CN110996776A

CN110996776A - Method for merging cardiac mapping and model

Info

Publication number: CN110996776A
Application number: CN201880052802.3A
Authority: CN
Inventors: 史蒂夫·阿德勒
Original assignee: Catheter Precision Inc
Current assignee: Catheter Precision Inc
Priority date: 2017-08-01
Filing date: 2018-08-01
Publication date: 2020-04-10
Anticipated expiration: 2038-08-01
Also published as: WO2019028103A2; JP7244108B2; CN110996776B; JP2020529879A; WO2019028103A3; EP3661406A2

Abstract

Various embodiments provide a method of cardiac mapping and model merging, comprising: generating a Premature Ventricular Contraction (PVC) activation map of the heart based on a three-dimensional (3D) heart model and a PVC ECG data record during the PVC; generating a 3D inner surface model of the heart by triangulating point-by-point contact data collected during an Electrophysiology (EP) procedure; merging the 3D activation map and the 3D interior surface model to form a PVC activation surface model; and pacing the heart at a first pacing location disposed in an earliest activation region identified in the PVC activation surface model.

Description

Method for merging cardiac mapping and model

Cross Reference to Related Applications

This application claims priority from the following patent applications: us provisional patent application No. 62/539,740, entitled "method of cardiac mapping and directed guidance," filed 2017, 8, month 1; us provisional patent application No. 62/539,787, entitled "method of cardiac mapping and directed guidance," filed 2017, 8, month 1; us provisional patent application No. 62/539,802, entitled "method for cardiac mapping and model merging," filed 2017, 8, month 1; and us provisional patent application No. 62/711,777 filed 2018, 7, 30, entitled "cardiac mapping system, method, and kit containing fiducial markers," all of which are incorporated herein by reference in their entirety.

Background

Some cardiac defects in the conduction system cause asynchronous contractions (arrhythmias) of the heart and are sometimes referred to as conduction disorders. As a result, the heart does not pump enough blood, which may ultimately lead to heart failure. Conduction disorders have a variety of causes, including age, heart (muscle) injury, drug therapy, and genetics.

Premature Ventricular Contractions (PVCs) are those that begin with an abnormal or abnormal heart beat somewhere in the ventricle, not in the upper chamber of the heart as does a normal sinus beat. PVC generally results in a reduction in cardiac output because the ventricles contract before having an opportunity to fill completely with blood. PVC may also trigger ventricular tachycardia (VT or V-Tach).

Ventricular tachycardia (VT or V-Tach) is another arrhythmia disorder caused by abnormal electrical signals in the ventricles. In VT, abnormal electrical signals cause the heart to beat faster than normal, typically more than 100 beats per minute, with beats beginning from the ventricles. VT typically occurs in populations with potential cardiac abnormalities. VT sometimes occurs in structurally normal hearts, and in these patients, the source of the abnormal electrical signal may be at multiple locations in the heart. One common location is the Right Ventricular Outflow Tract (RVOT), which is the path for blood to flow from the right ventricle to the lungs. In patients with a heart attack, scarring from the heart attack creates an intact myocardial environment and scars that predispose the patient to VT.

Other common causes of conduction disorders include defects in the left and/or right ventricles that rapidly activate fibers, the chikungunya system, or scar tissue. As a result, the left and right ventricles may be out of synchronization. This is called Left Bundle Branch Block (LBBB) or Right Bundle Branch Block (RBBB).

Cardiac Resynchronization Therapy (CRT), also known as biventricular pacing or multipoint ventricular pacing, is a known method of improving cardiac function in the case of LBBB or RBBB. CRT involves pacing the Right Ventricle (RV) and Left Ventricle (LV) simultaneously using a pacemaker. To achieve CRT, in addition to the conventional RV endocardial lead (with or without the Right Atrial (RA) lead), a Coronary Sinus (CS) lead is placed for LV pacing. The basic goal of CRT is to improve the mechanical function of the LV by restoring LV synchrony and enlarged QRS cycle (which is primarily a result of LBBB) in dilated cardiomyopathic patients.

Catheter ablation is the first treatment option for patients with VT and/or symptomatic PVC. The target of ablation is the location in the heart where a PVC occurs or where a VT episode occurs. To determine the appropriate ablation location, the treating physician may first use the proposed location of the electrical cross-stimulation in order to determine whether ablation at the proposed location will provide the desired electrical activation mode stimulation of the heart.

Currently, determining the correct position of the leads to achieve maximum cardiac synchronization or the desired pattern of electrical activation requires a degree of guesswork by the surgeon.

However, current methods do not allow for the determination of the optimal location of the electrical connection on a patient-by-patient basis. Further, if the desired activation pattern is not achieved when the heart is stimulated at a given location, the current methods do not provide directional guidance for adjusting the lead location to provide an improved activation pattern. Thus, improved guidance is needed in determining the correct location of the electrical leads of the CRT and in determining the ablation location.

Disclosure of Invention

Various embodiments provide a method of cardiac mapping and model merging, comprising: generating a Premature Ventricular Contraction (PVC) activation map of the heart based on a three-dimensional (3D) heart model and a PVC ECG data record during the PVC; generating a 3D inner surface model of the heart by triangulating point-by-point contact data collected during an Electrophysiology (EP) procedure; merging the 3D activation map and the 3D interior surface model to form a PVC activation surface model; the heart was paced using an EP catheter at a first pacing location, which was placed in the earliest activation region identified in the PVC activation surface model.

Various embodiments provide a method of cardiac mapping, comprising: attaching 12 electrodes of an Electrocardiogram (ECG) device to a chest of a patient; recording Electrocardiogram (ECG) data using an ECG device; generating an activation map of the heart based on the ECG data, the 3D chest model, and a two-dimensional (2D) image of the patient's heart, the PVC activation map containing regions of earliest activation; determining an offset between an actual position of each electrode and an ideal position of each electrode contained in the 3D chest model based on a comparison of an earliest activated region and an earliest activated predicted region in the activation model; and adjusting the activation map based on the determined offset. Some embodiments include applying a fiducial marker to a patient's body (e.g., chest or torso) to identify an anatomical location, the marker configured to be identified in image data by detecting light reflected from the fiducial marker contained in the image data, such that a patient-specific three-dimensional (3D) anatomical model may be generated that incorporates the image data with the 3D anatomical model of the patient's chest by registering the identified anatomical location with a corresponding anatomical location in an image obtained from a CT or MRI scan.

Drawings

The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate exemplary embodiments of the invention and, together with the general description given above and the detailed description given below, serve to explain the features of the invention.

Fig. 1 is an example of a 3D model of a heart according to various embodiments.

Fig. 2A is a plan view of an electrically activated 3D model of a heart, according to various embodiments.

Figure 2B is a plan view of an electrically activated 3D model of a heart, according to various embodiments.

Fig. 2C is a plan view of a synchronicity map according to various embodiments.

Fig. 2D is a plan view of a synchronicity map according to various embodiments.

Fig. 3 is a schematic representation of a cardiac imaging system according to various embodiments.

Fig. 4A and 4B are plan views of electrically activated 3D models of a heart according to various embodiments.

Fig. 4C and 4D are plan views of a synchronicity map according to various embodiments.

Figure 5 is a schematic representation of a cardiac imaging system, in accordance with various embodiments.

Fig. 6 is a flow diagram illustrating a method according to various embodiments.

Fig. 7A is a schematic representation of LAO and PA views of an electrically activated 3D model of a heart, according to various embodiments.

Fig. 7B is a schematic representation of LAO and PA views of a synchronization map, in accordance with various embodiments.

Fig. 8A is a schematic representation of LAO and PA views of an electrically activated 3D model of a heart, according to various embodiments.

Fig. 8B is a schematic representation of LAO and PA views of a synchronization map, in accordance with various embodiments.

Fig. 9 is a schematic diagram of a surgical imaging system according to various embodiments.

Fig. 10 is a flow diagram of a method of using the system of fig. 9, in accordance with various embodiments.

Fig. 11A is a flow diagram of a method of using the system of fig. 9, in accordance with various embodiments.

Fig. 11B shows an example of a reference cardiac image generated during the method of fig. 11A.

Fig. 11C and 11D illustrate activation maps that may be generated during the method of fig. 11A.

Fig. 12 is a flow diagram of a method of using the system of fig. 9, in accordance with various embodiments.

Fig. 13 is a system block diagram of a cardiac imaging system according to various embodiments.

Figures 14A and 14B are 3D images of electrical leads and fiducial markers on a torso of a patient according to various embodiments.

Detailed Description

Various embodiments are described in detail with reference to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. References to specific examples and implementations are for illustrative purposes, and are not intended to limit the scope of the invention or the claims.

An Electrocardiogram (ECG) is defined herein as any method that (preferably non-invasively) correlates the actual electrical activity of the myocardium with a measurement or derivation of the heart (electrical activity). In the case of a classical electrocardiogram, the potential difference between the body surface electrodes is related to the electrical activity of the heart. The derived ECG may also be obtained by other means, e.g. by measurement by a so-called ICD (implantable cardioverter defibrillator). In order to obtain such a functional image, an estimate of the motion of the electrical activity must be provided.

Dyssynchrony of the heart has a deleterious effect on cardiac function by reducing Left Ventricular (LV) mechanical properties, while increasing myocardial oxygen consumption. Furthermore, cardiac dyssynchrony may lead to LV reconstruction. Thus, cardiac dyssynchrony accelerates the progression of chronic Congestive Heart Failure (CHF) and decreases patient survival.

During normal conduction, cardiac activation begins in the Left (LV) and Right (RV) ventricular endocardium. In particular, the electrical pulse (i.e., the depolarization wave) travels through the left and right ventricles substantially simultaneously. Bundle Branch Block (BBB) is a condition in which there is a delay or blockage along the path of an electrical pulse. A delay or obstruction may occur on the path of the electrical impulses sent to the left or right ventricle.

The left BBB is a condition where the electrical pulse to the LV is slow, and is one of the major causes of cardiac dyssynchrony. In particular, activation begins only in the RV and proceeds through the septum before reaching the LV endocardium.

A pacemaker is an electronic device, approximately the size of a pocket watch, that senses intrinsic heart rhythm and provides electrical stimulation when indicated. Cardiac pacing may be temporary or permanent.

Permanent pacing is most commonly accomplished by transvenously placing the leads to the endocardium (i.e., the right atrium or ventricle) or epicardium (i.e., through the LV surface of the coronary sinus), which are then connected to a pacing generator placed subcutaneously in the subclavian region. However, miniaturized pacemakers have been developed for direct cardiac surface grafting or implantation into the heart.

Cardiac Resynchronization Therapy (CRT) is a special pacemaker therapy that provides biventricular pacing. CRT is performed with or without an Implanted Cardioverter Defibrillator (ICD), a device used to treat and prevent patients at risk for Ventricular Tachycardia (VT) or Ventricular Fibrillation (VF).

In this application, the region of the heart that is electrically stimulated (e.g., paced) by pacing electrodes, microcatheters, etc., may be interchangeably referred to as a "pacing site" or "stimulation site".

Fig. 1 shows a three-dimensional (3D) model of a heart 1 as seen from two different directions. The 3D model contains a mesh 6 representing the outer surface of the heart, here the surface of the myocardium. In this example, the mold may also contain a membrane wall. The mesh 6 has a plurality of nodes 8. In this example, the mesh is a triangular mesh, where the surface of the heart is approximated by adjacent triangles.

Fig. 2A-2D are 3D models 4 of the heart showing the initial electrical activation of the heart 1 from various single stimulation locations 10. Fig. 2A-2C show the ventricular surface of a myocardium with a septal wall 2. In general, the 3D model 4 may contain a mesh 6 representing the ventricular surface of the heart, here the outer surface of the ventricular myocardium with a septal wall as shown in fig. 1. The mesh 6 has a plurality of nodes 8. In the example shown, the heart 1 is electrically stimulated at a stimulation site 10. When electrical stimulation is performed at the stimulation site 10, electrical signals will pass through the heart tissue. Thus, different parts of the heart will be activated at different times. Each location on the heart has a specific delay with respect to the initial stimulation. Each node 8 has a value associated with it that represents the time delay between stimulating the heart 1 at the stimulation location 10 and activating the heart at the respective node 8. Locations that share the same delay time are connected by the isochrones 12 in fig. 2A-2D. In this application, isochrones are defined as lines drawn on a 3D cardiac surface model that connect points on the model where activation occurs or arrives simultaneously. In this example, the delay times of the nodes across the surface of the heart are also displayed by different rendered shadows. The vertical bar indicates the time delay (milliseconds) associated with the respective color. It should be understood that the stimulation site 10 may be an intrinsic activation site of the heart 1.

Fig. 3 is a system block diagram of system 100 for providing a representation of the synchronicity of electrical activation of cardiac tissue. System 100 includes a processing unit 102 and a memory 104.

The 3D electro-active model 4 may be obtained by combining electrocardiogram and medical imaging data in the system 100. This data may be stored in the memory 104. The processing unit 102 may be connected to an electrocardiogram system 106 and a medical imaging system 108 for retrieving data and storing corresponding data in the memory 104. The processing unit 102 may apply an Electrocardiography (ECGI) method capable of determining cardiac activation from a 12-lead ECG to determine the electrically activated 3D model 4 of the heart. In the ECGI method, the ECG signal may be combined with a patient-specific 3D anatomical model of the heart, lungs and/or torso in order to calculate the position of the cardiac isochrone. The patient-specific 3D anatomical model may be obtained from a Magnetic Resonance Image (MRI) or a Computed Tomography (CT) image received from the medical imaging system 108. Alternatively or additionally, the 3D anatomical model showing the closest agreement with the patient may be selected from a database containing a plurality of 3D anatomical models and optionally modified. The selected and optionally modified 3D anatomical model may be used as a patient-specific 3D anatomical model.

The 3D model 4 may also contain further information. In the example shown in fig. 2A, the 3D model 4 may contain cardiac vessels 14 and/or veins on the myocardium. This information may be added to the 3D model 4 as nodes are indicated as being associated with such vessels. The blood vessel 14 may then be identified and optionally displayed in the 3D model 4. Optionally, the processing unit 102 may comprise a first identification unit 110 arranged for automatically retrieving information representative of the location of such blood vessels from a 3D anatomical model of the heart of the patient. The processing unit 102 may then automatically insert this information into the 3D model 4.

The 3D model 4 may also contain information about scar tissue. Scar tissue locations may be obtained from delayed enhancement Magnetic Resonance Imaging (MRI) images and added to the 3D model 4. Scar tissue can be modeled in the 3D model 4 by reducing the propagation velocity of the electrical signal. Scar tissue may also be explained by selling transitions from one node to another node to very slow or non-transitions in areas of the heart wall where scar tissue is present. Optionally, the processing unit 102 may comprise a second recognition unit 112 configured and arranged for automatically retrieving information representative of the location of such scar tissue from a 3D anatomical model of a patient-specific heart. The processing unit 102 may automatically insert this information into the 3D model 4.

In various embodiments, the obtained 3D model 4 may be used to obtain further information about the electrical activation of the heart. For example, a time delay for activation from one node to another node may be determined. This can be used to generate other views based on the 3D model 4 resulting from initial stimulation at other nodes of the mesh 6. To achieve this, the processing unit 102 may comprise an insertion unit 114, which may take the 3D model 4 and define a certain node as the stimulation location. It should be understood that the 3D model 4 may assume stimulation at predetermined nodes. For calculation purposes, the insertion unit 114 may remove the stimulus at the predetermined node.

Fig. 2B shows an example of a 3D model 4 resulting from an initial stimulus at another stimulus location 10'. It should be understood that a view may be generated for each node of the mesh 6 that results from the initial stimulus at the other nodes of the mesh 6.

The particular electrical activation sequence of the entire heart 1 resulting from stimulation at a particular node may be summarized as a single parameter, i.e. heart activation synchronicity. Cardiac activation synchronicity provides an indication of how the entire heart is activated in synchronization. For the general case, a more synchronous activation of the heart is considered to be beneficial. The measure of synchronicity of cardiac activation in this example is the standard deviation (std) of the depolarization (dep) time of the heart. Thus, cardiac activation synchronicity provides an indication of the synchronicity of activation of the entire heart as a result of stimulation at the respective node. The processing unit 102 may comprise a synchronicity determination unit 116 configured to determine synchronicity of cardiac activation.

In various embodiments, cardiac activation synchronicity may be determined separately for stimulation at each node. Thus, each node of the mesh may be provided with a measure of cardiac activation synchronicity. The processing unit 102 may comprise a synchronicity map generation unit 118 configured to generate a synchronicity map based on the calculation of the synchronicity of the cardiac activation of each node by the synchronicity determination unit 116. The processing unit 102 may be connected with an output unit 120 arranged to output the synchronicity map 15 and/or the replacement data to a user. The output unit may be a display unit, a printer, a message unit, etc.

Fig. 2C shows an example of cardiac synchrony fig. 15. In the example shown in fig. 2C, cardiac activation synchronicity is indicated for each node in fig. 15. In this example, the indication may be displayed by providing a false and/or equivalent synchronization line 16. The isochrone 16 connects nodes with the same heart activation synchronicity. Cardiac synchrony fig. 15 provides a single 3D overview showing locations on the heart that result in good cardiac activation synchrony, and locations on the heart that result in poor cardiac activation synchrony if the heart is stimulated at those locations. In the example shown in fig. 2C, it can be seen that the original stimulation site 10 does not provide particularly good synchronization, with the heart activation synchronicity value being about 45ms standard deviation of the heart depolarization time. The worst stimulation location (here the location with the highest heart activation synchronicity value) is indicated with S-. In this example, the most favorable stimulation location where the lowest cardiac activation synchronicity value occurs is indicated with S +. In some cases, as shown in fig. 2D, the most favorable stimulation location S + can be best seen when the synchronicity map 15 is viewed from another direction.

Another example of a measure of cardiac activation synchronicity is the range of depolarization times (maximum depolarization time-minimum depolarization time). The range of depolarization times may be corrected for cycle length. Another example of a measure of cardiac activation synchronicity is the standard deviation of the depolarization time of the Left Ventricle (LV) only. Another example of a measure of synchronicity of cardiac activation is the delay between stimulation and diaphragm activation. Another example of a measure of cardiac activation synchronicity is AV delay. Another example of a measure of cardiac activation synchronicity is VV delay. It should be appreciated that the measure of synchronicity of cardiac activation may be selected based on the task at hand and/or based on the particular condition or abnormality experienced by the patient.

Fig. 4A shows a second example, in which a second stimulation location 18 is defined. The electrical activation of the heart is calculated using the 3D model 4 and the simultaneous stimulation at the first stimulation location 10 and the second stimulation location 18. In this example, for calculation purposes, the insertion unit 114 does not remove the stimulus at the first location 8. Figure 4A shows the calculated resulting electrical activation of the heart 1. In the example shown in fig. 4A, the total activation time is shortened due to the addition of the second stimulation site 18. In this example, the first stimulation location 10 represents an intrinsic activated location of the heart, or a first selected stimulation location, or stimulation produced by a pacemaker lead already present within the heart.

Fig. 4B shows an example of electrical activation of the heart resulting from the initial stimulation at the second stimulation site 18' simultaneously with the stimulation at the first stimulation site 10. It should be understood that a view resulting from an initial stimulus at a second node of the mesh 6 (concurrent with a stimulus at a first node associated with the first stimulus location 10) may be generated for each node of the mesh 6.

In the examples shown in fig. 4C and 4D, specific electrical activation sequences for the entire heart are combined and shown as heart activation synchronicity. In this example, the electrical activation sequence includes stimulation at the second stimulation site 18 (while stimulation occurs at the first stimulation site 10). Cardiac activation synchronicity again provides an indication of how to activate the entire heart synchronously. In some embodiments, cardiac activation synchronicity may be determined separately for stimulation of each node (stimulation occurring at both the first stimulation location 10 and the second stimulation location 18). This provides a measure of the synchronicity of cardiac activation for each node that serves as the third stimulation location for the mesh 6.

Fig. 4C shows an example of a cardiac synchrony map, which shows locations on the heart that, if stimulated simultaneously at the first and

second stimulation locations

10, 18, stimulate the heart at those locations, resulting in good cardiac activation synchrony, and locations on the heart that result in poor cardiac activation synchrony. In the example shown in fig. 4C, the most unfavorable third stimulation location S-has the highest cardiac activation synchronicity value of about 41ms when the first stimulation location 10 and the second stimulation location 18 are stimulated simultaneously. In this example, the most favorable third stimulation location S + has the lowest cardiac activation synchronicity value when stimulating the first stimulation location 10 and the second stimulation location 18 simultaneously. In some cases, the most favorable stimulation location S + can be best seen when the synchronicity map 15 is viewed from another direction, as shown in fig. 4D.

Fig. 5 is a data flow representation of a system 100 for providing a synchronicity map. Fig. 6 illustrates a method of determining cardiac synchrony using the system 100 illustrated in fig. 3 and 5, according to an embodiment. Referring to fig. 3 and 5, the system 100 includes a processing unit 102 that receives data from hardware modules. Optionally, the processing unit 102 may receive ECG data from the electrocardiogram system 106. The processing unit may receive patient-specific anatomical data from the medical imaging system 108.

The processing unit 102 may receive information from the positioning system 109 regarding the location of the ECG leads relative to the patient's anatomy, such as a 3D image of the patient's chest containing the electrodes. The 3D image and the torso model may be aligned and the positions of the electrodes in the model may be adjusted to coincide with the positions of the electrodes in the 3D image. Knowledge of the location of the ECG electrodes relative to the heart, particularly the V1-6 precordial electrode, may be particularly important for accurately calculating the location of the onset of the PVC.

In some embodiments, the offset of the electrode from its assumed ideal position, particularly the offset of the V1-6 electrode, may be determined based on a comparison of the detected ECG signal of normal heart beats with the ideal ECG normal heart beat signal. For example, the offset may be determined based on how the detected ECG signal will be affected by the change in position of the electrode relative to the ideal electrode position. In particular, the recorded ECG data can be used to determine the location of the stimulation episode for normal beats. Because the normal attack position in the SA node is known, the determined offset position can be compared to this known attack position and their offset can be inferred based on the change between the electrodes. Thus, the electrode offset may be determined without generating a 3D map.

From the patient-specific anatomical data, the processing unit 102 may determine the synchronicity map 15. The processing unit 102 may contain the following elements and may perform the operations of the method 200 shown in fig. 6 and described below to generate the synchronicity map. In the method 200, the processing unit 102 may use a patient-specific 3D anatomical model of the patient's chest cavity and the size, orientation, and position of the heart within the chest cavity. Such a model may be selected in block 201 for further use by the processing unit 102. The processor may determine whether such a model is already available in determination block 202. If a model is not yet available (i.e. determination block 202 ═ N), the retrieval unit 103 may check in determination block 204 whether a suitable anatomical model of the patient is present in the database 117.

If no suitable patient-specific anatomical model is available in the database 117 (i.e. it is determined that block 202 is N), the retrieving unit 103 may generate a patient-specific anatomical model based on the received patient-specific anatomical 3D image data in block 208.

If a suitable patient-specific anatomical model is available in the database 117 (i.e. it is determined that block 202 is Y), the retrieving unit 103 retrieves the suitable anatomical model from the database 117 in block 206. Also in block 206, the retrieving unit 103 may adapt the anatomical model from the database to the 3D image of the patient in order to convert the selected anatomical model into a (quasi-) patient-specific 3D anatomical model. Optionally, the patient-specific 3D model may also contain the size, orientation and/or location of other structures in the patient's body, such as the lungs and/or other organs. The patient-specific 3D model may be a volumetric conductor model.

If a patient model is available (i.e., determine block 202 ═ Y), or the patient model created in block 208 or the stored model adapted to the patient in block 206, the locations of the ECG leads, and the patient-specific model are used, lead locator module 105 can determine the corresponding locations of the ECG leads in the patient-specific 3D model to provide an enhanced patient-specific model in block 210.

In determination block 212, when a patient-specific anatomical model and/or enhanced patient-specific model is available, it is determined whether ECG data representative of intrinsic or stimulation activation is available. If intrinsic activation data or pacing stimulation from one or more already existing pacemaker leads is available (i.e., it is determined that block 212 ═ Y), then in block 214, the activation unit 107 may generate a 3D electrical model showing the current activation of the patient's heart based on the patient-specific model and ECG data.

If no ECG data regarding intrinsic or stimulation activation is available (i.e., determination block 212 ═ N), then in block 216, the virtual stimulation unit 111 may add initial virtual stimulation to the electrical model of the heart based on previously determined and/or assumed rates of transition between nodes. For example, the assumed transition speed may be 0.8 ms. As described above, the electrical model may contain arterial, venous, and/or scar tissue. In block 218, a virtually-activated 3D electrical model of the patient's heart may be generated.

As described above, in block 222, the synchronicity determination unit 116 may generate the synchronicity map 15 from an intrinsic, stimulated or virtually activated 3D electrical model of the patient's heart. Based on the synchronicity map, the processing unit 102 may determine whether the artificial stimulation location or the virtual stimulation location results in optimal activation and synchronicity in determination block 230. If so (i.e., determine block 230 ═ Y), the processing unit may calculate the optimal stimulation location for the patient's heart in block 234.

If it is determined in block 230 that the best synchronicity has not been achieved (i.e., determination block 230 ═ N), then the method 200 proceeds to determination block 232 where it is determined whether additional virtual stimulation locations are needed or should be added, or whether the virtual stimulation locations should be moved or changed relative to the timing parameters. Such a determination may be made by the clinician, the processing unit, or the clinician based on information or recommendations presented by the processing unit on the display.

If it is determined that additional virtual leads are needed (i.e., determination block 232 ═ Y), then in block 224, virtual pacing locations may be added according to the determined synchronicity. If it is determined that no additional virtual leads are needed and the virtual stimulation location should be moved or changed (i.e., determination block 232 ═ N), then the artificial or virtual stimulation location may be adjusted accordingly in block 225.

In block 226, a new activation may be generated. The synchronicity may then be recalculated in block 222, and the process may be repeated until it is determined in determination block 230 that the desired activation is achieved.

The system 100 may also virtually adjust the current artificial stimulation location, i.e., the pacemaker lead location, relative to its current stimulation parameters to achieve optimal synchronicity.

The system 100 may also be used to assess multiple stimuli. For example, the multiple stimulation may be a combination of intrinsic activation and stimulation activation (pacing). For example, the multiple stimulation may be multiple stimulation activation (pacing). It is possible for the user or the processing unit 102 to determine 232 whether additional stimulation locations, such as additional pacemaker leads, are needed.

If additional stimulation locations are desired, additional stimulation locations may be inserted through insertion unit 114. Then the activation of the situation with the original stimulation location and the added virtual stimulation location may again be determined in block 226 and the synchronicity may be recalculated in block 222. Based on the synchronicity map, the processing unit 102 may determine whether the additional virtual stimulation locations result in optimal synchronicity in determination block 230. If optimal synchronicity is not achieved, the method 200 proceeds to block 232 where it is determined whether additional virtual stimulation locations should be added with respect to the timing parameters or whether virtual stimulation locations should be moved or removed. In this case, the process may be repeated one or more times.

Based on the patient-specific cardiac activation model, a cardiac synchronicity model may be generated. The synchronicity model may be a 3D heart surface model containing isochrones as described above, where the isochrones represent the activation synchronicity of the heart. This synchronicity may be based on a particular activation condition, such as right ventricular activation at a lead location of the pacemaker.

As an example, a synchronicity model may be generated and the activation isochrones in LBBB mode may be determined in the following block.

1A) Patient-specific anatomical 3D models of the heart, lungs and chest can be generated, for example, based on MRI or CT images of the patient, or derived from models taken from a database of fitting patient sizes, for example, using a 3D camera. The anatomical 3D model may comprise a 3D surface model of the heart, a 3D surface model of the lungs and a 3D surface model of the chest cavity. The 3D surface model may be a close approximation of the actual surface of the heart by a mesh of multiple polygons (such as triangles) that are connected at their corners. The interconnected corners form nodes of the mesh.

1B) An ECG, such as a 12 lead ECG, may be measured. The exact position of the electrodes of the ECG device on the chest can be recorded. The position of the electrodes in the 3D anatomical model is used to estimate the distribution, fluctuations and/or movement of electrical activity through the cardiac tissue. The exact location of the recording leads or the ECG device can be entered into the anatomical 3D representation of the chest.

1C) Alternatively, scar tissue may be incorporated into the anatomical 3D representation of the heart. The presence and location of scar tissue can be derived from the delayed enhancement MRI images.

1D) The measured values for each recorded lead of the ECG device may be related to the geometry of the heart and torso. Using the reverse process, intrinsic activation can be determined. The distribution, fluctuation, and/or movement of electrical activity through the cardiac tissue may be based on a myocardial distance function, a fastest path algorithm, a shortest path algorithm, and/or a fast marching algorithm.

2) Once the activation isochrones of the intrinsic LBBB pattern are determined, stimulation sites may be added to the intrinsic activation of each node on the heart, and the desired synchronicity of the heart may be calculated from the results. "node" refers to the intersection of triangles on which the anatomical 3D heart model is based.

The above method may also be used to determine the optimal location for placement of the cardiac pacemaker electrodes. To determine the optimal pacing site, a synchronicity map may be calculated. The intrinsic activation map, in combination with the determined stimulation points, may be applied to a new cardiac isochrone location map.

Fig. 7A shows an example of a 3D synchronicity map of LBBB activation patterns of the heart. On the left, fig. 7A shows a left anterior oblique (LOA) view. On the right, fig. 7A shows a back-front (PA) view. Fig. 7B shows a synchronicity map of the heart of fig. 7A. On the left side, fig. 7B shows the LAO view, and on the right side, fig. 7B shows the PA view.

The synchronicity map of fig. 7B shows the standard deviation of the depolarization time of the heart due to one additional stimulation location in combination with the intrinsic activation of the heart. As can be seen in fig. 7B, selecting additional stimulation locations on basal left free wall 20 minimizes the standard deviation of the depolarization time of the heart. Thus, in this example, the region on the left free wall of the base may be selected as the optimal location for the pacemaker electrode.

An updated 3D model of the electrical activation of the heart may be generated, containing intrinsic activation (while stimulation occurs in the region on the left free wall of the fundus). This updated 3D map can then be used to generate a new synchronicity map to check lead locations in the RV. By doing so, the clinician can determine whether the lead should also be stimulated, not just sensed. The clinician may also determine whether the lead should be moved. The clinician may also determine whether additional stimulation leads should be added.

The clinician may also determine whether intrinsic AV conduction is beneficial. Intrinsic AV conduction will typically be conducted to the right tract, after which the LV needs to be activated by stimulating the LV. This can be reversed, i.e., the RBBB waits for LV activation and stimulates RV free wall at the optimal location. By repeating this process for the left and right ventricles, the exact location and timing of cardiac pacing can be fine tuned.

When intrinsic activation signals are not available due to severe damage to the heart, the entire procedure may be performed using only analog (pacemaker) stimulation instead of intrinsic activation. In this case, the above blocks 1B and 1D may be omitted. The whole process will then be based on manual activation.

Fig. 8A shows an example of left stimulation activation of LBBB pattern. On the left, fig. 8A shows the LAO view and on the right the PA view. Fig. 8B shows an example of the synchronicity of the heart shown in fig. 8A fig. 15. On the left, fig. 8B shows the LAO view and on the right the PA view. The synchronicity chart of fig. 8B illustrates the standard deviation of depolarization times of the heart due to one additional stimulation location in combination with left stimulation activation of the heart. As can be seen from fig. 8B, selecting additional stimulation locations in the region on the basal left free wall 20 minimizes the standard deviation of the depolarization time of the heart. Thus, in this example, the region on the left free wall of the base may be selected as the optimal location for the pacemaker electrode. An updated 3D model of the electrical activation of the heart may be generated, containing intrinsic activation (while stimulation occurs in the region on the left free wall of the fundus).

The entire procedure described above may be performed during the implantation procedure to find the optimal pacing site.

Fig. 9 is a block diagram of a cardiac imaging system according to various embodiments. Fig. 10 is a flow diagram illustrating a method 300 of implanting an electrode using the system of fig. 9, in accordance with various embodiments. Referring to fig. 9 and 10, in block 301, a 3D activation map of a heart of a patient may be generated by a processing unit 400 of the system. In particular, a 3D model of the patient's chest and/or heart may be generated by the CT or MRI device 108, ECG data of the patient may be recorded by the ECG recorder 106, and a 3D image of the patient's torso may be generated by the 3D camera 109. This data may be provided to the activation map generator 320 of the processing unit 400. The ECG data may contain extrinsic and/or intrinsic stimulation signals received from the patient.

In block 302, the location of one or more predicted optimal pacing locations may be identified. For example, the activation map may be provided to the synchronicity determination unit 322 to determine cardiac synchronicity. This data may then be used by virtual stimulation point generator 324 to identify one or more suggested pacing locations.

In CRT patients, the pacing site may be located where cardiac dyssynchrony occurs, thereby predicting its stimulation to generate the maximum amount of cardiac activation and/or synchrony. Pacing locations may be based on, for example, differences between LV and RV activation times, earliest and/or latest activation of the LV and/or RV, detected depolarization wave blockages, and the like.

In block 304, one or more virtual pacing locations may be displayed. For example, one or more pacing locations may be added to the activation map as virtual pacing locations. Optionally, activation maps and images generated by a real-time imaging device 328, such as a fluoroscope, a radiographic device, an x-ray Computed Tomography (CT) device, and the like, may be provided to the image integrator 326. The image integrator 326 may compare and/or align the activation map with the real-time image. Based on the comparison and/or alignment, an activation map containing stimulation points may be overlaid on the real-time image. In other embodiments, virtual stimulation points may be added to the real-time image to produce a modified real-time image, which may be provided to display 330 for rendering.

In some embodiments, in addition to displaying the activation map, block 304 may include providing a reference image showing the internal structure of the heart to display 330. The additional image may be based on a 2D cardiac image, such as one of the MRI or CT images used to generate the activation map. Such 2D images may be modified to show additional features. For example, the 2D cardiac image may be modified to identify structures contained in the region of earliest activation and/or pacing locations contained in the activation map. Thus, when positioning the electrodes using the real-time imaging device 328, reference images may be referenced. The reference image is discussed in detail below with reference to fig. 11B.

In block 306, one or more pacing electrodes may be located at the identified virtual stimulation points. The physician may use the reference image and/or activation map shown in display 330 to align the pacing electrodes with the virtual stimulation points. The heart may then be paced, and the resulting ECG data may be collected.

In block 308, the collected ECG data may be used to generate an updated activation map to show the effect of the stimulation. In some embodiments, ECG data may be used to identify a pacing location, which may be displayed on an activation map. Since the pacing electrode is disposed at the pacing location, the pacing location may represent the current location of the pacing electrode. Thus, the pacing electrode location may be displayed when navigating to the pacing location. Thus, additional mapping applications may not be needed to determine the location of the pacing electrodes, thereby significantly reducing the cost of the pacing procedure.

In decision block 310, it may be determined whether the pacing electrode is disposed at a suitable cardiac location. For example, in CRT patients, it may be determined whether the stimulation is a sufficient amount of synchrony and/or a desired amount of cardiac function is restored. If so (i.e., determine block 310 — yes), the electrode may be stitched into place in block 312. If not (i.e., it is determined that block 310 is no), a new cardiac stimulation point may be generated in block 302 based on the updated activation map generated in block 308. For example, one or more virtual stimulation points may be moved to a new location, and/or additional virtual stimulation points may be added. Then, in block 304, the virtual stimulation points may be added to the real-time cardiac image. In some embodiments, the pacing interval for stimulation of the LV and RV may also be adjusted.

For PVC and/or VT patients, determination block 310 may comprise using the updated activation map to determine whether the stimulus replicated the patient's PVC. In other words, determination block 310 may comprise determining whether the stimulation point is a suitable ablation point. If so (i.e., it is determined that block 310 is yes), the heart may be ablated at the stimulation point in block 312. If not (i.e., it is determined that block 310 is no), a new stimulation point may be generated in block 302 based on ECG data collected during a previous stimulation.

In some embodiments, the activation map may be used to determine whether CRT is appropriate for the patient. For example, if the patient's cardiac output is not predicted to reach an acceptable level after optimal placement of a pacemaker or pacing lead, it may be determined that CRT is not appropriate for the patient.

In various embodiments, a workstation may be used that includes the processing unit 400, the display 330, and wired or wireless connections to other hardware, such as the CT/MRI device 108, the 3D camera 109, the ECG recorder 106, and/or the real-time imaging device 328. The workstation may also contain an interface for controlling surgical equipment, such as a catheter implantation device or other robotic surgical equipment.

Fig. 11A is a flow diagram illustrating a cardiac imaging method 500 using the system of fig. 9, in accordance with various embodiments. 11B and 11C illustrate activation maps that may be generated during the method of FIG. 11A.

Ablation is an effective treatment for PVC and/or VT. However, some patients may experience paroxysmal VT and/or PVC, in which case an event or symptom may not occur when the patient is tested in a hospital during catheterization or at an electrophysiology facility during electrophysiology testing. To ensure that sufficient ECG data is obtained for patients exhibiting symptoms of paroxysmal VT and/or PVC, the ECG data may be recorded using a portable ECG recording device 106, such as a Holter-type device.

Referring to fig. 9 and 11A, the processing unit 400 may generate a PVC activation map showing electrical activation during a PVC process in block 501. For example, the PVC activation map may identify the region in the PVC process that was activated earliest. The PVC activation map may be based on ECG data collected during a PVC procedure, as well as CT and/or MRI data from the patient as described above. In particular, the data may be provided to the activation map generator 320 of the processing unit 400. In some embodiments, ECG data from a single PVC beat may be sufficient to generate a PVC activation map. The PVC activation map may identify the region of the heart that is the earliest activation during a PVC heart beat.

In some embodiments, the method may optionally include block 502. In block 502, the processor 400 may be used to generate a reference image showing the internal structure of the heart. The activation map and the reference image may be displayed on the same display or on different displays, either simultaneously or at different times. In other words, blocks 501 and 502 may include providing the generated activation map and reference image to the display 330.

The reference image may be based on a cardiac image, such as one of the 2D MRI or CT images used to generate the activation map. The reference image may contain additional features in addition to the internal cardiac structure shown in the cardiac image. For example, to form a reference image, the cardiac image may be modified to show the structures contained in the earliest activation region and/or the virtual pacing locations contained in the activation map.

In some embodiments, the processing unit 400 may be configured to select the cardiac image that is closest to the image provided by the real-time imaging device 328, as discussed in block 503. In other embodiments, the reference image may be based on a manually selected cardiac image. Thus, when positioning the electrodes using the real-time imaging device 328, reference cardiac images may be referenced.

FIG. 11B shows an example of a reference image of a PVC/VT patient. Referring to fig. 11B, the reference image may identify an earliest activated region 340 (e.g., a cardiac structure in a 2D image contained in the earliest activated region may be identified). The reference image may also contain pacing location 342. Pacing location 342 may be a virtual pacing location generated by stimulation point generator 324. In some embodiments, pacing location 342 may be the actual pacing/catheter location. For example, when the heart is paced, processing unit 400 may analyze the resulting ECG data to identify the corresponding pacing location 342, thereby identifying the current location of the pacing catheter, pacing electrode, or the like.

In some embodiments, if pacing location 342 does not provide a desired cardiac response (such as a simulated PVC or desired cardiac synchrony), then guidance information generator 332 may provide guidance information (such as vector 344 showing the direction in which the electrodes should move).

In block 503, the method includes performing an Electrophysiology (EP) procedure that includes inserting a catheter into the heart to analyze the electrical activity and determine where the arrhythmia is located. In PVC patients, the goal of the EP procedure may be to pace the heart at a location that produces a PVC that is very close to the patient's symptomatic PVC. For example, an EP procedure may involve pacing the heart using a catheter at the location of the earliest activation region. Additional electrodes may also be inserted to detect ECG data internally during EP. For example, pacing data may be recorded by recording ECG data during pacing.

The EP procedure may also include mapping internal features of the patient's heart, such as features in and around the region of earliest activated PVC. In some embodiments, the EP procedure may involve generating a 3D triangulated inner surface model on a point-by-point basis by contacting different points of the heart with a catheter. Suitable systems for performing EP procedures include the EnSite Precision mapping system and the Carto 3 mapping system. Such a system is able to track the 3D position of the catheter in the body and record the position of the inner surface of the heart each time the catheter comes into contact with the heart tissue. The collection of these 3D locations is synchronized with the heart beat, ensuring that each point is collected when the heart is in the same state as the other recorded points (i.e., full volume as opposed to systole). In addition to modeling, relative ECG activation times may be recorded and mapped onto a heart model.

As described above, block 503 may also include generating a real-time image of the heart using the real-time imaging device 328. In some embodiments, block 502 may be performed after the real-time image is generated, such that the reference image may be based on an image of the heart that approximates the real-time image.

The EP procedure may also include positioning the catheter in contact with a location in the earliest activation region. In block 504, the catheter may then be used to pace the heart through electrical stimulation. The goal of pacing may be to pace the heart at a location that produces a PVC that closely approximates the patient's symptoms PVC. Additional electrodes may also be inserted to detect ECG data internally during EP. For example, pacing data may be recorded by recording ECG data during pacing.

Although the EP procedure and pacing are shown as separate blocks in fig. 11A, the present disclosure is not so limited. For example, both the EP procedure and pacing may occur in a single procedure.

In some embodiments, block 504 may involve using the collected ECG data to generate an updated activation map to display the effect of the stimulation. In some embodiments, ECG data may be used to identify a pacing location, which may be displayed on an activation map. Since the pacing electrode is disposed at the pacing location, the pacing location may represent the current location of the pacing electrode. Thus, the pacing electrode location may be displayed when navigating to the pacing location. Thus, additional mapping applications may not be needed to determine the location of the pacing electrodes, thereby significantly reducing the cost of the pacing procedure.

In decision block 506, the pacing data may be analyzed to determine whether the pacing electrodes are disposed at the appropriate cardiac locations for achieving the desired cardiac response. For example, the pacing data may be compared to ECG data used to generate the activation map. In PVC, pacing may be analyzed to determine if the pacing data sufficiently matches the PVC ECG data recorded during the PVC presentation of the patient. In other words, the pacing data is analyzed to determine whether the catheter has identified locations that may be ablated to reduce the patient's PVC and/or VT. In CRT patients, the pacing data may be analyzed to determine whether sufficient cardiac synchronization and/or activation has been achieved.

If it is determined that the desired cardiac response has been achieved (i.e., determination block 506 — yes), then in block 510 the catheter may be used to ablate the heart at the ablation site of the PVC patient. In CRT patients, the pacing electrodes and/or micro-pacemakers may be sutured into place in block 510.

If it is determined that the desired cardiac response is not achieved (i.e., no determination block 506), then in block 508, the processing unit 400 may use the pacing data, the PVC ECG data, and/or the catheter position data to identify a direction in which the catheter should be moved in order to better simulate the patient's PVC. For example, the pacing data and catheter position data may be provided to the guidance information generator 332 of the processing unit 400. The guidance information generator 332 may contain an algorithm configured to compare the pacing data and/or the location data with the PVC ECG data in order to determine the direction and/or distance the catheter should be moved in order to properly simulate the patient's PVC. This information may be presented using icons and/or text. In CRT patients, the pacing data may be analyzed to determine whether one or more pacing electrodes should be moved to achieve a desired cardiac response.

The guide information generator 332 may provide the guide information to the activation map generator 320. The activation map generator 320 may update the activation map based on the guidance information provided by the guidance information generator 332, as discussed below with reference to fig. 11B and 11C. In other embodiments, the guidance information generator 332 may provide guidance information to the image integrator 326 for integration with the image provided by the real-time imaging device 328. In other embodiments, the guidance information may be provided to the EP system and displayed on the EP map generated thereby.

After the guidance information is displayed in block 508, the method returns to block 504 to pace the heart again. However, in some embodiments, the method may return to block 503 to perform the EP process. Thus, in a PVC/VT patient, multiple locations may be stimulated until pacing produces a PVC that accurately replicates the patient's PVC and the corresponding ablation location is identified. In CRT patients, the stimulation location can be adjusted until the desired cardiac response is achieved. In addition, guidance information may be provided to the physician to help identify the stimulation points.

In some embodiments, block 503 may include recording ECG data externally during cardiac pacing using the mapping system of fig. 9. Further, block 504 may also include determining a pacing location within the heart based on the recorded ECG data using the mapping system. For example, the pacing location may be determined by identifying the region of earliest activation during cardiac pacing. Further, block 508 may also include adding the pacing site to the PVC activation map. In this way, at least the location of the pacing electrode of the catheter may be identified on the PVC activation map because the pacing electrode is disposed at the pacing location during pacing.

Referring to fig. 11C, the updated activation map may contain a first point 700 showing the pacing/stimulation locations corresponding to the most recent pacing location and/or catheter location. The updated activation map may also contain a region 710 of earliest activation, which may be the target region for ablation. In some embodiments, the activation map may contain a vector 712 showing direction and distance recommendations for moving the catheter to a new stimulation location in the earliest activation region 710.

In some embodiments, as shown in fig. 11D, the updated activation map may contain one or more third points 704 showing previous pacing locations. For example, the updated activation map may contain a first point 700 representing a first stimulation location, a second point 702 representing a second stimulation location, a third point 704 representing a third (e.g., current) stimulation location, and a fourth point 706 representing a proposed stimulation location. In some embodiments, the earliest activated region 710 may be recalculated based on ECG data from each pace.

The points 700-706 may be different colors, shades, and/or shapes to provide timing information. For example, points 700-706 may be shaded to indicate the order in which the points were created to identify the path of the catheter. For example, the points 700-706 may gradually brighten or dim. In some embodiments, the fourth point 706 may be illuminated more than the others. Once pacing occurs at the location represented by the fourth point 706, each of the points 700-706 may be dimmed or modified to indicate that the points represent previous pacing locations.

In other embodiments, the points may be connected by a line 708 to represent the path of the catheter during EP. In some embodiments, vector 712 of FIG. 11B may also be applied to the activation map of FIG. 11C in addition to, or instead of, fourth point 706.

Fig. 12 is a block diagram illustrating an image integration method 800 according to various embodiments. Method 800 may be performed using the system of fig. 9. Referring to fig. 9 and 12, in block 801, a PVC activation map of a patient's heart may be generated using the processor 400, as described above.

In block 802, a 3D inner surface model of the heart may be generated on a point-by-point basis by 3D triangulation. In particular, internal surface features of the patient's heart, such as ventricular surface features, may be mapped on a point-by-point basis by point contact between the internal surface of the heart and the EP catheter. Suitable systems for performing EP procedures include the EnSite Precision mapping system and the Carto 3 mapping system. Such a system is able to track the 3D position of the catheter in the body and record the position of the surface of the heart each time the catheter comes into contact with the heart tissue. This collection of point-by-point contact data is synchronized with the heart beat, thereby ensuring that each point is collected when the heart is in the same state as the other recorded contact points (i.e., the volume of the heart is substantially the same). For example, when a point contact is made, the heart may be at full volume or fully contracted.

In conventional EP systems, an interior surface model is combined with an acquired MRI or CT data set to form a heart model. In particular, merging may include adjusting the inner surface model data to more accurately represent the true geometry of the heart, as well as displaying additional cardiac features that are not mapped during EP. This procedure involves calculating at which point in the CT or MR the size represents tissue versus blood. Adjustments may then be made to better represent the heart geometry.

The EP process may also include recording relative ECG data (e.g., activation time) during the point-by-point contact. In some embodiments, this ECG data may be mapped onto an inner surface model. This may include mapping normal ECG signals as this allows for rapid collection of points when heart/catheter contact occurs.

To determine the ablation points, a PVC activation map may be generated because the PVC activation map contains the areas that were activated earliest during the PVC. However, when generating PVC activation maps using conventional EP systems, the catheter must be in contact with the heart during PVC. Since PVC may only occur intermittently, generating a PVC activation map using conventional methods may take significantly longer than using asymptomatic ECG data. This increases the stress on the patient and the use of surgical resources.

Thus, in block 804, the internal surface model generated in block 802 may be merged with the PVC activation map generated in block 801 to form a PVC activation surface model. In particular, the PVC activation data contained in the PVC activation map may be applied to the inner surface model. Further, the surface features contained in the PVC activation map (which already contain MRI or CT data) may be merged with triangulated point-by-point data contained in the internal surface model. In this way, the PVC inner surface model can be generated without performing the conventional process of merging triangulated point-by-point data with MRI or CT data, which further simplifies the process.

In block 806, the catheter may be located in the earliest activation region of PVC displayed on the EP PVC activation model and may pace the heart. Pacing ECG data may be recorded during pacing.

In block 808, the pacing data may be analyzed to determine whether an ablation location has been identified. In particular, the pacing data may be analyzed to determine whether the pacing data sufficiently matches ECG data recorded during a PVC episode of the patient. In other words, the pacing data is analyzed to determine whether the catheter has paced a location that can be ablated to reduce the patient's PVC and/or VT.

In decision block 810, it is determined whether an ablation location has been identified. If an ablation location has been identified (i.e., determination block 810 — yes), then in block 814 the catheter is used to ablate the heart at the identified ablation location.

If an ablation location is not identified (i.e., determination block 810 is no), guidance information may be provided in block 812, as discussed above with respect to the method of fig. 11A. The method may then proceed to block 806. However, in some embodiments, when the ablation location is not identified (i.e., determination block 810 is no), block 812 may be omitted and the method may proceed directly from determination block 810 to block 806. The method 800 may then repeat until an ablation location is identified and ablated in block 814.

In some embodiments, the method may include displaying the pacing location on a PVC activation map. For example, the PVC activation surface model may be registered with a PVC activation map, and the pacing location may be added to the PVC activation map. The pacing location may also represent the location of the EP catheter during pacing. In other embodiments, processor 400 may analyze ECG data recorded during pacing to determine pacing and/or pacing catheter locations, which are then added to the PVC activation map.

In some embodiments, method 800 may include generating and displaying a reference image with a PVC activation map and/or displaying guidance information, as discussed above with reference to fig. 11A-11D.

Some embodiments include a hardware system that includes a processing unit configured with software to receive patient-specific data, generate and display a 3D model of electrical activation of the heart in the form of a synchrony map of the patient's heart based on ECG imaging data, and associate or register the 3D model/map with the patient's body using identifiable markers on the body that serve as fiducial reference points (referred to herein as "fiducial markers"). An external imaging system, such as a 3D camera, may be used to obtain 3D image data of the patient's body (e.g., torso or chest) with key anatomical reference points (e.g., clavicle, shoulder, ribs, etc., indicated by markers applied to the patient by the clinician as part of the CRT procedure setup). The patient-specific 3D anatomical model may incorporate the image data with a 3D anatomical model of the patient's chest by registering the identified anatomical locations with corresponding anatomical locations in an image obtained from a CT or MRI scan.

Fig. 13 is a system block diagram of a cardiac imaging system 1000 in accordance with various embodiments. Referring to fig. 13, system 1000 includes a processing unit 102 that may be electrically connected to hardware modules, such as electrocardiogram system 106, internal imaging system 1080, external imaging system 1090, and output unit 1200.

The processing unit 1020 receives patient-specific data from the hardware modules. From the patient-specific anatomical data, the processing unit 1020 may generate a synchronicity map of the patient's heart, which may be output to the output unit 1200. The output unit 1200 may be configured to output the synchronization map and/or the substitute data to a user. The output unit may be a display unit, a printer, a message unit, etc.

For example, the processing unit 1020 may receive Electrocardiogram (ECG) imaging data from an electrocardiogram system 1060, such as a 12-lead ECG device. The processing unit 1020 may use the ECG data to determine an electrically activated 3D model 4 of the heart. In particular, to calculate the position of the cardiac isochrone, the ECG signal may be combined with a patient-specific 3D anatomical model of the heart, lungs and/or torso.

The patient-specific 3D anatomical model may be obtained from an internal imaging system 1080, such as an MRI device or a CT device. Alternatively or additionally, the 3D anatomical model showing the closest agreement with the patient may be selected from a database containing a plurality of 3D anatomical models and optionally modified. The selected and optionally modified 3D anatomical model may be used as a patient-specific 3D anatomical model.

Further, the processing unit 1020 may receive patient image data from an external imaging system 1090. For example, the external imaging system 1090 may be a 3D camera and the processing unit 1020 may receive 3D image data of the patient's chest surface, as shown in fig. 14A or 14B.

Referring to fig. 14A, the 3D image data may contain the location of the ECG leads relative to the patient's anatomy, such as the V1-6 precordial electrode shown in fig. 14A. Knowledge of the location of the ECG electrodes relative to the heart, particularly the V1-6 precordial electrode, may be particularly important for accurately calculating the location of the onset of the PVC.

The processing unit 1020 may be configured to align and/or combine the 3D image data generated by the external imaging system 1090 with an anatomical torso and/or heart model generated by the internal imaging system 1080, and the electrode positions in the torso model may be adjusted to coincide with the electrode positions in the 3D image data. However, if the external imaging system 1090 is not properly aligned with the torso, it may be difficult to properly align the 3D image data and the anatomical model.

To facilitate alignment of the 3D image data and the anatomical torso model, the system 100 may include fiducial markers previously placed on (e.g., adhered to) the torso of the patient captured in the 3D image data generated by the external imaging system 109. The clinician may place fiducial markers on the patient at the set anatomical locations identified in the torso model to facilitate alignment of the 3D image of the patient with the anatomical torso model. In some embodiments, the fiducial marker may be a sticker with an adhesive backing configured to adhere to skin, with a shape, color, and/or surface material (e.g., reflective or retroreflective material) that is capable of automatically identifying and locating the marker by a processor processing the 3D image data.

For example, the first fiducial marker 900 may be placed at a set anatomical location on the shoulder of the patient, such as the distal end of each clavicle. The second fiducial markers 902 may be placed at set anatomical locations between the first fiducial markers 902, such as at set locations on the patient's sternum.

The processing unit 1020 may be configured to identify the

fiducial markers

900, 902 and their corresponding anatomical positions based on one or more identifying features of the two fiducial markers and their corresponding anatomical positions contained in the 3D image data collected by the external imaging device. In some embodiments, the processing unit 1020 may be configured to identify the anatomical location corresponding to the

fiducial marker

900, 902 based on the color, shape, and/or reflectivity of the respective anatomical marker contained in the image data.

In some embodiments, the

fiducial markers

900, 902 may be configured to reflect light of a particular wavelength. For example, the first fiducial marker 900 may have a first color and the second fiducial marker 902 may have a second color. In some embodiments, each

marker

900, 902 may have a different color.

In some embodiments, the

fiducial markers

900, 902 may comprise a reflective material, which may be in the form of a reflective coating. In some embodiments, the reflective material may be configured to reflect one or more particular wavelengths or wavelength ranges of light. For example, in some embodiments, the

fiduciary markers

900, 902 may be formed of a material configured to reflect visible light, infrared light, ultraviolet light, or a combination thereof. In some embodiments, the external imaging system 1090 may include a light source, and the reflective material may be configured to reflect all or a portion of the light emitted from the light source. For example, the

fiducial markers

900, 902 may be configured to selectively reflect emitted light of a particular wavelength or range of wavelengths. The processing unit 1020 may be configured to identify the

fiducial marker

900, 902 based on the light reflected thereby.

In some embodiments, the

fiduciary markers

300, 302 may comprise a retroreflective material. In particular, the retroreflective material can be configured to reflect incident light or a portion thereof (i.e., directly back to the source of the incident light) at an angle substantially equal to the incident angle of the incident light. For example, retroreflective materials are well known for use in safety vests and traffic signs. In such embodiments, the processing unit 102 may be configured to detect light such as luminance peaks in image data received from an external imaging system.

In some embodiments, the fiduciary marker may have one or more different shapes. For example, as shown in figure 14B, system 1000 may include triangular fiducial markers 904, cross fiducial markers 906, and/or trapezoidal fiducial markers 908. The processing unit 1020 may be configured to identify an anatomical position corresponding to the fiducial marker based on the shape of the fiducial marker.

However, the various embodiments are not limited to any particular fiducial marker that identifies a characteristic, so long as the fiducial marker contains a characteristic that is identifiable by the processing unit 1020 and detectable by the external imaging system 1090. Further, although three fiducial markers are shown in fig. 14A and 14B, any suitable number of fiducial markers may be used.

The foregoing method descriptions and process flow diagrams are provided merely as illustrative examples and are not intended to require or imply that the steps of the various embodiments must be performed in the order presented. As will be appreciated by those skilled in the art, the order of steps in the foregoing embodiments may be performed in any order. Words such as "thereafter," "then," "next," etc. are not intended to limit the order of the steps; these words are simply used to guide the reader through the description of the method. Further, any reference to claim elements in the singular, for example, using the articles "a," "an," or "the" is not to be construed as limiting the element to the singular.

The various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The hardware used to implement the various illustrative logics, logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration). Alternatively, some steps or methods may be performed by circuitry that is specific to a given function.

In one or more exemplary aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a non-transitory computer-readable medium or a non-transitory processor-readable medium. The steps of a method or algorithm disclosed herein may be embodied in processor-executable software modules and/or processor-executable instructions, which may reside on non-transitory computer-readable or non-transitory processor-readable storage media. The non-transitory server-readable, computer-readable, or processor-readable storage medium may be any storage medium that is accessible by a computer or a processor. By way of example, and not limitation, such non-transitory server-readable, computer-readable, or processor-readable media can comprise RAM, ROM, EEPROM, flash memory devices, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. Disk and disc, as used herein, includes Compact Disc (CD), laser disc, optical disc, Digital Versatile Disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of non-transitory server-readable, computer-readable, and processor-readable media. Additionally, the operations of a method or algorithm may reside as one or any combination or set of codes and/or instructions on a non-transitory server-readable, processor-readable medium, and/or computer-readable medium, which may be included in a computer program product.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the claims. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the following claims and the principles and novel features disclosed herein.

Claims

1. A method of cardiac mapping and model merging, comprising:

generating a Premature Ventricular Contraction (PVC) activation map of a heart based on a three-dimensional (3D) heart model and a PVC ECG data record during the PVC;

generating a 3D inner surface model of the heart by triangulating point-by-point contact data collected during an Electrophysiology (EP) procedure;

merging the 3D activation map and the 3D interior surface model to form a PVC activation surface model; and

pacing the heart at a first pacing location disposed in an earliest activation region identified in the PVC activation surface model.

2. The method of claim 1, wherein merging the 3D activation map and the 3D interior surface model to form a PVC activation surface model comprises merging the activation map and point-by-point contact data.

3. The method of claim 1, further comprising:

determining whether the first pacing site is an ablation site that can be ablated to prevent the PVC by comparing ECG data recorded during the pacing of the first pacing site with the PVC ECG data;

identifying a second pacing location in response to determining that the first pacing location is not an ablation location;

displaying guidance information related to the second pacing location on one or both of the activation map and the inner surface map;

moving an EP catheter from the first pacing location to the second pacing location based on the guidance information; and

pacing the heart at the second pacing location.

4. The method of claim 1, wherein the 3D heart model is based on a Magnetic Resonance (MRI) image or a Computed Tomography (CT) image of the heart.

5. The method of claim 4, wherein the 3D interior surface model is not based on a Magnetic Resonance (MRI) image or a Computed Tomography (CT) image of the heart.

6. The method of claim 4, further comprising:

generating a reference image by modifying one of the 2D images to identify the earliest activated region; and

and displaying the PVC activation graph and the reference image.

7. The method of claim 1, wherein the PVC ECG data is recorded during one heart beat comprising PVC.

8. The method of claim 1, wherein the point-by-point contact data is collected by repeatedly contacting the heart with an EP catheter during normal beats of the heart.

9. The method of claim 8, wherein contact occurs between the EP catheter and the heart when the heart is in substantially the same volume.

10. A method of cardiac mapping, comprising:

attaching 12 electrodes of an Electrocardiogram (ECG) device to a chest of a patient;

recording Electrocardiogram (ECG) data using an ECG device;

generating an activation map of the patient's heart based on the ECG data, a three-dimensional (3D) chest model, and a two-dimensional (2D) image of the heart, the PVC activation map containing an earliest activation region;

determining an offset between an actual position of each electrode contained in the 3D thoracic model and an ideal position of each electrode based on a comparison of the earliest activated region and the earliest activated predicted region in the activation model; and

adjusting the activation map based on the determined offset.

11. The method of claim 10, wherein the 3D chest model is generated by:

applying a fiducial marker to the patient's body, wherein the fiducial marker is configured to be identifiable using image processing;

generating external image data of the patient's body including imaging the fiducial markers and the electrodes;

identifying an anatomical location corresponding to the fiducial marker by detecting light reflected from the fiducial marker contained in the image data; and

merging the image data with a 3D anatomical model of the patient's chest generated using the 2D image by registering the identified anatomical locations with corresponding anatomical locations in an image obtained from a CT or MRI scan.

12. The method of claim 11, wherein identifying an anatomical location corresponding to the fiducial marker by detecting light reflected from the fiducial marker contained in the image data comprises detecting light of two different wavelengths reflected from two different fiducial markers.

13. The method of claim 12, wherein:

two of the fiducial markers are disposed on the shoulders of the patient; and

one of the fiducial markers is disposed on the sternum of the patient.

14. The method of claim 11, wherein identifying an anatomical location corresponding to the fiducial marker by detecting light reflected from the fiducial marker contained in the image data comprises detecting three different wavelengths of light reflected from three different fiducial markers.

15. The method of claim 11, wherein:

the fiduciary markers have different shapes; and

identifying an anatomical location corresponding to the fiducial markers by detecting light reflected from the fiducial markers contained in the image data includes detecting a shape of each fiducial marker.