Display control device and method of operating the display control device

Abstract

To provide a display control unit enabling a medical worker to identify an abnormal part of the cardiac muscle, and an operation method for the same.SOLUTION: A display control unit 1 includes: an acquisition part 2 acquiring a subject's inner electrocardiogram; a computation part 3 which computes for generating visualization data indicating an excited state of the cardiac muscle on the basis of the inner electrocardiogram; a discrimination part 4 discriminating the kind of the excited state of the cardiac muscle on the basis of the visualization data; and a display control part 6 which displays onto a stereoscopic image of the subject's heart a part whose inner electrocardiogram is acquired in color in accordance with the rate of the discriminated kind of an excited mode.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a display control device for displaying data acquired from a cardiac catheter and a method of operating the display control device.

Background Art

[0002] Generally, atrial fibrillation refers to an arrhythmia in which the atria of the heart spasm and the normal movement of the heart cannot be performed. When atrial fibrillation occurs, blood stagnates in the atria and blood clots are likely to occur, increasing the risk of cerebral infarction and the like.

[0003] Therefore, conventionally, when an arrhythmia such as atrial fibrillation occurs, it is known to selectively ablate (ablation) the abnormal site causing the arrhythmia using a cardiac catheter for treatment. To perform this treatment, it is important to accurately identify the position to be ablated. For example, in Patent Documents 1 and 2 below, by performing arithmetic processing on an intracardiac electrocardiogram measured from the electrodes of a cardiac catheter, visualization data indicating the excitation state of the myocardium is created, and a technique for identifying the ablation position from the visualization data has been proposed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The state of myocardial excitation during atrial fibrillation is roughly classified into types called, for example, several typical excitation dynamics depending on the pattern of change in the state. In conventional technology, healthcare professionals must visually observe the state of the myocardium, visualized based on visualization data, to determine the type of myocardial excitation dynamics. However, the state of the myocardium during atrial fibrillation changes rapidly and irregularly, and these changes can sometimes occur too quickly to be detected visually. Due to these circumstances, conventional technology has sometimes made it difficult for healthcare professionals to visually determine the excitation dynamics while simultaneously identifying the abnormal area of ​​the myocardium.

[0006] Therefore, the present invention aims to provide a display control device and a method for operating the display control device that can assist medical professionals in identifying abnormal areas of the myocardium. [Means for solving the problem]

[0007] One embodiment for achieving the above objective is a display control device comprising: an acquisition unit for acquiring an intracardiac electrocardiogram of a subject; a calculation unit for generating visualization data representing the excitation state of the myocardium based on the intracardiac electrocardiogram; a discrimination unit for determining the type of excitation dynamics of the myocardium based on the visualization data; and a display control unit for color-coding the areas where the intracardiac electrocardiogram was acquired on a three-dimensional image of the subject's heart according to the proportion of the determined types of excitation dynamics.

[0008] With this configuration, the proportion of each type of identified excitation dynamics (e.g., the proportion of "Non Passive Ratio: NP") is displayed in color on a three-dimensional image of the heart. This allows healthcare professionals to visually and intuitively identify areas that are likely to be abnormal in the myocardium, making it easier for them to formulate treatment strategies.

[0009] Furthermore, another embodiment for achieving the above objective includes the steps of: an acquisition unit acquiring an intracardiac electrocardiogram of the subject; a calculation unit performing calculations to generate visualization data representing the excitation state of the myocardium based on the intracardiac electrocardiogram; a discrimination unit determining the type of excitation dynamics of the myocardium based on the visualization data; and a display control unit color-coding the area where the intracardiac electrocardiogram was acquired on a three-dimensional image of the subject's heart according to the proportion of the determined type of excitation dynamics. [Effects of the Invention]

[0010] According to the above embodiment, it is possible to provide a display control device and a method for operating the display control device that can assist medical professionals in identifying abnormal areas of the myocardium. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram of a display control device according to Embodiment 1 of the present invention. [Figure 2] Figures (a) to (c) show the excitation dynamics of representative types of cardiac muscle. [Figure 3] This is a schematic diagram showing a catheter placed in the atrium. [Figure 4] This diagram illustrates the number of excitation grids included in the frames that make up the visualization data. [Figure 5] This diagram illustrates a method for identifying the type of excitation dynamics of the myocardium. [Figure 6] This is an illustrative diagram showing how visualization data can be displayed continuously in a time series. [Figure 7] This is a diagram illustrating the data structure of the memory unit. [Figure 8] This is an image showing a 3D view of the patient's heart. [Modes for carrying out the invention]

[0012] Hereinafter, an example of this embodiment will be described with reference to the drawings. (Embodiment 1) As shown in FIG. 1, the display control device 1 according to Embodiment 1 includes an acquisition unit 2, a calculation unit 3, a discrimination unit 4, a storage unit 5, and a display control unit 6. The display control device 1 is used as a device for executing one function in, for example, a catheter inspection device. The display control device 1 is connected to a display device 7.

[0013] The acquisition unit 2 acquires an intracardiac electrocardiogram of a subject recorded by a recording unit (for example, a cardiac catheter A) having a plurality of electrodes.

[0014] The calculation unit 3 performs calculations for visualizing the excitation state of the myocardium of the subject on the intracardiac electrocardiogram acquired by the acquisition unit 2. The calculation unit 3 includes a first generation unit 11, a first complementation unit 12, a correction unit 13, a second generation unit 14, a second complementation unit 15, a third generation unit 16, and a detection unit 17. The operation contents of each part of the calculation unit 3 will be described later.

[0015] The discrimination unit 4 discriminates the type of myocardial excitation dynamics based on the visualization data. The discrimination unit 4 has a calculation unit 18 for calculating a predetermined number of data included in the visualization data. The visualization data for discriminating the type of myocardial excitation dynamics is composed of frames for each predetermined time unit. The calculation unit 18 calculates the total number of predetermined grids included in the frame for each predetermined time unit as the predetermined number of data included in the visualization data. The discrimination unit 4 discriminates the type of myocardial excitation dynamics based on the predetermined number of grid numbers calculated by the calculation unit 18 and the number of phase singularity points detected by the detection unit 17.

[0016] The type of myocardial excitation dynamics means the pattern of changes in the myocardial state in which atrial fibrillation occurs. The types of myocardial excitation dynamics are roughly classified into, for example, MR (Meandering Rotor) as shown in Fig. 2(a), PA (Passive Activation) as shown in Fig. 2(b), and MW (Multiple Wavelets) as shown in Fig. 2(c). PA refers to the state (an example of the first state) in which the excitation wave is spreading. MR refers to the state (an example of the second state) in which the excitation wave rotates around the phase singularity. MW refers to the state (an example of the third state) in which multiple phase singularities exist simultaneously.

[0017] The storage unit 5 stores the 3D data Z that forms a three-dimensional image of the subject's heart, the discrimination result data X1 to X10 by the discrimination unit 4, and the three-dimensional color display data C (see Fig. 7).

[0018] The display control unit 6 acquires data from the storage unit 5, generates the three-dimensional color display data C, and transmits it to the display device 7. The display device 7 is composed of, for example, a touch panel type liquid crystal monitor screen.

[0019] Next, the operation of the display control device 1 will be described with reference to Figs. 3 to 8. As shown in Fig. 3, first, a heart catheter A having a plurality of electrodes B is inserted into the atrium of the subject and left at a predetermined location for a predetermined time (for example, 10 seconds in one trial).

[0020] A plurality (10 in this example) of intracardiac electrocardiogram waveforms are recorded by the electrodes B of the heart catheter A. The recorded intracardiac electrocardiogram waveforms are acquired by the acquisition unit 2.

[0021] Next, the first generation unit 11 generates pseudo-action potential waveforms for each of the multiple intracardiac electrocardiograms acquired by the acquisition unit 2. The first complementation unit 12 defines a virtual electrode (virtual electrode) in the myocardium within the atrium at a location where the electrodes of the inserted cardiac catheter A are not placed, that is, at a location where there is a large distance from the surrounding electrodes among the multiple electrodes that are each placed. The first complementation unit 12 complements the pseudo-action potential waveform for the virtual electrode based on the pseudo-action potential waveforms generated for the electrodes surrounding the virtual electrode.

[0022] The correction unit 13 removes noise components contained in the pseudo-action potential waveforms output from the first generation unit 11 and the first interpolation unit 12, and performs correction to equalize the amplitude of each beat. The second generation unit 14 generates a shifted waveform from the action potential waveform output from the correction unit 13, in which the time phase of the action potential waveform is shifted by a predetermined amount of time. The second complementation unit 15 complements the action potential waveform and shift waveform based on the action potential waveform and shift waveform generated for the surrounding electrodes at positions where the electrodes and virtual electrodes of cardiac catheter A are not placed, i.e., positions where there is a distance between each electrode and the surrounding electrodes.

[0023] The third generation unit 16 creates a phase portrait based on the action potential waveform output from the correction unit 13, the shift waveform output from the second generation unit 14, and the action potential waveform and shift waveform output from the second interpolation unit 15. The third generation unit 16 also calculates the phase based on the phase portrait and generates visualization data (Phase Map) representing the excitation state of the myocardium. Visualization data refers to frames that visualize the excitation potential of the myocardium. Electrical excitation occurs in the membrane potential of myocardial cells, and this causes the heart to contract. This excitation-contraction phenomenon is caused by action potentials. An action potential is the excitation response of myocardial cells caused by depolarization due to the influx of Na+ into the cell and repolarization due to the influx and outflow of Ca2+ and K+. The detection unit 17 detects phase singularities in the visualization data generated by the third generation unit 16, i.e., the rotors that cause fibrillation on the atrial wall.

[0024] The discrimination unit 4 sequentially calculates the number of excitation grids in each frame of the visualization data generated by the third generation unit 16 using the calculation unit 18. An excitation grid refers to a grid that indicates the excitation state of the myocardium, and for example, it refers to a grid drawn in a warm color indicating R=255. The number of excitation grids in each frame calculated by the calculation unit 18 is shown, for example, as in graph 81 in Figure 4. Furthermore, the discrimination unit 4 sequentially calculates the moving average of the number of excitation grids in frames (for example, 15 frames) within a predetermined time period using the calculation unit 18. The moving average number of excitation grids is shown, for example, as in graph 82 in Figures 4 and 5.

[0025] Furthermore, the discrimination unit 4 calculates, for example, the average number of excitation grids and sets positive and negative thresholds based on the calculated average number of excitation grids. The average number of excitation grids is shown in Figure 5 as, for example, the average value 83, and the positive and negative thresholds are shown in Figure 5 as, for example, thresholds 84a and 84b. The discrimination unit 4 determines whether the moving average number of excitation grids exceeds the thresholds 84a and 84b, and if it exceeds the threshold, it determines that the excitation dynamics of the myocardium are PA. In graph 82 shown in Figure 5, the moving average number of excitation grids exceeds the thresholds 84a and 84b in range 85, for example, and the excitation dynamics of the myocardium during this time period are determined to be PA. If the moving average number of excitation grids exceeds the threshold, it may also be possible to determine whether the excitation wave occurred within or outside the region of cardiac catheter A by identifying the position of the excitation grid in each frame. In this way, the excitation state PA of the myocardium is further divided into two.

[0026] Furthermore, if the moving average number of excitation grids does not exceed the thresholds 84a, 84b (for example, in the range 86, 87 in Figure 5), the discrimination unit 4 determines the type of myocardial excitation dynamics based on the number of phase singularities 62 of the frames detected by the detection unit 17. If there are multiple phase singularities in the frames, the discrimination unit 4 determines that the myocardial excitation dynamics are MW, and if there are no multiple phase singularities, it determines that the myocardial excitation dynamics are MR.

[0027] Figure 6 is a video image showing the visualization data displayed continuously in a time series, depicting in real time how the excitation state of the subject's myocardium changes. The length of the video is displayed at double speed (e.g., 1 / 10th speed) the time it takes to acquire an intracardiac electrocardiogram in one trial with cardiac catheter A (e.g., 5 seconds). As shown in Figure 6, the discrimination results (types and percentages of excitation dynamics) for the entire video are displayed simultaneously with the start of the video. Specifically, it is displayed as Meandering Rotor (R) = 28%, Multiple Wavelets (M) = 47%, the sum of (R) and (M) (Non Passive Ratio: NP) = 75%, Passive Activation (P) = 25%, and so on. This discrimination result data is stored in the memory unit 5 as discrimination result data X1 at a predetermined location Y1 in the atrium.

[0028] Subsequently, as shown in Figure 7, cardiac catheter A is sequentially moved to predetermined locations Y2 to Y10 within the atrium, and the discrimination result data X2 to X10 are stored in the storage unit 5 by the same process. In this example, for the sake of explanation, the process from acquiring the intracardiac electrocardiogram to obtaining the discrimination result data has been described as a single unit, but this is not the only way. For example, cardiac catheter A could first be sequentially moved to predetermined locations Y1 to Y10 within the atrium, and the intracardiac electrocardiogram waveform data for each location could be prepared and stored, and then the discrimination result data could be obtained for each piece of data.

[0029] After the discrimination result data X1 to X10 for each predetermined location Y1 to Y10 within the atrium is stored in the storage unit 5, the display control unit 6 generates three-dimensional color display data C based on the 3D data Z that forms a three-dimensional image of the heart and the discrimination result data X1 to X10, and stores it in the storage unit 5. At this time, the display control unit 6 determines the color to be displayed at each position on the stereoscopic image corresponding to the predetermined locations Y1 to Y10, based on a predetermined excitation dynamic, for example, the ratio of "Non Passive Ratio: NP", and a predetermined color standard, for each discrimination result data X1 to X10.

[0030] As shown in Figure 8, the color standard is such that, for example, the "Non Passive Ratio: NP" changes in stages from 0% to 100%, sequentially from white, red, orange, yellow, yellow-green, blue, and purple. The display control unit 6 sequentially interpolates the colors in the region between a predetermined location Y1 and a predetermined location Y2, so that the colors change in stages according to the color standard, from the color of the predetermined location Y1 (e.g., white) to the color of the predetermined location Y2 (e.g., purple). In this way, the display control unit 6 completes the three-dimensional color display data C for the entire patient's heart and transmits this three-dimensional color display data C to the display device 7 for display on its screen.

[0031] Figure 8 is an image showing a 3D image of the patient's heart displayed on the display device 7 based on the 3D color display data C. Specifically, it is an example of when the percentage of "Non Passive Ratio: NP" is displayed in color (color-mapped) on the 3D image of the atrium.

[0032] Traditionally, when medical professionals determined the type of myocardial excitation dynamics, they created visualization data showing the excitation state of the myocardium and visually identified the type of excitation dynamics based on that visualization data. However, myocardium during atrial fibrillation can generate oscillations of about 300 times per minute, for example, and it has been difficult to accurately visually identify the excitation dynamics from such rapidly changing myocardial data.

[0033] In contrast, according to the display control device 1 of this embodiment, three-dimensional color display data C is generated based on each of the discrimination result data X1 to X10 and the color standard. The display control unit 6 transmits the three-dimensional color display data C to the display device 7 for display, so that the percentage of "Non Passive Ratio: NP" is displayed in color on the 3D image of the heart, as shown in Figure 8. As a result, medical professionals can visually and intuitively grasp areas with a high percentage of NP, making it easier to formulate treatment strategies.

[0034] Furthermore, the present invention is not limited to the embodiments described above, and can be freely modified and improved as appropriate. In addition, the material, shape, dimensions, numerical values, form, number, and placement of each component in the embodiments described above are arbitrary and not limited as long as they can achieve the present invention.

[0035] For example, in the above embodiment, a phase diagram and visualization data are created using the action potential waveform and the shift waveform, and the type of myocardial excitation dynamics is determined based on the visualization data. However, the configuration is not limited to this, and for example, a Hilbert transform may be performed on the intracardiac electrocardiogram to create a phase diagram and visualization data, and the type of myocardial excitation dynamics may be determined based on the visualization data.

[0036] Further details of exemplary myocardial excitation determination methods are described in U.S. Publication No. 2019 / 0076041, “Myocardial Excitation Determining Apparatus,” filed on March 14, 2017, and the full disclosure thereof is incorporated herein by reference. All features described in this published patent can be implemented together with the features described herein. [Explanation of Symbols]

[0037] 1: Display control discrimination device, 2: Acquisition unit, 3: Calculation unit, 4: Discrimination unit, 5: Storage unit, 6: Display control unit, 11: First generation unit, 12: First completion unit, 13: Correction unit, 14: Second generation unit, 15: Second completion unit, 16: Third generation unit, 17: Detection unit, 18: Calculation unit

Claims

1. An acquisition unit that acquires the intracardiac electrocardiogram of the subject, A calculation unit that performs calculations to generate visualization data representing the excitation state of the myocardium based on the intracardiac electrocardiogram, A discrimination unit that determines the type of myocardial excitation dynamics based on the aforementioned visualization data, A display control unit that displays the area where the intracardiac electrocardiogram was acquired in color on a three-dimensional image of the subject's heart, according to the temporal proportion of the type of myocardial excitation dynamics during a predetermined time period, Equipped with, The acquisition unit acquires intracardiac electrocardiograms of the entire atrium of the subject in multiple steps, sequentially. The calculation unit performs calculations to generate the visualization data for each acquired intracardiac electrocardiogram. The discrimination unit determines the type of excitation dynamics for each site from which the intracardiac electrocardiogram was acquired. The display control unit calculates the ratio for each part from which the intracardiac electrocardiogram was acquired, and fills in the area between the part from which the intracardiac electrocardiogram was acquired and other parts from which the intracardiac electrocardiogram was acquired, according to a color standard that shows the correspondence between the ratio and color. Display control device.

2. The types of excitation dynamics of the myocardium include a first state (PA) indicating a state in which excitation waves are propagating, a second state (MR) indicating a state in which excitation waves are rotating around a phase singularity representing the center of rotation of the excitation state of the myocardium, and a third state (MW) indicating a state in which multiple such phase singularities exist. The display control unit displays the areas where the intracardiac electrocardiogram was acquired in color on a three-dimensional image of the subject's heart, according to the combined proportion of the second state and the third state. The display control device according to claim 1.

3. The visualization data is composed of frames for each predetermined time unit, and each of the frames is composed of multiple grids. The discrimination unit includes a calculation unit that calculates the total number of excitation grids representing the excitation state of the myocardium among the plurality of grids constituting the frame, and determines the type of excitation dynamics of the myocardium based on the total number of excitation grids for each frame and the total number of phase singularities. The display control device according to claim 2.

4. A method for operating a display control device, The acquisition unit performs the step of acquiring the subject's intracardiac electrocardiogram, The calculation unit performs calculations to generate visualization data representing the excitation state of the myocardium based on the intracardiac electrocardiogram, The discriminant unit performs the step of determining the type of myocardial excitation dynamics based on the visualization data, The display control unit performs the steps of color-coding the area where the intracardiac electrocardiogram was acquired on a three-dimensional image of the inside of the subject's atrium, according to the temporal proportion of the type of myocardial excitation dynamics during a predetermined time period, Equipped with, The acquisition unit acquires intracardiac electrocardiograms of the entire atrium of the subject in multiple steps, sequentially. The calculation unit performs calculations to generate the visualization data for each acquired intracardiac electrocardiogram. The discrimination unit determines the type of excitation dynamics for each site from which the intracardiac electrocardiogram was acquired. The display control unit calculates the ratio for each part from which the intracardiac electrocardiogram was acquired, and fills in the area between the part from which the intracardiac electrocardiogram was acquired and other parts from which the intracardiac electrocardiogram was acquired, according to a color standard that shows the correspondence between the ratio and color. How to operate the display control device.

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