Catheter motion trace visualization

Abstract

To monitor a medical procedure.SOLUTION: Methods, apparatus and computer software products implement embodiments of the present invention that include applying energy to a probe that is in contact with tissue in a body cavity so as to ablate the tissue. While applying the energy, signals indicative of a location of the probe in the body cavity are received from a location transducer in the probe. The signals are processed to derive 3D location coordinate points corresponding to the location of the probe at a sequence of times during which the energy was applied. While applying the energy, a 3D representation of the body cavity is displayed on a display, and visual indicators are superimposed on the 3D representation, the visual indicators corresponding to the 3D location coordinate points at the sequence of times. Finally, a linear trace connecting the coordinate points in accordance with the sequence is superimposed on the 3D representation.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 62 / 828,925, filed April 3, 2019, which is incorporated herein by reference.

[0002] FIELD OF THEINVENTION The present invention relates generally to medical imaging, and more particularly to generating and displaying three-dimensional representations of body cavities that track the position of a treatment catheter during an ablation procedure. [Background technology]

[0003] Some medical procedures, such as ablation of tissue in a body organ (e.g., the heart), are performed by inserting a medical probe into the organ. The medical probe includes an ablation electrode that can deliver radio frequency (RF) energy to ablate tissue in contact with the electrode to achieve a therapeutic result. In alternative configurations, the medical probe can deliver a different energy source, such as laser, ultrasound, or cryogenic cooling, to provide a therapeutic result.

[0004] U.S. Patent Application Publication No. 2012 / 0209260 to Lambert et al. describes a method for predicting electrical reconnection of the atrial wall based on contact forces measured during RF ablation, which includes displaying tracing lines that indicate the order in which lesions form during ablation.

[0005] U.S. Patent Application Publication No. 2013 / 0281839 to Yan et al. describes a method for visualizing a catheter during a three-dimensional ultrasound procedure, which involves using illustrated geometric constraints that reduce a six degree of freedom ("DOF") catheter tracking problem [x, y, z, a, b, c] (where xyz are translations and a, b, and c are rotations) to a four DOF problem [r, a, b, c] (where r is translation along a trace line associated with the catheter tip).

[0006] U.S. Patent Application No. 2010 / 0256558 to Olson et al. describes a robotic system for steering a catheter that includes a user interface that allows a user to select a target point that can be used to identify a lesion point for intended or completed therapy delivery, an intermediate point for semi-automated stepwise catheter movement, an end point for fully automated movement, or as a relative marker or virtual electrophysiology sensor that may have no effect on relative movement.

[0007] U.S. Patent Application No. 2008 / 0255505 to Carlson et al. describes a user interface for controlling a robotic catheter system. The user interface displays to an operator the catheter within or relative to a three-dimensional (3D) space of a body cavity or organ, such as a ventricle of a patient's heart. The operator can use a mouse to click on points within the body cavity, and the user interface projects a tracing line into the 3D space that can be used to guide the robotic catheter. Summary of the Invention [Means for solving the problem]

[0008] According to an embodiment of the present invention, there is provided a method of monitoring a medical procedure comprising applying energy to a probe in contact with tissue to ablate tissue within a body cavity of a living subject; receiving, by a processor, signals from a position transducer in the probe indicating a position of the probe within the body cavity while the energy is being applied; processing the signals to derive three-dimensional (3D) position coordinate points corresponding to positions of the probe in a time sequence during which the energy is applied; and displaying a 3D representation of the body cavity on a display while the energy is being applied and superimposing on the 3D representation visual indicators corresponding to the 3D position coordinate points in the time sequence together with a linear trace connecting the coordinate points according to the sequence.

[0009] In one embodiment, the body cavity includes a ventricle of the heart.

[0010] In some embodiments, the method also includes displaying a bounding sphere having a surface that encircles the visual indicator.

[0011] In a first embodiment, the bounding sphere comprises a minimum bounding sphere.

[0012] In a second embodiment, the method further includes calculating a weighted average of the 3D position coordinate points, and displaying the bounding sphere includes centering the bounding sphere at a graph position in the 3D display that corresponds to the weighted average of the 3D position coordinate points.

[0013] In a third embodiment, the method further includes counting the individual number of instances of each of the 3D position coordinate points during the time sequence, and displaying the bounding sphere includes centering the bounding sphere at a graph position in the 3D display corresponding to the 3D position point having the highest number of these instances.

[0014] In another embodiment, the visual indicator and visual trace include a solid line that intersects graph locations on the 3D display that correspond to the series of coordinate points.

[0015] In an additional embodiment, the visual trace includes a line segment connecting each successive pair of the visual indicators.

[0016] In a further embodiment, the method also includes counting a respective number of instances of each of the 3D position coordinate points during the time sequence, and overlaying each given visual indicator includes displaying the given visual indicator using a color based on the respective number of instances of the given visual indicator.

[0017] In a supplemental embodiment, the method further includes identifying a threshold number, and upon detecting that a number of the 3D position coordinate points exceed the threshold number, overlaying the visual indicator includes displaying a visual indicator on the display corresponding to the threshold number of proximate 3D coordinate points.

[0018] In another embodiment, the method further includes identifying a threshold period of time, and when the time sequence exceeds the threshold period of time, overlaying a visual indicator includes displaying on the display a visual indicator corresponding to a 3D coordinate point during the most recent threshold period of time.

[0019] According to an embodiment of the present invention, there is provided a medical device for monitoring a medical procedure, the medical device including a probe, an ablation module configured to apply energy to the probe in contact with tissue to ablate tissue in a body cavity of a living subject, a display, and a processor configured to receive signals from a position transducer in the probe indicating a position of the probe in the body cavity while the ablation module is applying energy, process the signals to derive three-dimensional (3D) position coordinate points corresponding to the position of the probe in a time sequence during which the energy is being applied, and display a 3D representation of the body cavity on the display while the ablation module is applying energy, and superimpose on the 3D representation visual indicators corresponding to the 3D position coordinate points in the time sequence together with a linear trace connecting the coordinate points according to the sequence.

[0020] According to an embodiment of the present invention, there is further provided a computer software product operated in conjunction with an ablation module configured to apply energy to a probe in contact with tissue to ablate tissue within a body cavity of a living subject, the product comprising a non-transitory computer readable medium having stored thereon program instructions which, when read by a computer, cause the computer to receive signals from a position transducer in the probe indicative of a position of the probe within the body cavity while the ablation module is applying energy, process the signals to derive three-dimensional (3D) position coordinate points corresponding to the position of the probe in a time sequence during which the energy is being applied, and display a 3D representation of the body cavity on a display while the ablation module is applying energy, and superimpose on the 3D representation visual indicators corresponding to the 3D position coordinate points in the time sequence together with a linear trace connecting the coordinate points according to the sequence.

[0021] According to an embodiment of the present invention, there is further provided a method of monitoring a medical procedure comprising receiving, by a processor, signals indicative of a position of a probe within a body cavity from a position transducer in a probe in contact with tissue within the body cavity of a living subject, processing the signals to derive three-dimensional (3D) position coordinate points corresponding to the position of the probe in a time sequence, and displaying on a display a 3D representation of the body cavity while the probe is in contact with the tissue, superimposing on the 3D representation visual indicators corresponding to the 3D position coordinate points in the time sequence along with a linear trace connecting the coordinate points in accordance with the sequence, and displaying on the display a bounding sphere having a surface that encloses the plurality of visual indicators.

[0022] In some embodiments, the bounding sphere comprises a minimum bounding sphere.

[0023] In one embodiment, the method also includes calculating a weighted average of the 3D position coordinate points, and displaying the bounding sphere includes centering the bounding sphere at a graph position in the 3D representation that corresponds to the weighted average of the 3D position coordinate points.

[0024] In another embodiment, the method further includes counting a respective number of instances of each of the 3D position coordinate points during the time sequence, and displaying the bounding sphere includes centering the bounding sphere at a graph position in the 3D display corresponding to the 3D position point having the highest number of instances.

[0025] According to an embodiment of the present invention, there is also provided a medical device for monitoring a medical procedure, the medical device including a probe, a display, and a processor configured to receive signals indicative of a position of the probe within a body cavity from a position transducer in the probe contacting tissue in the body cavity of a living subject, process the signals to derive three-dimensional (3D) position coordinate points corresponding to the position of the probe in a time sequence, and display a 3D representation of the body cavity on the display while the probe is in contact with the tissue, superimpose on the 3D representation visual indicators corresponding to the 3D position coordinate points in the time sequence together with a linear trace connecting the coordinate points according to the sequence, and display on the display a bounding sphere having a surface that encloses the plurality of visual indicators.

[0026] According to an embodiment of the present invention, there is further provided a computer software product operating in conjunction with a probe in contact with tissue within a body cavity of a living subject, the product comprising a non-transitory computer readable medium having program instructions stored thereon, the instructions, when read by a computer, causing the computer to receive signals from a position transducer in the probe indicative of a position of the probe in the body cavity, process the signals to derive three-dimensional (3D) position coordinate points corresponding to the position of the probe in a time sequence, and display a 3D representation of the body cavity on a display while the probe is in contact with the tissue, superimpose on the 3D representation visual indicators corresponding to the 3D position coordinate points in the time sequence together with a linear trace connecting the coordinate points in accordance with the sequence, and display on the display a bounding sphere having a surface that encloses the plurality of visual indicators. [Brief description of the drawings]

[0027] The present disclosure is herein described, by way of example only, with reference to the accompanying drawings. [Figure 1] 1 is a simplified schematic diagram of a medical system including a control console and a medical probe having a treatment electrode affixed to a distal end thereof, in accordance with an exemplary embodiment of the present invention. [Diagram 2] 1 is a flow diagram that diagrammatically illustrates a method for displaying a three-dimensional (3D) representation tracing the movement of treatment electrodes during a medical procedure, according to an exemplary embodiment of the invention; [Diagram 3] 1 is a schematic diagram of a distal end of a medical probe inside a heart chamber, in accordance with an exemplary embodiment of the present invention. [Figure 4A] 1 is a schematic diagram of a 3D display according to an exemplary embodiment of the present invention; [Figure 4B] 1 is a schematic diagram of a 3D display according to an exemplary embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] When using a medical probe with a treatment electrode for treating tissue in a body cavity, it may be difficult to maintain the safety of the treatment electrode. For example, during a cardiac ablation procedure, when an ablation catheter is used to ablate a specific area of ​​intracardiac tissue, the motion of the heart may make it difficult to keep the ablation catheter stable while the heart is moving (e.g., cardiac cycle). This may be especially true during high-power ablations having a short duration. Additionally or alternatively, insufficient pressure applied by the distal end of the ablation catheter to the intracardiac tissue surface may cause the distal end to slip during the procedure.

[0029] Exemplary embodiments of the present invention provide a system and method for monitoring a medical procedure (e.g., cardiac ablation) by tracing the movement of a medical probe (e.g., an ablation catheter) during the procedure. As described hereinafter, energy is applied to a probe in contact with tissue within a body cavity of a living subject to ablate the tissue, and while the energy is being applied, a processor receives signals from a position transducer in the probe indicating the position of the probe within the body cavity. The signals are processed to derive three-dimensional (3D) position coordinate points corresponding to the position of the probe in a time sequence during which the energy is being applied. Finally, while the energy is being applied, a 3D representation of the body cavity is displayed on a display, and visual indicators are superimposed on the 3D representation corresponding to the 3D position coordinate points in the time sequence along with a linear trace connecting the coordinate points according to the sequence.

[0030] By providing a linear trace during the procedure, where the length of the linear trace is directly proportional to the amount of probe movement during the procedure, a system embodying an exemplary embodiment of the present invention can provide valuable real-time feedback to a medical professional regarding the effectiveness of the medical procedure being performed.

[0031] System Description 1 is a schematic diagram of a medical system 20 comprising a medical probe 22 and a control console 24 according to an exemplary embodiment of the present invention. The medical system 20 may be based, for example, on the CARTO® system manufactured by Biosense Webster Inc., 33 Technology Drive, Irvine, CA 92618 USA. In the exemplary embodiment described hereinafter, the medical probe 22 comprises an intrapericardial catheter that can be used for diagnostic or therapeutic procedures, such as for ablating tissue in a heart 26 of a patient 28. Alternatively, the medical probe 22 may be used, mutatis mutandis, for other therapeutic and / or diagnostic purposes in the heart or other body organs.

[0032] The probe 22 includes an insertion tube 30 and a handle 32 coupled to the proximal end of the insertion tube. By manipulating the handle 32, a medical professional 34 can insert the probe 22 into a body cavity of a patient 28. For example, the medical professional 34 can insert the probe 22 through the vascular system of the patient 28 so that a distal end 36 of the probe 22 enters a ventricle of the heart 26 and engages intracardiac tissue at a desired location or locations.

[0033] The control console 24 is connected by a cable 38 to body surface electrodes, which typically comprise adhesive skin patches 40 affixed to the patient 28. In the configuration shown in Figure 1, the system 20 uses impedance-based location detection to determine the position of the distal end 36.

[0034] To perform impedance-based location detection, the control console 24 includes a processor 42 that, in conjunction with a current tracking module 44, determines position coordinates of the distal end 36 inside the heart 26 based on impedance and / or current measured between the adhesive skin patch 40 and a position electrode 46 comprising an electrode affixed to the distal end 36.

[0035] As noted above, the processor 42, in conjunction with the current tracking module 44, can determine position coordinates of the distal end 36 inside the heart 26 based on the impedance and / or current measured between the adhesive skin patch 40 and the electrodes 46. Such determination typically occurs after a calibration process has been performed that relates the impedance or current to a known location of the distal end.

[0036] The processor 42 may comprise a real-time noise reduction circuit 48, typically configured as a field programmable gate array (FPGA), followed by an analog-to-digital (A / D) signal conversion integrated circuit 50. The processor may be programmed to execute one or more algorithms disclosed herein, each of which includes the steps described herein below. The processor uses the circuitry 48 and circuitry 50 in FIG. 1 and the mechanisms of the modules described herein to execute the one or more algorithms.

[0037] The medical system shown in FIG. 1 uses an impedance-based position transducer with an adhesive skin patch 40 and electrodes 46 to measure the position of the distal end 36, although other position tracking techniques may be used (e.g., techniques using magnetic-based sensors). Impedance-based position tracking techniques are described, for example, in U.S. Patent Nos. 5,983,126, 6,456,864, and 5,944,022, the disclosures of which are incorporated herein by reference. Magnetic-based position tracking techniques using position transducers with magnetic field sensors are described, for example, in U.S. Patent Nos. 5,391,199, 5,443,489, 6,788,967, 6,690,963, 5,558,091, 6,172,499, and 6,177,792, the disclosures of which are incorporated herein by reference. The location method described hereinabove is implemented in the above-mentioned CARTO® system and is described in detail in the above-cited patents.

[0038] The control console 24 also includes an input / output (I / O) communications interface 52 that enables the control console to transmit signals from and / or to the position electrodes 46 and the adhesive skin patch 40. Based on signals received from the position electrodes 46 and the adhesive skin patch 40, the processor 42 can generate a map 54 indicative of the location of the distal end 36 within the patient's body. During the procedure, the processor 42 can present the map 54 on a display 56 to the medical professional 34 and store data representing the map in a memory 58. The memory 58 may include any suitable volatile and / or non-volatile memory, such as a random access memory, a solid state disk, or a hard disk drive.

[0039] In some embodiments, the medical professional 34 can manipulate the map 54 using one or more input devices 60. In alternative embodiments, the display 56 may include a touch screen that, in addition to presenting the map 54, may be configured to receive input from the medical professional 34.

[0040] 1, the probe 22 includes a treatment electrode 62, which may include an ablation electrode, and the control console 24 includes an ablation module 64. In some exemplary embodiments, the treatment electrode 62 is affixed to a distal tip 66 of the probe 22 and may include gold covering the distal tip. The ablation module 64 may also be configured to monitor and control ablation parameters, such as the level and duration of ablation power (e.g., radio frequency energy) delivered to the treatment electrode 62. In some exemplary embodiments, the treatment electrode 62 may be configured to apply a signal to tissue within the heart 26 and / or measure certain physiological properties (e.g., local surface potentials) at locations within the pericardium.

[0041] Although the configuration of FIG. 1 shows probe 22 with position electrode 46 and treatment electrode 62, configurations in which a single electrode (e.g., electrode 62) is used for both location and ablation are considered to be within the spirit and scope of the present invention.

[0042] While medical professional 34 uses probe 22 to perform a medical procedure within a body cavity (e.g., heart 26) of patient 28, processor 42 can store in memory 58 the positions of treatment electrodes 62 graphing data 68. In an exemplary embodiment of the invention, processor 42 uses graph data 68 to generate a 3D representation 70 and displays the 3D representation on display 56 during the medical procedure, as described in the description with reference to Figures 2 and 4 hereinbelow.

[0043] 1 uses impedance-based location finding to determine the position and orientation of the distal end 36. In some exemplary embodiments, the position and orientation can include position coordinates within a three-dimensional coordinate system 72 that includes an X-axis 74, a Y-axis 76, and a Z-axis 78.

[0044] Location tracking and trace visualization FIG. 2 is an algorithm flow diagram that generally illustrates a method for generating and displaying a 3D representation 70 that traces the movement of a treatment electrode 62 during a medical procedure, and FIG. 3 is a schematic diagram of a distal end 36 inside a ventricle of a heart 26 during a medical procedure, in accordance with an exemplary embodiment of the invention.

[0045] Figures 4A and 4B, collectively referred to as Figure 4, are schematic diagrams of a 3D display 70, in accordance with an exemplary embodiment of the present invention. In some exemplary embodiments, as shown in Figure 4A, the 3D display 70 includes a number of visual indicators 120 that correspond to individual probe positions 112 of the treatment electrodes 62 during a medical procedure.

[0046] In standard step 80, processor 42 selects a display threshold. As described herein below, processor 42 displays a 3D representation 70 on display 56 that shows the positions of treatment electrodes 62 during a medical procedure. To select the display threshold, processor 42 may retrieve the display threshold from memory 58 or may receive a signal from one or more input devices 60 that indicates the display threshold.

[0047] In one exemplary embodiment, the display threshold may include a specified number of positions (e.g., 8, 10, or 12). In this exemplary embodiment, the processor 42 may present a 3D representation 70 that includes a specified number of recent positions of the treatment electrodes 62 during the medical procedure. In another exemplary embodiment, the display threshold may include a specified time period (e.g., 4 seconds, 6 seconds, or 8 seconds). In this exemplary embodiment, the processor 42 may display a 3D representation 70 that represents the positions of the treatment electrodes 62 during the medical procedure for the most recent specified time period.

[0048] In a first display step 82, processor 42 displays 3D representation 70 on display 56, and in an identification step 84, medical professional 34 identifies an area of ​​endocardial tissue 110 on the map for treatment (FIG. 3). In some exemplary embodiments, 3D representation 70 includes a 3D representation of a given body cavity (e.g., heart 26) in patient 28 and can be based on a previously required 3D image of the given body cavity.

[0049] At a positioning step 86, the medical professional 34 manipulates the handle 32 to position the distal end so that the treatment electrode 62 engages (i.e., contacts) a particular region of the endocardial tissue 110, and at a treatment step 88, the medical professional 34 begins the medical procedure. As noted above, examples of medical procedures that may be performed using exemplary embodiments of the present invention include, but are not limited to, delivering ablation energy to the endocardial tissue 110 or measuring particular physiological properties (e.g., local surface potentials) at the endocardial tissue. To deliver ablation energy to the endocardial tissue 110, the ablation module 64 applies energy to the treatment electrode 62, which is in contact with the endocardial tissue.

[0050] Although the steps in the flow diagram describe treatment of endocardial tissue 110 in heart 26, treatment of any tissue in any body cavity in patient 28 is considered to be within the spirit and scope of the present invention.

[0051] In a receiving step 90, the processor 42 receives a position signal from the adhesive skin patch 40 indicative of a given probe position 112 of the electrode 46 within the heart 26, and in step 92 the processor processes the received signal to derive a 3D position coordinate point (i.e., in the 3D coordinate system 72) where the treatment electrode 62 corresponds to the indicated position.

[0052] If in the first comparison step 94 a display threshold is not reached, then in a superimposition step 96, processor 42 superimposes on the 3D representation 70 a visual indicator 120 corresponding to the probe location of the treatment electrode in the given body cavity. As noted above, the display threshold may include a specified number of locations or a particular time period.

[0053] In a second decision step 98, if the 3D position coordinate derived in step 92 is the first 3D position coordinate derived during the medical procedure (i.e., started at step 90), then the method continues with process 90. However, if the derived 3D position coordinate is not the first derived position coordinate, then in a second display step 100, processor 42 displays on display 56 a linear trace connecting the superimposed visual indicator 120 and the most recent visual indicator that processor 42 superimposed on the 3D representation 70.

[0054] 4A, the linear trace includes a series of line segments 124 connecting successive pairs of visual indicators 120 at respective 3D view locations 122 on the 3D view 70 corresponding to the probe locations 112 of the treatment electrodes 62 during the procedure. For example, if the series of 3D view 70 includes first, second, third and fourth visual indicators 120, the successive pairs of visual indicators include the first and second visual indicators, the second and third visual indicators, and the third and fourth visual indicators.

[0055] In the example shown in FIG. 4B, the linear trace includes a single solid line 140 that intersects the graph location 122 of the 3D display 70 that corresponds to the probe location 112 of the treatment electrode 62 during the procedure.

[0056] In a third display step 102, processor 42 displays on display 56 a bounding sphere 126 that includes a surface 128 that encircles the currently displayed visual indicator 120. In one exemplary embodiment, bounding sphere 126 may include a minimum bounding sphere, which may be defined as the bounding sphere having the smallest radius among all possible bounding spheres 126.

[0057] In one exemplary embodiment, the processor 42 can calculate the center 130 of the sphere 126 as a given graph location 122 on the 3D display 70 that corresponds to the most visited probe location 112 of the treatment electrode 62 during the procedure. In one exemplary embodiment, the processor can identify the most visited probe location 112 of the treatment electrode 62 during the procedure by counting the individual number of instances of each of the 3D position coordinate points during the medial procedure and identifying the given probe location 112 having the highest number of instances.

[0058] In another exemplary embodiment, the processor 42 can calculate the center 130 of the sphere 126 for a given graph location 122 on the 3D display 70 corresponding to the given location by calculating a weighted average (i.e., based on position and time) of the probe positions 112 of the treatment electrodes 62 during the procedure and centering the sphere at the graph location corresponding to the calculated weighted average.

[0059] In additional exemplary embodiments, the processor 42 can calculate the number of individual instances of each of the probe positions during a medical procedure and represent each of the given visual indicators 120 in a color corresponding to the amount of time the treatment electrodes were positioned at the probe position corresponding to the given visual indicator. For example: If an electrode is positioned in a given location for less than one second, the processor 42 may display a given indicator 120 in yellow. If the electrode is positioned at a given location between 1 second and 2 seconds, the processor 42 may display a given indicator 120 in green. If an electrode is positioned in a given location for more than 2 seconds, the processor 42 may display a given indicator 120 in red.

[0060] In a third comparison step 104, if the medical professional 34 has completed the medical procedure (i.e., using the treatment electrodes 62), the method ends. However, if the medical procedure is not completed, the method continues with step 90.

[0061] Returning to step 94 , if the display threshold has been reached, then in a removal step 106 processor 42 removes the oldest visual indicator from 3D representation 70 on display 56 and the method continues with step 96 .

[0062] In a first example, if the display threshold includes eight positions when processor 42 derives a ninth 3D position coordinate point during the procedure, the processor detects that the display threshold has been reached and removes from the 3D display 70 a visual indicator corresponding to the first position coordinate point derived during the procedure and adds to the 3D display a new visual indicator 120 corresponding to the ninth position coordinate point derived during the procedure.

[0063] In a second example, if the display threshold includes 10 seconds during which processor 42 derives the position coordinate point during second 11 of the procedure, the processor detects that the display threshold has been reached and removes from the 3D display 70 the new visual indicator corresponding to the position coordinate point derived during second 1 of the procedure and adds to the 3D display a new visual indicator 120 corresponding to the position coordinate point derived during second 11 of the procedure.

[0064] By repeating steps 90-106 during the medical procedure, processor 42 receives position signals in a time sequence during the procedure, and the line segments displayed by processor 42 in 3D display 70 represent linear traces according to the sequence and corresponding to probe positions 112. As noted above, the linear traces may include line segments 124 or solid lines 140.

[0065] Although the steps presented thus far herein describe capturing position data and presenting the 3D representation 70 in real time during a medical procedure, it is considered within the spirit and scope of the present invention to use the graph data 68 to generate and later display the 3D representation 70. For example, prior to completing a medical procedure, the medical professional 34 may review the procedure by having the control console display the 3D representation 70 in a series of five second "windows" (i.e., periods). Thus, if the medical procedure includes a 30 second ablation, the processor 42 may display a series of six 3D representations 70 tracing the positions of the electrodes 62 during each five second period.

[0066] It will be understood that the above-described embodiments are given by way of example, and that the present invention is not limited to what has been particularly shown and described above, but rather the scope of the present invention includes both combinations of the various features described above and sub-combinations thereof, as well as variations and modifications thereof which will occur to those skilled in the art upon reading the above description and which have not been disclosed in the prior art.

[0067] [Embodiment] (1) A method for monitoring a medical procedure, comprising: applying energy to a probe in contact with tissue to ablate the tissue within a body cavity of a living subject; receiving, by a processor, a signal from a position transducer in the probe indicative of a position of the probe within the body cavity while applying the energy; processing the signals to derive three-dimensional (3D) position coordinates corresponding to the position of the probe during the time sequence during which the energy is applied; displaying a 3D representation of the body cavity on a display while applying the energy, and superimposing on the 3D representation visual indicators corresponding to the 3D position coordinate points in the time sequence together with linear traces connecting the coordinate points in response to the sequence. A method comprising: (2) The method of embodiment 1, wherein the body cavity comprises a ventricle of the heart. (3) The method of claim 1, further comprising displaying a bounding sphere having a surface that encircles the visual indicator. (4) The method of claim 3, wherein the bounding sphere comprises a minimum bounding sphere. (5) The method of claim 3, further comprising calculating a weighted average of the 3D position coordinate points, and displaying the bounding sphere includes centering the bounding sphere at a graph position in the 3D display that corresponds to the weighted average of the 3D position coordinate points.

[0068] (6) The method of claim 3, further comprising counting a respective number of instances of each of the 3D position coordinate points during the time series, and displaying the bounding sphere includes centering the bounding sphere at a graph position in the 3D display corresponding to the 3D position point having the highest number of instances. (7) The method of embodiment 1, wherein the visual indicator and visual trace include a solid line intersecting a graph location on the 3D representation corresponding to the series of coordinate points. (8) The method of claim 1, wherein the visual trace comprises a line segment connecting each successive pair of the visual indicators. (9) The method of embodiment 1, further comprising counting a distinct number of instances of each of the 3D position coordinate points during the time sequence, and wherein overlaying each given visual indicator comprises displaying the given visual indicator using a color based on the distinct number of instances of the given visual indicator. (10) The method of embodiment 1, further comprising identifying a threshold number, and upon detecting that some of the 3D position coordinate points exceed the threshold number, overlaying the visual indicator comprises displaying on the display the visual indicator corresponding to the threshold number of nearest 3D coordinate points.

[0069] (11) The method of embodiment 1, further comprising identifying a threshold period of time, and when the time sequence exceeds the threshold period of time, overlaying the visual indicator comprises displaying on the display the visual indicator corresponding to the 3D coordinate point during the most recent threshold period of time. (12) A medical device for monitoring a medical procedure, comprising: A probe; an ablation module configured to apply energy to the probe in contact with tissue to ablate the tissue within a body cavity of a living subject; A display and 1. A processor comprising: receiving a signal from a position transducer in the probe indicative of a position of the probe in the body cavity while the ablation module is applying the energy; processing the signals to derive three-dimensional (3D) position coordinates corresponding to the position of the probe during the time sequence during which the energy is applied; and displaying a 3D representation of the body lumen on the display while the ablation module is applying the energy, and superimposing on the 3D representation, in response to the sequence, visual indicators corresponding to the 3D position coordinate points in the time sequence together with a linear trace connecting the coordinate points. Configured with a processor 23. A medical device comprising: (13) The medical device of embodiment 12, wherein the body cavity comprises a ventricle of the heart. (14) The medical device of claim 12, wherein the processor is further configured to display a bounding sphere having a surface that encircles the visual indicator. (15) The medical device of claim 14, wherein the bounding sphere comprises a minimum bounding sphere.

[0070] (16) The medical device of embodiment 14, wherein the processor is further configured to calculate a weighted average of the 3D position coordinate points, and the processor is configured to display the bounding sphere by centering the bounding sphere at a graph position in the 3D representation that corresponds to the weighted average of the 3D position coordinate points. (17) The medical device of embodiment 14, wherein the processor is further configured to count a respective number of instances of each of the 3D position coordinate points during the time sequence, and the processor is configured to display the bounding sphere by centering the bounding sphere at a graph position in the 3D representation corresponding to the 3D position point having the highest number of instances. (18) The medical device of embodiment 12, wherein the visual indicator and visual trace include a solid line intersecting a graph location on the 3D display corresponding to the series of coordinate points. (19) The medical device of embodiment 12, wherein the visual trace includes a line segment connecting each successive pair of the visual indicators. (20) The medical device of embodiment 12, wherein the processor is further configured to count a distinct number of instances of each of the 3D position coordinate points during the time sequence, and wherein the processor is configured to overlay each of the given visual indicators by displaying the given visual indicator using a color based on the distinct number of instances of the given visual indicator.

[0071] (21) The medical device of embodiment 12, wherein the processor is further configured to identify a threshold number, and upon detecting that some of the 3D position coordinate points exceed the threshold number, the processor is configured to overlay the visual indicator by displaying the visual indicator corresponding to the threshold number of proximate 3D coordinate points on the display. (22) The medical device of embodiment 12, wherein the processor is further configured to identify a threshold period of time, and when the time sequence exceeds the threshold period of time, the processor is configured to overlay the visual indicator by displaying the visual indicator corresponding to the 3D coordinate point on the display during the most recent threshold period of time. (23) A computer software product operated in conjunction with an ablation module configured to apply energy to a probe in contact with tissue to ablate tissue within a body cavity of a living subject, the product comprising a non-transitory computer readable medium having stored thereon program instructions, the instructions, when read by a computer, causing the computer to: receiving a signal from a position transducer in the probe indicative of a position of the probe within the body cavity while the ablation module is applying the energy; processing the signals to derive three-dimensional (3D) position coordinates corresponding to the position of the probe during the time sequence during which the energy is applied; and displaying a 3D representation of the body lumen on a display while the ablation module is applying the energy, and, in response to the sequence, superimposing on the 3D representation a visual indicator corresponding to the 3D position coordinate points in the time sequence together with a linear trace connecting the coordinate points. Computer software products. (24) A method for monitoring a medical procedure, comprising: receiving, by a processor, a signal from a position transducer in a probe in contact with tissue within a body cavity of a living subject, the signal being indicative of a position of the probe within the body cavity; processing the signals to derive three-dimensional (3D) position coordinates corresponding to the positions of the probe in a time sequence; While the probe is in contact with the tissue, displaying a 3D representation of the body cavity on a display; responsive to said sequence, superimposing on said 3D display a visual indicator corresponding to said 3D position coordinate points in said time sequence together with a linear trace connecting said coordinate points; displaying on the display a bounding sphere having a surface that encloses the plurality of visual indicators; A method comprising: (25) The method of claim 24, wherein the bounding sphere comprises a minimum bounding sphere.

[0072] (26) The method of claim 24, further comprising calculating a weighted average of the 3D position coordinate points, and displaying the bounding sphere includes centering the bounding sphere at a graph position in the 3D representation that corresponds to the weighted average of the 3D position coordinate points. (27) The method of claim 24, further comprising counting a respective number of instances of each of the 3D position coordinate points during the time series, and displaying the bounding sphere includes centering the bounding sphere at a graph position in the 3D display corresponding to the 3D position point having the highest number of instances. (28) A medical device for monitoring a medical procedure, comprising: A probe; A display and 1. A processor comprising: receiving a signal from a position transducer in a probe contacting tissue in a body cavity of a living subject, the signal being indicative of a position of the probe within the body cavity; processing the signals to derive three-dimensional (3D) position coordinates corresponding to the positions of the probe in a time sequence; and While the probe is in contact with the tissue, displaying a 3D representation of the body cavity on the display; responsive to said sequence, superimposing on said 3D display a visual indicator corresponding to said 3D position coordinate points in said time sequence together with a linear trace connecting said coordinate points; displaying on said display a bounding sphere having a surface that encompasses said plurality of visual indicators; Configured with a processor 23. A medical device comprising: (29) The medical device of claim 28, wherein the bounding sphere comprises a minimum bounding sphere. (30) The medical device of embodiment 28, wherein the processor is further configured to calculate a weighted average of the 3D position coordinate points, and the processor is configured to display the bounding sphere by centering the bounding sphere at a graph position in the 3D representation that corresponds to the weighted average of the 3D position coordinate points.

[0073] (31) The medical device of embodiment 28, wherein the processor is further configured to count a respective number of instances of each of the 3D position coordinate points during the time sequence, and wherein the processor is configured to display the bounding sphere by centering the bounding sphere at a graph position in the 3D representation corresponding to the 3D position point having the highest number of instances. (32) A computer software product operative in conjunction with a probe in contact with tissue within a body cavity of a living subject, the product comprising a non-transitory computer-readable medium having stored thereon program instructions, the instructions, when read by a computer, causing the computer to: receiving a signal from a position transducer in the probe indicative of a position of the probe within the body cavity; processing the signals to derive three-dimensional (3D) position coordinates corresponding to the positions of the probe in a time sequence; and While the probe is in contact with the tissue, displaying a 3D representation of the body cavity on a display; responsive to said sequence, superimposing on said 3D display a visual indicator corresponding to said 3D position coordinate points in said time sequence together with a linear trace connecting said coordinate points; displaying on said display a bounding sphere having a surface that encompasses said plurality of visual indicators; Computer software products.

Claims

1. 1. A medical device for monitoring a medical procedure, comprising: A probe; an ablation module configured to apply energy to the probe in contact with tissue to ablate the tissue within a body cavity of a living subject; A display and 1. A processor comprising: receiving a three-dimensional (3D) representation of the body cavity; receiving a signal from a position transducer in the probe indicative of a position of the probe in the body cavity to which the ablation module applied the energy; processing the signals to derive a plurality of 3D position coordinate points each corresponding to the position of the probe; displaying the 3D representation of the body cavity on the display and superimposing on the 3D representation visual indicators corresponding to the plurality of 3D position coordinate points along with linear traces connecting the plurality of 3D position coordinate points; and to display a bounding sphere having a surface surrounding said visual indicator; Configured with a processor Including, The processor, (i) further configured to calculate a weighted average of the plurality of 3D position coordinate points, and wherein the processor is configured to display the bounding sphere by centering a location in the 3D representation corresponding to the weighted average of the plurality of 3D position coordinate points at the center of the bounding sphere; or (ii) counting the number of times the energy has been applied at each of the plurality of 3D position coordinate points, the processor being configured to display the bounding sphere by centering a position in the 3D representation corresponding to the 3D position coordinate point having the highest number of times. Medical equipment.

2. The medical device of claim 1 , wherein the bounding sphere has a minimum radius required to enclose all of the visual indicators.

3. The medical device of claim 1 , wherein the visual indicator and the linear trace comprise a solid line that intersects locations on the 3D representation that correspond to the plurality of 3D position coordinate points.

4. The medical device of claim 1 , wherein the linear trace comprises a line segment connecting each successive pair of the visual indicators.

5. 2. The medical device of claim 1, wherein the processor is further configured to measure an amount of time that the ablation module applies the energy at the location of the probe, and the processor is configured to overlay each of the given visual indicators by displaying the given visual indicator using a color based on the amount of time.

6. 2. The medical device of claim 1, wherein the processor is further configured to identify a threshold for the number of visual indicators displayed, and upon detecting that the number of visual indicators displayed exceeds the threshold, the processor is configured to remove an initially displayed visual indicator from among the displayed visual indicators and overlay the visual indicators by displaying the visual indicator corresponding to the closest 3D position coordinate point on the display.

7. 2. The medical device of claim 1, wherein the processor is further configured to identify a threshold for a display time of the visual indicator, and when the display time of the visual indicator exceeds the threshold, the processor is configured to remove the visual indicator whose display time exceeds the threshold.

8. 1. A computer software product operated in conjunction with an ablation module configured to apply energy to a probe in contact with tissue to ablate tissue within a body cavity of a living subject, the product comprising a non-transitory computer readable medium having stored thereon program instructions, the instructions, when read by a computer, causing the computer to: receiving a three-dimensional (3D) representation of the body cavity; receiving a signal from a position transducer in the probe to which the ablation module applied the energy indicative of a position of the probe within the body cavity; processing the signals to derive a plurality of 3D position coordinate points each corresponding to the position of the probe; displaying the 3D representation of the body cavity on a display and superimposing on the 3D representation visual indicators corresponding to the plurality of 3D position coordinate points along with linear traces connecting the plurality of 3D position coordinate points; and displaying a bounding sphere having a surface surrounding the visual indicator; The computer further comprises: (i) displaying the bounding sphere by calculating a weighted average of the plurality of 3D position coordinate points and centering a position in the 3D representation corresponding to the weighted average of the plurality of 3D position coordinate points at the center of the bounding sphere; or (ii) counting the number of times the energy is applied at each of the plurality of 3D position coordinate points, and displaying the bounding sphere by centering the position in the 3D representation corresponding to the 3D position coordinate point having the highest number of times. Computer software products.

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