Patent Publication Number: US-2019192220-A1

Title: Ablation Catheter with a Patterned Textured Active Area

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 U.S.C. §119 (e) of U.S. provisional patent application Ser. No. 62/610,760, filed Dec. 27, 2017, which is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Field 
     Embodiments of the invention relate to designs of, and methods of using, an ablation catheter with one or more patterned, textured active areas. 
     Background 
     Ablation is a medical technique for producing tissue necrosis. It is used to help treat different pathologies including cancer, Barret&#39;s esophagus, or cardiac arrhythmias, among others. For radiofrequency (RF) ablation, the application of alternating current with an oscillating frequency above several hundreds of kHz avoids the stimulation of excitable tissue while delivering heat by means of the Joule&#39;s effect. The increase in tissue temperature produces denaturation of the biological molecules, including proteins such as collagen, myosin, or elastin. Traditionally, RF ablation is done by placing an external electrode on the patient&#39;s body, and applying an alternating potential to the tip of a catheter that is placed in contact with the tissue to be treated within the patient&#39;s body. In some cases, various energy sources may be utilized for ablation, including cryogenic cooling for cryoablation, radiofrequency, microwave, laser, ultrasound, and the like. The ablation effect depends on a number of factors, including applied electrical power, quality of the electrical contact, local tissue properties, presence of blood flow close to the tissue surface, and the effect of irrigation. Because of the variability of these parameters, it is difficult to obtain consistent results. 
     Additionally, challenges of ablation catheters include maintaining contact between catheter electrodes and target tissues. For example, a clinician performing an ablation procedure inserts an ablation catheter through a vein in the patient&#39;s body, in which the catheter is guided to cardiac tissue in the patient&#39;s heart where RF energy is applied through the electrode to the cardiac tissue. Contact between an ablation catheter electrode and cardiac tissue is particularly important in order to ablate the appropriate region of the patient&#39;s heart and for efficacy of the treatment for correcting the patient&#39;s pathological condition. However, it is difficult to maintain contact between a catheter electrode and a heart wall, such as an endocardial surface of the heart, and prevent the catheter electrode from shifting during an ablation because of the continuous movements of the heart during typical or irregular heartbeat patterns. Clinicians may attempt to apply additional force at a catheter tip to maintain contact between the catheter and the tissue; yet such approaches increase the risk of edema, perforation, and/or bruising of the tissue. 
     BRIEF SUMMARY 
     Conventional ablation catheters and methods for providing sufficient ablation treatments are limited because of the challenges associated with maintaining the interaction between catheter electrodes and target tissues during ablation procedures. 
     In the embodiments presented herein, an ablation catheter with a patterned and textured active area to enhance surface to surface contact between the active area and tissue is described. In some embodiments, the active area of the ablation catheter is an electrode having a patterned and textured surface that increases a coefficient of friction between the target tissue and the electrode during ablation in order to provide proper grip and surface contact. Additionally, the patterned and textured surface of the electrode may improve heat transfer between the electrode of the ablation catheter and the blood surrounding the target tissue. In the embodiments presented herein, devices and methods for performing ablation using ablating catheters with one or more patterned and textured active areas are described. 
     In an embodiment, an ablation catheter includes a proximal section, a distal section, and a sheath coupled between the distal section and the proximal section. The distal section includes an active area with a patterned, textured surface that is configured to apply RF energy, cryogenic cooling, or laser energy output to a portion of target tissue, such that the portion of target tissue is ablated. The patterned, textured surface of the active area is configured to maintain contact between the target tissue and the active area. 
     In another embodiment, a catheter for performing tissue ablation in a patient is described. The catheter includes a proximal section, a distal section, and a sheath coupled between the distal section and the proximal section. The distal section includes an active area with a plurality of patterned, textured surfaces, wherein the active area is configured to apply RF energy, cryogenic cooling, or laser energy output to a portion of target tissue, such that the portion of target tissue is ablated. The plurality of patterned, textured surfaces of the active area is configured to maintain contact between the target tissue and the active area. 
     An example method for performing tissue ablation is described. The method includes providing an ablation catheter for the tissue ablation, wherein the ablation catheter comprises a distal end with one or more active areas, wherein at least one active area comprises a patterned, textured surface. The method further includes ablating a portion of target tissue using RF energy, cryogenic cooling, or laser energy output from the patterned, textured surface of the at least one active area and using the patterned, textured surface of the at least one electrode to facilitate steady contact between the at least one active area and the portion of target tissue. 
     Further features and advantages, as well as the structure and operation of various embodiments, are described in detail below with reference to the accompanying drawings. It is noted that the specific embodiments described herein are not intended to be limiting. Such embodiments are presented herein for illustrative purposes only. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES 
       The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments of the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. 
         FIG. 1  illustrates an example diagram of a catheter, according to embodiments of the present disclosure. 
         FIGS. 2A and 2B  illustrate cross sections of a catheter, according to embodiments of the present disclosure. 
         FIGS. 3A and 3B  illustrate a patterned, textured electrode located at a distal end of a catheter, according to embodiments of the present disclosure. 
         FIGS. 4A and 4B  illustrate example diagrams of patterned, textured electrode surfaces, according to embodiments of the present disclosure. 
         FIG. 5  illustrates an example image of a patterned, textured electrode, according to embodiments of the present disclosure. 
         FIG. 6  illustrates an example graph of friction coefficient values for various ablation catheter electrodes, according to embodiments of the present disclosure. 
         FIG. 7  illustrates an example method, according to embodiments of the present disclosure. 
     
    
    
     Embodiments of the present invention will be described with reference to the accompanying drawings. 
     DETAILED DESCRIPTION 
     Although specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the pertinent art will recognize that other configurations and arrangements can be used without departing from the spirit and scope of the present invention. It will be apparent to a person skilled in the pertinent art that this invention can also be employed in a variety of other applications. 
     It is noted that references in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Further, when a particular feature, structure or characteristic is described in connection with an embodiment, it would be within the knowledge of one skilled in the art to effect such feature, structure or characteristic in connection with other embodiments whether or not explicitly described. 
     It should be noted that although this application may refer specifically to cardiac ablation, the embodiments described herein may target other pathologies as well, along with additional energy sources for ablation. The principles of using RF energy to treat other pathologies are similar, and therefore the techniques used to apply the RF energy are similar. 
     Disclosed herein are embodiments of an ablation catheter with a patterned, textured active area surface that is configured to enhance device stability and contact between the active area and target tissue during an ablation procedure. As described herein, an active area of an ablation catheter may indicate an electrode that is configured to ablate target tissue. In some embodiments, the patterned, textured surface of the electrode is located at the distal end of an ablation catheter and configured to apply RF energy, laser energy, or cryogenic cooling to a portion of target tissue for tissue ablation. The patterned and textured surface may include a repeating pattern of a predefined shape that is sanded, etched, stamped, machined, or applied by laser ablation to one or more surfaces of the electrode. Each patterned and textured surface of the electrode is electrically conductive and facilitates steady contact between the electrode and target tissue. In particular, the patterned, textured surface of the electrode tip of the ablation catheter has a coefficient of friction value that is higher than the coefficient of friction value of a conventional catheter. 
     The increased coefficient of friction value of the textured electrode surface enhances device stability of the ablation catheter at the target tissue during ablation procedures for patients and prevents displacement of the electrode from the location of the target tissue. By applying the patterned texture solely to the electrode surface, the distal end of the ablation catheter is stabilized with a proper grip at the patterned, textured surface of the electrode while allowing flexibility to the proximal end and sheath of the ablation catheter to move freely and be directed into specific regions of interest for ablation procedures without obstruction from textures. Although embodiments herein describe the use of an RF ablation catheter, other ablation techniques may be utilized as well without deviating from the scope or spirit of the invention, such as, for example, laser ablation, cryoablation, or the like. Furthermore, the embodiments described herein may be used on any catheter where maintaining contact between one or more active areas at a distal end of the catheter and tissue is desired. 
     Herein, the terms “electromagnetic radiation,” “light,” and “beam of radiation” are all used to describe the same electromagnetic signals propagating through the various described elements and systems. 
     Catheter Embodiments 
       FIG. 1  illustrates a catheter  100  according to embodiments of the present disclosure. Catheter  100  includes a proximal section  102 , a distal section  104 , and a sheath  106  coupled between proximal section  102  and distal section  104 . In an embodiment, sheath  106  includes one or more radiopaque markers for navigation purposes. In one embodiment, catheter  100  includes a communication interface  110  between catheter  100  and a processing device  108 . Communication interface  110  may include one or more wires between processing device  108  and catheter  100 . In other examples, communication interface  110  is an interface component that allows wireless communication, such as Bluetooth, WiFi, cellular, etc. Communication interface  110  may communicate with one or more transceiver elements located within either proximal section  102  or distal section  104  of catheter  100 . 
     In an embodiment, sheath  106  and distal section  104  are disposable. As such, proximal section  102  may be reused by attaching a new sheath  106  and proximal section  104  each time a new procedure is to be performed. In another embodiment, proximal section  102  is also disposable. Distal section  104  includes a tip with at least one active area of one or more external, patterned and textured electrodes for ablation, as will be described in further detail below. Each of the one or more electrodes at the tip of the distal section includes at least one surface that is patterned and textured with a predefined, repeating pattern applied to the surface of each electrode by sanding, etching, stamping, electric discharge machining (EDM), casting, laser ablation, or the like. Additionally or alternatively, one or more surfaces of each electrode may be textured with a random pattern by applying a controlled process to the electrode, such as sand-blasting, which results in one or more surfaces with stochastically defined properties such as root mean square (RMS) surface roughness, maximum valley depth, maximum peak height, or average wavelength. The patterned and textured surface of each of the one or more electrodes may include shapes patterned and raised textures to increase surface roughness and friction coefficients at the surface interactions between the electrode(s) and target tissue. For example, the raised textures of a surface may exhibit peak to valley height differences of more than 10 μm. In some embodiments, there may be any number of patterned and textured electrodes at the tip of the distal end of the catheter  100 . For simplicity, in the remainder of the description it is considered that only one ablation electrode with one or more patterned and textured surfaces is present at the tip of the catheter. In an embodiment, the tip of the distal section  104  includes a plurality of optical view ports for sending and receiving optical signals. One or more of the optical view ports may be machined in the patterned and textured electrode at the tip of the catheter. 
     The patterned, textured electrode used for ablation is in electrical connection with at least one cable running along the length of sheath  106 . The optical view ports are distributed over the outside of distal section  104 , resulting in a plurality of distinct viewing directions, according to an embodiment. In an embodiment, each of the plurality of viewing directions is substantially non-coplanar. The optical view ports may also be designed with irrigation functionality to cool distal section  104  and surrounding tissue from overheating during ablation. Further details on the design of distal section  104  and the patterned, textured electrode of the catheter  100  are discussed with reference to  FIGS. 3A, 3B, 4A, and 4B . 
     Proximal section  102  may house various electrical and optical components used in the operation of catheter  100 . For example, a power supply may be included within proximal section  102  to apply RF energy, cryogenic cooling, laser energy, or the like to the patterned, textured electrode located at the tip of distal section  104  for tissue ablation. The power supply may be designed to generate an alternating current at frequencies at least between 350 and 500 kHz. As such, one or more conductive wires (or any electrical transmission medium) may lead from the power supply to distal section  104  within sheath  106 . Furthermore, proximal section  102  may include an optical source for generating a beam of radiation. The optical source may include one or more laser diodes or light emitting diodes (LEDs). The beam of radiation generated by the optical source may have a wavelength within the infrared range. In one example, the beam of radiation has a central wavelength of 1.3 μm. The optical source may be designed to output a beam of radiation at only a single wavelength, or it may be a swept source and be designed to output a range of different wavelengths. The generated beam of radiation may be guided towards distal section  104  via an optical transmission medium connected between proximal section  102  and distal section  104  within sheath  106 . Some examples of optical transmission media include single mode and multimode optical fibers and integrated optical waveguides. In one embodiment, the electrical transmission medium and the optical transmission medium are provided by the same hybrid medium allowing for both electrical and optical signal propagation. 
     Proximal section  102  may include further interface elements with which a user of catheter  100  can control the operation of catheter  100 . For example, proximal section  102  may include a deflection control mechanism that controls a deflection angle of distal section  104 . The deflection control mechanism may require a mechanical movement of an element on proximal section  102 , or the deflection control mechanism may use electrical connections to control the movement of distal section  104 . Proximal section  102  may include various buttons or switches that allow a user to control when RF energy, cryogenic cooling, laser energy, or the like is applied through the electrode at distal end  104 , or when the beams of radiation are transmitted from the electrode at distal end  104 , allowing for the acquisition of optical data. In some embodiments, proximal section  102  may include and/or interface with a robotic catheter control system or steering system to steer the catheter  100  to the target tissue. 
       FIGS. 2A and 2B  illustrate cross-section views of sheath  106 , according to embodiments of the present disclosure. Sheath  106  may include some or all of the elements interconnecting proximal section  102  with distal section  104 . Sheath  106   a  illustrates an embodiment that houses an irrigation channel  202 , RF conductive medium  204 , deflection mechanism  206 , electrical connections  208 , and optical transmission medium  210 .  FIG. 2A  illustrates a protective cover  212  wrapped around both electrical connections  208  and optical transmission media  210 . Electrical connections  208  may be used to provide signals to optical modulating components located in distal section  104 . One or more optical transmission media  210  guide light generated from the optical source (exposure light) towards distal section  104 , while another subset of optical transmission media  210  guides light returning from distal section  104  (scattered or reflected light) back to proximal section  102 . In another example, the same one or more optical transmission media  210  guides light in both directions. 
     Irrigation channel  202  may be a hollow tube used to guide cooling fluid towards distal section  104 . Irrigation channel  202  may include heating and/or cooling elements disposed along the channel to affect the temperature of the fluid. In another embodiment, irrigation channel  202  may also be used as an avenue for drawing fluid surrounding distal section  104  back towards proximal section  102 . 
     RF conductive medium  204  may be a wire or cable used to provide RF energy to the patterned, textured electrode located at distal section  104 . Deflection mechanism  206  may include electrical or mechanical elements designed to provide a signal to distal section  104  in order to change a deflection angle of distal section  104 . The deflection system enables guidance of distal section  104  by actuating a mechanical control placed in proximal section  102 , according to an embodiment. This system may be based on a series of aligned and uniformly spaced cutouts in sheath  106  aimed at providing unidirectional deflection of distal section  104 , in combination with a wire which connects the deflection mechanism control in proximal section  102  with the patterned, textured electrode tip at distal section  104 . In this way, a certain movement of the proximal section may be projected to the distal section. Other embodiments involving the combination of several control wires attached to the catheter tip may enable the deflection of the catheter tip along different directions. 
       FIG. 2B  illustrates a cross-section of sheath  106   b.  Sheath  106   b  depicts an embodiment having most of the same elements as sheath  106   a  from  FIG. 2A , except that there are no electrical connections  208 . Sheath  106   b  may be used in situations where modulation (e.g., multiplexing) of the generated beam of radiation is performed in proximal section  102 . 
     Patterned and Textured Electrode Embodiments 
       FIGS. 3A and 3B  illustrate example diagrams of the patterned, textured electrode located within distal section  104  of catheter  100 , according to embodiments of the present disclosure. In particular,  FIG. 3A  illustrates an example electrode  300 . Electrode  300  acts as an outer body of distal section  104 , and RF energy, cryogenic cooling, laser energy, or the like is applied to electrode  300  to ablate a portion of target tissue, such as an atrial wall of a patient&#39;s heart. Electrode  300  may represent one or more electrodes in distal section  104  and may be referred to herein as one or more active areas. Although the electrode  300  is depicted as a cylindrical shape in  FIG. 3A , electrode  300  may be of any shape and/or size for use with the catheter  100  and for ablation of target tissue. For example, electrode  300  may have a diameter in the range of 1.5 mm to 5 mm and a length of 0.1 to 2 cm down from the distal end of the catheter. In some embodiments, electrode  300  may be formed of a material, such as platinum, platinum-iridium alloy, titanium, gold, copper, or another electrically conductive material. 
     According to an embodiment, electrode  300  includes a patterned texture  302 , a plurality of view ports  304 , and a plurality of openings  306 . Patterned texture  302  may include a predefined, repeating pattern that is applied to one or more surfaces of the electrode  300 . Although patterned texture  302  of electrode  300  is shown in  FIG. 3A  as a hexagonal pattern, the repeating pattern of patterned texture  302  may further include pentagons, octagons, triangles, squares, circles, or other predefined shapes or patterns on the surface of electrode  300 . The repeating pattern of patterned texture  302  may have dimensions on the scale of nanometers, micrometers, or millimeters, and patterned texture  302  may be applied to the electrode surface in a direction along the length and/or width of electrode  300 . In some embodiments, patterned texture  302  may be applied to all surfaces of electrode  300 , as shown in  FIG. 3A . In other embodiments, patterned texture  302  may be applied partially on one or more surfaces of electrode  300 , such that certain areas of electrode  300  are textured and other areas are left without the texture. Patterned texture  302  may be produced by applying a predefined shape or pattern to one or more surfaces of electrode  300  by laser ablation, electric discharge machining (EDM), casting, stamping, or the like. Additionally or alternatively, patterned texture  302  may be produced by applying a texture to one or more surfaces of electrode  300  by sanding, blasting, etching, or the like. 
     In some cases, patterned texture  302  may include a random or stochastic design or texture that is applied asymmetrically to the surfaces of electrode  300 . Patterned texture  302  may increase surface roughness of electrode  300  and increase a coefficient of friction at the interface between electrode  300  and a target tissue by a factor of three. In some embodiments, patterned texture  302  may result in raised textures, indentations, or grooves in the one or more surfaces of electrode  300  which may prevent electrode  300  from shifting or moving from the target tissue during an ablation procedure. Patterned texture  302  may be designed to facilitate steady contact between the electrode and target tissue such that the target tissue is properly ablated to correct pathological conditions in patients. By applying patterned texture  302  solely to electrode  300  of catheter  100 , sheath  106  and proximal section  102  of catheter  100  are flexible and can move (e.g., in blood) without obstructing the catheter from being navigated through the cardiac chamber into the specific tissue or region of interest for the ablation procedure (e.g., tissue of atrial wall). In some embodiments, patterned texture  302  may include a random pattern produced by applying a controlled process, such as sand-blasting one or more surfaces of the electrode  300 , which results in one or more surfaces with stochastically defined properties such as root mean square (RMS) surface roughness, maximum valley depth, maximum peak height, or average wavelength. 
     Plurality of view ports  304  may be arranged around the outside of electrode  300  in any pattern to achieve various views of the target tissue. For example, optical fibers (not shown) in distal section  106  may be used at each of plurality of view ports  304  to both transmit and receive light through each of plurality of view ports  304 . For example, exposure light is transmitted through view ports  304  away from distal section  103  and onto a portion of target tissue, while light that is scattered or reflected by the portion of target tissue is received through view ports  304 . Each view port of plurality of view ports  304  may include more than one optical fiber, for example, a fiber bundle. 
     Plurality of openings  306  in electrode  300  may be associated with one or more irrigation channels (e.g., irrigation channel  202 ) located at a tip of the distal end of the catheter. For example, plurality of openings  306  may comprise holes that are used by the irrigation channels to deliver fluid to tissue for cooling during the ablation procedure. In other embodiments, plurality of openings  306  may be designed to deliver therapeutic fluids to a sample or target tissue. 
       FIG. 3B  illustrates another embodiment of the patterned, textured electrode, depicted as electrode  310 . In some embodiments, electrode  310  may be similar to electrode  300  depicted in  FIG. 3A . Electrode  310  is depicted as a different shape than electrode  300  by way of example. Electrode  310  further includes a patterned texture  312 , a plurality of view ports  314 , and a plurality of openings  316 . In some embodiments, patterned texture  312 , plurality of view ports  314 , and plurality of openings  316  may be the same as or similar to patterned texture  302 , plurality of view ports  304 , and plurality of openings  306 , respectively, of electrode  300  depicted in  FIG. 3A . In particular, patterned texture  312  shown in  FIG. 3B  includes a repeating diagonal line pattern along the length of electrode  310 . By selecting different patterns for the electrode, the resulting patterned, textured electrode may be customized with a particular coefficient of friction value based on the type of patterned texture applied to the electrode of catheter  100 . 
       FIGS. 4A and 4B  illustrate example diagrams of patterned, textured electrode surfaces, according to embodiments of the present disclosure.  FIG. 4A  illustrates electrode  400  of an ablation catheter, including a patterned texture  402  and a plurality of view ports  404 . Patterned texture  402  may include a repeating hexagonal pattern that is applied to one or more surfaces of electrode  400 , resulting in raised hexagonal structures that protrude from the surfaces of electrode  400 . In another example, the hexagons of patterned texture  402  may be machined into one or more surfaces of electrode  400 , resulting in indentations or recesses on the surface(s) of electrode  400 . Additionally, plurality of view ports  404  may be arranged around the outside of electrode  400  in any pattern to achieve various views of the target tissue during an ablation procedure. 
       FIG. 4B  illustrates an additional example of patterned, textured electrode  410 . Electrode  410  includes a patterned texture  412  with a plurality of view ports  414 . Patterned texture  412  may be a random design or texture that is applied asymmetrically to a surface of electrode  410 . For example, patterned texture  412  may be produced by sanding or abrasion blasting to roughen the electrode surface and increase a coefficient of friction of the electrode surface. 
       FIG. 4B  further illustrates electrode  420 , which includes a surface  422  and a plurality of view ports  414 . Surface  422  of electrode  420  may be polished or smooth without any patterned texture applied to surface  422 . In some embodiments, electrode  410  may have a higher coefficient of friction value than a coefficient of friction value of electrode  420 . 
       FIG. 5  illustrates an example image of a patterned, textured electrode, according to embodiments of the present disclosure. In particular,  FIG. 5  illustrates a scanning electron microscopy (SEM) image of a patterned, textured electrode  500  of an ablation catheter. The patterned, textured electrode  500  includes a patterned texture  502  and a plurality of view ports  504 . Patterned texture  502  may be a repeating hexagonal pattern that is applied to a plurality of surfaces of the electrode  500  by laser ablation. Additionally, the plurality of view ports  504  may be arranged around the outside of the patterned, textured electrode  400  in any pattern to achieve various views of the target tissue during an ablation procedure. 
       FIG. 6  illustrates an example graph  600  of friction coefficient values for various ablation catheter electrodes, according to embodiments of the present disclosure. For example, graph  600  provides values of static friction coefficients for “Electrode  1 ,” “Electrode  2 ,” and “Patterned, Textured Electrode  3 .” In some embodiments, the static friction coefficient value for each electrode may be measured at the interface between the electrode and ventricular tissue. “Electrode  1 ” and “Electrode  2 ” may represent polished and/or smooth ablation catheter electrodes without any patterned texture applied to one or more electrode surfaces. “Patterned, Textured Electrode  3 ” may represent a patterned, textured ablation catheter electrode, in which a patterned texture has been applied to one or more surfaces of the electrode, as described herein. As shown in  FIG. 6 , applying a patterned texture to one or more surfaces of an ablation catheter electrode results in an increased static friction coefficient value with respect to the static friction coefficient values of ablation catheter electrodes without any patterned texture. 
     Example Method of Operation 
     Catheter  100  may be used to perform ablation by applying high-frequency alternating current to tissue in contact with the patterned, textured electrode of distal section  104  of catheter  100 . Oscillating frequencies ranging from 350 to 500 kHz may be used. It should be understood that other frequencies may be used as well and that any frequencies above about 1 kHz rarely produce electrical stimulation of excitable cells. An adjustable-power high-frequency power source providing the RF energy to electrode  306  at distal section  104  may be used. The physics underlying the heat transfer to tissue is based on a high electrical impedance of the patterned, textured electrode-tissue interface. The impedance of this tissue-electrode interface, at the ablation frequency, may be substantially greater than that of the returning electrode. For a given current delivered though the body, a greater voltage drop may be generated at this interface producing heat at the desired location. In this way, a small tissue volume surrounding the patterned, textured electrode is ablated, instead of all the tissue volume from the patterned, textured electrode of the catheter to the ground contact, which is typically placed on the patient&#39;s back during cardiac ablation treatment. By adjusting the RF power and ablation time, the total energy delivered to tissue may be accurately controlled. Other ablation techniques based on cryogenic or optical means (e.g., laser ablation) may also be used for the treatment of different pathologies. In additional embodiments, the patterned, textured electrode-tissue interface may also provide additional cooling to surrounding blood flow around the target tissue. This benefit may be achieved through the turbulence promoting effect of texture, which may result in an increased Nusselt number and improved heat transfer to the surrounding fluid around the target tissue. 
     Various ablation methods and other embodiments of ablation catheters with patterned, textured electrodes described thus far can be implemented, for example, using catheter  100  shown in  FIG. 1 , along with one or more patterned, textured electrodes, such as electrodes  300 ,  310 ,  400 ,  410 , or  500  shown in  FIGS. 3A, 3B, 4A, 4B, and 5 , respectively. 
       FIG. 7  illustrates an example method  700  for performing ablation according to embodiments of the present disclosure. Method  700  may be performed by ablation catheters with one or more patterned textured electrodes as described herein (e.g., electrodes  300 ,  310 ,  400 ,  410 , and/or  500 ). 
     At block  702 , an ablation catheter for ablation is provided. For example, an ablation catheter with one or more active areas at the distal end of the ablation catheter is provided, in which at least one active area includes a patterned, textured surface. For example, the at least one active area may include at least one electrode, in which the patterned, textured surface of the at least one electrode may be produced by applying a predefined pattern to a surface of the at least one electrode by laser ablation, electric discharge machining (EDM), sanding, blasting, etching, casting, or stamping. 
     At block  704 , a portion of target tissue is ablated using RF energy, cryogenic cooling, or laser energy output from the patterned, textured surface of the at least one active area of the ablation catheter. For example, the patterned, textured surface may be electrically conductive, and RF energy, cryogenic cooling, or laser energy may be output to ablate a portion of target tissue, such as a portion of one or more layers of an atrial wall in a patient&#39;s heart. 
     At block  706 , the patterned, textured surface of the at least one active area may be used to facilitate steady contact between the at least one active area and the portion of target tissue. For example, the patterned, textured surface may increase a friction coefficient of contact between the target tissue and the at least one electrode and prevent one or more active areas of the catheter from shifting or moving from the target tissue during an ablation procedure. 
     It is to be appreciated that the Detailed Description section, and not the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present invention as contemplated by the inventor(s), and thus, are not intended to limit the present invention and the appended claims in any way. 
     Embodiments of the present invention have been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed. 
     The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present invention. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance. 
     The breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.