3D cardiac activity demonstration

Abstract

The present invention is entitled “3D Intracardiac Activity Presentation.” In one embodiment, a medical system includes a catheter configured to be inserted into a chamber of the heart of a living subject and including catheter electrodes configured to contact tissue at corresponding locations within the chamber of the heart; a display; and processing circuitry configured to receive signals from the catheter and sample voltage values ​​of the signals at corresponding sampling times in response to the signals; calculate corresponding curved three-dimensional surfaces describing the electrical activity of the tissue on the catheter electrodes at corresponding sampling times in response to: (a) corresponding locations of the corresponding catheter electrodes, and (b) corresponding sampled voltage values ​​indicating the electrical activity of the tissue sensed by the corresponding catheter electrodes at the corresponding locations at the corresponding sampling times, and present the corresponding three-dimensional surfaces to the display over time.

Description

Technical Field

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

[0002] The electrical activity at a point in the heart can be measured by advancing a multi-electrode catheter to simultaneously measure the electrical activity at multiple points in the heart chambers. Other methods, such as the use of an external vest, can provide an indication of cardiac activity. The record derived from the time-varying electrical potentials measured by one or more electrodes is called an electrogram. The electrogram can be measured with a unipolar lead or a bipolar lead and is used, for example, to determine the onset of electrical propagation at a point, which is called the local activation time (LAT).

[0003] U.S. Patent 5,782,773 to Kuo et al. describes a three-dimensional electrocardiogram display method for 3-D representation of multiple cardiac signals. In this method, a 3-D rectangular coordinate system is defined to display the 3-D representation of the cardiac signals. In addition, an amplitude display scheme, preferably an amplitude to color mapping table, is defined to assign various quantization levels of the amplitude to specified different colors. A 3-D representation of the cardiac signals can be generated and displayed by a graphics processing and display device. The doctor can choose to observe the 3-D curve graph in various views, including perspective, cross-sectional and top rectangular views. This allows the physician to make a diagnosis of cardiac disease by observing only one or two 3-D representations of the cardiac signals. Therefore, the physician can have an overall integrated view of a large number of cardiac signals, making it easier to diagnose the patient's cardiac condition.

[0004] Luo's U.S. Patent Publication 2011 / 0021936 describes an apparatus and method for displaying medical data for a stress test monitoring system. The computer-implemented method and apparatus for displaying human cardiac electrical pulse data for analysis includes receiving electrocardiographic pulse data generated by a plurality of electrode leads adapted for placement on a patient during a cardiac stress test, calculating parameters for a plurality of display windows based on the data, and providing a main display in which the plurality of display windows are positioned. A three-dimensional color map is displayed in one of the plurality of display windows, and a two-dimensional color map is displayed in another of the plurality of display windows. Additionally, a graph of raw lead data from at least one lead is displayed in one of the plurality of display windows.

[0005] U.S. Patent Publication 2012 / 0130232 to Markowitz et al. describes a volume of a patient that can be mapped using a system operable to identify multiple positions of a mapping device and store the multiple positions of the mapping device. The mapping device may include one or more electrodes that can sense a voltage that can be correlated with the three-dimensional position of the electrodes when sensing or measuring. Thus, a map of the volume can be determined based on sensing of multiple points without the use of other imaging devices. An implantable medical device can then be navigated relative to the mapping data.

[0006] International Patent Publication WO 2017 / 192769 by Acutus Medical Inc. describes a positioning system and method that can be used to acquire and analyze cardiac information. For example, the positioning system and method can be used with systems that perform cardiac mapping, diagnosis, and treatment of cardiac abnormalities, and in the retrieval, processing, and interpretation of such information. The positioning system and method utilize high-impedance inputs, improved isolation, and relatively high drive currents for electrode pairs used to establish a multi-axis coordinate system. These axes can be rotated and scaled to improve positioning. Summary of the Invention

[0007] According to an embodiment of the present disclosure, a medical system is provided, which includes a catheter configured to be inserted into a chamber of the heart of a living subject and including a catheter electrode configured to contact tissue at a corresponding position within the chamber of the heart; a display; and a processing circuit configured to receive a signal from the catheter and sample a voltage value of the signal at a corresponding sampling time in response to the signal; calculate a corresponding curved three-dimensional surface describing the electrical activity of the tissue on the catheter electrode at a corresponding sampling time in response to the following items: (a) a corresponding position of the corresponding catheter electrode, and (b) a corresponding sampled voltage value, the corresponding sampled voltage value indicating the electrical activity of the tissue sensed by the corresponding catheter electrode at the corresponding position at the corresponding sampling time; and present the corresponding three-dimensional surface to the display over time.

[0008] Further in accordance with an embodiment of the present disclosure, the processing circuit is configured to colorize a respective region of the respective three-dimensional surface in response to respective ones of the sampled voltage values.

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

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

[0011] Furthermore, according to an embodiment of the present disclosure, the processing circuit is configured to sample the voltage value of the signal at corresponding sampling times at a rate exceeding ten times per second, and to render corresponding three-dimensional surfaces to a display over time, wherein a new one of the three-dimensional surfaces is 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 at the catheter electrode.

[0012] Further according to an embodiment of the present disclosure, the system interface is configured to receive user input to change the perspective of some of the three-dimensional surfaces, wherein the processing circuit is configured to present some of the three-dimensional surfaces at different perspectives in response to the received user input.

[0013] In further 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 respective positions of the respective catheter electrodes are 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 respective projected positions projected onto a plane perpendicular to the axis of the shaft.

[0015] Furthermore, according to an embodiment of the present disclosure, a catheter includes a shaft having a distal end and a distal tip assembly on which catheter electrodes are disposed, and the processing circuit is configured to calculate respective positions of respective catheter electrodes.

[0016] In further accordance with an embodiment of the present disclosure, the respective positions of the respective catheter electrodes are respective projected positions projected onto a plane perpendicular to the axis of the shaft.

[0017] According to another embodiment of the present disclosure, a medical method is also provided, which includes receiving a signal from a catheter configured to be inserted into a chamber of the heart of a living subject and including a catheter electrode configured to contact tissue at a corresponding position in the chamber of the heart; sampling a voltage value of the signal at a corresponding sampling time in response to the signal; calculating a corresponding curved three-dimensional surface that describes the electrical activity of the tissue on the catheter electrode at a corresponding sampling time in response to the following items: (a) a corresponding position of the corresponding catheter electrode, and (b) a corresponding sampled voltage value, the corresponding sampled voltage value indicating the electrical activity of the tissue sensed by the corresponding catheter electrode at the corresponding position at the corresponding sampling time; and presenting the corresponding three-dimensional surface to a display over time.

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

[0019] In addition, according to an embodiment of the present disclosure, the corresponding positions of the corresponding catheter electrodes are corresponding projected positions projected onto the plane, and the method further includes calculating corresponding displacements perpendicular to the plane from corresponding projected positions of the corresponding catheter electrodes in response to corresponding sampled voltage values ​​in the corresponding sampled voltage values ​​in the sampling times, and fitting corresponding curved three-dimensional surfaces describing electrical activity of tissue on the catheter electrodes in response to corresponding displacements in the displacements perpendicular to the plane from corresponding projected positions in the projection positions.

[0020] Furthermore, according to an embodiment of the present disclosure, the method includes coloring respective regions of respective three-dimensional surfaces in response to respective ones of the displacements.

[0021] Further in accordance with an embodiment of the present disclosure, the method includes sampling voltage values ​​of the signal at corresponding sampling times at a rate exceeding ten times per second, wherein the rendering includes rendering the corresponding three-dimensional surface to a display over time, wherein a new one of the three-dimensional surfaces is 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 at the catheter electrode.

[0022] Still further in accordance with an embodiment of the present disclosure, the method includes receiving user input to change a perspective of some of the three-dimensional surfaces, and presenting some of the three-dimensional surfaces at different perspectives in response to the received user input.

[0023] Additionally, according to an embodiment of the present disclosure, the catheter includes a shaft having a distal end and a distal end assembly on which catheter electrodes are disposed, and the respective positions of the respective catheter electrodes are derived from a static computer model of the catheter.

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

[0025] In further 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, and the method further includes calculating respective positions of respective catheter electrodes.

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

[0027] According to another embodiment of the present disclosure, a software product is also provided, which includes a non-transitory computer-readable medium having program instructions stored therein, which instructions, when read by a central processing unit (CPU), cause the CPU to receive a signal from a catheter, the catheter being configured to be inserted into a chamber of the heart of a living subject and including a catheter electrode configured to contact tissue at a corresponding position within the chamber of the heart; sampling a voltage value of the signal at a corresponding sampling time in response to the signal; calculating a corresponding curved three-dimensional surface describing the electrical activity of the tissue on the catheter electrode at a corresponding sampling time in response to: (a) a corresponding position of the corresponding catheter electrode, and (b) a corresponding sampled voltage value, the corresponding sampled voltage value indicating the electrical activity of the tissue sensed by the corresponding catheter electrode at the corresponding position at the corresponding sampling time; and presenting the corresponding three-dimensional surface to 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, in which:

[0029] Figure 1 is a partially schematic, partially block diagram illustration of a cardiac analysis system constructed and operative in accordance with an embodiment of the present invention;

[0030] Figures 2A to 2B To show the Figure 1 Schematic diagram of the projection position of the electrodes in the system onto the plane;

[0031] Figure 3 For Figure 1 Schematic diagram of intracardiac signals sampled in the system;

[0032] Figures 4A to 4F for the reason Figure 1a schematic diagram of a curved three-dimensional surface depicting electrical activity presented by a system; and

[0033] Figure 5 To include Figure 1 Flowchart of each step in the operating method of the system. DETAILED DESCRIPTION

[0034] Overview

[0035] Due to the geometric distribution of electrodes, the number of catheters from complex and diverse catheters (e.g., Biosense Webster, Inc., Irvine, CA USA) Presenting electrical activity signals from multiple electrodes on a catheter (or basket catheter) or linear catheter in a manner that is intuitive to physicians is challenging. Presenting electrical activity in a two-dimensional (2D) list, such as showing multiple intracardiac electrograms (IEGMs), does not reflect the geometry of the catheter.

[0036] Embodiments of the present invention address the aforementioned problems by providing a three-dimensional (3D) representation comprising corresponding curved three-dimensional surfaces describing the electrical activity of tissue over the catheter electrodes at corresponding sampling times.

[0037] At different sampling times, the intracardiac (IC) signals received from the electrodes of the catheter are collected and sampled. 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 can be limited by three axes (x, y, and z) or any other suitable coordinate system. The x-axis and y-axis indicate the 2D positions of the electrodes of the catheter (for example, by projecting the electrode positions onto the plane defined by the x-axis and y-axis). The z-axis indicates the voltage of the electrical activity captured by the electrodes at the sampling time. The curved 3D surface is calculated by fitting the 3D surface to the data points defined by the xy coordinates of the electrode positions of the catheter electrodes and the corresponding z coordinates of the sampled voltage. The fitting of the 3D surface can be performed by interpolating (and optionally extrapolating) between the above-mentioned data points. The region of the 3D surface can optionally be colored according to the voltage level associated with the region.

[0038] The 3D presentation can be static (eg, for a single sampling time) or dynamic (eg, a video), showing how electrical activity moves as activation waves across the catheter's electrodes, providing a useful diagnostic tool for the physician.

[0039] Any suitable catheter may be used in the above embodiments, for example, a variety of catheters (e.g., those from Biosense Webster, Inc., Irvine, CA USA). catheter or basket catheter) or other multi-electrode catheters (e.g., balloon catheters or lasso catheters).

[0040] A catheter is inserted into a cardiac chamber of a living subject. The catheter may include a shaft having a distal end and a distal end assembly on which catheter electrodes are disposed. The catheter electrodes contact tissue at corresponding locations within the cardiac chamber. Processing circuitry receives a signal from the catheter and, in response to the signal, samples a voltage value of the signal at corresponding sampling times.

[0041] In some embodiments, the processing circuit calculates the respective positions of the respective catheter electrodes, for example, in response to signals received from position transducers, such as one or more position sensors of the catheter or externally placed sensors.

[0042] In other embodiments, the positions of the respective catheter electrodes used in the calculations described below are derived from a static computer model of the catheter. For example, if the catheter used is a multi-strip catheter having deflectable splines, the positions used in the calculations described below may be based on the positions of the deflectable splines in a non-deflected position, even if the splines are actually deflected at the respective sampling times.

[0043] Whether the position is calculated from one or more received signals or derived from a static computer model or any other suitable source, the position of the catheter electrode is typically a projected position onto a plane (e.g., the xy axis described above). In some embodiments, the plane is perpendicular to the axis of the catheter's shaft.

[0044] The processing circuit calculates a corresponding curved three-dimensional surface that describes the electrical activity of the tissue on the catheter electrode at a corresponding sampling time in the sampling time. It should be noted that any one of the three-dimensional surfaces describes the electrical activity for a corresponding sampling time in the sampling time, rather than for multiple sampling times. Sampled voltages at different sampling times produce different three-dimensional surfaces. The three-dimensional surface is calculated in response to the following items: (a) the corresponding position of the corresponding catheter electrode (e.g., two-dimensional position coordinates); and (b) the corresponding sampled voltage value, the corresponding sampled voltage value indicating the electrical activity of the tissue sensed by the corresponding catheter electrode at the corresponding position (on the tissue) at the corresponding sampling time. For example, a three-dimensional surface is calculated in response to the following items: (a) the corresponding position of the corresponding catheter electrode (e.g., two-dimensional position coordinates); and (b) the corresponding sampled voltage value sampled at one sampling time in the corresponding sampling time.

[0045] In some embodiments, the processing circuitry colors the respective regions of the respective three-dimensional surfaces in response to respective ones of the sampled voltage values.

[0046] In some embodiments, the processing circuit calculates a corresponding displacement perpendicular to the plane (e.g., along the z-axis away from the xy-axis) from the corresponding projected position of the corresponding catheter electrode in response to the corresponding sampled voltage value at the corresponding sampling time. When a Cartesian coordinate system is used, each displacement provides a z-axis coordinate. For example, the displacement z is calculated based on the sampled voltage sampled at time t1 of the signal sensed by electrode number n of the catheter. n Electrode number n has a position coordinate x on the plane defined by the xy axis. n ,y n Therefore, the data point for electrode number n at time t1 in the 3D representation has coordinates x n ,y n ,z n The processing circuitry fits a corresponding curved three-dimensional surface describing the electrical activity of tissue over the catheter electrode at the corresponding sampling time, e.g., from the data points in the coordinate system representing the electrical activity of each of the electrodes, in response to the corresponding calculated displacements perpendicular to the plane from the corresponding ones of the projected positions. In some embodiments, the processing circuitry colors the corresponding region of the corresponding three-dimensional surface in response to the corresponding ones of the displacements.

[0047] The processing circuitry is configured to render the respective three-dimensional surfaces to a display over time. In some embodiments, the processing circuitry renders the respective three-dimensional surfaces to the display over time, wherein a new one of the three-dimensional surfaces is displayed frequently enough (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 on the catheter electrode.

[0048] The user interface may receive user input to change the perspective of the three-dimensional surfaces and may then present the three-dimensional surfaces at different perspectives in response to the received user input.

[0049] System Description

[0050] Now see Figure 1 , which is a partially illustrative, partially block diagram illustration of a cardiac analysis system 10 constructed and operative in accordance with an embodiment of the present invention.

[0051] Turning now to the drawings, see first Figure 1, which is an illustrative illustration of a cardiac analysis system 10 constructed and operated in accordance with a disclosed embodiment of the present invention for calculating and evaluating electrical activity and optionally for performing an ablation procedure on a heart 12 of a living subject. The system includes a catheter 14, such as a catheter that is inserted percutaneously through the 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 the distal tip 18 of the catheter 14 to the wall of the heart, for example, at an ablation target site, to capture electrical potentials over time at a plurality of sampling locations on the surface of one or more chambers of the heart 12. Electrical activity maps may be prepared according to the methods disclosed in U.S. Patents 6,226,542, 6,301,496, and 6,892,091. One commercial product embodying elements of the system 10 is the 3 system is commercially available from Biosense Webster, Inc. This system can be modified by one skilled in the art to embody the principles of the invention as described herein.

[0052] Ablation can be performed by applying thermal energy to areas that are determined to be abnormal, for example, by evaluating electrical activity maps, for example, by conducting radiofrequency current through wires in the catheter to one or more electrodes at the distal tip 18, which apply radiofrequency energy to the myocardium. The energy is absorbed in the tissue, heating the tissue to a temperature (typically about 50°C) at which the tissue permanently loses its electrical excitability. After a successful procedure, non-conductive lesions are formed in the heart tissue, which can interrupt the abnormal electrical pathways that cause the arrhythmia. The principles of the present invention can be applied to different chambers of the heart to diagnose and treat a variety of different arrhythmias.

[0053] The catheter 14 typically includes a handle 20 having appropriate 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 includes position sensors (not shown) that provide signals to processing circuitry 22 located in a console 24. The processing circuitry 22 may perform several processing functions as described below.

[0054] Ablation energy and electrical signals can be transmitted back and forth between the heart 12 and the console 24 via a cable 34 through a catheter electrode 32 located at or near the distal tip 18. In this manner, the electrodes 32 are configured to bring tissue at corresponding locations into contact with the chambers of the heart 12 and to capture electrical potentials at the corresponding locations over time. Additionally or alternatively, other electrodes can be configured to capture electrical potentials over time at multiple sampling locations on the surface of one or more chambers of the heart 12. Pacing signals and other control signals can be transmitted from the console 24 to the heart 12 via the cable 34 and electrodes 32. The catheter 14 can be implemented as an exploratory device with electrodes configured to capture electrical potentials over time at multiple sampling locations on the surface of one or more chambers of the heart 12 without ablation capabilities.

[0055] Wire connector 35 connects console 24 to body surface electrodes 30 and other components of a positioning subsystem for measuring the position and orientation coordinates of catheter 14. Processing circuit 22 or another processor (not shown) may be an element of the positioning subsystem. Electrodes 32 and body surface electrodes 30 may be used to measure tissue impedance at the ablation site, as taught in U.S. Patent 7,536,218. A sensor for bioelectrical information, such as a temperature sensor (not shown) (typically a thermocouple or thermistor) may be mounted on or near each of electrodes 32.

[0056] The console 24 typically contains one or more ablation power generators 25. The catheter 14 can be adapted to deliver ablation energy to the heart using any known ablation technique, such as radiofrequency energy, ultrasound energy, and laser-generated light energy. Such methods are disclosed in U.S. Patents 6,814,733, 6,997,924, and 7,156,816.

[0057] In one embodiment, the positioning subsystem includes a magnetic position tracking arrangement that determines the position and orientation of the catheter 14 by generating magnetic fields in a predetermined workspace using magnetic field generating coils 28 and sensing these magnetic fields at the catheter 14. This positioning subsystem is described in U.S. Patents 7,756,576 and 7,536,218.

[0058] As described above, the catheter 14 is coupled to the console 24, which enables the operator 16 to observe and control the functions of the catheter 14. The processing circuit 22 can be embodied as a computer with appropriate signal processing circuitry. The processing circuit 22 is coupled to drive the display 29, which includes a display screen 37. The signal processing circuitry can receive, amplify, filter, and digitize signals from the catheter 14, including signals generated by sensors such as electrical sensors, temperature sensors, and contact force sensors, and position sensing electrodes (not shown) located distal to the catheter 14. The console 24 and the positioning subsystem receive and use the digitized signals to calculate the position and orientation of the catheter 14 and analyze the electrical signals from the electrodes.

[0059] 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 .

[0060] In implementation, some or all of the functions of the processing circuit 22 may be combined in a single physical component, or alternatively, implemented using multiple physical components. These physical components may include hard-wired or programmable devices, or a combination of the two. In some embodiments, at least some of the functions of the processing circuit may be implemented by a programmable processor under the control of suitable software. The software may be downloaded to the device in electronic form over a network, for example. Alternatively or in addition, the software may be stored in a tangible, non-transitory computer-readable storage medium, such as an optical, magnetic, or electronic memory.

[0061] Console 24 may also include an interface 39 for receiving input commands from operator 16 via any suitable user input device, such as, but not limited to, a pointing device (a mouse such as a stylus), a keyboard, and / or a touch-sensitive screen implemented in display screen 37 .

[0062] Typically, the system 10 includes other elements, but they are not shown in the drawings for the sake of simplicity. For example, the system 10 may include an electrocardiogram (ECG) monitor that is connected to receive signals from surface electrodes 30 so as to provide ECG synchronization signals to the console 24. As mentioned above, the system 10 also typically includes a reference position sensor, which is located on an external reference patch attached to the outside of the subject's body, or on an internal catheter inserted into the heart 12 and maintained in a fixed position relative to the heart 12. A conventional pump and tubing can be provided for circulating fluid through the catheter 14 to cool the ablation site. The system 10 can receive image data from an external imaging modality such as an MRI unit and include an image processor that can be incorporated into the processing circuit 22 or called by the processing circuit 22 for generating and displaying images.

[0063] Now see Figures 2A to 2B , which is shown for Figure 1 Schematic diagram of the projection position of the electrode 32 in the system 10 onto the plane 40. Figure 2A The illustrated catheter 14 includes a shaft 44 having a distal end 62, and a distal tip assembly 64 including a plurality of splines on which 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 distal tip assembly.

[0064] Figure 2A Electrodes 32-1 and 32-2, respectively, are shown projected onto plane 40 by projection at 42-1, 42-2 in a direction perpendicular to plane 40 and parallel to axis 45 of shaft 44 of catheter 14. Electrodes 32 may be projected onto plane 40 in any suitable direction. Figure 2B The projected positions 42 of all electrodes 32 of catheter 14 are shown (only some are labeled for simplicity). Position 42-1 of electrode 32-1 has coordinates x1, y1 in plane 40, which are defined as lying on the x-axis and y-axis.

[0065] Now see Figure 3 , which is in Figure 1 Schematic diagram of intracardiac (IC) signals 46 sampled in the system 20. From the corresponding electrodes 32 ( Figure 1 ) receives the corresponding IC signal 46. Figure 3 The graph shows the voltage from electrode 32-1 ( Figure 2A )Exemplary signal 46 received. Figure 3 The signal 46 is shown sampled at 1200 milliseconds, corresponding 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.

[0066] Now see Figure 4A , which is described by Figure 1 Schematic diagram of system 10 presenting electrical activity on a curved three-dimensional surface 48 . Figure 4A The electrode 32 ( Figure 2A ) are projected onto plane 40 at positions 42 that lie on xy axis 58. For example, electrode 32-1 ( Figure 2A ) at position 42-1 on plane 40. The sampling voltage of electrode 32-1 at time 1200 milliseconds is -0.1 millivolts, as shown in FIG. Figure 3As shown. Data point 50-1 of three-dimensional surface 48 is derived from position 42-1 and the associated sampled voltage of -0.1 volts. A displacement 52-1 of data point 50-1 from plane 40 in a direction perpendicular to plane 40 (e.g., along z-axis 60) is calculated based on the sampled voltage of electrode 32-1 at time 1200 milliseconds. Similarly, corresponding data points 50 (only some of which are shown for simplicity) are calculated based on the corresponding projected positions 42 and the calculated corresponding displacements 52. Three-dimensional surface 48 is fitted to data points 50 using any suitable surface fitting method, which may include interpolation based on data points 50 and, optionally, extrapolation. Figure 4A An xy axis 58 and a z axis 60 are shown labeled with appropriate displacement units and voltage units, respectively.

[0067] Regions 54 of the three-dimensional surface 48 have been colored in different colors according to the voltage values ​​associated with the regions 54. For example, region 54-1 may be red, while region 54-2 may be yellow. Figure 4A A legend 56 is included that provides a mapping between colors and voltage values.

[0068] Now refer to 4B to Figure 4F , which is described by Figure 1 Schematic diagram of system 10 presenting electrical activity on a curved three-dimensional surface 48 . Figure 4B The three-dimensional surface 48 shown represents the electrode 32 ( Figure 2A ) on the electrical activity. Figure 4C More of the top of one of the three-dimensional surfaces 48 is shown. Figure 4D One of the three-dimensional surfaces 48 is shown directly above, so that the z-axis is not even visible. Figure 4E and Figure 4F is another example of a three-dimensional surface 48 .

[0069] Now see Figure 5 , which includes Figure 1 Flowchart 70 of the steps in the method of operating system 10.

[0070] The catheter is inserted (block 72) into the heart 12 of a living subject ( Figure 1 ) in the chamber. The corresponding catheter electrode 32 ( Figure 2A ) contact tissue at corresponding locations within the chambers of heart 12. Some of catheter electrodes 32 may contact tissue while other electrodes 32 do not. In some cases, all electrodes 32 may contact tissue.

[0071] Processing circuit 22 ( Figure 1 ) is configured to be drawn from the conduit 14 ( Figure 1 )Receive signal 46( Figure 3 )(Block 74), and in response to the signal 46, the voltage value of the signal 46 is sampled at the corresponding sampling time (Block 76), and the corresponding curved three-dimensional surface 48 ( Figures 4A to 4F ), and presents the three-dimensional surface 48 to the display 29. These steps are described in more detail below.

[0072] The signal 46 of each electrode 32 is typically sampled at each corresponding sampling time. In some embodiments, the processing circuit is configured to sample the voltage value of the signal 46 at a rate exceeding ten times per second at the corresponding sampling time. In other embodiments, the sampling rate is less than or equal to ten times per second.

[0073] In some embodiments, processing circuitry 22 is configured to calculate respective positions 42 ( s ) of respective catheter electrodes 32 , for example, in response to at least one signal received from a position transducer (not shown). Figures 2A to 2B )(Block 78), the position transducer can be part of the catheter and / or part of an external device (such as a body patch or external position sensor). In other embodiments, the respective positions 42 of the respective catheter electrodes 32 used in the calculations described below are respective positions 42 derived from a static computer model of the catheter 14.

[0074] The corresponding position 42 of the corresponding catheter electrode 32 can be projected onto the plane 40 ( Figures 2A to 2B ) corresponding projected position 42 on the axis 44. In some embodiments, the corresponding position 42 of the corresponding catheter electrode 32 is the corresponding projected position 42 projected onto the plane 40, which is perpendicular to the axis 45 ( Figures 2A to 2B ).

[0075] The processing circuit 22 is configured to calculate the corresponding curved three-dimensional surface 48 ( Figures 4A-4F )(block 80), the curved three-dimensional surface describing the electrical activity of the tissue on the catheter electrode 32 at a corresponding one of the sampling times. It should be noted that any one of the three-dimensional surfaces 48 describes the electrical activity for one of the sampling times, but not for a plurality of sampling times. The sampled voltages at different sampling times produce different three-dimensional surfaces 48. The three-dimensional surface 48 is calculated in response to: (a) the corresponding position 42 of the corresponding catheter electrode 32 (e.g., represented by two-dimensional coordinates); and (b) the corresponding sampled voltage values, which indicate the electrical activity of the tissue sensed by the corresponding catheter electrode 32 at the corresponding position (on the tissue) at the corresponding sampling time.

[0076] In some embodiments, processing circuit 22 is configured to calculate a voltage perpendicular to plane 40 ( Figure 4A) from the corresponding projected position 42 of the corresponding catheter electrode 32 ( Figure 4A )(Block 82). From position 42 (on xy axis 58 ( Figure 4A ) in) displacement 52 (in z axis 60 ( Figure 4A ) defines data points 50 with x, y, z coordinates ( Figure 4A ). The processing circuitry 22 is configured to fit a corresponding curved three-dimensional surface 48 (block 84) that describes the electrical activity of the tissue on the catheter electrode 32 at the corresponding one of the sampling times in response to the corresponding one of the displacements 52 from the corresponding one of the projection positions 42 perpendicular to the plane 40. In other words, the processing circuitry 22 is configured to fit a corresponding curved three-dimensional surface 48 that describes the electrical activity of the tissue on the catheter electrode 32 at the corresponding one of the sampling times in response to the corresponding one 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 three-dimensional surface 48 perpendicular to the plane 40 ( Figure 4A ) from the corresponding projected position 42 of the corresponding catheter electrode in the catheter electrodes 32 ( Figure 4A ), thereby generating corresponding data points 50, and in response to the corresponding displacements in displacement 52 (i.e., data points 50), fitting a curved three-dimensional surface 48 that describes the electrical activity of the tissue over catheter electrode 32 at the sampling time.

[0077] The processing circuit 22 is configured to present the corresponding three-dimensional surface 48 to the display 29 ( Figure 1 )(Block 86). In some embodiments, processing circuitry 22 is configured to present respective three-dimensional surfaces 48 to display 29 over time, wherein a new one of three-dimensional surfaces 48 (e.g., corresponding to the next sampling time) is displayed at least every tenth of a second, such that the presented three-dimensional surfaces 48 provide an animation of activation waves associated with electrical activity of tissue over catheter electrode 32. In some embodiments, processing circuitry 22 is configured to present respective three-dimensional surfaces 48 to display 29 over time, wherein a new one of three-dimensional surfaces 48 is displayed at a rate of less than every tenth of a second.

[0078] In some embodiments, the processing circuit is configured to respond to a corresponding sampled voltage value or displacement 52 ( Figure 4A ) to adjust the corresponding region 54 ( Figure 4A ) is colored (box 88).

[0079] Interface 39( Figure 1 ) is configured to receive user input (block 90) to change the viewing angle of some of the three-dimensional surfaces 48. Processing circuitry 22 is configured to present some of the three-dimensional surfaces 48 at different viewing angles in response to the received user input (block 92).

[0080] As used herein, the term "about" or "approximately" for any numerical value or range indicates a suitable dimensional tolerance that allows the component or collection of elements to achieve its intended purpose as described herein. More specifically, "about" or "approximately" can refer to a range of ±20% of the value of the recited value, for example, "about 90%" can refer to a range of values ​​from 71% to 99%.

[0081] For clarity, various features of the invention described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, for simplicity, various features of the invention are described in the context of a single embodiment and may also be provided separately or in any suitable subcombination.

[0082] The above embodiments are cited by way of example, and the present invention is not limited by what has been specifically shown and described hereinabove. On the contrary, the scope of the present invention includes combinations and subcombinations of the various features described above, as well as variations and modifications thereof, which will occur to those skilled in the art upon reading the above description and which are not disclosed in the prior art.

Claims

1. A medical system comprising: a catheter configured to be inserted into a chamber of a heart of a living subject and comprising catheter electrodes configured to contact tissue at corresponding locations within the chamber of the heart; monitor; as well as processing circuitry configured to receive a signal from the catheter and, in response to the signal: Sampling the voltage value of the signal at a corresponding sampling time; computing respective curved three-dimensional surfaces describing electrical activity of the tissue on the catheter electrodes at respective ones of the sampling times in response to: (a) respective positions of respective catheter electrodes; and (b) a corresponding sampled voltage value indicative of electrical activity of the tissue sensed by the corresponding catheter electrode at the corresponding location at the corresponding sampling time; and The respective three-dimensional surfaces are rendered to the display over time. 2 . The system of claim 1 , wherein the processing circuit is configured to colorize a respective region of the respective three-dimensional surface in response to respective ones of the sampled voltage values.

3. The system of claim 1 , wherein: The corresponding positions of the corresponding catheter electrodes are corresponding projected positions projected onto a plane; the processing circuitry being configured to calculate, in response to respective ones of the sampled voltage values ​​at respective ones of the sampling times, respective displacements perpendicular to the plane from respective ones of the projected positions of respective ones of the catheter electrodes; and The processing circuitry is configured to fit the respective curved three-dimensional surfaces describing the electrical activity of the tissue on the catheter electrode at respective ones of the sampling times in response to respective ones of the displacements perpendicular to the plane from respective ones of the 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 respective ones of the displacements.

5. The system of claim 1 , wherein the processing circuit is configured to: sampling the voltage value of the signal at the corresponding sampling time at a rate exceeding ten times per second; and The respective three-dimensional surfaces are rendered to the display over time, wherein a new one of the three-dimensional surfaces is 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.

6. The system according to claim 1 further includes an interface configured to receive user input to change the perspective of some of the three-dimensional surfaces, wherein the processing circuit is configured to present some of the three-dimensional surfaces at different perspectives in response to the received user input.

7. The system of claim 1 , wherein: The catheter comprises: a shaft having a distal end; and a distal end assembly on which the catheter electrode is disposed; and The respective positions of the respective catheter electrodes are respective positions derived from a static computer model of the catheter. 8 . The system of claim 7 , wherein the respective positions of the respective catheter electrodes are respective projected positions projected onto a plane perpendicular to an axis of the shaft.

9. The system of claim 1 , wherein: The catheter comprises: a shaft having a distal end; and a distal end assembly on which the catheter electrode is disposed; and The processing circuit is configured to calculate the respective positions of the respective catheter electrodes.

10. The system of claim 9, wherein the respective positions of the respective catheter electrodes are respective projected positions projected onto a plane perpendicular to an axis of the shaft.

11. A software product comprising a non-transitory computer-readable medium having program instructions stored therein, 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 comprising catheter electrodes configured to contact tissue at corresponding locations within the chamber of the heart; In response to the signal, sampling a voltage value of the signal at a corresponding sampling time; computing respective curved three-dimensional surfaces describing electrical activity of the tissue on the catheter electrodes at respective ones of the sampling times in response to: (a) respective positions of respective catheter electrodes; and (b) a corresponding sampled voltage value indicative of electrical activity of the tissue sensed by the corresponding catheter electrode at the corresponding location at the corresponding sampling time; and The respective three-dimensional surfaces are rendered to a display over time.

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