Medical devices and computer products used to monitor medical procedures

Abstract

The present invention relates to visualization of the motion trajectory of a catheter, and provides methods, devices and computer software products for implementing embodiments of the present invention, which include applying energy to a probe in contact with tissue in a body cavity to ablate the tissue. While applying energy, a signal from a position sensor in the probe is received, which indicates the position of the probe in the cavity. The signal is processed to obtain a 3D position coordinate point corresponding to the position of the probe at a time sequence during the application of energy. While applying energy, a 3D representation of the body cavity is rendered to a display, and a visual indication is superimposed on the 3D representation, which corresponds to the 3D position coordinate point at the time sequence. Finally, a linear trajectory connecting the coordinate points according to the sequence is superimposed on the 3D representation.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the benefit of U.S. Provisional Patent Application No. 62 / 828,925, filed April 3, 2019, which is incorporated herein by reference. Technical Field

[0003] The present invention relates generally to medical imaging and, more particularly, to generating and presenting a three-dimensional representation of a body lumen that tracks the position of a therapeutic catheter during an ablation procedure. Background Art

[0004] Some medical procedures, such as ablating 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 provide 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.

[0005] US Patent Application 2012 / 0209260 to Lambert et al. describes a method for predicting atrial wall electrical reconnection based on contact forces measured during RF ablation. The method includes presenting a trace showing the order in which lesions are formed during ablation.

[0006] U.S. Patent Application 2013 / 0281839 to Yan et al. describes a method for visualizing a catheter during a three-dimensional ultrasound procedure. The method includes using a geometric constraint as shown that reduces a six-degree-of-freedom ("DOF") catheter tracking problem [x, y, z, a, b, c] (where xyz is a translation and a, b, and c are rotations) to a four-DOF problem about [r, a, b, c] (where r is a translation along a trace associated with the catheter tip).

[0007] U.S. Patent Application 2010 / 0256558 to Olson et al. describes a robotic system for manipulating a catheter. The system includes a user interface that enables a user to select a target point that can be used to identify an ablation point for intended or completed therapy delivery, a reference point for semi-automatic step-wise catheter movement, an end point for fully automated movement, or a relative marker or virtual electrophysiological sensor that may not have any effect on relative movement.

[0008] U.S. Patent Application 2008 / 0255505 to Carlson et al. describes a user interface for controlling a robotic catheter system. The user interface presents to an operator a catheter in or relative to a three-dimensional (3D) space, such as a body cavity or organ, e.g., a chamber of a patient's heart. The operator can use a mouse to click on a point in the body cavity, and the user interface projects a trajectory that can be used to guide the robotic catheter into the 3D space. Summary of the invention

[0009] According to an embodiment of the present invention, a method for monitoring a medical procedure is provided, comprising: applying energy to a probe in contact with tissue in a cavity within a living subject so as to ablate the tissue; while applying the energy, receiving, by a processor, a signal from a position sensor in the probe indicating the position of the probe in the cavity; processing the signal to obtain three-dimensional (3D) position coordinate points corresponding to the position of the probe at a time series during the application of energy; and while applying the energy, rendering a 3D representation of the body cavity to a display, and superimposing on the 3D representation visual indications of the 3D position coordinate points corresponding to the time series, together with a linear trajectory connecting the coordinate points according to the sequence.

[0010] In one embodiment, the cavity comprises a chamber of the heart.

[0011] In some embodiments, the method further includes rendering a bounding sphere having a surface that encloses the visual indication.

[0012] In a first embodiment, the bounding sphere comprises a minimum bounding sphere.

[0013] In a second embodiment, the method further comprises calculating a weighted average of the 3D position coordinate points, and rendering the bounding sphere comprises centering the bounding sphere at a graphical location in the 3D representation corresponding to the weighted average of the 3D position coordinate points.

[0014] In a third embodiment, the method further includes counting a corresponding number of instances of each of the 3D position coordinate points during the time series, and rendering a bounding sphere includes centering the bounding sphere at a certain graphical location in the 3D representation corresponding to the 3D position point having the highest number of instances.

[0015] In another embodiment, the visual indication and visual track comprises a continuous line that traverses the graphical locations in the 3D representation corresponding to the sequence of coordinate points.

[0016] In further embodiments, the visual track includes a line segment connecting each consecutive pair of visual indications.

[0017] In yet another embodiment, the method further includes counting a corresponding number of instances of each of the 3D position coordinate points during the time series, and superimposing each given visual indication includes rendering the given visual indication using a color based on the corresponding number of instances of the given visual indication.

[0018] In a supplementary embodiment, the method further includes specifying a threshold number, and wherein upon detecting that the number of 3D position coordinate points exceeds the threshold number, superimposing the visual indication includes rendering a visual indication corresponding to the threshold number of latest 3D coordinate points to the display.

[0019] In another embodiment, the method further comprises specifying a threshold time period, and wherein when the time series exceeds the threshold time period, superimposing the visual indication comprises rendering a visual indication corresponding to the 3D coordinate point during the most recent threshold time period to the display.

[0020] According to one embodiment of the present invention, a medical device for monitoring medical procedures is also provided, which includes: a probe; an ablation module, which is configured to apply energy to the probe in contact with tissue in a cavity in a living subject so as to ablate the tissue; a display; and a processor, which is configured to receive a signal from a position sensor in the probe while the ablation module applies energy, the signal indicating the position of the probe in the cavity, process the signal to obtain three-dimensional (3D) position coordinate points corresponding to the position of the probe at a time series during the application of energy, and render a 3D representation of the body cavity to the display while the ablation module applies energy, and superimpose visual indications of the 3D position coordinate points corresponding to the time series on the 3D representation, together with a linear trajectory connecting the coordinate points according to the sequence.

[0021] According to one embodiment of the present invention, there is further provided a computer software product operating in conjunction with an ablation module, the ablation module being configured to apply energy to a probe in contact with tissue in a cavity in a living subject so as to ablate the tissue, the product comprising a non-transitory computer-readable medium storing program instructions, the instructions, when read by a computer, causing the computer to receive a signal from a position sensor in the probe while the ablation module applies energy, the signal indicating the position of the probe in the cavity, process the signal to obtain three-dimensional (3D) position coordinate points corresponding to the position of the probe at a time series during the application of energy, and render a 3D representation of the body cavity to a display while the ablation module applies energy, and superimpose on the 3D representation visual indications of the 3D position coordinate points corresponding to the time series, together with a linear trajectory connecting the coordinate points according to the sequence.

[0022] According to one embodiment of the present invention, a method for monitoring medical procedures is also provided, comprising: receiving, by a processor, a signal from a position sensor in a probe, the probe being in contact with tissue in a cavity within a living subject, the signal indicating the position of the probe in the cavity; processing the signal to obtain three-dimensional (3D) position coordinate points corresponding to the position of the probe at a time series; and, while the probe is in contact with the tissue, rendering a 3D representation of the body cavity to a display, superimposing on the 3D representation visual indications corresponding to the 3D position coordinate points at a time series, together with linear trajectories connecting the coordinate points according to the sequence; and rendering to the display a bounding sphere having a surface enclosing multiple visual indications.

[0023] In some embodiments, the bounding sphere comprises a minimum bounding sphere.

[0024] In one embodiment, the method also includes calculating a weighted average of the 3D position coordinate points, and rendering the bounding sphere includes centering the bounding sphere at a graphical location in the 3D representation corresponding to the weighted average of the 3D position coordinate points.

[0025] In another embodiment, the method further includes counting a corresponding number of instances of each of the 3D position coordinate points during the time series, and rendering the bounding sphere includes centering the bounding sphere at a certain graphical location in the 3D representation corresponding to the 3D position point having the highest number of instances.

[0026] According to one embodiment of the present invention, a medical device for monitoring medical procedures is also provided, which includes a probe, a display and a processor, the processor being configured to receive a signal from a position sensor in the probe, the probe being in contact with tissue in a cavity in a living subject, the signal indicating the position of the probe in the cavity; processing the signal to obtain three-dimensional (3D) position coordinate points corresponding to the position of the probe at a time series; and while the probe is in contact with the tissue, rendering a 3D representation of the body cavity to a display, superimposing visual indications of the 3D position coordinate points corresponding to the time series, together with linear trajectories connecting the coordinate points according to the sequence on the 3D representation; and rendering a bounding sphere having a surface enclosing multiple visual indications to the display.

[0027] According to one embodiment of the present invention, there is further provided a computer software product that operates in conjunction with a probe, the probe being in contact with tissue in a cavity within a living subject, the product comprising a non-transitory computer-readable medium storing program instructions, the instructions, when read by a computer, causing the computer to receive a signal from a position sensor in the probe indicating the position of the probe in the cavity, process the signal to obtain three-dimensional (3D) position coordinate points corresponding to the position of the probe at a time series, and render a 3D representation of the body cavity to a display while the probe is in contact with the tissue, superimposing on the 3D representation visual indications of the 3D position coordinate points corresponding to the time series, together with linear trajectories connecting the coordinate points according to the sequence, and rendering to the display a bounding sphere having a surface enclosing a plurality of visual indications. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present disclosure is herein described, by way of example only, with reference to the accompanying drawings, in which:

[0029] Figure 1 is a schematic illustration of a medical system according to an exemplary embodiment of the present invention, the medical system comprising a console and a medical probe having a treatment electrode attached to a distal end thereof;

[0030] Figure 2 A flowchart schematically illustrates a method for presenting a three-dimensional (3D) representation of tracking the motion of a therapy electrode during a medical procedure according to an exemplary embodiment of the present invention;

[0031] Figure 3 is a schematic illustration of a distal end of a medical probe according to an exemplary embodiment of the present invention within a cardiac cavity; and

[0032] Figure 4A and Figure 4B is a schematic illustration of a 3D representation of an exemplary embodiment according to the present invention; DETAILED DESCRIPTION

[0033] When a medical probe including a treatment electrode is used to treat tissue in a body cavity, it may be difficult to maintain stability of the treatment electrode. For example, when an ablation catheter is used to ablate a specific area of ​​intracardiac tissue during a cardiac ablation procedure, the movement of the heart may make it difficult to maintain the ablation catheter stable while the heart moves (e.g., due to motion caused by the cardiac cycle). This may be particularly true during high power ablations of short duration. Additionally or alternatively, insufficient force applied by the distal end of the ablation catheter to the intracardiac tissue may cause the distal end to slip during the procedure.

[0034] Exemplary embodiments of the present invention provide a system and methods for monitoring a medical procedure (e.g., cardiac ablation) by tracking the movement of a medical probe (e.g., an ablation catheter) during the procedure. As described below, energy is applied to a probe in contact with tissue in a cavity in a living subject to ablate the tissue, and while applying energy, a processor receives a signal from a position sensor in the probe indicating the position of the probe in the cavity. The signal is processed to obtain a three-dimensional (3D) position coordinate point corresponding to the position of the probe at a time sequence during the application of energy. Finally, while applying energy, a 3D representation of the body cavity is rendered to a display, and a visual indication of the 3D position coordinate points corresponding to the time sequence is superimposed on the 3D representation, together with a linear trajectory connecting the coordinate points according to the sequence.

[0035] By providing a linear trajectory during a procedure, a system implementing an exemplary embodiment of the present invention can provide medical professionals with valuable real-time feedback regarding the effectiveness of the medical procedure being performed, as the length of the linear trajectory is directly proportional to the amount of movement of the probe during the procedure.

[0036] System Description

[0037] Figure 1 FIG. 2 is a schematic illustration of a medical system 20 according to an exemplary embodiment of the present invention, the system including a medical probe 22 and a console 24. The medical system 20 may be based on, for example, a medical system manufactured by Biosense Webster Inc. (33 Technology Drive, Irvine, CA 92618 USA). In the exemplary embodiment described below, the medical probe 22 comprises an intracardiac catheter that can be used to perform diagnostic or therapeutic treatments, such as for ablating tissue in the heart 26 of a patient 28. Alternatively, the medical probe 22 can be used mutatis mutandis for other therapeutic and / or diagnostic purposes in the heart or other body organs.

[0038] Probe 22 includes an insertion tube 30 and a handle 32 coupled to the proximal end of the insertion tube. By manipulating handle 32, a medical professional 34 can insert probe 22 into a body cavity of a patient 28. For example, a medical professional 34 can insert probe 22 through the vascular system of patient 28 so that a distal end 36 of probe 22 enters a chamber of heart 26 and engages intracardiac tissue at one or more desired locations.

[0039] Console 24 is connected by cables 38 to body surface electrodes, which typically include adhesive skin patches 40 that are attached to patient 28. Figure 1 In the illustrated configuration, the system 20 uses impedance-based position sensing to determine the position of the distal end 36 .

[0040] To implement impedance-based position sensing, the console 24 includes a processor 42 that, in conjunction with a current tracking module 44, determines the position coordinates of the distal end 36 within the heart 26 based on impedance and / or current measured between the adhesive skin patch 40 and a position electrode 46 including an electrode attached to the distal end 36.

[0041] As described above, in conjunction with current tracking module 44, processor 42 may determine the position coordinates of distal tip 36 within heart 26 based on the impedance and / or current measured between adhesive skin patch 40 and position electrode 46. This determination is typically made after a calibration process has been performed that correlates the impedance or current to a known position of the distal tip.

[0042] The processor 42 may include real-time noise reduction circuitry 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 below. The processor uses the circuitry 48 and circuitry 50, as well as the circuitry described herein. Figure 1 The functions of the modules in order to execute one or more algorithms.

[0043] Figure 1 The medical system shown uses an impedance-based position sensor that includes an adhesive skin patch 40 and an electrode 46 to measure the position of the distal end 36, but other position tracking techniques (e.g., techniques using magnetic-based sensors) may be used. Impedance-based position tracking techniques are described, for example, in U.S. Patents 5,983,126, 6,456,864, and 5,944,022, the disclosures of which are incorporated herein by reference. Magnetic position tracking techniques using position sensors that include magnetic field sensors are described, for example, in U.S. Patents 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 method of position sensing described above is described in the above The invention is implemented in the system and is described in detail in the patent cited above.

[0044] The console 24 also includes an input / output (I / O) communication interface 52 that enables the console to transmit signals from and / or to the position electrodes 46 and the adhesive skin patch 40. Based on the signals received from the position electrodes 46 and the adhesive skin patch 40, the processor 42 can generate a map 54 showing the position of the distal end 36 in the patient's body. During a procedure, the processor 42 can present the map 54 to the medical professional 34 on a display 56 and store data representing the map in a memory 58. The memory 58 can include any suitable volatile memory and / or non-volatile memory, such as a random access memory, a solid state disk, or a hard drive.

[0045] In some exemplary embodiments, medical professional 34 may manipulate map 54 using one or more input devices 60. In alternative exemplary embodiments, display 56 may include a touch screen that may be configured to accept input from medical professional 34 in addition to presenting map 54.

[0046] exist Figure 1 In the illustrated configuration, the probe 22 includes a treatment electrode 62, which may include an ablation electrode, and the console 24 includes an ablation module 64. In some exemplary embodiments, the treatment electrode 62 is attached to the 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., radiofrequency energy) delivered to the ablation electrode 62. In some exemplary embodiments, the treatment electrode 62 may be configured to apply a signal to tissue in the heart 26 and / or measure a certain physiological property (e.g., local surface potential) at a certain location in the heart.

[0047] Although Figure 1 The configuration in shows probe 22 including position electrode 46 and treatment electrode 62, but configurations in which a single electrode (e.g., electrode 62) is used for both position sensing and ablation are considered to be within the spirit and scope of the present invention.

[0048] While medical professional 34 performs a medical procedure within a body cavity (e.g., heart 26) of patient 28 using probe 22, processor 42 may store the position of therapy electrode 62 relative to graphical data 68 in memory 58. In an exemplary embodiment of the present invention, processor 42 uses graphical data 68 to generate 3D representation 70 and presents the 3D representation on display 56 during the medical procedure, as described below with reference to FIG. Figure 2 and as described in the description of FIG. 4 .

[0049] As mentioned above, Figure 1Impedance-based position sensing is used to determine the position and orientation of the distal end 36. In some exemplary embodiments, the position and orientation may include position coordinates in a three-dimensional coordinate system including an X-axis, a Y-axis, and a Z-axis.

[0050] Position tracking and trajectory visualization

[0051] According to an exemplary embodiment of the present invention, Figure 2 is a flow chart of an algorithm schematically illustrating a method for generating and presenting a 3D representation 70 that tracks the movement of a therapy electrode 62 during a medical procedure, and Figure 3 is a schematic illustration of distal end 36 within a chamber of heart 26 during a medical procedure.

[0052] Figure 4A and Figure 4B (collectively referred to as FIG. 4 ) is a schematic illustration of a 3D representation 70 according to an exemplary embodiment of the present invention. In some exemplary embodiments, as Figure 4A As shown, 3D representation 70 includes a plurality of visual indications 120 corresponding to respective probe positions of therapy electrodes 62 during the medical procedure.

[0053] In a designation step 80, processor 42 selects a display threshold. As described below, processor 42 renders a 3D representation 70 representing the position of therapy electrode 62 during the medical procedure to display 56. To select the display threshold, processor 42 may retrieve the display threshold from memory 58 or receive a signal from one or more input devices 60 indicating the display threshold.

[0054] In one exemplary embodiment, the display threshold may include a specific number of positions (e.g., 8, 10, or 12). In this exemplary embodiment, processor 42 may present 3D representation 70 that includes the specific number of the most recent positions of therapy electrode 62 during the medical procedure. In another exemplary embodiment, the display threshold may include a specified time period (e.g., 4, 6, or 8 seconds). In this exemplary embodiment, processor 42 may present 3D representation 70 that presents the position of therapy electrode 62 during the medical procedure within the most recent specified time period.

[0055] In a first rendering step 82, the processor 42 renders the 3D representation 70 to the display 56, and in an identification step 84, the medical professional 34 identifies the region of the intracardiac tissue 110 for treatment on the map ( Figure 3 ). In some exemplary embodiments, 3D representation 70 includes a 3D representation of a given body cavity (eg, heart 26) within patient 28 and may be based on a previously acquired 3D image of the given body cavity.

[0056] In 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) the identified region of the intracardiac tissue 110, and in a treatment step 88, the medical professional 34 begins a medical procedure. As described above, examples of medical procedures that can be performed using exemplary embodiments of the present invention include, but are not limited to, delivering ablation energy to the intracardiac tissue 110, or measuring certain physiological properties (e.g., local surface potential) in the intracardiac tissue. In order to deliver ablation energy to the intracardiac tissue 110, the ablation module 64 applies energy to the treatment electrode 62 in contact with the intracardiac tissue.

[0057] Although the steps in the flowchart describe treating intracardiac tissue 110 in heart 26, treating any tissue in any body cavity in patient 28 is deemed to be within the spirit and scope of the present invention.

[0058] In a receiving step 90, the processor 42 receives a position signal from the adhesive skin patch 40 indicating a given probe position of the electrode 46 in the heart 26, and in step 92, the processor processes the received signal to obtain a 3D position coordinate point (i.e., in a 3D coordinate system) of the treatment electrode 62 corresponding to the indicated position.

[0059] In first comparison step 94, if the display threshold has not been reached, processor 42 superimposes visual indications 120 of probe positions corresponding to the therapy electrodes in a given body cavity on 3D representation 70 in superimposition step 96. As described above, the display threshold may include a particular number of positions or a particular time period.

[0060] In a second decision step 98, if the 3D position coordinates obtained in step 92 are the first 3D position coordinates obtained during the medical procedure (i.e., the position coordinates started in step 90), the method continues from step 90. However, if the obtained 3D position coordinates are not the first obtained position coordinates, then in a second rendering step 100, the processor 42 renders a linear track to the display 56 that connects the superimposed visual indication 120 with the most recent previous visual indication that the processor 42 superimposed on the 3D representation 70.

[0061] exist Figure 4A In the example shown, the linear trajectory includes a sequence of line segments 124 that connect consecutive pairs of visual indications 120 at respective 3D representation locations 122 on the 3D representation 70 that correspond to probe positions of the therapy electrode 62 during the procedure. For example, if the 3D representation 70 includes a sequence of first, second, third, and fourth visual indications 120, the consecutive pairs of visual indications include the first and second visual indications, the second and third visual indications, and the third and fourth visual indications.

[0062] exist Figure 4B In the example shown, the linear trajectory includes a single continuous line that traverses the graphical locations 122 of the 3D representation 70 corresponding to the probe positions of the therapy electrode 62 during the procedure.

[0063] In a third rendering step 102, processor 42 renders to display 56 a bounding sphere 126 including a surface 128 that encloses the currently rendered visual indication 120. In an exemplary embodiment, bounding sphere 126 may include a minimum bounding sphere, which may be defined as a bounding sphere with the smallest radius among all possible bounding spheres 126.

[0064] In one exemplary embodiment, processor 42 may calculate center 130 of sphere 126 as a given graphical location 122 on 3D representation 70 that corresponds to the probe location most visited by therapy electrode 62 during a procedure. In some exemplary embodiments, processor 42 may identify the probe location most visited by therapy electrode 62 during a procedure by counting a corresponding number of instances of each of the 3D location coordinate points during the medical procedure and identifying the given probe location having the highest number of instances.

[0065] In another exemplary embodiment, the processor 42 may calculate the center 130 of the sphere 126 to be a given graphical position 122 on the 3D representation 70 corresponding to a given position by calculating a weighted average (i.e., based on position and time) of the probe positions of the treatment electrode 62 during the procedure and centering the sphere at the graphical position corresponding to the calculated weighted average.

[0066] In further exemplary embodiments, processor 42 may count the corresponding number of instances of each probe position during a medical procedure and present each given visual indication 120 in a color corresponding to the number of times the therapy electrode was positioned at the probe position corresponding to the given visual indication. For example:

[0067] • If the therapy electrode is positioned at a given location for less than one second, processor 42 may render a given indication 120 yellow.

[0068] • If the therapy electrode is positioned at a given location for between one second and two seconds, processor 42 may render a given indication 120 green.

[0069] • If the therapy electrode is positioned at a given location for more than two seconds, processor 42 may render a given indication 120 red.

[0070] In a third comparison step 104 , if medical professional 34 has completed the medical procedure (ie, using therapy electrode 62 ), the method ends. However, if the medical procedure is not completed, the method continues from step 90 .

[0071] Returning to step 94 , if the display threshold has been reached, then in a removal step 106 , the processor 42 removes the oldest visual indication from the 3D representation 70 on the display 56 , and the method continues from step 96 .

[0072] In a first embodiment, if the display threshold includes eight positions, when the processor 42 obtains a ninth 3D position coordinate point during the procedure, the processor detects that the display threshold has been reached, and removes the visual indication corresponding to the first position coordinate point obtained during the procedure from the 3D representation 70, and adds a new visual indication 120 corresponding to the ninth position coordinate point obtained during the procedure to the 3D representation.

[0073] In a second embodiment, if the display threshold includes ten seconds, when the processor 42 obtains a position coordinate point during the eleventh second of the procedure, the processor detects that the display threshold has been reached, and removes the visual indication corresponding to the position coordinate point obtained during the first second of the procedure from the 3D representation 70, and adds a new visual indication 120 corresponding to the position coordinate point obtained during the eleventh second of the procedure to the 3D representation.

[0074] As steps 90-106 are repeated during a medical procedure, processor 42 receives position signals at a temporal sequence during the procedure, and processor 42 renders line segments in 3D representation 70 representing a linear trajectory corresponding to the probe position according to the sequence. As described above, the linear trajectory may include line segments 124 or a continuous line.

[0075] While the steps provided above describe capturing position data and presenting a 3D representation 70 in real time during a medical procedure, it is considered within the spirit and scope of the present invention to generate and present a 3D representation 70 using the graphical data 68 at a later time. For example, before completing a medical procedure, the medical professional 34 may review the procedure by causing the console to present a sequence of five-second "windows" (i.e., time periods) of 3D representations 70. Thus, if the medical procedure includes a 30-second ablation, the processor 42 may present a sequence of six 3D representations 70 that track the position of the electrode 62 during each five-second period.

[0076] It should be understood that the above embodiments are cited by way of example, and the present invention is not limited to what is specifically shown and described above. On the contrary, the scope of the present invention includes combinations and sub-combinations of the various features described above, as well as variations and modifications thereof, which should occur to those skilled in the art when reading the above description, and which are not disclosed in the prior art.

Claims

1. A medical device for monitoring a medical procedure, comprising: Probe; an ablation module configured to apply energy to the probe in contact with tissue in a cavity within a living subject so as to ablate the tissue; monitor; as well as A processor configured to: receiving a signal from a position sensor in the probe while the ablation module applies the energy, the signal indicating the position of the probe in the cavity; processing the signal to obtain three-dimensional (3D) position coordinate points corresponding to the position of the probe at a time sequence during application of the energy, and While the ablation module applies the energy, a 3D representation of the cavity is rendered to the display, and visual indications of the 3D position coordinate points corresponding to the time sequence are superimposed on the 3D representation, along with a linear trajectory connecting the coordinate points according to the sequence.

2. The medical device of claim 1, wherein the cavity comprises a chamber of the heart. 3 . The medical device of claim 1 , wherein the processor is further configured to render a bounding sphere having a surface surrounding the visual indication. The medical device of claim 3 , wherein the bounding sphere comprises a minimum bounding sphere.

5. The medical device of claim 3 , wherein the processor is further configured to calculate a weighted average of the 3D position coordinate points, and wherein the processor is configured to render the bounding sphere by centering the bounding sphere at a graphical position in the 3D representation corresponding to the weighted average of the 3D position coordinate points.

6. The medical device of claim 3 , wherein the processor is further configured to count a corresponding number of instances of each of the 3D position coordinate points during the time series, and wherein the processor is configured to render the bounding sphere by centering the bounding sphere at a graphical location in the 3D representation corresponding to the 3D position coordinate point having the highest number of instances.

7. The medical device of claim 1, wherein the visual indication and linear trajectory comprises a continuous line that traverses graphical locations on the 3D representation corresponding to the sequence of coordinate points.

8. The medical device of claim 1, wherein the linear track comprises a line segment connecting each consecutive pair of the visual indications.

9. The medical device of claim 1 , wherein the processor is further configured to count a corresponding number of instances of each of the 3D position coordinate points during the time series, and wherein the processor is configured to superimpose each given visual indication by rendering the given visual indication using a color based on the corresponding number of instances of the given visual indication.

10. The medical device of claim 1 , wherein the processor is further configured to specify a threshold number, and wherein upon detecting that the number of the 3D position coordinate points exceeds the threshold number, the processor is configured to superimpose the visual indication by rendering the visual indication corresponding to the threshold number of the latest 3D position coordinate points on the display.

11. The medical device of claim 1 , wherein the processor is further configured to specify a threshold time period, and wherein when the time series exceeds the threshold time period, the processor is configured to superimpose the visual indication by rendering the visual indication corresponding to the 3D position coordinate point during the latest threshold time period on the display.

12. A computer software product for monitoring a medical procedure, the computer software product operating in conjunction with an ablation module configured to apply energy to a probe in contact with tissue in a cavity in a living subject so as to ablate the tissue, the product comprising a non-transitory computer readable medium having program instructions stored therein, the instructions, when read by a computer, causing the computer to: receiving a signal from a position sensor in the probe while the ablation module applies the energy, the signal indicating the position of the probe in the cavity; processing the signal to obtain three-dimensional (3D) position coordinate points corresponding to the position of the probe at a time sequence during application of the energy; as well as While the ablation module applies the energy, a 3D representation of the cavity is rendered to a display, and visual indications of the 3D position coordinate points corresponding to the time sequence are superimposed on the 3D representation, along with a linear trajectory connecting the coordinate points according to the sequence.

13. A medical device for monitoring a medical procedure, comprising: Probe; monitor; as well as A processor configured to: receiving a signal from a position sensor in a probe in contact with tissue in a cavity in a living subject, the signal indicating a position of the probe in the cavity; processing the signal to obtain three-dimensional (3D) position coordinate points corresponding to the position of the probe at a time sequence, and While the probe is in contact with the tissue: rendering a 3D representation of the cavity to the display, superimposing on the 3D representation a visual indication corresponding to the 3D position coordinate points at the temporal sequence, together with a linear track connecting the coordinate points according to the sequence, and A bounding sphere having a surface surrounding a plurality of the visual indications is rendered to the display. The medical device of claim 13 , wherein the bounding sphere comprises a minimum bounding sphere.

15. The medical device of claim 13, wherein the processor is further configured to calculate a weighted average of the 3D position coordinate points, and wherein the processor is configured to render the bounding sphere by centering the bounding sphere at a graphical location in the 3D representation corresponding to the weighted average of the 3D position coordinate points.

16. The medical device of claim 13, wherein the processor is further configured to count a corresponding number of instances of each of the 3D position coordinate points during the time series, and wherein the processor is configured to render the bounding sphere by centering the bounding sphere at a graphical location in the 3D representation corresponding to the 3D position coordinate point having the highest number of instances.

17. A computer software product for monitoring a medical procedure, the computer software product operating in conjunction with a probe that contacts tissue in a cavity in a living subject, the product comprising a non-transitory computer readable medium having program instructions stored therein, the instructions, when read by a computer, causing the computer to: receiving a signal from a position sensor in the probe, the signal indicating a position of the probe in the cavity; processing the signal to obtain three-dimensional (3D) position coordinate points corresponding to the position of the probe at a time sequence, and while the probe is in contact with the tissue: rendering a 3D representation of the cavity to a display; superimposing on the 3D representation a visual indication of the 3D position coordinate points corresponding to the temporal sequence, together with a linear track connecting the coordinate points according to the sequence; and A bounding sphere having a surface surrounding a plurality of the visual indications is rendered to the display.

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