3D Heart Activity Tips

Abstract

To provide a medical system.SOLUTION: In one embodiment, a medical system includes: a catheter configured to be inserted into a chamber of a heart of a living subject, and including catheter electrodes configured to contact tissue at respective locations within the chamber of the heart; a display; and processing circuitry configured to receive signals from the catheter and, in response to the signals, sample voltage values of the signals at respective sampling times, compute respective curved three-dimensional surfaces describing electrical activity of the tissue over the catheter electrodes at respective ones of the sampling times, responsively to (a) respective positions of the respective catheter electrodes, and (b) the respective sampled voltage values indicative of electrical activity of the tissue that is sensed by the respective catheter electrodes at the respective locations at the respective sampling times, and render the respective three-dimensional surfaces to the display over time.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to medical systems and particularly, but not exclusively, to the analysis of electrical activity. [Background technology]

[0002] Electrical activity at a location in the heart can be measured by advancing a multi-electrode catheter to simultaneously measure electrical activity at multiple locations in the heart chamber. Other methods, such as the use of an external vest, can provide an indication of cardiac activity. The recording obtained from the time-varying electrical potentials measured by one or more electrodes is known as an electrogram. Electrograms can be measured by unipolar or bipolar leads and are used, for example, to determine the onset of electrical propagation at a point, known as the local activation time (LAT).

[0003] US Patent No. 5,782,773 to Kuo et al. describes a three-dimensional electrocardiogram display method for 3D presentation of multiple cardiac signals. In this method, a 3D rectangular coordinate system is defined to display the 3D presentation of the cardiac signals. Furthermore, an amplitude display scheme, preferably an amplitude-to-color mapping table, is defined to assign various quantization levels of amplitude to designated distinct colors. The 3D presentation of the cardiac signals can be generated and displayed by a graphic processing and display means. A physician can choose to view the 3D graph in various views, including oblique, cross-sectional, and top rectangular views. This allows a physician to make a diagnosis of a cardiac disease by viewing only one or two 3D presentations of the cardiac signals. A physician can thus have an overall integrated view of a rich number of cardiac signals, thereby making it easier to diagnose a patient's cardiac condition.

[0004] U.S. Patent Application Publication No. 2011 / 0021936 to Luo describes a device and method for displaying medical data for a stress test monitoring system. A computer-implemented method and apparatus for displaying human cardiac electrical impulse data for analysis includes receiving cardiac electrical impulse data generated during a cardiac stress test with multiple electrode leads adapted for placement on a patient, calculating parameters for multiple display windows based on the data, and providing a main display having the multiple display windows disposed thereon. A three-dimensional color mapping plot is displayed in one of the multiple display windows and a two-dimensional color mapping plot is displayed in another of the multiple display windows. Also, a plot of raw lead data from at least one lead is displayed in one of the multiple display windows.

[0005] U.S. Patent Application Publication No. 2012 / 0130232 to Markowitz et al. describes a volume of a patient that can be mapped by a system operable to identify and store the locations of a mapping instrument. The mapping instrument can include one or more electrodes that can sense a voltage that can be related to the three-dimensional position of the electrode at the time of sensing or measuring. Thus, a map of the volume can be determined based on sensing of the multiple points without the use of other imaging equipment. The implantable medical instrument can then be manipulated in conjunction with the mapping data.

[0006] WO 2017 / 192769 to Acutus Medical Inc. describes a localization system and method useful for acquiring and analyzing cardiac information. The localization system and method can be used, by way of example, in systems that perform cardiac mapping, diagnosis and treatment of cardiac abnormalities, as well as in retrieving, processing, and interpreting such types of information. The localization system and method uses high impedance input, improved isolation, and relatively high drive currents for pairs of electrodes that are used to establish a multi-axis coordinate system. The axes can be rotated and scaled to improve localization. Summary of the Invention [Means for solving the problem]

[0007] According to an embodiment of the present disclosure, there is provided a medical system including: a catheter configured to be inserted into a chamber of a heart of a living subject, the catheter electrodes configured to contact tissue at respective locations within the chamber of the heart; a display; and a processing circuit configured to receive a signal from the catheter; and in response to the signal, sample voltage values ​​of the signal at respective sampling times; and in response to the respective sampled voltage values ​​indicative of (a) the respective positions of the respective catheter electrodes and (b) the electrical activity of the tissue sensed by the respective catheter electrodes at the respective locations at the respective sampling times, calculate respective curved three-dimensional surfaces depicting the electrical activity of the tissue above the catheter electrodes at each of the sampling times; and render the respective three-dimensional surfaces over time on the display.

[0008] Further, in accordance with an embodiment of the present disclosure, the processing circuitry is configured to color respective regions of the respective three-dimensional surfaces in response to respective sampled voltage values.

[0009] Still further, in accordance with an embodiment of the present disclosure, the respective positions of the respective catheter electrodes are respective projection positions projected onto a plane, the processing circuitry is configured to calculate respective displacements perpendicular to the plane from the respective projection positions of the respective catheter electrodes in response to the respective sampled voltage values ​​at each of the sampling times, and the processing circuitry is configured to fit respective curved three-dimensional surfaces in response to the respective displacements perpendicular to the plane from the respective projection positions, depicting electrical activity of tissue above the catheter electrodes at each of the sampling times.

[0010] Additionally, according to an embodiment of the present disclosure, the processing circuitry is configured to color respective regions of the respective three-dimensional surfaces in response to the respective displacements.

[0011] Moreover, according to embodiments of the present disclosure, the processing circuitry is configured to sample the voltage values ​​of the signal at each sampling time at a rate of greater than 10 times per second and render each three-dimensional surface on the display over time, with a new one of the three-dimensional surfaces being displayed at least every tenth of a second, such that the rendered three-dimensional surfaces provide an animation of activation waves associated with electrical activity of the tissue above the catheter electrodes.

[0012] Further, in accordance with an embodiment of the present disclosure, the system includes an interface configured to receive user input for changing a viewing angle of the three-dimensional surface object, and the processing circuitry is configured to render the three-dimensional surface object at a different viewing angle in response to the received user input.

[0013] Still further, in accordance with an embodiment of the present disclosure, a catheter includes a shaft having a distal end and a distal tip assembly having catheter electrodes disposed thereon, the respective positions of the respective catheter electrodes being derived from a static computer model of the catheter.

[0014] Additionally, according to an embodiment of the present disclosure, the respective positions of the respective catheter electrodes are projected onto a plane perpendicular to the axis of the shaft.

[0015] Moreover, according to an embodiment of the present disclosure, the catheter includes a shaft having a distal end and a distal tip assembly having catheter electrodes disposed thereon, and the processing circuitry is configured to calculate respective positions of each of the catheter electrodes.

[0016] Furthermore, according to an embodiment of the present disclosure, the respective positions of the respective catheter electrodes are their respective projected positions projected onto a plane perpendicular to the axis of the shaft.

[0017] Also provided in accordance with another embodiment of the present disclosure is a medical method including: receiving a signal from a catheter configured to be inserted into a heart chamber of a living body and including catheter electrodes configured to contact tissue at respective locations within the heart chamber; in response to the signal, sampling voltage values ​​of the signal at respective sampling times; and in response to the respective sampled voltage values ​​indicative of (a) respective positions of the respective catheter electrodes and (b) tissue electrical activity sensed by the respective catheter electrodes at the respective locations at the respective sampling times, calculating respective curved three-dimensional surfaces depicting the electrical activity of the tissue above the catheter electrodes at each of the sampling times; and rendering the respective three-dimensional surfaces on a display over time.

[0018] Still further, in accordance with an embodiment of the present disclosure, the method includes coloring respective regions of the respective three-dimensional surfaces in response to each of the sampled voltage values.

[0019] Additionally, according to an embodiment of the present disclosure, the respective positions of each of the catheter electrodes are respective projection positions projected onto a plane, and the method further includes calculating respective displacements, perpendicular to the plane, from each of the respective projection positions of the catheter electrodes in response to each of the sampled voltage values ​​at each of the sampling times, and fitting respective curved three-dimensional surfaces, depicting the electrical activity of the tissue above the catheter electrodes at each of the sampling times, in response to each of the displacements perpendicular to the plane from each of the projection positions.

[0020] Further, in accordance with an embodiment of the present disclosure, the method includes coloring respective regions of the respective three-dimensional surfaces in response to each of the displacements.

[0021] Further, in accordance with an embodiment of the present disclosure, the method includes sampling voltage values ​​of the signal at each sampling time at a rate of greater than 10 times per second, and the rendering includes rendering each three-dimensional surface on the display over time, with a new one of the three-dimensional surface being displayed at least every tenth of a second, such that the rendered three-dimensional surface provides an animation of activation waves associated with electrical activity of tissue above the catheter electrodes.

[0022] Still further, in accordance with an embodiment of the present disclosure, the method includes receiving a user input for changing a viewing angle of the three-dimensional surface thing, and rendering the three-dimensional surface thing at a different viewing angle in response to the received user input.

[0023] Additionally, in accordance with an embodiment of the present disclosure, the catheter includes a shaft having a distal end and a distal tip assembly having catheter electrodes disposed thereon, the respective positions of the catheter electrodes being derived from a static computer model of the catheter.

[0024] Moreover, according to an embodiment of the present disclosure, the respective positions of the respective catheter electrodes are respective projection positions projected onto a plane perpendicular to the axis of the shaft.

[0025] Further, in accordance with an embodiment of the present disclosure, the catheter includes a shaft having a distal end and a distal tip assembly having catheter electrodes disposed thereon, and the method further includes calculating a respective position of each of the catheter electrodes.

[0026] Still further, according to an embodiment of the present disclosure, the respective positions of the respective catheter electrodes are respective projection positions projected onto a plane perpendicular to the axis of the shaft.

[0027] Also provided in accordance with yet another embodiment of the present disclosure is a software product including a non-transitory computer readable medium having stored thereon program instructions which, when read by a central processing unit (CPU), cause the CPU to receive signals from a catheter configured to be inserted into a heart chamber of a living body and including catheter electrodes configured to contact tissue at respective locations within the chamber of the heart, in response to the signals, sample voltage values ​​of the signals at respective sampling times, in response to the respective sampled voltage values ​​indicative of (a) respective positions of the respective catheter electrodes and (b) tissue electrical activity sensed by the respective catheter electrodes at the respective locations at the respective sampling times, calculate respective curved three-dimensional surfaces depicting the electrical activity of the tissue above the catheter electrodes at each of the sampling times, and render the respective three-dimensional surfaces on a display over time. [Brief description of the drawings]

[0028] The present invention will be understood from the following detailed description taken in conjunction with the accompanying drawings. [Figure 1] 1 is a partially pictorial, partially block diagram of a cardiac analysis system constructed and operative in accordance with an embodiment of the present invention; [Figure 2A] FIG. 2 is a schematic diagram showing the projected positions of electrodes onto a plane for use in the system of FIG. 1. [Figure 2B] FIG. 2 is a schematic diagram showing the projected positions of electrodes onto a plane for use in the system of FIG. 1. [Diagram 3] FIG. 2 is a schematic diagram of a cardiac signal sampled by the system of FIG. 1. [Figure 4A] FIG. 2 is a schematic diagram of a curved three-dimensional surface depicting electrical activity rendered by the system of FIG. 1. [Figure 4B] FIG. 2 is a schematic diagram of a curved three-dimensional surface depicting electrical activity rendered by the system of FIG. 1. [Figure 4C]FIG. 2 is a schematic diagram of a curved three-dimensional surface depicting electrical activity rendered by the system of FIG. 1. [Figure 4D] FIG. 2 is a schematic diagram of a curved three-dimensional surface depicting electrical activity rendered by the system of FIG. 1. [Figure 4E] FIG. 2 is a schematic diagram of a curved three-dimensional surface depicting electrical activity rendered by the system of FIG. 1. [Figure 4F] FIG. 2 is a schematic diagram of a curved three-dimensional surface depicting electrical activity rendered by the system of FIG. 1. [Diagram 5] 2 is a flow chart including steps in a method of operation of the system of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Overview Presenting electrical activity signals from multiple electrodes on complex multi-spline catheters (e.g., PENTARAY® catheters from Biosense Webster, Inc. (Irvine, Calif. USA), or basket catheters) or linear catheters in an intuitive manner for a physician is difficult due to the geometric distribution of the electrodes. Presenting electrical activity in a two-dimensional (2D) list, such as showing multiple intracardiac electrograms (IEGMs), does not reflect the geometry of the catheter.

[0030] Embodiments of the present invention solve the above problems by providing a three-dimensional (3D) presentation that includes respective curved three-dimensional surfaces depicting the electrical activity of the tissue above the catheter electrodes at respective sampling times.

[0031] Intracardiac (IC) signals received from the catheter electrodes are collected and sampled at different sampling times. The electrical activity of the catheter electrodes at one of the sampling times is plotted on a 3D presentation as a curved 3D surface. The 3D presentation may be defined by three axes (x, y and z) or any other suitable coordinate system. The x- and y-axes indicate the 2D positions of the catheter electrodes (e.g., by projecting the electrode positions onto a plane defined by the x- and y-axes). The z-axis indicates the voltage of the electrical activity captured by the electrodes at the sampled times. The curved 3D surface is calculated by fitting the 3D surface to data points defined by the xy-coordinates of the electrode positions of the catheter electrodes and the respective z-coordinates of the sampled voltages. The fitting of the 3D surface may be performed by interpolating (and optionally extrapolating) between the aforementioned data points. Regions of the 3D surface may optionally be colored according to the voltage levels associated with the regions.

[0032] The 3D presentation may be static (e.g., for a single sampling time) or may be dynamic (e.g., video) showing how the electrical activity travels as waves of activation on the catheter's electrodes providing the physician with a useful diagnostic tool.

[0033] In the above-described embodiments, any suitable catheter may be used, such as a multi-spline catheter (e.g., a PENTARAY® catheter or a basket catheter from Biosense Webster, Inc. (Irvine, Calif. USA)) or other multi-electrode catheter (e.g., a balloon catheter or a lasso catheter).

[0034] The catheter is inserted into a chamber of the living heart. The catheter may include a shaft having a distal end and a distal tip assembly having catheter electrodes disposed thereon. The catheter electrodes contact tissue at respective locations within the chamber of the heart. The processing circuitry receives signals from the catheter and is responsive to the signals to sample voltage values ​​of the signals at respective sampling times.

[0035] In some embodiments, the processing circuitry calculates the respective positions of each of the catheter electrodes in response to signal(s) received, for example, from a position transducer (such as a position sensor or sensors on the catheter or externally disposed sensor(s)).

[0036] In other embodiments, the position of each catheter electrode used in the calculations described below is derived from a static computer model of the catheter. For example, if the catheter used is a multi-spline catheter with deflectable splines, the positions used in the calculations described below may be based on the positions of the deflectable splines in their undeflected positions, even if the splines are actually deflected at each sampling time.

[0037] Whether the positions are calculated from the received signal(s) or derived from a static computer model or any other suitable source, the positions of the catheter electrodes are typically projected onto a plane (e.g., the x-y axes mentioned above). In some embodiments, the plane is perpendicular to the axis of the catheter shaft.

[0038] The processing circuitry calculates respective curved three-dimensional surfaces depicting the electrical activity of the tissue on the catheter electrodes at each of the sampling times. Note that any one of the three-dimensional surfaces depicts the electrical activity of a corresponding one of the sampling times, not multiple sampling times. Sampled voltages at different sampling times result in different three-dimensional surfaces. The three-dimensional surfaces are calculated in response to (a) the respective positions (e.g., two-dimensional position coordinates) of the respective catheter electrodes, and (b) the respective sampled voltage values ​​indicative of the electrical activity of the tissue sensed by the respective catheter electrodes at the respective locations (on the tissue) at the respective sampling times. For example, one three-dimensional surface is calculated in response to (a) the respective positions (e.g., two-dimensional position coordinates) of the respective catheter electrodes, and (b) the respective sampled voltage values ​​sampled at one of the respective sampling times.

[0039] In some embodiments, the processing circuitry colors respective regions of the respective three-dimensional surfaces in response to respective sampled voltage values.

[0040] In some embodiments, the processing circuitry calculates respective displacements perpendicular to the plane (e.g., along the z-axis away from the x-y axes) from the respective projected positions of the respective catheter electrodes in response to the respective sampled voltage values ​​at the respective sampling times. Each displacement provides a z-axis coordinate when a Cartesian coordinate system is used. For example, a displacement z n is calculated according to the sampled voltage sampled at time t1 of the signal sensed by electrode number n of the catheter. Electrode number n is the position coordinate x on the plane defined by the x and y axes. n , y n Thus, the data point of electrode number n in the 3D presentation at time t1 has coordinates x n , y n , z nThe processing circuitry fits respective curved three-dimensional surfaces depicting the electrical activity of the tissue above the catheter electrodes at respective sampling times in response to respective calculated displacements perpendicular to the plane from respective projection locations, e.g., according to data points representing the electrical activity of each electrode in a coordinate system. In some embodiments, the processing circuitry colors respective regions of the respective three-dimensional surfaces in response to respective displacements.

[0041] The processing circuitry is configured to render each three-dimensional surface on the display over time, in some embodiments, the processing circuitry renders each three-dimensional surface on the display over time such that a new one of the three-dimensional surfaces is displayed sufficiently frequently (e.g., at least every tenth of a second) such that the rendered three-dimensional surfaces provide an animation of activation waves associated with electrical activity of tissue above the catheter electrodes.

[0042] The user interface may receive user input to change the viewing angle of the three-dimensional surface, which may then be rendered at a different viewing angle in response to the received user input.

[0043] System Description Reference is now made to FIG. 1, which is a partial pictorial, partial block diagram of a cardiac analysis system 10 constructed and operative in accordance with an embodiment of the present invention.

[0044] Turning now to the drawings, reference is first made to FIG. 1, which is a pictorial illustration of a cardiac analysis system 10 constructed and operable in accordance with a disclosed embodiment of the present invention for calculating and evaluating electrical activity, and optionally performing an ablation procedure, on a living heart 12. The system includes a catheter 14, such as a catheter, that is percutaneously inserted through a patient's vascular system into a chamber or vascular structure of the heart 12 by an operator 16. The operator 16, typically a physician, contacts a distal tip 18 of the catheter 14 with a heart wall to acquire electrical potentials over time, for example, at an ablation target site or at multiple sample locations across the surface of one or more chambers of the heart 12. Electrical activity maps may be prepared according to methods disclosed in U.S. Pat. Nos. 6,226,542, 6,301,496, and 6,892,091. One commercially available product embodying elements of system 10 is available as the CARTO® 3 system (available from Biosense Webster, Inc.), which may be modified by one of skill in the art to embody the inventive principles described herein.

[0045] Regions determined to be abnormal, for example by evaluation of electrical activity maps, can be ablated by application of thermal energy, such as by passing radio frequency current through wires in the catheter to one or more electrodes at the distal tip 18 that apply radio frequency energy to the myocardium. The energy is absorbed by the tissue, heating it to a temperature (usually about 50° C.) at which electrical excitability is permanently lost. If successful, this procedure creates non-conducting lesions in the cardiac tissue that interrupt the abnormal electrical pathways causing the arrhythmia. The principles of the present invention can be applied to different heart chambers to diagnose and treat a number of different cardiac arrhythmias.

[0046] The catheter 14 typically includes a handle 20 having suitable controls thereon to enable the operator 16 to steer, position, and orient the distal tip 18 of the catheter 14 as desired for ablation. To assist the operator 16, the distal portion of the catheter 14 contains a position sensor (not shown) that provides signals to a processing circuit 22 located in a console 24. The processing circuit 22 can perform several processing functions, as described below.

[0047] Ablation energy and electrical signals can be transmitted to and from the heart 12 through a catheter electrode 32 located at or near the distal tip 18, via a cable 34 to the console 24. In this manner, the electrodes 32 are configured to contact tissue at respective locations with the chambers of the heart 12 and capture electrical potentials at the respective locations over time. Additionally or alternatively, other electrodes may be configured to acquire electrical potentials at multiple sample locations over time across a surface of one or more chambers of the heart 12. Pacing and other control signals can be transmitted from the console 24 through the cable 34 and the electrodes 32 to the heart 12. The catheter 14 may be implemented without ablation capabilities as an exploration device having electrodes configured to acquire electrical potentials over time at multiple sample locations over a surface of one or more chambers of the heart 12.

[0048] Wire connections 35 link the console 24 with the body surface electrodes 30 and other components of a positioning subsystem for measuring position and orientation coordinates of the catheter 14. The processing circuitry 22 or another processor (not shown) may be an element of the positioning subsystem. The electrodes 32 and the body surface electrodes 30 may be used to measure tissue impedance at the ablation site, as taught in U.S. Pat. No. 7,536,218. Sensors for bioelectrical information, such as temperature sensors (not shown), typically thermocouples or thermistors, may be mounted on or near each of the electrodes 32.

[0049] The console 24 typically houses one or more ablation power generators 25. The catheter 14 may be adapted to deliver ablation energy to the heart using any known ablation technique, such as, for example, radiofrequency energy, ultrasound energy, and laser-generated light energy. Such methods are disclosed in U.S. Patent Nos. 6,814,733, 6,997,924, and 7,156,816.

[0050] In one embodiment, the positioning subsystem includes a magnetic position tracker that uses field generating coils 28 to generate magnetic fields in a predetermined range of motion and senses these fields at the catheter 14 to determine the position and orientation of the catheter 14. Positioning subsystems are described in U.S. Patent Nos. 7,756,576 and 7,536,218.

[0051] As mentioned above, catheter 14 is coupled to console 24, which allows operator 16 to observe and adjust the functions of catheter 14. Processing circuitry 22 may be embodied as a computer with appropriate signal processing circuitry. Processing circuitry 22 is coupled to drive display 29, which includes display screen 37. The signal processing circuitry may receive, amplify, filter, and digitize signals from catheter 14, including signals generated by sensors, such as electrical, temperature, and contact force sensors, as well as location sensing electrodes (not shown) located distally within catheter 14. The digitized signals are received and used by console 24 and a positioning subsystem to calculate the position and orientation of catheter 14 and to analyze electrical signals from the electrodes.

[0052] To generate the electroanatomical map, processing circuitry 22 typically includes an electroanatomical map generator, an image registration program, an image or data analysis program, and a graphical user interface configured to present graphical information on display 29.

[0053] In practice, some or all of these functions of the processing circuitry 22 may be incorporated within a single physical component or may be implemented using multiple physical components. These physical components may comprise hardwired or programmable devices, or a combination of the two. In some embodiments, at least some of the functions of the processing circuitry may be performed by a programmable processor under the control of appropriate software. This software may be downloaded to the device in electronic form, for example over a network. Alternatively or additionally, the software may be stored on a tangible, non-transitory computer-readable medium, such as optical, magnetic, or electronic memory.

[0054] The console 24 may also include an interface 39 for receiving input commands from the operator 16 via any suitable user input device, such as, but not limited to, a pointing device (such as a pen-type mouse), a keyboard, and / or a touch-sensitive screen implemented within the display screen 37.

[0055] System 10 typically also includes other elements, not shown for simplicity. For example, system 10 may include an electrocardiogram (ECG) monitor coupled to receive signals from body surface electrodes 30 to provide ECG synchronized signals to console 24. As mentioned above, system 10 typically also includes a reference position sensor on an externally applied reference patch attached to the outside of the subject's body or on an internally placed catheter that is inserted into and maintained in a fixed position relative to heart 12. Conventional pumps and lines may be provided to circulate liquid through catheter 14 to cool the ablation site. System 10 may receive image data from an external imaging device, such as an MRI unit or the like, and includes an image processor that may be incorporated into or activated by processing circuitry 22 for generating and displaying images.

[0056] Reference is now made to Figures 2A-B, which are schematic diagrams illustrating the projected location of electrodes 32 onto a plane 40 for use in the system 10 of Figure 1. The catheter 14 shown in Figure 2A includes a shaft 44 having a distal end 62 and a distal tip assembly 64 including multiple splines on which the electrodes 32 are disposed. Any suitable distal tip assembly may be used, such as, but not limited to, a basket distal tip assembly, a balloon distal tip assembly, or a lasso style distal tip assembly.

[0057] Figure 2A shows the projection of each of the electrodes 32-1 and 32-2 onto the plane 40, onto positions 42-1, 42-2, by projecting in a direction perpendicular to the plane 40 and parallel to the axis 45 of the shaft 44 of the catheter 14. The electrodes 32 may be projected onto the plane 40 in any suitable direction. Figure 2B shows the projected positions 42 (only some labels for simplicity) of all the electrodes 32 of the catheter 14. The position 42-1 of the electrode 32-1 has coordinates x1, y1 in the plane 40, which are defined as lying on the x-axis and y-axis.

[0058] Reference is now made to Figure 3, which is a schematic diagram of an intracardiac (IC) signal 46 sampled by the system 20 of Figure 1. Each IC signal 46 is received from a respective electrode 32 (Figure 1). Figure 3 shows an example of a signal 46 received from electrode 32-1 (Figure 2A). Figure 3 shows the signal 46 sampled at 1200 milliseconds, which corresponds to a voltage of approximately -0.1 millivolts. Similarly, in this example, the signals received from the other electrodes 32 are also sampled at 1200 milliseconds to find the voltages of the other electrodes 32.

[0059] Reference is now made to FIG. 4A, which is a schematic diagram of a curved three-dimensional surface 48 depicting electrical activity rendered by the system 10 of FIG. 1. FIG. 4A shows a portion of the positions 42 of the electrodes 32 (FIG. 2A) projected onto the plane 40 lying on the xy-axis 58. For example, the position 42-1 of the electrode 32-1 (FIG. 2A) is shown on the plane 40. As shown in FIG. 3, the sampled voltage of the electrode 32-1 at time 1200 ms is −0.1 millivolts. A data point 50-1 on the three-dimensional surface 48 originates from the position 42-1 and the associated sampled voltage of −0.1 volts. A displacement 52-1 of the data point 50-1 from the plane 40 in a direction perpendicular to the plane 40 (e.g., along the z-axis 60) is calculated based on the sampled voltage of the electrode 32-1 at time 1200 ms. Similarly, each data point 50 (only a portion of which is shown for simplicity) is calculated based on the respective projected positions 42 and the respective calculated displacements 52. A three-dimensional surface 48 is fitted to the data points 50 using any suitable surface fitting method, which may include interpolation and optionally extrapolation based on the data points 50. Figure 4A shows x-y axes 58 and z-axis 60 labeled in suitable units of displacement and voltage, respectively.

[0060] Regions 54 of three-dimensional surface 48 are colored differently according to the voltage values ​​associated with region 54. For example, region 54-1 may be red, while region 54-2 may be yellow. Figure 4A includes a legend 56 that provides a mapping between colors and voltage values.

[0061] Reference is now made to Figures 4B-F, which are schematic illustrations of curved three-dimensional surfaces 48 depicting electrical activity rendered by the system 10 of Figure 1. The three-dimensional surface 48 shown in Figure 4B represents electrical activity on the electrode 32 (Figure 2A) at different sampling times, for example at a sampling time of 1250 ms. Figure 4C shows a rather top view of the three-dimensional surface 48. Figure 4D shows a directly top view of the three-dimensional surface 48, such that the z-axis is not visible. Figures 4E and 4F are further examples of three-dimensional surfaces 48.

[0062] Reference is now made to FIG. 5, which is a flow chart 70 including steps in a method of operation of the system 10 of FIG.

[0063] The catheter is inserted (block 72) into a chamber of the living heart 12 (FIG. 1). Each catheter electrode 32 (FIG. 2A) contacts tissue at a respective location within the chamber of the heart 12. Some of the catheter electrodes 32 may be in contact with tissue while other electrodes 32 are not in contact with tissue. In some cases, all of the electrodes 32 may be in contact with tissue.

[0064] Processing circuitry 22 (FIG. 1) is configured to receive signals 46 (FIG. 3) from catheter 14 (FIG. 1) (block 74), and in response to signals 46, sample voltage values ​​of signals 46 at respective sampling times (block 76), calculate respective curved three-dimensional surfaces 48 (FIGS. 4A-F), and render three-dimensional surfaces 48 on display 29. These steps are described in more detail below.

[0065] The signal 46 of each electrode 32 is typically sampled at each respective sampling time. In some embodiments, the processing circuitry is configured to sample the voltage value of the signal 46 at each sampling time at a rate greater than 10 times per second. In other embodiments, the sampling rate is 10 times per second or less.

[0066] In some embodiments, the processing circuitry 22 is configured to calculate (block 78) the respective positions 42 (FIGS. 2A-B) of each catheter electrode 32 in response to at least one signal received from a position transducer (not shown), which may be part of the catheter and / or part of an external device such as a body patch or an external position sensor, for example. In other embodiments, the respective positions 42 of each catheter electrode 32 used in the calculations described below are the respective positions 42 derived from a static computer model of the catheter 14.

[0067] Each position 42 of each catheter electrode 32 may be a respective projection position 42 projected onto a plane 40 (FIGS. 2A-B). In some embodiments, each position 42 of each catheter electrode 32 is a respective projection position 42 projected onto a plane 40 that is perpendicular to an axis 45 of a shaft 44 (FIGS. 2A-B).

[0068] The processing circuitry 22 is configured to calculate (block 80) respective curved three-dimensional surfaces 48 (FIGS. 4A-F) depicting the electrical activity of the tissue on the catheter electrodes 32 at each of the sampling times. Note that any one of the three-dimensional surfaces 48 depicts the electrical activity at one of the sampling times but not multiple sampling times. The sampled voltages at the different sampling times result in different three-dimensional surfaces 48. The three-dimensional surfaces 48 are calculated in response to (a) the respective positions 42 (e.g., represented by two-dimensional coordinates) of the respective catheter electrodes 32 and (b) respective sampled voltage values ​​indicative of the electrical activity of the tissue sensed by the respective catheter electrodes 32 at the respective locations (on the tissue) at the respective sampling times.

[0069] In some embodiments, the processing circuitry 22 is configured to calculate (block 82) respective displacements 52 (FIG. 4A) perpendicular to the plane 40 (FIG. 4A) from respective projection positions 42 of the catheter electrodes 32 in response to the respective sampled voltage values ​​at each of the sampling times. The displacements 52 (on the z-axis 60 (FIG. 4A)) from the positions 42 (on the xy-axes 58 (FIG. 4A)) define data points 50 (FIG. 4A) having x, y, and z coordinates. The processing circuitry 22 is configured to fit (block 84) respective curved three-dimensional surfaces 48 depicting the electrical activity of the tissue above the catheter electrodes 32 at each of the sampling times in response to the respective displacements 52 perpendicular to the plane 40 from the respective projection positions 42. In other words, the processing circuitry 22 is configured to fit a respective curved three-dimensional surface 48 depicting the electrical activity of the tissue above the catheter electrode 32 at each of the sampling times in response to each of the data points 50 (e.g., having x, y, z coordinates). For example, for one three-dimensional surface 48, the processing circuitry 22 is configured to calculate a respective displacement 52 (FIG. 4A) perpendicular to the plane 40 (FIG. 4A) from a respective one of the projection positions 42 of the catheter electrode 32 in response to a respective one of the sampled voltage values ​​at a sampling time resulting in a respective data point 50, and to fit a curved three-dimensional surface 48 depicting the electrical activity of the tissue above the catheter electrode 32 at that sampling time in response to each of the displacements 52 (i.e., data points 50).

[0070] Processing circuitry 22 is configured to render (block 86) each of the three-dimensional surfaces 48 on display 29 (FIG. 1) over time. In some embodiments, processing circuitry 22 is configured to render each of the three-dimensional surfaces 48 on display 29 over time such that a new one of the three-dimensional surfaces 48 (e.g., corresponding to the next sampling time) is displayed at least every tenth of a second, such that the rendered three-dimensional surfaces 48 provide an animation of activation waves associated with electrical activity of tissue on catheter electrode 32. In some embodiments, processing circuitry 22 is configured to render each of the three-dimensional surfaces 48 on display 29 over time such that a new one of the three-dimensional surfaces 48 is displayed at a rate less than every tenth of a second.

[0071] In some embodiments, the processing circuitry is configured to color (block 88) respective regions 54 (FIG. 4A) of respective three-dimensional surfaces 48 in response to respective sampled voltage values ​​or respective displacements 52 (FIG. 4A).

[0072] Interface 39 (FIG. 1) is configured to receive (block 90) a user input for changing the viewing angle of the one of three-dimensional surface 48. Processing circuitry 22 is configured to render (block 92) the one of three-dimensional surface 48 at a different viewing angle in response to the received user input.

[0073] The term "about" or "approximately" as used herein with respect to any numerical value or range of numerical values ​​indicates a suitable dimensional tolerance that enables a portion of a component or a collection of components to function according to its intended purpose as described herein. More specifically, "about" or "approximately" may refer to a range of values ​​of ±20% of the recited value, for example, "about 90%" may refer to a range of values ​​of 71% to 99%.

[0074] Various different features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.

[0075] The embodiments described above are cited by way of example, and the present invention is not limited to what has been particularly shown and described in the above specification. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described in the above specification, as well as variations and modifications thereof not disclosed in the prior art that would occur to one skilled in the art upon reading the foregoing description.

[0076] [Embodiment] (1) A health care system, comprising: a catheter configured to be inserted into a chamber of a heart of a living subject and including catheter electrodes configured to contact tissue at respective locations within the chamber of the heart; A display and a processing circuit for receiving a signal from the catheter and, in response to the signal, Sampling a voltage value of the signal at each sampling time; (a) calculating respective curved three-dimensional surfaces depicting the electrical activity of the tissue above the catheter electrodes at each of the sampling times in response to respective sampled voltage values ​​indicative of the electrical activity of the tissue sensed by the respective catheter electrodes at the respective locations at the respective sampling times; and processing circuitry configured to render the respective three-dimensional surfaces over time on the display. (2) The system of claim 1, wherein the processing circuitry is configured to color respective regions of the respective three-dimensional surfaces in response to respective sampled voltage values. (3) the respective positions of the respective catheter electrodes are projected positions onto a plane; the processing circuitry is configured to calculate, in response to each of the sampled voltage values ​​at each of the sampling times, a respective displacement perpendicular to the plane from each of the projected positions of each of the catheter electrodes; The system of embodiment 1, wherein the processing circuitry is configured to fit respective curved three-dimensional surfaces depicting the electrical activity of the tissue above the catheter electrodes at the respective sampling times in response to respective displacements perpendicular to the plane from the respective projection positions. (4) The system of claim 3, wherein the processing circuitry is configured to color respective regions of the respective three-dimensional surfaces in response to each of the displacements. (5) The processing circuit, sampling the voltage values ​​of the signal at each of the sample times at a rate greater than 10 times per second; The system of embodiment 1, configured to render each of the three-dimensional surfaces on the display over time, with a new one of the three-dimensional surfaces being displayed at least every tenth of a second, such that the rendered three-dimensional surfaces provide an animation of activation waves associated with the electrical activity of the tissue on the catheter electrodes.

[0077] (6) The system of embodiment 1, further comprising an interface configured to receive user input for changing a viewing angle of the three-dimensional surface, wherein the processing circuit is configured to render the three-dimensional surface at a different viewing angle in response to the received user input. (7) The catheter comprises a shaft having a distal end and a distal tip assembly in which the catheter electrode is disposed; 2. The system of claim 1, wherein the respective positions of the respective catheter electrodes are respective positions derived from a static computer model of the catheter. (8) The system of embodiment 7, wherein the respective positions of the respective catheter electrodes are respective projection positions projected onto a plane perpendicular to the axis of the shaft. (9) The catheter comprises a shaft having a distal end and a distal tip assembly in which the catheter electrode is disposed; 2. The system of claim 1, wherein the processing circuitry is configured to calculate the respective positions of the respective catheter electrodes. (10) The system of embodiment 9, wherein the respective positions of the respective catheter electrodes are respective projection positions projected onto a plane perpendicular to the axis of the shaft.

[0078] (11) A medical method comprising: receiving a signal from a catheter configured to be inserted into a chamber of a heart of a living subject and including catheter electrodes configured to contact tissue at respective locations within the chamber of the heart; Sampling a voltage value of the signal at each sample time in response to the signal; (a) calculating respective curved three-dimensional surfaces depicting the electrical activity of the tissue above the catheter electrodes at each of the sampling times in response to respective sampled voltage values ​​indicative of the electrical activity of the tissue sensed by the respective catheter electrodes at the respective locations at the respective sampling times; and rendering said respective three-dimensional surfaces over time on a display. 12. The method of claim 11, further comprising coloring respective regions of the respective three-dimensional surfaces in response to the respective sampled voltage values. (13) The respective positions of the respective catheter electrodes are respective projection positions projected onto a plane, and the method further comprises: calculating a respective displacement perpendicular to the plane from each of the projected positions of each of the catheter electrodes in response to each of the sampled voltage values ​​at each of the sampling times; 12. The method of claim 11, further comprising fitting the respective curved three-dimensional surfaces depicting the electrical activity of the tissue above the catheter electrodes at the respective sampling times in response to the respective displacements perpendicular to the plane from the respective projection positions. 14. The method of claim 13, further comprising coloring respective regions of said respective three-dimensional surfaces in response to said respective displacements. (15) The method of embodiment 11, further comprising sampling the voltage values ​​of the signal at each sampling time at a rate of greater than 10 times per second, and wherein the rendering comprises rendering each of the three-dimensional surfaces on the display over time, a new one of the three-dimensional surfaces being displayed at least every tenth of a second, such that the rendered three-dimensional surfaces provide an animation of activation waves associated with the electrical activity of the tissue on the catheter electrodes.

[0079] (16) receiving a user input to change a view angle of the three-dimensional surface; and 12. The method of claim 11, further comprising: rendering the three-dimensional surface at different viewing angles in response to the received user input. (17) The catheter comprises a shaft having a distal end and a distal tip assembly in which the catheter electrode is disposed; 12. The method of claim 11, wherein the respective positions of the respective catheter electrodes are respective positions derived from a static computer model of the catheter. (18) The method of embodiment 17, wherein the respective positions of the respective catheter electrodes are respective projection positions projected onto a plane perpendicular to the axis of the shaft. (19) The method of claim 11, wherein the catheter comprises a shaft having a distal end and a distal tip assembly in which the catheter electrodes are disposed, the method further comprising calculating the respective positions of the respective catheter electrodes. (20) The method of embodiment 19, wherein the respective positions of the respective catheter electrodes are respective projection positions projected onto a plane perpendicular to the axis of the shaft.

[0080] (21) A software product including a non-transitory computer-readable medium having stored thereon program instructions, the instructions, when read by a central processing unit (CPU), causing the CPU to: receiving a signal from a catheter configured to be inserted into a chamber of a heart of a living subject and including catheter electrodes configured to contact tissue at respective locations within the chamber of the heart; sampling a voltage value of the signal at each sampling time in response to the signal; (a) calculating, in response to each of the sampled voltage values ​​indicative of the electrical activity of the tissue sensed by each of the catheter electrodes at each of the locations at each of the sampling times, respective curved three-dimensional surfaces depicting the electrical activity of the tissue above the catheter electrodes at each of the sampling times; a software product that causes each of said three-dimensional surfaces to be rendered over time on a display.

Claims

1. 1. A health care system comprising: a catheter configured to be inserted into a chamber of a heart of a living subject and including catheter electrodes configured to contact tissue at respective locations within the chamber of the heart; A display and a processing circuit for receiving a signal from the catheter and, in response to the signal, Sampling a voltage value of the signal at each sampling time; (a) calculating respective curved three-dimensional surfaces depicting the electrical activity of the tissue above the catheter electrodes at each of the sampling times in response to respective sampled voltage values ​​indicative of the electrical activity of the tissue sensed by each of the catheter electrodes at each of the locations at each of the sampling times; and processing circuitry configured to render each of the three-dimensional surfaces on the display over time; The catheter comprises a shaft having a distal end and a distal tip assembly in which the catheter electrode is disposed; A medical system, wherein the positions of each of the catheter electrodes are respective projected positions projected onto a plane perpendicular to an axis of the shaft.

2. The system of claim 1 , wherein the processing circuitry is configured to color respective regions of respective ones of the three-dimensional surfaces in response to respective ones of the sampled voltage values.

3. the processing circuitry is configured to calculate, in response to each of the sampled voltage values ​​at each of the sampling times, a respective displacement perpendicular to the plane from each of the projected positions of each of the catheter electrodes; 2. The system of claim 1, wherein the processing circuitry is configured to fit respective curved three-dimensional surfaces depicting the electrical activity of the tissue above the catheter electrodes at each of the sampling times in response to respective displacements perpendicular to the plane from each of the projection locations.

4. The system of claim 3 , wherein the processing circuitry is configured to color respective regions of respective ones of the three-dimensional surfaces in response to respective ones of the displacements.

5. The processing circuitry comprises: sampling the voltage value of the signal at each of the sample times at a rate greater than 10 times per second; 2. The system of claim 1, configured to render each of the three-dimensional surfaces on the display over time, with a new one of the three-dimensional surfaces being displayed at least every tenth of a second, such that the rendered three-dimensional surfaces provide an animation of activation waves associated with the electrical activity of the tissue on the catheter electrodes.

6. 10. The system of claim 1, further comprising an interface configured to receive user input for changing a viewing angle of the three-dimensional surface thing, the processing circuitry configured to render the three-dimensional surface thing at a different viewing angle in response to the received user input.

7. The system of claim 1, wherein each of the positions of each of the catheter electrodes is a respective position derived from a static computer model of the catheter.

8. The system of claim 1, wherein the processing circuitry is configured to calculate the position of each of the catheter electrodes.

9. A method of operating a processing circuit, comprising: the processing circuitry receiving signals from a catheter configured to be inserted into a chamber of a heart of a living subject and including catheter electrodes configured to contact tissue at respective locations within the chamber of the heart; the processing circuitry is responsive to the signal to sample a voltage value of the signal at each sample time; the processing circuitry responding to (a) each position of each of the catheter electrodes and (b) each of the sampled voltage values ​​indicative of the electrical activity of the tissue sensed by each of the catheter electrodes at each of the locations at each of the sampling times to calculate respective curved three-dimensional surfaces depicting the electrical activity of the tissue above the catheter electrodes at each of the sampling times; the processing circuitry rendering each of the three-dimensional surfaces over time on a display; The catheter comprises a shaft having a distal end and a distal tip assembly in which the catheter electrode is disposed; A method of operating a processing circuit, wherein the positions of each of the catheter electrodes are their respective projected positions projected onto a plane perpendicular to the axis of the shaft.

10. A method of operating a processing circuit as described in claim 9, further comprising the processing circuit coloring respective regions of each of the three-dimensional surfaces in response to each of the sampled voltage values.

11. The method of claim 10, wherein the processing circuitry calculates, in response to each of the sampled voltage values ​​at each of the sampling times, a respective displacement perpendicular to the plane from each of the projected positions of each of the catheter electrodes; 10. The method of claim 9, further comprising: the processing circuit fitting respective curved three-dimensional surfaces depicting the electrical activity of the tissue above the catheter electrodes at each of the sampling times in response to each of the displacements perpendicular to the plane from each of the projection positions.

12. A method of operating a processing circuit as described in claim 11, further comprising the processing circuit coloring respective regions of each of the three-dimensional surfaces in response to each of the displacements.

13. A method of operating a processing circuit as described in claim 9, further comprising: the processing circuit sampling the voltage values ​​of the signal at each of the sampling times at a rate of greater than 10 times per second; and wherein the rendering includes the processing circuit rendering each of the three-dimensional surfaces on the display over time, a new one of the three-dimensional surfaces being displayed at least every tenth of a second, such that the rendered three-dimensional surfaces provide an animation of activation waves associated with the electrical activity of the tissue on the catheter electrode.

14. The method of claim 13, further comprising: receiving a user input for changing a viewing angle of the three-dimensional surface object; and 10. The method of claim 9, further comprising: the processing circuitry responsive to the received user input rendering ones of the three-dimensional surface at different viewing angles.

15. A method of operating a processing circuit as described in claim 9, wherein the respective positions of each of the catheter electrodes are respective positions derived from a static computer model of the catheter.

16. A method of operating a processing circuit as described in claim 9, further comprising the processing circuit calculating the position of each of the catheter electrodes.

17. A non-transitory computer-readable medium having program instructions stored thereon, the program instructions, when read by a central processing unit (CPU), causing the CPU to: receiving a signal from a catheter configured to be inserted into a chamber of a heart of a living subject and including catheter electrodes configured to contact tissue at respective locations within the chamber of the heart; sampling a voltage value of the signal at each sampling time in response to the signal; (a) in response to respective sampled voltage values ​​indicative of the electrical activity of the tissue sensed by each of the catheter electrodes at each of the locations at each of the sampling times, calculating respective curved three-dimensional surfaces depicting the electrical activity of the tissue above the catheter electrodes at each of the sampling times; rendering each of said three-dimensional surfaces over time on a display; The catheter comprises a shaft having a distal end and a distal tip assembly in which the catheter electrode is disposed; The non-transitory computer readable medium, wherein the positions of each of the catheter electrodes are respective projected positions projected onto a plane perpendicular to an axis of the shaft.

Images