Patent Description:
Various medical systems, such as cardiac ablation, display to a physician visual markers indicative of procedure-related medical parameters.

For example, <CIT> describes a method and system for presenting information representative of lesion formation. The system comprises an electronic control unit (ECU). The ECU is configured to acquire a value for an ablation description parameter and/or a position signal metric, wherein the value corresponds to a location in the tissue. The ECU is further configured to evaluate the value, assign it a visual indicator of a visualization scheme associated with the parameter/metric corresponding to the value, and generate a marker comprising the visual indicator such that the marker is indicative of the acquired value.

<CIT> describes a visualization apparatus for visualizing a quality of applying energy to an object. The quality of applying energy at a location on the object is visualized based on a) a provided image of the object and b) a provided quality value which is a depth value indicative of the depth to which the applied energy has altered the object, representing the quality of applying energy to the object at the location on the object.

<CIT> describes image processing systems, which utilize various methods and processing algorithms for enhancing or facilitating visual detection and/or sensing modalities for images captured in vivo by an intravascular visualization and treatment catheter.

<CIT>) describes a system and method of recording and displaying, in context of an image, a location of at least one point-of-interest in a body during an intra-body medical procedure. In one example, the target location to which the user wishes to navigate may be indicated in a user sensible manner that varies according to the proximity of the tool to the target location. For example, the target location may be indicated by a blinking light, the color may change the brightness may be increased, or the size may be increased, as the tool is brought closer to it. Conversely, the variances may regress as the tool moves away from the target location. A certain blink rate, color, brightness, size, or combination thereof, may then symbolize being right on target.

<CIT>) describes a method of graphically presenting an indicating marker over a <NUM>-D model of a tissue surface during a catheterization procedure. In one example, indicating marks are used for showing a current position of a tip of a probe positioned within a <NUM>-D model of a body lumen. The body lumen modeled comprises a region of a right atrium interconnecting between a superior vena cava and an inferior vena cava. The position, including orientation, and movements of probe within <NUM>-D model are synchronized to actual movement of the probe within a body lumen corresponding to <NUM>-D model. Two indicating marks are displayed, each mapped to a surface of <NUM>-D model. The center point of the first mark shows the position at which a longitudinal axis extending distally from probe intersects the surface of model. The center point of the second mark is centered on a surface point of <NUM>-D model which is closest to a point at the tip of the probe. During a procedure, the marks are moved around, each according to their respective placement rule, as data indicating the new position, including orientation, of the probe are received. Optionally, size of marks varies with distance from the probe; for example, size is optionally chosen to maintain a fixed angular size (or fixed angular size with offset, similar to a flashlight beam emanating from an extended source) with respect to an origin located at some reference location defined by the position of probe.

<CIT>) describes a system and use thereof to provide indication of proximity between catheter and location of interest in <NUM>-D space.

<CIT>) describes a system for determining cardiac targets.

Some medical systems, such as cardiac ablation systems, may display supplemental information on an operating display, for assisting the procedure workflow.

Embodiments of the present invention that are described hereinbelow provide methods and systems for increasing the visibility of a medical catheter and of tissue during a medical invasive procedure such as an ablation procedure. In some embodiments, a system that displays an ablation catheter in a patient's heart comprises a processor, which is electrically coupled to the ablation catheter, and an output device. The processor is configured to display on the output device a map of at least part of the heart, and one or more visual markers, which are overlaid on the map and visualize ablation parameters, such as temperature, duration and/or contact force, applied to the heart tissue. The markers are typically displayed as opaque objects.

In some cases, the opaque markers may visually obstruct one or more sections of the medical catheter and/or some of the tissue, which are essential for performing the procedure.

In some embodiments, the processor is configured to receive electrical position signals, which are indicative of one or more positions of the catheter distal end within the heart, wherein at least one of the positions falls within the map boundaries. The processor is configured to identify that the current position of the distal end is within a predefined vicinity of at least one of the opaque visual markers, meaning that the opaque visual marker may obstruct the visibility of at least a section of the distal end. In some embodiments, the processor is configured to modify the visual appearance of that opaque visual marker, e.g., by displaying a translucent (i.e., semi-transparent) visual marker instead of the opaque visual marker. By replacing the opaque visual marker with a translucent visual marker, a user of the ablation system can see the previously-obstructed sections through the marker, and is able to carry out the ablation procedure successfully.

In some practical cases, the display of visual markers may be important for the workflow of the ablation procedure. For example, displaying opaque visual markers may provide the user with information essential for performing the ablation procedure accurately. In some embodiments, after the user moves the distal end away from the aforementioned visual markers, the processor is configured to redisplay the one or more opaque visual markers, which were modified into translucent visual markers.

The disclosed techniques improve the patient safety and quality of ablation procedures, by providing physicians with procedure-assisting clear visual information, and improving the visibility of tissue and catheters used in the ablation procedure. Moreover, generally speaking, and in the context of examples useful to understand the claimed invention, the disclosed techniques may be applied to any sort of tagging or other visual markers displayed on any anatomical map during any sort of medical procedure carried out on a patient organ.

<FIG> is a schematic, pictorial illustration of a catheter-based magnetic position-tracking and ablation system <NUM>, in accordance with an embodiment of the present invention. System <NUM> comprises a catheter <NUM>, having a shaft distal end <NUM> that is navigated by a physician <NUM> into an organ, in the present example a heart <NUM>, of a patient <NUM> via the vascular system. In some embodiments, physician <NUM> inserts shaft distal end <NUM> through a sheath <NUM>, while manipulating distal end <NUM> using a manipulator <NUM> located at the proximal end of catheter <NUM>.

Reference is now made to an inset <NUM>. In some embodiments, system <NUM> comprises a magnetic sensor <NUM>, also referred to herein as a magnetic position tracking sensor or sensor <NUM> for brevity, and an ablation catheter <NUM>, which are coupled to distal end <NUM>.

In the embodiments, catheter <NUM> may be used for various procedures, such as electrophysiological (EP) mapping of heart <NUM> and for ablating selected tissue of heart <NUM>.

In some embodiments, the proximal end of catheter <NUM> is electrically connected to a control console <NUM> via electrical leads and/or traces. In an embodiment, console <NUM> comprises a processor <NUM> and interface circuits <NUM>, which is configured to exchange signals between processor <NUM> and various components and assemblies of system <NUM>.

In some embodiments, interface circuits <NUM> are configured to receive electrical signals from catheter <NUM> and other sensors of system <NUM>. Circuits <NUM> are further configured to send electrical signals from processor <NUM> to various components and assemblies of system <NUM>, such as applying power via catheter <NUM> for ablating tissue of heart <NUM>, and for controlling the other components and assemblies of system <NUM>.

In some embodiments, system <NUM> comprises multiple (e.g., three) magnetic field generators <NUM>, configured to produce alternating magnetic fields. Field generators <NUM> are placed at known positions external to patient <NUM>, for example, below a patient table <NUM>.

In some embodiments, console <NUM> further comprises a driver circuit <NUM>, which is configured to drive magnetic field generators <NUM>, and an output device, in the present example a display <NUM>.

During a medical procedure physician <NUM> navigates distal end <NUM> of catheter <NUM> in heart <NUM>. In some embodiments, in response to the magnetic fields irradiated from field generators <NUM>, magnetic sensor <NUM> is configured to produce a differential electrical signal, also referred to herein as a differential signal or a position signal, indicative of the current position of distal end <NUM> in heart <NUM>.

In some embodiments, based on the differential signal received from sensor <NUM>, processor <NUM> is configured to display, e.g., on display <NUM>, the current position of distal end <NUM> in the coordinate system of system <NUM>.

This method of position sensing is implemented, for example, in the CARTO™ system, produced by Biosense Webster Inc. (Irvine, Calif. ) and is described in detail in <CIT>, <CIT>, <CIT>,<CIT>, <CIT> and<CIT>, in <CIT>, and in <CIT> <CIT>, <CIT>and <CIT>.

Processor <NUM> typically comprises a general-purpose processor, which is programmed in software to carry out the functions described herein. The software may be downloaded to the computer in electronic form, over a network, for example, or it may, alternatively or additionally, be provided and/or stored on non-transitory tangible media, such as magnetic, optical, or electronic memory.

<FIG> is a schematic, pictorial illustration of an anatomical map <NUM> of heart <NUM>, in accordance with an embodiment of the present invention. In some embodiments, processor <NUM> is configured to display one or more visual markers, such as visual markers 66A, 66B and 66C, overlaid on anatomical map <NUM>, also referred to herein as map <NUM> for brevity. In the context of the present invention and in the claims, the term "visual marker" refers to any sort of tag, displayed, e.g., by processor <NUM> on display <NUM>, so as to provide physician <NUM> with supplemental information that may assist physician <NUM> in navigating and positioning distal end <NUM> in tissue of heart <NUM>, as will be described in detail below.

In some embodiments, the dimension and shape of visual markers 66A, 66B and 66C may be indicative of the respective dimension and shape of the lesion formed by ablating tissue of heart <NUM>. The attributes of visual markers 66A, 66B and 66C, such as color, shape, and dimension, may be determined by ablation parameters applied to the tissue of heart <NUM>, such as but not limited to ablation energy, duration, contact force and temperature.

The processor <NUM> is configured to display distal end <NUM> of catheter <NUM> in map <NUM>. In the example of <FIG>, visual markers 66A, 66B and 66C are opaque and have a round shape. Therefore, visual markers 66A and 66B may obstruct the visibility of at least sections of distal end <NUM> and of tissue of heart <NUM>, but visual marker 66C is sufficiently far from and therefore does not obscure the tissue of interest and/or distal end <NUM>. Note that in order to perform electrophysiological (EP) mapping, and/or tissue ablation procedure, it is important for physician <NUM>, to have high visibility of both distal end <NUM> and the ablated tissue of heart <NUM>.

<FIG> is a schematic, pictorial illustration of anatomical map <NUM> of heart <NUM>, in accordance with another embodiment of the present invention. After inserting catheter <NUM> into the body of patient <NUM>, processor <NUM> is configured to receive position signals indicative of the current position of distal end <NUM>, e.g., in heart <NUM>. Processor <NUM> may receive the position signals from position sensor <NUM> of the magnetic position tracking system, as described in <FIG> above, or from any other suitable source.

The processor <NUM> is configured to estimate the distance between the positions of distal end <NUM> and each of the visual markers displayed on map <NUM>. The distance may be the minimal distance between the nearest edges of distal end <NUM> and the respective visual marker, or any other suitable calculated distance. In the example of <FIG>, processor <NUM> is configured to estimate a distance 80A, which is the minimal distance between distal end <NUM> and visual marker 77A. Similarly, processor <NUM> is configured to estimate a distance 80B between distal end <NUM> and visual marker 77B, and a distance 80C between distal end <NUM> and visual marker 66C.

The processor <NUM> holds a threshold distance, indicative of the allowed proximity between the visual marker and distal end <NUM>. In response to identifying that the current position of distal end <NUM> is within a predefined vicinity of the visual marker, processor <NUM> is configured to modify at least one attribute of the visual marker, so as to increase the visibility of distal end <NUM>. The attributes may comprise dimension, shape, opacity or position.

The modification in dimension, which is depicted for example in <FIG> below, may be lateral, e.g., on the surface of heart <NUM>, and/or in the depth of the tissue of heart <NUM>. The shape may be modified from round to elliptical or any other suitable shape. The change in position may be used in one or more visual markers, so as to visualize a specific tissue of heart <NUM> (e.g., ostium of pulmonary vein) or a specific element of distal end <NUM> (e.g., an ablation electrode). The change in opacity will be described in detail in the following example, and is shown in <FIG>.

For example, distances 80A and 80B are below the aforementioned threshold distance stored in processor <NUM>. In some embodiments, processor <NUM> is configured to display translucent visual markers 77A and 77B, instead of opaque visual markers 66A and 66B, and thereby, to improve the visibility of distal end <NUM> and the tissue of heart <NUM>. In an embodiment, visual markers 66A and 77A have substantially similar position, size and shape, but different level of transparency, which allows the improved visibility of distal end <NUM> and the tissue of heart <NUM>, which are within the vicinity of visual marker 77A.

Note that distance 80C is larger than the threshold distance, in other words distal end <NUM> is not within the predefined vicinity of visual marker 66C. In this embodiment, processor <NUM> is configured to continue displaying opaque visual marker 66C in map <NUM>.

Moreover, during the ablation procedure, physician <NUM> may move distal end <NUM> away from visual markers 77A and 77B. In some embodiments, upon identifying that the current position of distal end <NUM> is no longer within the predefined vicinity of visual markers 77A and 77B, processor <NUM> is configured to re-display at least one of opaque visual markers 66A and 66B instead of translucent visual markers 77A and 77B.

<FIG> is a schematic, pictorial illustration of anatomical map <NUM> of heart <NUM>, in accordance with an alternative embodiment of the present invention. In some embodiments, instead of displaying visual markers 66A and 66B that obstruct the visibility of distal end <NUM>, as shown in <FIG> above, processor <NUM> is configured to display at the same respective positions, visual markers 88A and 88B.

As described for visual markers 77A and 77B in <FIG> above, in the example of <FIG>, visual markers 88A and 88B may be based on visual markers 66A and 66B with a modification of one or more attributes.

In some embodiments, visual marker 88A may have a round shape, similar to visual marker 66A, but a smaller diameter therefrom. By reducing the diameter of the visual marker, a minimal distance 90A between the edges of distal end <NUM> and visual marker 88A, is larger than the predefined threshold described in <FIG> above. In this configuration, distal end <NUM> is not within the predefined vicinity of visual marker 88A, which increases the visibility of at least one of the map of heart <NUM> and distal end <NUM>, relative to visual marker 66A. In some embodiments, processor <NUM> is configured to estimate the distance between a center of gravity (COG) 89A and the nearest edge of distal end <NUM>, and based on the estimated distance, to adjust the diameter of visual marker 88A, so as to have distance 90A equal to or larger than the predefined threshold distance stored in processor <NUM>.

In some embodiments, processor <NUM> is configured to display visual marker 88B on map <NUM>, by setting a COG 89B and the diameter of visual marker 88B so that a minimal distance 90B, between distal end <NUM> and visual marker 88B, is larger than the predefined threshold distance stored in processor <NUM>.

As described in <FIG> above, visual marker 66C is sufficiently far from distal end <NUM> and therefore processor <NUM> may not display another visual marker instead of visual marker 66C.

In the exemplary configuration shown in <FIG>, visual markers 88A, 88B and 66C have a round shape but different respective diameters so as to increase the visibility of at least one of map <NUM> and distal end <NUM>, relative to visual markers 66A and 66B. In other embodiments, processor <NUM> is configured to modify the penetration depth of the displayed visual marker in the tissue of heart <NUM>. The change in depth may improve the aforementioned visibility when physician <NUM> may rotate map <NUM> so as to view the tissue of heart <NUM> from a different perspective. In such embodiments, processor <NUM> is configured to set a symmetrically round shape of the visual marker, or may form an elliptical-shape visual marker for visualizing, in a selected dimension, a specific tissue of heart <NUM> or a specific element of distal end <NUM>.

In other embodiments, processor <NUM> is configured to set a similar diameter to all visual markers overlaid on map <NUM>. For example, in the configuration of <FIG>, processor may set the diameter of visual marker 88A, also to visual markers 88B and 66C.

Additionally or alternatively, processor <NUM> is configured to modify the shape and/or opacity and/or COG of one or more of the visual markers displayed in map <NUM>. Moreover, processor <NUM> is configured to temporarily remove one or more visual markers from map <NUM>. Note that at least some of the visual markers are used in the workflow of the medical procedure, therefore, processor <NUM> may not remove or shift any visual marker that is essential for the workflow of the medical procedure.

Additionally or alternatively, processor <NUM> is configured to temporarily shift the COG of a visual marker that may come across the moving direction of distal end <NUM> across map <NUM>. Note that in case the visual marker is essential for the workflow of the medical procedure, processor <NUM> may not shift or temporarily remove the respective visual marker from map <NUM>.

In other examples useful to understand the claimed invention, the visual markers shown in <FIG>, may be indicative of any parameter other than the ablation parameters described above. For example, electro-potential sensed in tissue of heart <NUM> by electrodes mounted on distal end <NUM>, or estimated lesion size based on ablation parameters to be applied to heart <NUM>, or any other suitable parameter. In such embodiments, by modifying the display of the visual markers, processor <NUM> may assist physician <NUM> with the navigation and placement of distal end <NUM> in a densely pre-ablated tissue of heart <NUM>.

In other embodiments, processor <NUM> or any other processor connected to system <NUM>, may display the visual markers on any output device other than display <NUM>. For example, physician <NUM> may use augmented reality (AR) goggles configured to display the visual markers and/or related information overlaid on map <NUM> and/or on any suitable anatomical image of heart <NUM>. Additionally or alternatively, the display of the visual markers may be implemented using any other suitable technique.

This particular configuration of the displayed visual markers is shown in <FIG> by way of example, in order to illustrate certain problems that are addressed by embodiments of the present invention and to demonstrate the application of these embodiments in enhancing the visualization of distal end <NUM> and selected tissue of heart <NUM>. Embodiments of the present invention, however, are by no means limited to this specific sort of example configurations, and the principles described herein may similarly be applied to other sorts of user interfaces and display systems.

<FIG> is a flow chart that schematically illustrates a method for increasing visibility of heart <NUM> and distal end <NUM> of catheter <NUM> during an electrophysiological procedure, in accordance with an embodiment of the present invention.

The method begins at a first displaying step <NUM>, in which processor <NUM> displays on an output device, such as display <NUM>, map <NUM> of heart <NUM> or any other organ of patient <NUM>. In some embodiments, processor <NUM> overlays one or more visual markers, such as visual markers 66A-66C on map <NUM>.

At a position receiving step <NUM>, processor <NUM> receives, from sensor <NUM> of the magnetic position tracking system, signal indicative of the current position of distal end <NUM>, which is navigated by physician <NUM> or by any other suitable operator of system <NUM>. In some embodiments, at least some of the signals are indicative of one or more positions that fall within the boundaries of map <NUM>.

At a proximity identification step <NUM>, processor <NUM> is configured to identify one or more visual markers, such as visual markers 66A and 66B, within a predefined vicinity of distal end <NUM>. In some embodiments, processor <NUM> may hold a threshold distance or a set of criteria and/or algorithms that determine the aforementioned predefined vicinity.

At a visual marker modifying step <NUM>, processor <NUM> is configured to modify the visual appearance of at least some of the visual markers identified in step <NUM>. For example, processor <NUM> may display translucent visual markers 77A and 77B instead of opaque visual markers 66A and 66B, which may otherwise obscure at least a section of distal end <NUM> or tissue of heart <NUM> that is essential for the workflow of the medical procedure.

Note that in the context of the present invention and in the claims, the sentences "modify the visual appearance of at least some of the visual markers," "display translucent visual markers 77A and 77B instead of opaque visual markers 66A and 66B" and the claim language "displaying the second visual marker, instead of the first visual marker" refer to the same technique applied by processor <NUM> to visual markers 66A and 66B, so as to improve the visualization of distal end <NUM> and tissue of heart <NUM>, as described for example in <FIG> above.

At a second displaying step <NUM> that concludes the method, after distal end <NUM> is moved away from map <NUM>, and therefore is no longer within the predefined vicinity of the modified visual markers, processor <NUM> may redisplay the visual markers as described in step <NUM> above. In other words, when distal end <NUM> is in close proximity to one or more given visual markers, processor <NUM> is configured to modify the visual appearance (e.g., opaqueness and size) of the one or more given visual markers, as described step <NUM> above, but after distal end <NUM> is moved to a sufficiently large distance from the given visual markers, processor <NUM> may redisplay the original visual appearance of the one or more given visual markers.

Although the embodiments described herein mainly address electrophysiological (EP) mapping and cardiac ablation procedures, generally speaking, the methods and systems described herein can also be used in any other minimally invasive medical application having tissue and/or medical tool located at a region of interest, which is obstructed by visual markers. Moreover, the embodiments described herein may be used in any application having an operator navigating through any given space and attempting to perform an operation in one specific narrow region of interest. The disclosed techniques may be applied to any visual obstructions related to the region of interest.

Claim 1:
A system for improving visualization of at least a catheter in an organ of a patient, the organ comprising a heart, the system comprising:
an output device (<NUM>); and
a processor (<NUM>), which is configured to:
display, on the output device (<NUM>), a map of the organ and at least a first visual marker (66A-66C) overlaid on the map;
receive a position, falling within the map, of a distal end of the catheter (<NUM>); and
display on the map (i) the distal end of the catheter (<NUM>) in accordance with the received position, and (ii) instead of the first visual marker (66A-66C), at least a second visual marker (77A-77C, 88A-88C), which increases visibility of at least one of the map and the distal end (<NUM>), relative to the first visual marker (66A-66C), wherein the processor is configured to display the second visual marker (77A-77C, 88A-88C) instead of the first visual marker (66A-66C), in response to identifying that the position of the distal end is within a predefined vicinity of the first visual marker (66A-66C), wherein the processor (<NUM>) is configured to produce the second visual marker (77A-77C, 88A-88C) by modifying at least one attribute of the first visual marker (66A-66C), wherein the at least one attribute comprises at least one of dimension, shape, opacity or position, and wherein the first and second visual markers are indicative of one or more parameters of ablation applied to tissue of the heart.