EnSite NavX Navigation and Visualization Technology EnSite Fusion Registration Module Procedure Guide

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1 EnSite NavX Navigation and Visualization Technology EnSite Fusion Registration Module Procedure Guide The EnSite Fusion Module enables Dynamic Registration, allowing a DIF model (a surface rendering of a CT scan) to be used as a geometry surface, including the display of mapping and labeling on the surface of the DIF model. EnSite Fusion is intended for use with the EnSite NavX Surface Electrode Kit and cardiac models from CT scans segmented into a compatible file format.

2 EnSite Fusion Registration Module Procedure Guide Performing a Registration: The dynamic registration process is described in the following steps. 1) Loading a DIF model: A segmented 3D model is a surface rendering that been segmented from a 3D image data set. Segmented CT models for import into the EnSite system can be created using the Verismo Segmentation tool. Other files supported by the EnSite system are CardEP and Inventor file formats. To load a Digital Image Fusion (DIF) file from either the hard drive or a CD. a) Click on the Geometry control window; select [Load DIF files]. The import Digital Images window will appear. b) Select either the Hard Drive, or DVD/CD tab as the file source. c) Find the DIF file in the list and you can either select [Load] or [View]. The view option allows you to view the DIF file prior to loading it onto the study. The load button will check that the patient name from both the DIF file and the current study match and then proceed to load the DIF file onto the study. d) Bring up Dual Maps or Dual Maps and Waveforms views so that you can see both the DIF file and the EnSite NavX geometry. 2 EnSite Fusion TM Navigation and Visualization Technology

3 2) Field Scaling: Field Scaling uses measured inter-electrode spacing at collected geometry points in the chamber to compensate for inhomogeneities in the EnSite NavX field. Field Scaling is recommended prior to the registration process. a) Once the complete geometry has been created with catheters that have been entered with the interelectrode spacing data, apply Field Scaling For further information, see the EnSite System with EnSite 7 Software Instructions for Use or the EnSite 7 Geometry Creation procedure guide. b) Under the Geometry controls window select [Field Scaling] and then [Compute]. 3) EnSite Fusion Process: EnSite Fusion uses paired locations between the EnSite NavX navigation field and a DIF model to perform registration. The points used to fuse the two surfaces are called fiducial points. During the Fusion process these fiducial points are represented by yellow springs between the two surfaces as reference points of fused surfaces. Fusion registration is the process of aligning the EnSite NavX coordinate system and geometry points to the DIF model. When three points are used, EnSite Fusion uses a Dynamic Registration algorithm to locally adjust the EnSite NavX navigation field and geometry surface to the size and shape of a DIF model surface. This is done in three phases. Phase one is typically completed by placing a minimum number of fiducial points (three is recommended) to initially register the two surfaces. a) With the map display in a Dual Map view, select the EnSite Fusion Icon to display the EnSite Fusion tools. The field scaled EnSite NavX geometry and the DIF model will appear adjacent to one another in the map display. The composite point cloud for all EnSite NavX surfaces will appear in the EnSite NavX geometry. Note: The Show Points toggle may be used to show or hide the display of points. b) Under Registration Action, select either [Add At Surface] or [Add At EnGuide]. n Add At Surface (recommended): While this toggle is enabled, the left mouse is used to place fiducial points on both the EnSite NavX and the DIF surfaces. When the cursor is over the EnSite NavX map display, it will be a cross-hair box. This control is also available by right-clicking the map display and selecting DIF Action and Add at Surf. n Add At EnGuide: Placing a fiducial point can also be done at the Active Electrode location by manipulating the catheter to an anatomic location that can also be easily recognized on the DIF model. This control is also available by right-clicking the map display and selecting DIF Action and Add at EnGuide. A point will be created at the Active EnGuide position when the mouse is clicked on the DIF geometry. You will then need to left-click on the matching anatomic location on the DIF surface.

4 EnSite Fusion Registration Module Procedure Guide b) Identify correlating locations between the EnSite NavX geometry and the DIF model. The locations selected should be easily identifiable on both images and near the main body of the chamber. Examples would be the carina between pulmonary veins and the ridge between the left pulmonary veins and the left atrial appendage. c) Place fiducial point pairs. Place a fiducial point on the NavX geometry (using either Add at Surface or Add at EnGuide). The point will link to the nearest geometry point and a circle will appear at the selected location. When placing a fiducial point on an area of false space or where there is a very sparse sampling of points may result in the fiducial point being placed in a different location than desired. Then left click on the corresponding location on the DIF model. A yellow spring-shaped graphic will appear indicating that the locations have been linked. Note: The first point in a fiducial pair is always placed on the EnSite NavX geometry. b) The second and third points should span the extent of the chamber being registered. This means that they should be distributed around the chamber or in other words, not clustered in one location. Place the initial fiducial points within the main LA body: i.e. at the roof of the two superior pulmonary veins and at the anterior mitral valve annulus. Note: Placing a larger number of points at all known locations is likely to result in a more complete initial registration result. c) Once the initial fiducial points have been placed select [Compute]. This will cause the two surfaces to register and are then fused together. It is recommended that the user periodically click on [Compute] during the Fusion process to evaluate the benefit of the most recent fiducial point(s) placed. If more than three registration points have been used, Dynamic Registration will fuse the spring shaped icons to small yellow dots, as the locations intersect. Dynamic registration is an inherently local registration algorithm. When additional points are added they have a local effect on the registration and have a minimal affect at a distance from their placement. This is beneficial because it permits the refinement of the registration in one location without the registration being affected in other areas where the user has already placed fiducial points and for which they are already satisfied with the registration in that location. Phase two is further matching of identifiable points, but these can be further away from the body of the chamber. Vessel bifurcations serve as good examples, as long as care is taken to confirm that the structures are the same on both images. Note: Remember that even in overlapping view, the initial fiducial point will be placed on the EnSite NavX geometry. a) Concentrate on placing fiducial points along the antrum of the PV s and the LAA. Again start by placing the first point of the fiducial on the EnSite NavX geometry and the second point of the fiducial on the DIF surface in the corresponding location. b) Repeat this process to line up the PV antrums with the DIF surface. You can line up the venous structure out further as well if need be. Click on [Compute] periodically during the process at about every 3-5 fiducials Placing fiducials along the vein. Fiducial compute applied you place. This will allow you to see how things are progressing. c) If you need to move or delete a fiducial point at any time just highlight the fiducial point you wish to edit and either click [delete fiducial] or on the [Move] toggle button. You will need to re-compute within the Fusion window in order to see the change after editing fiducial points. 4 EnSite Fusion TM Navigation and Visualization Technology

5 Phase three (complete the Fusion process) uses the alignment of points on both surfaces in anatomic and orthogonal views. Resetting the image to AP (and clicking the mouse twice in the same location in order to snap the two surfaces together at that location). Repeating this process in orthogonal planes (right lateral, PA, left lateral, directly cephalic, and directly caudal) will further align the various surfaces. Three fiducial points placed in phase three along the anterior wall. The user can further staple the surfaces together in oblique orientations, but this should be done at the very end and only to an already well registered model. This will allow the surfaces to come together in very close proximity at any location the user wishes a) With both surfaces now fused together, line up the surface so that it is facing you directly and doubleclick with your mouse on the EnSite NavX surface within the LA body. The first click will land a fiducial on the EnSite NavX surface and the second click will land one on the DIF surface and will staple the two surfaces together. b) The end point is that both structures are fused to allow the catheter navigation within the DIF image. The EnSite NavX point cloud The EnSite NavX point cloud should be shown within the DIF model. Geometry point cloud shown within the DIF model. Any locations that show geometry points outside the DIF model (which are expected to fall within the model) may be candidates for supplemental fiducial points to bring those geometry points within the DIF model and further refine the registration. c) Once done with the Fusion process you can shut off the EnSite surface by clicking on the toggle button [Show EnSite Geometry] in the Fusion control window.

6 EnSite Fusion Registration Module Procedure Guide d) With Translucency turned on, maneuver the EnGuide catheter to known anatomical locations to validate that the DIF image is a good match with your navigation field. The Proximity tool may also be used to evaluate the registration. The user can place the catheter on the endocardium and then observe how close the proximity indicator reads that the catheter is from the surface. At any time after the registration has been completed, if the user believes that the registration needs to be updated in the area in which they are navigating, this process is as simple as adding additional fiducial points in that region and recomputing the registration. LA Fused Geometry surface RA Fused Geometry surface Points to consider are: n The more fiducial points that are used, the better the surfaces will match, with enough time and effort the match could be near perfect. n The quality of the registration will be dependent on the quality of the Verismo segmentation performed. The quality of the registration will be dependent on the quality of the scan and the segmentation. n The EnSite Fusion tool will match points assigned by the user and dynamically fuse to the EnSite NavX Navigation Field. If the user matches the right inferior pulmonary vein on one surface to the left inferior pulmonary vein on the other, the algorithm will morph the point cloud and surface into a grossly incorrect shape. False space in the geometry, areas of geometry that do not contain geometry points, occasionally found near vein ostia should be identified and removed by editing the points in the geometry surface prior to registration. n Finally, it should be noted that Fusion and Field Scaling can be applied independently, but are complimentary in the effort to register images. Fusion can be applied to studies acquired on prior software versions capable of displaying DIF images. Field Scaling cannot be applied to any study except those done with Version 7 and only then if the catheter dimension have been defined prior to point collection. 6 EnSite Fusion TM Navigation and Visualization Technology

7 Display Options: Show Fiducials The [Show Fiducials] toggle under the Fusion controls will show or hide the fiducials while the Fusion controls are displayed. Show Points The [Show Points] toggle under the EnSite Fusion controls will show or hide the NavX geometry point cloud while the Fusion controls are open. The point cloud will include all surfaces included in the geometry. Show EnSite Geometry Under the Fusion controls, or the Map Settings controls you can toggle on or off the display of the NavX geometry. Show DIF Geometry Under the Fusion controls, or the Map Settings controls you can toggle on or off the display of the DIF surface. The EnSite NavX geometry must be displayed in order to place fiducial points. Viewport Synch In dual map views with a DIF file loaded, disabling the Viewport Synch toggle will allow the NavX geometry and the DIF surface to rotate independently. To sync the two surfaces again simply click on the Viewport Synch again and hit a saved view such as the AP or ROA button. Proximity To Surface This toggle enables/disables the 3D display showing the projected distance from the active electrode to either the DIF or the EnSite geometry. Project On DIF Surface After registration, enabling the Project on DIF Surface toggle will allow the following projected items to display on the DIF surface. Proximity Indicator On Surface Projection Diagnostic Landmarking (DxL) Lesions placed at EnGuide Map labels placed at EnGuide Note: Disabling the toggle allows the objects to project onto the EnSite Geometry. Fused LA Geometry surface with a DxL map. Anatomical Markers Markers can also be applied to the DIF surface to allow valve markers to be cut out on the DIF surface. Tape Measures Tape measure can be used on the DIF surface once Field Scaling and registration has been computed. Fused LA Geometry surface with surface lesion markers.

8 EnSite Fusion Registration Module Procedure Guide EnSite Rx Only Brief Summary: Please review the Instructions for Use prior to using these devices for a complete listing of indications, contraindications, warnings, precautions, potential adverse events and directions for use. 8 EnSite Fusion TM Navigation and Visualization Technology Rev St. Jude Medical