number of sensors 208 (example with 2 - 3 mm spacing) around the CS 20 chamber allows selection of sensors 208 with atrial or ventricular activity, thus allowing selective detection of atrial or ventricular activity. Additionally, when the left and right atria are separated, the activity of each atrium can be tracked independently. The sensors 208 can be oriented to be sensitive along and transverse to the distal segment axis 204, thus providing an accurate view of the activity in any direction. This can be achieved by obtaining a wide bipolar signal to subtract more than just the nearest adjacent electrodes. Having a complete view of the CS 20 provides better tracking of the activation pattern, which represents both the far field (activity further from the CS 20) and the near field (activity related to the ECG generated near the CS 20). This ability provides a more powerful tracking tool, thus allowing detection of similar ECG activity and supporting stitching of different positions of the mapping catheter (as used during LAT mapping). Some tachycardias involve activation in the CS20. Mapping the CS 20 with current tools is challenging because the activity can occur on one side close to the heart wall or the opposite side. In the case where the shape memory portion 200 is in a helical shape, complete activation mapping in the CS is possible.

[0059] Other elements of the catheter 100 are the lead lumen 112 and the shape memory lumen 114. The shape memory lumen 114 contains a shape memory alloy 116 (see Figure 14 ). The shape memory alloy 116 can be made of a material that can automatically recover its shape once released from a highly strained delivery configuration. Superelastic shape memory materials such as nitinol or alloys with similar properties are particularly suitable. These materials have sufficient elastic strain capacity such that when the shape memory portion 200 is constrained in the delivery configuration, the elastic limit is not exceeded. This elastic strain capacity allows the shape memory portion 200 to self - expand upon deployment. The shape memory lumen 114 can be the length of the catheter 100, or in one example, only the length of the shape memory portion 200 or the distal segment 106.

[0060] The catheter 100 may also include a puller wire lumen 118 containing a puller wire 120. The puller wire 120 may be used to deflect the distal tip 202. The puller wire 120 may be anchored to a handle (described in more detail below) at its proximal end. The puller wire 120 may be made of any suitable metal such as stainless steel or nitinol, and is preferably coated with Teflon 7 or any other coating that imparts lubricity to the puller wire 120.

[0061] Figures 7A - 13 Various examples of handle 300 are shown. Handle 300 may include body 301, distal tip deflection actuator 302, shape memory portion deployment actuator 304, and central axis 306. Handle 300 is designed to be easy to use. Figure 7A Handle controls 302, 304 are shown in an intermediate position and a delivery configuration. In the intermediate position, the distal tip 202 can be generally aligned with the central axis 306. In the intermediate position, the distal tip deflection actuator 302 is in a first position. The first position is the most proximal position of the distal tip deflection actuator 302. Figure 7A Also shown is a delivery configuration in which the shape memory portion 200 and the distal tip 202 are generally aligned with the central axis 306. Here, the shape memory portion deployment actuator 304 can be in its most distal position. The distal tip deflection actuator 302 is in a first position and the shape memory portion deployment actuator 304 is in its first position. The intermediate position and delivery configuration allow the catheter 100 to travel over the guidewire 40 to deliver the distal segment 106 into the CS 20.

[0062] Figure 7B The handle 300 and catheter 100 are shown in a deflected position. Here, the guidewire 40 has been completely removed or entered into the intermediate section 104, and the distal tip 202 is deflected out of alignment with the central axis 306. The deflection can be caused by the distal tip deflection actuator 302 moving to a second position that is more distal than the first position. Figure 8 , Figure 9A , Figure 9B and Figure 13 A deflection mechanism is shown. The pull wire 120 has a first end anchored in the distal tip 202 and a second end attached to a fixed point 303 (shown as a tension screw) in the body 301. A distal tip deflection actuator 302 can be attached to the pull wire 120 so that any movement along the central axis 306 displaces the pull wire 120. Extending the distal tip deflection actuator 302 can deflect the distal tip 302 by a deflection angle of about 0° to about 180°. Deflecting the distal tip 202 allows the distal segment 106 to be guided to the appropriate position within the CS 20 and the distal tip 202 to be guided into the inferior vena cava (Figure 6 )。

[0063] Figure 9A and Figure 9B shows the locked and unlocked positions of the deflection actuator lock 310. In this example, a simple twist can lock and unlock the ability to deflect the distal end 202. Thus, the deflection actuator lock 310 has an unlocked position that allows the distal end deflection actuator 302 to move between a first position (nearest side) and a second position (farthest side). Additionally, the locked position prevents the distal end deflection actuator 310 from moving between the first and second positions. Additionally, the handle deflection brake 308 is visibly present on the handle 300 to stop at different deflection angles, so that the user can view the handle 300 and determine how much the distal end 202 has deflected. The distal end 202 can be deflected when the shape memory portion 200 is not deployed and / or is in the delivery configuration.

[0064] Figure 7C and Figures 10 - 13 shows the deployment configuration of the shape memory portion 200. As described above, the shape memory alloy 116 can be disposed at least along the shape memory portion 200 and includes one end fixed in the body 301. The shape memory alloy 116 has been pre-set to an expanded shape that is configured to anchor the distal segment 106 of the coronary sinus catheter 100 in the coronary sinus 20. As shown, the pre-set shape is a helix that is offset relative to the central axis 306, but any shape that is non-invasive and can conform to the wall of the CS 20 can be considered.

[0065] For ease of the delivery configuration and the deployment configuration, a cover tube 312 can be disposed on the shape memory portion 200 or even on a portion of the shape memory alloy 116. In one example, the cover tube 312 can have a shape memory portion deployment end 314 that is fixed to the shape memory portion deployment actuator 304. In the delivery configuration, the cover tube 312 constrains the shape memory portion 200 / shape memory alloy 116, and in the deployment configuration, the shape memory portion 200 / shape memory alloy 116 is not constrained by the cover tube 312.

[0066] Figure 10 and Figure 11 shows the shape memory portion deployment actuator 304 at the farthest side position (its first position), which holds the cover tube 312 on the shape memory portion 200 / shape memory alloy 116, which prevents the shape memory alloy 116 from returning to its pre-determined shape. Moving the shape memory portion deployment actuator 304 to the proximal position (its second position) withdraws the cover tube 312 from the shape memory portion 200 / shape memory alloy 116, thus allowing the shape memory alloy 116 to return to its pre-determined shape. This position is shown in Figure 12 and Figure 13 is shown.

[0067] In other words, for one example, the sheath tube 312 covers substantially the entire catheter 100 from the handle 300 to before the distal end 202. The sheath tube 312 can be flexible, made of nitinol, stainless steel, or a semi-rigid polymer, and the tube can also be laser cut for additional flexibility. The sheath tube 312 needs to have sufficient rigidity to prevent the shape memory portion 200 / shape memory alloy 116 from reverting to its preformed shape, but is flexible enough to allow the catheter 100 to pass through blood vessels for deployment in the CS 20. The shape memory alloy 116 is fixed at one end within the body 301, and the sheath tube 312 is deployed thereover. The sheath tube 312 can be coaxial either externally over the entire catheter 100 or inside the shape memory lumen 114. The length of the sheath tube 312 is shorter than that of the shape memory alloy 116, and it is short to the extent that when the shape memory portion deploys actuator 304 distally to the first position, the sheath tube 312 covers and constrains the shape memory portion 200. Once the sheath tube 312 is pulled back by the shape memory portion deploying actuator 304 being moved positively to the second position, the difference in length causes the shape memory alloy 116 to now be unconstrained and able to revert to its preset shape.

[0068] Additionally, during or after the procedure, the shape memory portion deploying actuator 304 can be moved distally (i.e., back to the first position) to re-constrain the shape memory alloy 116, return the catheter 100 to its delivery configuration, and then remove it from the blood vessel. If for any reason it is necessary to reposition the shape memory portion 200 during the procedure, the shape memory alloy 116 can also be re-constrained.

[0069] Figure 15 And FIG. 16 shows other examples of coronary sinus catheters. Figure 15 An example is shown where the pull wire 120 can be used to deflect the distal end 202 and then pulled with additional force to deform the shape memory portion 200 into its deployed configuration. In this example, the shape memory alloy 116 can be preset to be straight, and the tension pulls the alloy "out of shape" into, for example, a helical shape. In the illustrated example, the pull wire 120 within the pull wire lumen 118 only extends to the intermediate segment 104. Then, the pull wire 120 is outside the lumen until the distal end 202. This allows the distal segment 106 to be deformed under tension.

[0070] Figure 16A and Figure 16BIllustrated is another stable coronary sinus catheter 400 having a primary sensor probe 402. The primary sensor probe 402 may function similarly to the distal end 202 having at least a single axis position sensor 424 above to guide the catheter 400 and includes a plurality of primary sensors 406 disposed along the length of the primary sensor probe 402. However, unlike the shape memory portion 200, this example has a plurality of secondary sensor probes 404. The plurality of secondary sensor probes 404 have a second length shorter than the first length and at least one secondary sensor 406 disposed at a distal position / tip. The second (shorter) length may be a plurality of different sub-lengths, and one or more of the secondary sensor probes 404 may have different sub-lengths.

[0071] The sheath 450 may have a lumen configured to allow the primary sensor probe 402 and the plurality of secondary sensor probes 404 to pass therethrough. During delivery, a sheathed position may enclose the plurality of secondary sensor probes 404 within the lumen and leave at least a portion of the primary sensor probe 402 outside the lumen. This allows a compact delivery profile to move the catheter 400 through the blood vessel to the CS 20. Once located in the CS 20, the catheter 400 may be sheathless, and the sheathless position may leave both the primary sensor probe 402 and the plurality of secondary sensor probes 404 outside the lumen. Additionally, the plurality of secondary sensor probes 404 may be angled α with respect to the primary sensor probe 402 and apply a lateral force to the coronary sinus 20. For all of the above reasons, this lateral force serves as an anchoring force to stabilize the catheter 400 in the CS 20.

[0072] In other words, the catheter 400 may have a midline axis 408, and the primary sensor probe 402 is disposed generally along the midline axis 408. Then, the plurality of secondary sensor probes 404 may be generally parallel to the midline axis 408 in the sheathed position and form an angle α with the midline axis in the sheathless position. Specifically, the secondary sensor probe angle α is formed between at least one secondary sensor probe 404 and the midline axis 408. The secondary sensor probe angle α may be between about 0° and about 90°, and more specifically between about 0° and about 10°. The secondary sensor probes 404 may be angled with respect to the midline axis 408 because they have a shape memory alloy or some other form of biasing member to move them away. The biasing member may also be formed of thin formed spring steel or other metal.

[0073] Figure 17A method of mapping the electrical activity of a heart 10 using a coronary sinus catheter (i.e., 100, 400) is shown. The coronary sinus catheters 100, 400 may include a distal segment 106 having a shape memory portion 200 and a distal tip 202 located distal to the shape memory portion 200. A handle 300 is also included, which is disposed proximal to the proximal segment 102 of the catheter and has a body 301, a distal tip deflection actuator 302, a shape memory deployment actuator 304, a sheath tube 312 disposed on a portion of the shape memory portion 200, and a central axis 306. Examples of steps may include delivering the coronary sinus catheter to the coronary sinus in a delivery configuration such that the distal segment of the coronary sinus catheter is generally in line with the central axis (1700). The coronary sinus catheter 100 may be manipulated by deflecting the distal tip 402 by actuating the distal tip deflection actuator 302 to be misaligned with the central axis 306 (1702). The shape memory portion 200 of the distal segment 106 may be deployed in the coronary sinus 20 (1704). Deploying the shape memory portion 200 may have additional steps of withdrawing the sheath tube from the shape memory portion (1706) and causing the shape memory portion to return to a preformed shape (1708). Additionally, the method may include applying a lateral force to the coronary sinus 20 using the deployed shape memory portion 200 (1710).

[0074] Certain aspects of the entire disclosure may include two configurations, one a straight configuration and the other having a helical shape. The helical shape is formed with a preformed wire of shape memory alloy (nitinol). The configuration is switched by extending / retracting a tube inside the catheter shaft. A deflectable tip is used for maneuverability. Multiple sensors allow visualization in the mapping system. A locking ring is provided on the plunger / distal tip deflection actuator to prevent unintended deflection while extending / retracting the tube. Multiple lumen plastic extrusion may be used to keep components separated, such as wires, nitinol, and tubes. Electrodes along the entire helical length allow multi-circumferential cardiac information.

[0075] For attachment points inside the handle, a pull wire may be anchored distally in a distal region of the deflectable tip and proximally to an axis in a proximal region of the handle body. The proximal attachment point of the pull wire allows adjustment of the tension in the wire during assembly. A nitinol wire having a preformed helical shape may be anchored distally to a catheter tip located distal to the helical shape. The nitinol wire may also be anchored proximally at a proximal end of a plunger component. This allows the entire length of the nitinol wire to move with the shaft during tip deflection. The distal end of the tube floats freely in the catheter lumen and is anchored to a bolt in the handle.

[0076] The nitinol and tube also have an exemplary behavior where the nitinol wire serves as a guide and a bearing surface for the tube, and the nitinol wire passes through the tube. The tube has two segments, with the distal segment being more flexible to facilitate movement over the helical shape and through the anatomical structure. The proximal segment has greater rigidity to allow for higher force transmission. To reduce friction during tube extension / retraction, a lubricant is used at the interface between the nitinol wire and the tube. The lubricant can also be used between the tube and the catheter lumen. The tube assembly can have protrusions ("beads") with a smooth profile around the outer perimeter, spaced along the distal length, including a protrusion at the distal end, for reducing friction during tube extension / retraction. The plunger and handle have clearance for the tube anchor bolt to allow the tube to move relative to these components.

[0077] Examples regarding tip deflection include: The handle has a travel limit feature that allows adjustment of the allowable pull wire deflection during assembly. Coils can be used in the shaft segments proximal and distal to the helical region, but not in the helical region, to increase the stiffness of the catheter and thus improve tip deflection. However, the distally deflectable tip is soft but still allows deflection.

[0078] Other features of a stable coronary sinus catheter with a distal strain relief include a proximal segment with proximal stiffness, an intermediate segment distal to the proximal segment with intermediate stiffness, and a distal segment distal to the intermediate segment. The distal segment can include a shape memory portion, a distal end distal to the shape memory portion, a shape memory lumen disposed along the shape memory portion, and a shape memory alloy disposed in the shape memory lumen. There can be a delivery configuration and a deployment configuration, the delivery configuration including a shape memory portion and a distal end that are generally in a straight line with the central axis, and the deployment configuration including a shape memory portion that forms a shape generally conforming to the shape of the coronary sinus. The distal end can have a flexibility greater than the proximal stiffness, the intermediate stiffness, and the stiffness of the shape memory alloy.

[0079] The stable coronary sinus catheter can have a distal end configured to hang in the right atrium when in the deployment configuration. The shape of the shape memory portion can have a generally helical shape and be configured to apply a lateral force to the coronary sinus. Additionally, the helix can be formed along a distal segment axis that is offset from the central axis. Multiple sensors can be disposed along the distal segment, and a sensor wire lumen (including a sensor cable disposed therein) can connect the multiple sensors.

[0080] The guidewire lumen can also be provided from the proximal segment to the distal segment such that the delivery configuration also has a distal segment conforming to the shape of the guidewire disposed in the guidewire lumen. Then, when the guidewire is partially removed from the guidewire lumen, a deployment configuration is formed. A pull wire lumen can be provided from the proximal segment to the distal end, and a pull wire is disposed in the pull wire lumen. The intermediate position can include a distal end substantially in line with the central axis and a deflection position that displaces the pull wire, at which position the distal end moves out of alignment with the central axis.

[0081] Another stable coronary sinus catheter system can have a coronary sinus catheter having a proximal segment, a distal segment (including a shape memory portion and a distal end distal to the shape memory portion), a shape memory lumen disposed along the shape memory portion, and a shape memory alloy disposed in the shape memory lumen. A handle can be provided proximal to the proximal segment and includes a distal end deflection actuator, a shape memory portion deployment actuator; and a central axis. The intermediate position can include a distal end substantially in line with the central axis and a distal end deflection actuator in a first position, and the deflection position includes a distal end that moves out of alignment with the central axis and a distal end deflection actuator in a second position. Next, the delivery configuration can include a shape memory portion and a distal end substantially in line with the central axis and a shape memory portion deployment actuator in a third position, and the deployment configuration includes a shape memory portion formed to substantially conform to the shape of the coronary sinus and a shape memory portion deployment actuator in a fourth position.

[0082] The pull wire lumen can be provided from the proximal segment to the distal end, and a pull wire is disposed in the pull wire lumen. The distal end deflection actuator can be attached to the pull wire, and the second position displaces the pull wire. The guidewire lumen is provided from the proximal segment to the distal segment.

[0083] An intermediate segment distal to the proximal segment can include an intermediate stiffness, the proximal segment includes a proximal stiffness, and the distal end includes a flexibility greater than the proximal stiffness, the intermediate stiffness, and the stiffness of the shape memory alloy. A plurality of sensors can be disposed along the distal segment, and a sensor cable lumen (having a sensor cable disposed therein) connects the plurality of sensors.

[0084] A method of using a coronary sinus catheter to map the electrical activity of the heart, the method comprising the steps of: delivering the coronary sinus catheter to the coronary sinus in a delivery configuration such that the distal segment of the coronary sinus catheter is substantially in line with the central axis. Deploying the shape memory portion of the distal segment of the coronary sinus catheter in the coronary sinus and, when deploying the shape memory portion, suspending the distal end of the distal segment in the right atrium. The method further includes applying a lateral force to the coronary sinus when deploying the shape memory portion.

[0085] Other stable coronary sinus catheters include a main sensor probe that includes a plurality of main sensors disposed along a first length of the main sensor probe and a plurality of secondary sensor probes. Each of the secondary sensor probes has a second length that is shorter than the first length and a secondary sensor disposed at a distal location. The sheath may have a lumen configured to allow the main sensor probe and the plurality of secondary sensor probes to pass therethrough. A sheathed position may enclose the plurality of secondary sensor probes within the lumen and have at least a portion of the main sensor probe outside of the lumen. An unsheathed position includes both the main sensor probe and the plurality of secondary sensor probes outside of the lumen, and the plurality of secondary sensor probes are angled with respect to the main sensor probe and apply a lateral force to the coronary sinus.

[0086] The second length of the stable coronary sinus catheter has a plurality of sub-lengths, and a portion of each of the plurality of secondary sensor probes has a different sub-length. A midline axis is included, and the main sensor probe is disposed generally along the midline axis. Additionally, the plurality of secondary sensor probes are generally parallel to the midline axis in the sheathed position and form an angle with the midline axis in the unsheathed position. The secondary sensor probe angle may be formed between the secondary sensor probe and the midline axis. Herein, the secondary sensor probe angle may be between approximately 0° and approximately 90°. More specifically, the secondary sensor probe angle may be between approximately 0° and approximately 10°.

[0087] The descriptions contained herein are examples of embodiments of the present disclosure and are not intended to limit the scope of the present disclosure in any way. As described herein, the present disclosure contemplates many variations and modifications of ablation tools and diagnostic tools, including alternative numbers of electrodes, alternative electrode combinations, combinations of components shown in separate figures, alternative materials, alternative component geometries, and alternative component arrangements. Modifications and variations that are obvious to one of ordinary skill in the relevant art in light of the teachings of the present disclosure are intended to fall within the scope of the appended claims.

Claims

1. A stable coronary sinus catheter system, comprising: A coronary sinus catheter, the coronary sinus catheter comprising: A proximal segment, wherein the proximal segment comprises a proximal stiffness; An intermediate segment distal to the proximal segment, the intermediate segment comprising an intermediate stiffness; A distal segment, the distal segment comprising: A shape memory portion; and A distal tip distal to the shape memory portion, wherein the distal tip comprises a flexibility greater than the stiffness of the proximal stiffness, the intermediate stiffness, and the shape memory portion; A handle, the handle disposed proximal to the proximal segment, the handle comprising: A body that defines a central axis; A distal tip deflection actuator configured to be in one of a first position, a second position, or a third position along the central axis such that: (a) In the first position of the actuator, the distal tip is substantially in line with the central axis; (b) In the second position of the actuator for deflection of the distal tip, the distal tip is misaligned with the central axis; and (c) In the third position of the actuator for delivery, the shape memory portion and the distal tip are substantially in line with the central axis; and A shape memory portion deployment actuator configured to be in one of a first position and a second position relative to the central axis such that the shape memory portion deployment actuator is in the first position during delivery or deflection of the tip and is in the second position for deploying the shape memory portion to form a predetermined shape that substantially conforms to the shape of the coronary sinus.

2. The stable coronary sinus catheter system according to claim 1, further comprising: A pull wire, the pull wire comprising: A first end anchored in the distal tip; and A second end fixed in the body; The distal tip deflection actuator is attached to the pull wire; and The second position displaces the pull wire.

3. The stable coronary sinus catheter system according to claim 1, further comprising: The distal tip includes a deflection angle between approximately 0° and approximately 180°.

4. The stable coronary sinus catheter system according to claim 1, further comprising: A single axis position sensor disposed substantially at the distal tip.

5. The stable coronary sinus catheter system according to claim 1, further comprising: A deflection actuator lock, the deflection actuator lock comprising: An unlocked position that allows the distal tip deflection actuator to move between the first position and the second position; and A locked position that prevents the distal tip deflection actuator from moving between the first position and the second position.

6. The stable coronary sinus catheter system according to claim 1, further comprising: A shape memory alloy disposed along the shape memory portion and having one end fixed in the body; A cover tube is provided on a portion of the shape memory alloy and includes a shape memory portion deployment end fixed to the shape memory portion for deploying the actuator; In the delivery configuration, the cover tube constrains the shape memory alloy; and In the deployment configuration, the shape memory alloy is not constrained by the cover tube.

7. The stable coronary sinus catheter system according to claim 6, The shape memory portion deployment actuator at the first position holds the cover tube on the shape memory alloy, thereby preventing the shape memory alloy from returning to the predetermined shape; and The shape memory portion deployment actuator at the second position withdraws the cover tube from the shape memory alloy, thereby allowing the shape memory alloy to return to the predetermined shape.

8. The stable coronary sinus catheter system according to claim 1, wherein the predetermined shape of the shape memory portion includes a substantially helical shape.

9. The stable coronary sinus catheter system according to claim 8, wherein the predetermined shape of the shape memory portion includes at least one of the following: A proximal segment bending radius between approximately 8.5 mm and approximately 9.5 mm; A distal segment bending radius between approximately 7.0 mm and approximately 8.0 mm; A proximal segment helix angle between approximately 110° and approximately 120°; A distal segment helix angle between approximately 150° and approximately 160°; A shape memory portion length between approximately 42.5 mm and approximately 44.5 mm; A major diameter of the first helical coil between approximately 14.0 mm and approximately 16.0 mm; and A cone angle between approximately 3.5° and approximately 5.5°.

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