| Methods and apparatus for treatment of atrial fibrillation -> Monitor Keywords |
|
|
  Methods and apparatus for treatment of atrial fibrillationUSPTO Application #: 20080015569Title: Methods and apparatus for treatment of atrial fibrillation Abstract: Apparatus and methods for the treatment of atrial fibrillation are described herein where tissue to be ablated may be monitored under direct visualization. Such a system may include a deployment catheter and an attached imaging hood deployable into an expanded configuration. In use, the imaging hood is placed against or adjacent to the tissue to be imaged in a body lumen that is normally filled with an opaque bodily fluid such as blood. A translucent or transparent fluid can be pumped into the imaging hood until the fluid displaces any blood leaving a clear region of tissue to be imaged via an imaging element in the deployment catheter. An ablation probe may be advanced into the contained region where the tissue may be ablated and monitored for changes in color as well as appropriate positioning. (end of abstract) Agent: Levine Bagade Han LLP - Palo Alto, CA, US Inventors: Vahid Saadat, Ruey-Feng Peh, Edmund A. Tam, Chris A. Rothe USPTO Applicaton #: 20080015569 - Class: 606041000 (USPTO) Related Patent Categories: Surgery, Instruments, Electrical Application, Applicators The Patent Description & Claims data below is from USPTO Patent Application 20080015569. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of priority to the following U.S. Prov. Pat. App. Ser. Nos. 60/806,923; 60/806,924; and 60/806,926 each filed Jul. 10, 2006; this is also a continuation-in-part of U.S. patent application Ser. No. 11/259,498 filed Oct. 25, 2005, which claims priority to U.S. Prov. Pat. App. Ser. No. 60/649,246 filed Feb. 2, 2005. Each application is incorporated herein by reference in its entirety. FIELD OF THE INVENTION [0002] The present invention relates generally to medical devices used for accessing, visualizing, and/or treating regions of tissue within a body. More particularly, the present invention relates to methods and apparatus for accessing, visualizing, and/or treating conditions such as atrial fibrillation within a patient heart. BACKGROUND OF THE INVENTION [0003] Conventional devices for visualizing interior regions of a body lumen are known. For example, ultrasound devices have been used to produce images from within a body in vivo. Ultrasound has been used both with and without contrast agents, which typically enhance ultrasound-derived images. [0004] Other conventional methods have utilized catheters or probes having position sensors deployed within the body lumen, such as the interior of a cardiac chamber. These types of positional sensors are typically used to determine the movement of a cardiac tissue surface or the electrical activity within the cardiac tissue. When a sufficient number of points have been sampled by the sensors, a "map" of the cardiac tissue may be generated. [0005] Another conventional device utilizes an inflatable balloon which is typically introduced intravascularly in a deflated state and then inflated against the tissue region to be examined. Imaging is typically accomplished by an optical fiber or other apparatus such as electronic chips for viewing the tissue through the membrane(s) of the inflated balloon. Moreover, the balloon must generally be inflated for imaging. Other conventional balloons utilize a cavity or depression formed at a distal end of the inflated balloon. This cavity or depression is pressed against the tissue to be examined and is flushed with a clear fluid to provide a clear pathway through the blood. [0006] However, such imaging balloons have many inherent disadvantages. For instance, such balloons generally require that the balloon be inflated to a relatively large size which may undesirably displace surrounding tissue and interfere with fine positioning of the imaging system against the tissue. Moreover, the working area created by such inflatable balloons are generally cramped and limited in size. Furthermore, inflated balloons may be susceptible to pressure changes in the surrounding fluid. For example, if the environment surrounding the inflated balloon undergoes pressure changes, e.g., during systolic and diastolic pressure cycles in a beating heart, the constant pressure change may affect the inflated balloon volume and its positioning to produce unsteady or undesirable conditions for optimal tissue imaging. [0007] Accordingly, these types of imaging modalities are generally unable to provide desirable images useful for sufficient diagnosis and therapy of the endoluminal structure, due in part to factors such as dynamic forces generated by the natural movement of the heart. Moreover, anatomic structures within the body can occlude or obstruct the image acquisition process. Also, the presence and movement of opaque bodily fluids such as blood generally make in vivo imaging of tissue regions within the heart difficult. [0008] Other external imaging modalities are also conventionally utilized. For example, computed tomography (CT) and magnetic resonance imaging (MRI) are typical modalities which are widely used to obtain images of body lumens such as the interior chambers of the heart. However, such imaging modalities fail to provide real-time imaging for intra-operative therapeutic procedures. Fluoroscopic imaging, for instance, is widely used to identify anatomic landmarks within the heart and other regions of the body. However, fluoroscopy fails to provide an accurate image of the tissue quality or surface and also fails to provide for instrumentation for performing tissue manipulation or other therapeutic procedures upon the visualized tissue regions. In addition, fluoroscopy provides a shadow of the intervening tissue onto a plate or sensor when it may be desirable to view the intraluminal surface of the tissue to diagnose pathologies or to perform some form of therapy on it. [0009] Thus, a tissue imaging system which is able to provide real-time in vivo images of tissue regions within body lumens such as the heart through opaque media such as blood and which also provide instruments for therapeutic procedures upon the visualized tissue are desirable. BRIEF SUMMARY OF THE INVENTION [0010] A tissue imaging and manipulation apparatus that may be utilized for procedures within a body lumen, such as the heart, in which visualization of the surrounding tissue is made difficult, if not impossible, by medium contained within the lumen such as blood, is described below. Generally, such a tissue imaging and manipulation apparatus comprises an optional delivery catheter or sheath through which a deployment catheter and imaging hood may be advanced for placement against or adjacent to the tissue to be imaged. [0011] The deployment catheter may define a fluid delivery lumen therethrough as well as an imaging lumen within which an optical imaging fiber or assembly may be disposed for imaging tissue. When deployed, the imaging hood may be expanded into any number of shapes, e.g., cylindrical, conical as shown, semi-spherical, etc., provided that an open area or field is defined by the imaging hood. The open area is the area within which the tissue region of interest may be imaged. The imaging hood may also define an atraumatic contact lip or edge for placement or abutment against the tissue region of interest. Moreover, the distal end of the deployment catheter or separate manipulatable catheters may be articulated through various controlling mechanisms such as push-pull wires manually or via computer control [0012] The deployment catheter may also be stabilized relative to the tissue surface through various methods. For instance, inflatable stabilizing balloons positioned along a length of the catheter may be utilized, or tissue engagement anchors may be passed through or along the deployment catheter for temporary engagement of the underlying tissue. [0013] In operation, after the imaging hood has been deployed, fluid may be pumped at a positive pressure through the fluid delivery lumen until the fluid fills the open area completely and displaces any blood from within the open area. The fluid may comprise any biocompatible fluid, e.g., saline, water, plasma, Fluorinert.TM., etc., which is sufficiently transparent to allow for relatively undistorted visualization through the fluid. The fluid may be pumped continuously or intermittently to allow for image capture by an optional processor which may be in communication with the assembly. [0014] In an exemplary variation for imaging tissue surfaces within a heart chamber containing blood, the tissue imaging and treatment system may generally comprise a catheter body having a lumen defined therethrough, a visualization element disposed adjacent the catheter body, the visualization element having a field of view, a transparent fluid source in fluid communication with the lumen, and a barrier or membrane extendable from the catheter body to localize, between the visualization element and the field of view, displacement of blood by transparent fluid that flows from the lumen, and a piercing instrument translatable through the displaced blood for piercing into the tissue surface within the field of view. [0015] The imaging hood may be formed into any number of configurations and the imaging assembly may also be utilized with any number of therapeutic tools which may be deployed through the deployment catheter. [0016] More particularly in certain variations, the tissue visualization system may comprise components including the imaging hood, where the hood may further include a membrane having a main aperture and additional optional openings disposed over the distal end of the hood. An introducer sheath or the deployment catheter upon which the imaging hood is disposed may further comprise a steerable segment made of multiple adjacent links which are pivotably connected to one another and which may be articulated within a single plane or multiple planes. The deployment catheter itself may be comprised of a multiple lumen extrusion, such as a four-lumen catheter extrusion, which is reinforced with braided stainless steel fibers to provide structural support. The proximal end of the catheter may be coupled to a handle for manipulation and articulation of the system. [0017] In additional variations of the imaging hood and deployment catheter, the various assemblies may be configured in particular for treating conditions such as atrial fibrillation while under direct visualization. In particular, the devices and assemblies may be configured to facilitate the application of energy to the underlying tissue in a controlled manner while directly visualizing the tissue to monitor as well as confirm appropriate treatment. Generally, the imaging and manipulation assembly may be advanced intravascularly into the patient's heart, e.g., through the inferior vena cava and into the right atrium where the hood maybe deployed and positioned against the atrial septum and the hood may be infused with saline to clear the blood from within to view the underlying tissue surface. [0018] Once the hood has been desirably positioned over the fossa ovalis, a piercing instrument, e.g., a hollow needle, may be advanced from the catheter and through the hood to pierce through the atrial septum until the left atrium has been accessed. A guidewire may then be advanced through the piercing instrument and introduced into the left atrium, where it may be further advanced into one of the pulmonary veins. With the guidewire crossing the atrial septum into the left atrium, the piercing instrument may be withdrawn or the hood may be further retracted into its low profile configuration and the catheter and sheath may be optionally withdrawn as well while leaving the guidewire in place crossing the atrial septum. A dilator may be advanced along the guidewire to dilate the opening through the atrial septum to provide a larger transseptal opening for the introduction of the hood and other instruments into the left atrium. Further examples of methods and devices for transseptal access are shown and described in further detail in commonly owned U.S. patent application Ser. No. 11/763,399 filed Jun. 14, 2007, which is incorporated herein by reference in its entirety. Those transseptal access methods and devices may be fully utilized with the methods and devices described herein, as practicable. [0019] With the hood advanced into and expanded within the left atrium, the deployment catheter and/or hood may be articulated to be placed into contact with or over the ostia of the pulmonary veins. Once the hood has been desirably positioned along the tissue surrounding the pulmonary veins, the open area within the hood may be cleared of blood with the translucent or transparent fluid for directly visualizing the underlying tissue such that the tissue may be ablated. An ablation probe, which may be configured in a number of different shapes, may be advanced into and through the hood interior while under direct visualization and brought into contact against the tissue region of interest for ablation treatment. One or more of the ostia may be ablated either partially or entirely around the opening to create a conduction block. In performing the ablation, the hood may be pressed against the tissue utilizing the steering and/or articulation capabilities of the deployment catheter as well as the sheath. Alternatively and/or additionally, a negative pressure may be created within the hood by drawing in the transparent fluid back through the deployment catheter to create a seal with respect to the tissue surface. Moreover, the hood may be further approximated against the tissue by utilizing one or more tissue graspers which may be advanced through the hood, such as helical tissue graspers, to temporarily adhere onto the tissue and create a counter-traction force. [0020] Because the hood allows for direct visualization of the underlying tissue in vivo, the hood may be used to visually confirm that the appropriate regions of tissue have been ablated and/or that the tissue has been sufficiently ablated. Visual monitoring and confirmation may be accomplished in real-time during a procedure or after the procedure has been completed. Additionally, the hood may be utilized post-operatively to image tissue which has been ablated in a previous procedure to determine whether appropriate tissue ablation had been accomplished. Continue reading... Full patent description for Methods and apparatus for treatment of atrial fibrillation Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Methods and apparatus for treatment of atrial fibrillation patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Methods and apparatus for treatment of atrial fibrillation or other areas of interest. ### Previous Patent Application: Hollow conductive coaxial cable for radio frequency based tissue ablation system Next Patent Application: Methods and systems for treating tumors using electroporation Industry Class: Surgery ### FreshPatents.com Support Thank you for viewing the Methods and apparatus for treatment of atrial fibrillation patent info. IP-related news and info Results in 0.6 seconds Other interesting Feshpatents.com categories: Tyco , Unilever , Warner-lambert , 3m |
||
