Online magnetic catheter calibration for medical device management

Abstract

To manage medical device equipment by online magnetic calibration of a catheter.SOLUTION: A method for calibrating a medical device is provided. The method is implemented by a calibration engine executed by one or more processors. The method includes capturing one or more voltage measurements by one or more components of a catheter, estimating calibration data based on the one or more voltage measurements, and outputting the calibration data to the catheter.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to medical devices and, more particularly, to managing medical devices through online magnetic calibration of catheters. [Background technology]

[0002] Currently, as part of the manufacturing process, catheters are calibrated to accurately visualize and navigate within a patient's body. During calibration, the catheter is placed in the center of a calibration chamber so that three orthogonal fields are applied. Sensors in the catheter take voltage measurements, and the orientation and sensitivity of each sensor are determined based on the applied three orthogonal fields. The orientation and sensitivity are stored in the catheter's memory (e.g., a read / write memory component such as an EEPROM). Currently, there is no technology to calibrate catheters in situ or in the field without using a local, expensive, and bulky calibration chamber. The lack of technology also leaves the issue of catheter aging (e.g., changes in calibration parameters over time) unaddressed. Summary of the Invention [Means for solving the problem]

[0003] An exemplary embodiment provides a method, performed by a calibration engine executed by one or more processors, that includes capturing one or more voltage measurements by one or more components of a catheter, estimating calibration data based on the one or more voltage measurements, and outputting the calibration data to the catheter.

[0004] According to one or more embodiments, the exemplary method embodiments described above may be implemented as an apparatus, a system, and / or a computer program product. [Brief explanation of the drawings]

[0005] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, in which like reference numerals indicate similar elements and in which: [Figure 1] 1 illustrates a diagram of an exemplary system in which one or more features of the presently disclosed subject matter can be implemented, in accordance with one or more embodiments. [Figure 2] 1 illustrates a block diagram of an exemplary system in accordance with one or more embodiments. [Figure 3] 1 illustrates an exemplary method according to one or more embodiments. [Figure 4] 1 illustrates an exemplary method according to one or more embodiments. [Figure 5] 1 illustrates a table according to one or more embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0006] Disclosed herein are systems and methods relating to managing medical device equipment through online magnetic calibration of catheters. The systems and methods can be implemented as an online magnetic calibration system driven by a calibration engine. In this manner, the calibration engine and online magnetic calibration system utilize and transform medical device equipment to enable / implement online magnetic calibration of catheters, particularly those not currently available or currently performed by cardiac physicians and medical professionals. The calibration engine can be processor-executable code or software implemented in performing processing operations by and within the processing hardware of the medical device equipment (e.g., the online magnetic calibration system). For ease of explanation, the calibration engine is described herein with respect to mapping the heart, however, any anatomical structure, body part, organ, or portion thereof can be targeted for mapping when operating the calibration engine described herein.

[0007] One or more advantages, technical effects, and / or benefits of the calibration engine and online magnetic calibration system include addressing the need for on-site or in-situ catheter calibration by generating automatic calibrations during catheter navigation within a patient. Note that the term "online" refers to the ability to calibrate during the actual procedure. Note that the term "automatic calibration" refers to the ability to adjust the sensitivity and / or orientation of the catheter during the actual procedure. Furthermore, the calibration engine and online magnetic calibration system eliminate the need for a local calibration chamber as the catheter is used post-calibration (e.g., months or years later), obviating catheter aging issues. Furthermore, the calibration engine and online magnetic calibration system can be adapted and implemented into existing surgical / mapping systems and can work with any catheter.

[0008] FIG. 1 is a diagram of an exemplary system (e.g., a medical device instrument) designated as system 100 in which one or more features of the subject matter herein may be implemented in accordance with one or more embodiments. All or a portion of system 100 may be used to collect information (e.g., biometric data and / or a training data set) and / or may be used to implement a calibration engine 101 as described herein. System 100, as illustrated, includes a probe 105 with a catheter 110 (including at least one electrode 111), a shaft 112, a sheath 113, and a manipulator 114. System 100 also, as illustrated, includes a physician 115 (or medical professional or clinician), a heart 120, a patient 125, and a bed 130 (or table). Note that insets 140 and 150 show heart 120 and catheter 110 in greater detail. System 100 also includes, as illustrated, a console 160 (including one or more processors 161 and memory 162) and a display 165. Furthermore, it should be noted that each element and / or item of system 100 represents one or more of that element and / or item. The example system 100 shown in FIG. 1 can be modified to implement the embodiments disclosed herein. The embodiments of the present disclosure can be similarly applied using other system components and configurations. Furthermore, system 100 can include additional components, such as elements for sensing electrical activity, wired or wireless connectors, processing and display devices, etc.

[0009] System 100 can be utilized to detect, diagnose, and / or treat cardiac conditions (e.g., using calibration engine 101). Cardiac conditions, such as cardiac arrhythmias, persist as common and dangerous medical ailments, especially in the elderly population. For example, system 100 can be part of a surgical system (e.g., the CARTO® system sold by Biosense Webster) configured to acquire biometric data (e.g., anatomical and electrical measurements of a patient's organs, such as heart 120) and perform cardiac ablation procedures. More particularly, treating cardiac disorders, such as cardiac arrhythmias, often requires obtaining detailed mapping of cardiac tissue, chambers, veins, arteries, and / or electrical pathways. For example, as a prerequisite for successful catheter ablation (as described herein), the source of the cardiac arrhythmia may be accurately localized in a chamber of heart 120. Such localization can be performed by electrophysiological studies, during which spatially resolved electrical potentials are detected by a mapping catheter (e.g., catheter 110) introduced into a chamber of heart 120. This electrophysiological test, also known as electroanatomical mapping, therefore provides 3D mapping data that can be displayed on a monitor. Often, mapping and therapy (e.g., ablation) functions are provided by a single catheter or a group of catheters, with the mapping catheter also simultaneously acting as a therapy (e.g., ablation) catheter. In this case, the calibration engine 101 can be stored and executed directly by the catheter 110 as an online magnetic calibration algorithm.

[0010] In a patient (e.g., patient 125) having normal sinus rhythm (NSR), the heart (e.g., heart 120), including the atria, ventricles, and excitable conduction tissue, is electrically excited to beat in a synchronized, patterned manner, which can be detected, for example, as intracardiac electrocardiogram (IC ECG) data.

[0011] In patients (e.g., patient 125) with cardiac arrhythmias (e.g., atrial fibrillation or aFib), abnormal regions of cardiac tissue do not follow the synchronous beating cycle associated with normal conductive tissue, in contrast to patients with NSR. In contrast, abnormal regions of cardiac tissue conduct abnormally to adjacent tissue, disrupting the cardiac cycle and resulting in asynchronous cardiac rhythms. Note that this asynchronous cardiac rhythm can also be detected in IC ECG data. Such abnormal conduction has previously been known to occur in various regions of the heart 120, such as in the region of the sinoatrial (SA) node along the atrioventricular (AV) node conduction pathway, or in the myocardial tissue forming the walls of the ventricles and atria. Other conditions, such as atrial flutter, exist in which abnormal conductive tissue patterns lead to reentry pathways, causing the heart chambers to beat in a regular pattern that can be multiples of sinus rhythm.

[0012] To assist system 100 in detecting, diagnosing, and / or treating a cardiac condition, probe 105 can be maneuvered by physician 115 into heart 120 of patient 125 lying on bed 130. For example, physician 115 can insert shaft 112 through sheath 113 while manipulating the distal end of shaft 112 using manipulator 114 near the proximal end of catheter 110 and / or deflection from sheath 113. As shown in inset 140, catheter 110 can be attached to the distal end of shaft 112. Catheter 110 can be inserted through sheath 113 in a collapsed state and then expanded within heart 120.

[0013] In general, electrical activity at a point within the heart 120 can typically be measured by advancing a catheter 110 (e.g., at least one electrode 111) containing an electrical sensor at or near its distal tip to the point within the heart 120, contacting tissue with the sensor, and acquiring data at the point. One difficulty with mapping a heart chamber using a catheter type containing only a single distal tip electrode can be the lengthy time required to collect data for each point across the necessary number of points required for a detailed map of the entire heart chamber. Therefore, multi-electrode catheters (e.g., catheter 110) have been developed to simultaneously measure electrical activity at multiple points within a heart chamber.

[0014] The catheter 110, which may include at least one electrode 111 and a catheter needle coupled on its body, may be configured to obtain biometric data, such as electrical signals, of a body organ (e.g., the heart 120) and / or ablate a tissue region thereof (e.g., a chamber of the heart 120). It is noted that the electrode 111 may represent any similar element or component, such as a tracking coil, piezoelectric transducer, electrode, or combination of elements configured to ablate a tissue region or obtain biometric data. According to one or more embodiments, the catheter 110 may include one or more position sensors used to determine trajectory information. This trajectory information may be used to infer motion characteristics, such as tissue contractility.

[0015] The biometric data (e.g., patient biometrics, patient data, or patient biometric data) may include one or more of local activation time (LAT), electrical activity, topology, bipolar mapping, baseline activity, ventricular activity, dominant frequency, impedance, etc. LAT may be a time point of threshold activity corresponding to local activation calculated based on a normalized initial starting point. Electrical activity may be any applicable electrical signal that can be measured based on one or more thresholds and sensed and / or enhanced based on signal-to-noise ratio and / or other filters. Topology may correspond to the physical structure of a body part or portion of a body part, and may correspond to changes in the physical structure for different portions of the body part or for different body parts. The dominant frequency may be a frequency or range of frequencies commonly found in a portion of a body part and may differ in different portions of the same body part. For example, the dominant frequency of the PVs of a heart may differ from the dominant frequency of the right atrium of the same heart. Impedance may be a resistance measurement in a particular region of a body part.

[0016] Examples of biometric data include, but are not limited to, patient identification data, IC ECG data, bipolar intracardiac reference signals, anatomical and electrical measurements, trajectory information, body surface (BS) ECG data, historical data, brain biometrics, blood pressure data, ultrasound signals, radio signals, audio signals, two-dimensional or three-dimensional image data, blood glucose data, and temperature data. Biometric data may generally be used to monitor, diagnose, and treat any number of various diseases, such as cardiovascular diseases (e.g., arrhythmias, cardiomyopathies, and coronary artery disease) and autoimmune diseases (e.g., type I and type II diabetes). Note that BS ECG data may include data and signals collected from electrodes on the patient's surface, IC ECG data may include data and signals collected from electrodes inside the patient's body, and ablation data may include data and signals collected from ablated tissue. Furthermore, BS ECG data, IC ECG data, and ablation data, along with catheter electrode position data, may be derived from one or more procedure records.

[0017] For example, catheter 110 may use electrodes 111 to perform intravascular ultrasound and / or MRI catheterization to image (e.g., acquire and process biometric data for) heart 120. Inset 150 shows a close-up of catheter 110 within a chamber of heart 120. While catheter 110 is shown as a point catheter, it will be understood that any shape that includes one or more electrodes 111 may be used to implement the exemplary embodiments disclosed herein.

[0018] Examples of the catheter 110 include, but are not limited to, a linear catheter with multiple electrodes, a balloon catheter including electrodes distributed on multiple spines forming a balloon, a lasso or loop catheter with multiple electrodes, or any other applicable shape. The linear catheter may be fully or partially elastic so that it can twist, bend, and / or otherwise change its shape based on received signals and / or the action of external forces (e.g., cardiac tissue) on the linear catheter. The balloon catheter may be designed to hold its electrodes in intimate contact with the endocardial surface when deployed within a patient's body. As an example, the balloon catheter may be inserted into a lumen such as a pulmonary vein (PV). The balloon catheter may be inserted into the PV in a deflated state so that the balloon catheter does not occupy its maximum volume while inserted into the PV. The balloon catheter may be expanded while inside the PV so that the electrodes on the balloon catheter contact the entire circular portion of the PV. Such contact with the entire circular portion of the PV or any other lumen enables efficient imaging and / or ablation.

[0019] According to another example, a body patch and / or BS electrodes, or one or more other transmitters, may also be positioned on or proximate to the body of the patient 125. A catheter 110 having one or more electrodes 111 may be positioned within the body (e.g., within the heart 120), and the position of the catheter 110 may be determined by the system 100 based on signals transmitted and received between one or more electrodes 111 of the catheter 110 and the body patch and / or BS electrodes (e.g., transmitters). For example, one or more transmitters (e.g., nine transmitters) may be positioned external to the patient 125, such as under the bed 130, to provide a magnetic field that induces one or more voltage measurements in one or more components for detection by the catheter 110. Additionally, the electrodes 111 may sense biometric data from within the body of the patient 125, such as within the heart 120 (e.g., the electrodes 111 sense tissue electrical potentials in real time). The biometric data can be associated with the determined position of the catheter 110, thereby displaying a rendering of the patient's body part (e.g., the heart 120) and showing the biometric data superimposed on the shape of the body part.

[0020] Probe 105 and other items of system 100 can be connected to console 160. Console 160 can include any computing device that employs an online magnetic calibration algorithm (which can be included in and / or represented as calibration engine 101). According to an exemplary embodiment, console 160 includes one or more processors 161 (any computing hardware) and memory 162 (any non-transitory tangible medium), where the one or more processors 161 execute computer instructions for calibration engine 101 and memory 162 stores these instructions for execution by one or more processors 161. For example, console 160 can be configured to receive and process biometric data to determine whether a particular tissue region conducts electricity. In some embodiments, console 160 can be further programmed (in software) with calibration engine 101 to perform the functions of capturing one or more voltage measurements by one or more components of the catheter, estimating calibration data based on the one or more voltage measurements, and outputting the calibration data to the catheter. According to one or more embodiments, calibration engine 101 can be external to console 160, e.g., located within catheter 110, an external device, a mobile device, a cloud-based device, or can be a stand-alone processor. In this regard, calibration engine 101 can be transferable / downloadable in electronic form over a network.

[0021] In one example, console 160 may be any computing device including hardware (e.g., processor 161 and memory 162), such as a general-purpose computer, with software (e.g., calibration engine 101) and / or front-end and interface circuitry suitable for sending and receiving signals to and from probe 105 and for controlling other components of system 100, as described herein. For example, the front-end and interface circuitry may include an input / output (I / O) communication interface that allows console 160 to receive signals from and / or transfer signals to at least one electrode 111. Console 160 may include real-time noise reduction circuitry, typically configured as an analog-to-digital (A / D) ECG or electrocardiogram / electromyogram (EMG) signal conversion integrated circuit followed by a field programmable gate array (FPGA). The console 160 may communicate signals from the A / D ECG or EMG circuitry to a separate processor and / or may be programmed to perform one or more of the functions disclosed herein.

[0022] A display 165, which may be any electronic device for visually presenting biometric data, is connected to the console 160. According to an exemplary embodiment, during a procedure, the console 160 may facilitate the presentation of a rendering of the body part to the physician 115 on the display 165 and store data representing the rendering of the body part in the memory 162. For example, a map indicative of motion characteristics may be rendered / constructed based on trajectory information sampled at a sufficient number of points within the heart 120. As an example, the display 165 may include a touch screen that, in addition to presenting the rendering of the body part, may be configured to receive input from the medical professional 115.

[0023] In some exemplary embodiments, physician 115 can use one or more input devices, such as a touchpad, mouse, keyboard, gesture recognizer, etc., to manipulate renderings of elements of system 100 and / or body parts. For example, the input devices can be used to change the position of catheter 110 so that renderings are updated. Note that display 165 can be located at the same location or at a remote location, such as another hospital or another healthcare provider network.

[0024] According to one or more embodiments, the system 100 can also obtain biometric data using ultrasound, computed tomography (CT), MRI, or other medical imaging techniques utilizing the catheter 110 or other medical equipment. For example, the system 100 can obtain ECG data and / or anatomical and electrical measurements (e.g., biometric data) of the heart 120 using one or more catheters 110 or other sensors. More specifically, the console 160 can be connected by a cable to BS electrodes, including adhesive skin patches, attached to the patient 125. The BS electrodes can acquire / generate biometric data in the form of BS ECG data. For example, the processor 161 can determine position coordinates of the catheter 110 within a body part (e.g., the heart 120) of the patient 125. The position coordinates can be based on impedance or electromagnetic fields measured between the BS electrodes and electrodes 111 of the catheter 110 or other electromagnetic components. Additionally or alternatively, the location pads that generate the magnetic fields used for steering may be located on the surface of the bed 130 or may be separate from the bed 130. The biometric data may be transmitted to the console 160 and stored in memory 162. Alternatively or additionally, the biometric data may be transmitted to a server, which may be local or remote, using a network as further described herein.

[0025] According to one or more exemplary embodiments, catheter 110 can be configured to ablate a tissue region of a chamber of heart 120. Inset 150 shows an enlarged view of catheter 110 within a chamber of heart 120. For example, an ablation electrode, such as at least one electrode 111, can be configured to apply energy to a tissue region of an internal organ (e.g., heart 120). The energy can be thermal energy and can cause damage to the tissue region starting from the surface of the tissue region and extending through the thickness of the tissue region. Biometric data related to the ablation procedure (e.g., ablated tissue, ablation location, etc.) can be considered ablation data.

[0026] According to one example, with respect to acquiring biometric data, a multi-electrode catheter (e.g., catheter 110) can be advanced into a chamber of heart 120. Anterior-posterior (AP) and lateral fluoroscopic photographs can be acquired to establish the position and orientation of each of the electrodes. An ECG can be recorded from each of the electrodes 111 in contact with the cardiac surface relative to a time reference, such as the occurrence of P waves in sinus rhythm from a BS ECG and / or signals from electrodes 111 of catheter 110 positioned within the coronary sinus. Systems further disclosed herein can distinguish between electrodes that record electrical activity and those that do not record electrical activity due to their lack of proximity to the endocardial wall. After the initial ECG is recorded, the catheter can be repositioned, and fluoroscopic photographs and ECGs can be recorded again. An electrical map (e.g., via cardiac mapping) can then be constructed from an iteration of the above process.

[0027] Cardiac mapping can be performed using one or more techniques. Generally, mapping of cardiac regions, such as the cardiac regions, tissues, veins, arteries, and / or electrical pathways of the heart 120, can lead to the identification of problem areas, such as scar tissue, arrhythmia sources (e.g., electrical rotors), healthy regions, etc. Cardiac regions can be mapped such that a visual rendering of the mapped cardiac region is provided using a display, as further disclosed herein. Furthermore, cardiac mapping (which is an example of cardiac imaging) can include mapping based on one or more modalities, such as, but not limited to, LAT, regional activation rate, electrical activity, topology, bipolar mapping, dominant frequency, or impedance. Data (e.g., biometric data) corresponding to multiple modalities can be captured using a catheter (e.g., catheter 110) inserted into the patient's body and provided for rendering simultaneously or at different times based on corresponding settings and / or physician 115 preferences.

[0028] As an example of the first technique, cardiac mapping can be implemented by sensing electrical properties of cardiac tissue, such as LAT, as a function of precise location within the heart 120. Corresponding data (e.g., biometric data) can be acquired by one or more catheters (e.g., catheter 110) advanced into the heart 120 and having electrical and location sensors (e.g., electrodes 111) at their distal tips. By way of example, location and electrical activity can be initially measured at about 10 to about 20 points on the interior surface of the heart 120. These data points can generally be sufficient to generate a preliminary reconstruction or map of the cardiac surface with satisfactory quality. This preliminary map can often be combined with data measured at additional points to generate a more comprehensive map of the cardiac electrical activity. In clinical practice, it is not uncommon to collect data from more than 100 sites (e.g., several thousand) to generate a detailed, comprehensive map of the electrical activity of the heart chambers. The detailed maps generated can then serve as the basis for making decisions about therapeutic action courses, such as tissue ablation as described herein, to alter the propagation of the heart's electrical activity and restore normal cardiac rhythm.

[0029] Furthermore, cardiac mapping can be generated based on the detection of intracardiac potential fields (e.g., IC ECG data and / or bipolar intracardiac reference signals, which are examples). Non-contact methods can be implemented to simultaneously acquire large amounts of cardiac electrical information. For example, a catheter type having a distal end portion can include a series of sensor electrodes distributed over its surface and connected to insulated conductors for connection to signal sensing and processing means. The size and shape of the end portion can be such that the electrodes are substantially spaced from the wall of the cardiac chamber. The intracardiac potential fields can be detected during one heartbeat. According to one example, the sensor electrodes can be distributed on a series of circumferentially spaced apart planes. These planes can be perpendicular to the longitudinal axis of the catheter end portion. At least two additional electrodes can be provided adjacent each end of the longitudinal axis of the end portion. As a more specific example, the catheter can include four circumferences with eight electrodes equiangularly spaced on each circumference. Thus, in this particular implementation, the catheter can include at least 34 electrodes (32 circumferential electrodes and two end electrodes). As another more specific example, the catheter may include other multi-spline catheters such as a five soft flexible branch, eight radial splines, or a turner type with parallel splines (e.g., any of which may have a total of 42 electrodes).

[0030] As an example of electrical or cardiac mapping, electrophysiological cardiac mapping systems and techniques based on non-contact and non-expandable multi-electrode catheters (e.g., catheter 110) can be implemented. An ECG can be obtained using one or more catheters 110 with multiple electrodes (e.g., 42 to 122 electrodes, etc.). This implementation allows knowledge of the relative geometry of the probe and endocardium to be obtained by an independent imaging modality, such as transesophageal echocardiography. After independent imaging, cardiac surface potentials can be measured using non-contact electrodes, and a map can be constructed from these surface potentials (e.g., possibly using a bipolar intracardiac reference signal). This technique can include (after the independent imaging step): (a) measuring potentials using multiple electrodes disposed on a probe positioned within heart 120; (b) determining the geometric relationship between the probe surface and the endocardial surface and / or other fiducials; (c) generating a matrix of coefficients representing the geometric relationship between the probe surface and the endocardial surface; and (d) determining the endocardial potentials based on the electrode potentials and the matrix of coefficients.

[0031] As another example of electrical or cardiac mapping, techniques and devices can be implemented for mapping the electrical potential distribution of a heart chamber. An intracardiac multi-electrode mapping catheter assembly can be inserted into heart 120. The mapping catheter (e.g., catheter 110) assembly can include a multi-electrode array or companion reference catheter having one or more integrated reference electrodes (e.g., one or more electrodes 111). Examples of mapping catheters include, but are not limited to, single-axis sensor (SAS) catheters, dual-axis sensor (DAS), and triaxial sensor (TAS) catheters.

[0032] According to one or more exemplary embodiments, the electrodes can be deployed in a generally spherical array, which can be spatially referenced to points on the endocardial surface by a reference electrode or by a reference catheter that is brought into contact with the endocardial surface. A preferred electrode array catheter can have a large number of individual electrode sites (e.g., at least 24). Additionally, this exemplary technique can be implemented by knowing the location of each of the electrode sites on the array and by knowing the cardiac geometry. These locations are preferably determined by impedance plethysmography.

[0033] From an electrical or cardiac mapping perspective, and according to another example, the catheter 110 can be a cardiac mapping catheter assembly that can include an electrode array defining multiple electrode sites. The cardiac mapping catheter assembly also includes a lumen for receiving a reference catheter having a distal tip electrode assembly that can be used to probe the heart wall. The cardiac mapping catheter assembly can include a braid of insulated wires (e.g., having 24 to 64 wires within the braid), each of which can be used to form an electrode site. The cardiac mapping catheter assembly can be easily positioned within the heart 120 to be used to acquire electrical activity information from a first set of non-contact electrode sites and / or a second set of contact electrode sites.

[0034] According to another example, a catheter 110 capable of mapping electrophysiological activity within the heart may include a distal tip adapted to deliver stimulation pulses for pacing the heart or an ablation electrode for ablating tissue in contact with the tip, and may further include at least one pair of orthogonal electrodes for generating a differential signal indicative of local cardiac electrical activity in the vicinity of the orthogonal electrodes.

[0035] As described herein, system 100 can be used to detect, diagnose, and / or treat cardiac conditions. In an exemplary operation, system 100 can implement a process for measuring electrophysiological data within a heart chamber. This process can include, in part, positioning a set of active and passive electrodes within heart 120, applying current to the active electrodes thereby generating an electric field within the heart chamber, and measuring the electric field at the passive electrode sites. The passive electrodes are included in an array positioned on an inflatable balloon of a balloon catheter. In a preferred embodiment, the array is said to have 60-64 electrodes.

[0036] As another exemplary operation, cardiac mapping may be performed by system 100 using one or more ultrasound transducers. The ultrasound transducers may be inserted into a patient's heart 120 and may acquire multiple ultrasound slices (e.g., two-dimensional or three-dimensional slices) at various locations and orientations within heart 120. The location and orientation of a particular ultrasound transducer may be known, and the acquired ultrasound slices may be stored for later display. One or more ultrasound slices corresponding to the position of probe 105 (e.g., a treatment catheter shown as catheter 110) may be displayed, and the probe 105 may be superimposed on one or more ultrasound slices.

[0037] Considering system 100, it can be seen that cardiac arrhythmias, including atrial arrhythmias, can be multiwavelet-reentrant, characterized by multiple asynchronous loops of electrical impulses scattered around the atria, often self-propagating (e.g., another example of IC ECG data). Alternatively, or in addition to multiwavelet-reentrant, cardiac arrhythmias can also have focal excitation sources, such as when isolated regions of atrial tissue are spontaneously excited in a rapid and repetitive manner (e.g., another example of IC ECG data). Ventricular tachycardia (V-tach or VT) is a tachycardia or fast heart rhythm originating from one of the ventricles. It is a potentially fatal arrhythmia because it can lead to ventricular fibrillation and sudden death.

[0038] For example, aFib occurs when normal electrical impulses generated by the sinoatrial node (e.g., another example of IC ECG data) are overwhelmed by chaotic electrical impulses (e.g., signal interference) originating in the atrial veins and PVs, causing irregular impulses to be conducted to the ventricles. This results in an irregular heartbeat that may persist for minutes to weeks, or even years. In many cases, aFib is a chronic condition that often carries a small increase in the risk of death from stroke. The treatment approach for aFib is medication to reduce the heart rate or restore normal cardiac rhythm. Furthermore, patients with aFib are often given anticoagulants to protect against stroke. The use of such anticoagulants carries its own risks of internal bleeding. In some patients, medication is insufficient, and their aFib is deemed drug-refractory, meaning it cannot be treated with standard pharmacological interventions. Synchronized cardioversion can also be used to convert aFib to a normal cardiac rhythm. Alternatively, patients with aFib may be treated with catheter ablation.

[0039] Catheter ablation-based therapy may involve mapping the electrical properties of cardiac tissue, particularly the endocardium and cardiac volumes, and selectively ablating cardiac tissue through the application of energy. Electrical or cardiac mapping (e.g., performed by any of the electrophysiological cardiac mapping systems and techniques described herein) involves creating an electrical potential map (e.g., a voltage map) of wave propagation along cardiac tissue or a map of arrival times (e.g., a LAT map) to points located in various tissues. Electrical or cardiac mapping (e.g., a cardiac map) can be used to detect localized cardiac tissue dysfunction. Ablation, such as cardiac mapping-based ablation, can stop or alter the propagation of unwanted electrical signals from one portion of the heart 120 to another.

[0040] Ablation techniques disrupt unwanted electrical pathways by creating non-conductive lesions. Various energy delivery modalities have been previously disclosed for creating lesions, including the use of microwave, laser, and more generally, radiofrequency energy to create conduction blocks along cardiac tissue walls. Another example of an energy delivery method is irreversible electroporation (IRE), which applies a high electric field that damages cell membranes. In a two-stage procedure (mapping followed by ablation), electrical activity at points within the heart 120 is typically sensed and measured by advancing a catheter 110 containing one or more electrical sensors (e.g., electrodes 111) into the heart 120 and acquiring / capturing data (e.g., biometric data generally or ECG data specifically) at multiple points. The ECG data is then used to select a target region of the endocardium where ablation will be performed.

[0041] Cardiac ablations and other cardiac electrophysiology procedures are becoming increasingly complex as physicians treat challenging conditions such as atrial fibrillation and ventricular tachycardia. Treatment of refractory arrhythmias can now rely on the use of three-dimensional (3D) mapping systems to reconstruct the anatomy of the target heart chamber. In this regard, the calibration engine 101 used by the system 100 herein implements online magnetic calibration algorithms and manipulates and evaluates biometric data in general, or ECG data in particular, to generate improved tissue data that enables more accurate diagnoses, images, scans, and / or maps for treating abnormal heart rhythms or arrhythmias. For example, cardiologists rely on software such as the Complex Fractionated Atrial Electrograms (CFAE) module of the CARTO® 3 3D mapping system, manufactured by Biosense Webster, Inc. (Diamond Bar, Calif.), to generate and analyze ECG data. The calibration engine 101 of the system 100 enhances this software to generate and analyze improved biometric data, which further provides multiple pieces of information regarding the electrophysiological properties of the heart 120 (including scar tissue) that are representative of the cardiac substrate (anatomical and functional) of the aFib.

[0042] Therefore, the system 100 can implement a 3D mapping system, such as the CARTO® 3 3D mapping system, to identify potential arrhythmogenic substrates of cardiomyopathies in terms of detecting abnormal ECGs. These cardiac disease-related substrates have been associated with the presence of endocardial and / or epicardial layer fragmentation of the ventricular cavities (right and left) and delayed ECG activity. For example, low- or medium-voltage regions may indicate ECG fragmentation and delayed activity. Furthermore, low- or medium-voltage regions during sinus rhythm may correspond to critical isthmuses identified in sustained, coherent ventricular arrhythmias (e.g., non-permissive ventricular tachycardia and within the atria). Generally, abnormal tissue is characterized by low-voltage ECGs. However, early clinical experience with endocardial-epicardial mapping has shown that low-voltage regions are not always present as the sole arrhythmogenic mechanism in these patients. In fact, areas of low or medium voltage may show ECG fragmentation and delayed activity during sinus rhythm, corresponding to critical isthmuses identified during sustained, coherent ventricular arrhythmias (e.g., only applicable to nonpermissive ventricular tachycardia). Furthermore, ECG fragmentation and delayed activity are often observed in areas showing normal or near-normal voltage amplitudes (>1–1.5 mV). These latter areas can be evaluated according to voltage amplitude but are not considered normal according to the intracardiac signal and therefore represent true arrhythmogenic substrates. 3D mapping can identify the location of arrhythmogenic substrates on the endocardial and / or epicardial layers of the right and / or left ventricles, whose distribution may vary depending on the primary disease progression.

[0043] As another exemplary operation, cardiac mapping may be performed by the system 100 using one or more multi-electrode catheters (e.g., catheter 110). The multi-electrode catheters are used to stimulate and map electrical activity within the heart 120 and to ablate sites of abnormal electrical activity. In use, the multi-electrode catheter is inserted into a major vein or artery, such as the femoral vein, and then guided into a target chamber of the heart 120. A typical ablation procedure involves inserting the catheter 110, which has at least one electrode 111 at its distal end, into the heart chamber. A reference electrode is provided by taping to the patient's skin, by a second catheter positioned in or near the heart, or by selecting one or other of the electrodes 111 on the catheter 110. Radio frequency (RF) current is applied to the tip electrode 111 of the ablation catheter 110, causing current to flow in the medium surrounding the tip electrode (i.e., blood and tissue) toward the reference electrode. The distribution of current depends on the amount of electrode surface in contact with the tissue compared to blood, which has a higher electrical conductivity than tissue. Tissue heating occurs due to the tissue's electrical resistance. Sufficient tissue heating induces cell destruction in the cardiac tissue, resulting in lesions within the non-conductive cardiac tissue. This process also heats the tip electrode 111 through conduction from the heated tissue to the electrode itself. If the electrode temperature becomes high enough, possibly exceeding 60°C, a thin, transparent film of dehydrated blood proteins can form on the surface of the electrode 111. As the temperature continues to rise, this dehydrated layer can gradually thicken, causing blood to coagulate on the electrode surface. Because dehydrated biological material has a higher electrical resistance than endocardial tissue, the impedance to the flow of electrical energy into the tissue also increases. If the impedance becomes high enough, the catheter 110 must be removed from the body and the tip electrode 111 must be cleaned.

[0044] Referring now to FIG. 2, a diagram of a system 200 capable of implementing one or more features of the presently disclosed subject matter is illustrated, in accordance with one or more exemplary embodiments. System 200 includes, for a patient 202 (e.g., an example of patient 125 in FIG. 1 ), an apparatus 204, a local computing device 206, a remote computing system 208, a first network 210, and a second network 211. Additionally, apparatus 204 may include a biometric sensor 221 (e.g., an example of catheter 110 in FIG. 1 ), a processor 222, a user input (UI) sensor 223, a memory 224, and a transceiver 225. Note that for ease of explanation and brevity, calibration engine 101 from FIG. 1 is reused in FIG. 2.

[0045] According to one embodiment, device 204 may be an example of system 100 of FIG. 1 , where device 204 may include both patient-internal and patient-external components. According to another embodiment, device 204 may be a patient 202-external device including an attachable patch (e.g., attached to the patient's skin). According to another embodiment, device 204 may be internal to the body of patient 202 (e.g., subcutaneously implantable), where device 204 may be inserted into patient 202 by any applicable method, including oral infusion, surgical insertion via a vein or artery, endoscopic procedure, or laparoscopic procedure. According to one embodiment, while a single device 204 is shown in FIG. 2 , an exemplary system may include multiple devices.

[0046] Thus, apparatus 204, local computing device 206, and / or remote computing system 208 can be programmed to execute computer instructions for calibration engine 101. By way of example, memory 223 stores these instructions for execution by processor 222 such that apparatus 204 can receive and process biometric data via biometric sensor 201. In this manner, processor 222 and memory 223 represent the processor and memory of local computing device 206 and / or remote computing system 208.

[0047] The apparatus 204, the local computing device 206, and / or the remote computing system 208 can be any combination of software and / or hardware that individually or collectively stores, executes, and implements the calibration engine 101 and its functions. Furthermore, the apparatus 204, the local computing device 206, and / or the remote computing system 208 can be an electronic computer framework that includes and / or uses any number and combination of computing devices and networks utilizing various communication technologies, as described herein. The apparatus 204, the local computing device 206, and / or the remote computing system 208 can be easily scalable, extensible, and modular, capable of being tailored for different services or reconfigured with some functions independently of others.

[0048] Networks 210 and 211 can be wired networks, wireless networks, or can include one or more wired and wireless networks. According to one embodiment, network 210 is an example of a short-range network (e.g., a local area network (LAN) or a personal area network (PAN)). Information can be transmitted between apparatus 204 and local computing device 206 over short-range network 210 using any one of a variety of short-range wireless communication protocols, such as Bluetooth, Wi-Fi, Zigbee, Z-Wave, near field communications (NFC), Ultraband, Zigbee, or infrared (IR). Furthermore, network 211 is an example of one or more of an intranet, a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), a direct connection or series of connections, a cellular telephone network, or any other network or medium capable of facilitating communication between local computing device 206 and remote computing system 208. Information can be transmitted over network 211 using any one of a variety of long-range wireless communication protocols (e.g., TCP / IP, HTTP, 3G, 4G / LTE, or 5G / New Radio). It should be noted that the wired connections of networks 210 and 211 can be implemented using Ethernet, Universal Serial Bus (USB), RJ-11, or any other wired connection, and the wireless connections can be implemented using Wi-Fi, WiMAX, Bluetooth, infrared, cellular networks, satellite communications, or any other wireless connection method.

[0049] In operation, device 204 may continuously or periodically acquire, monitor, store, process, and communicate biometric data related to patient 202 via network 210. Additionally, device 204, local computing device 206, and / or remote computing system 208 communicate via networks 210 and 211 (e.g., local computing device 206 may be configured as a gateway between device 204 and remote computing system 208). For example, device 204 may be an example of system 100 of FIG. 1 configured to communicate with local computing device 206 via network 210. Local computing device 206 may be, for example, a fixed / standalone device, a base station, a desktop / laptop computer, a smartphone, a smartwatch, a tablet, or any other device configured to communicate with other devices via networks 211 and 210. A remote computing system 208, implemented as a physical server on or connected to the network 211 or as a virtual server within a public cloud computing provider of the network 211 (e.g., Amazon Web Services (AWS)®), can be configured to communicate with the local computing device 206 over the network 211, thereby enabling communication of biometric data related to the patient 202 throughout the system 200.

[0050] The elements of device 204 are now described. Biometric sensor 221 may include, for example, one or more transducers configured to convert one or more environmental conditions into electrical signals so that different types of biometric data may be observed / acquired / obtained. For example, biometric sensor 221 may include one or more of an electrode (e.g., electrode 111 of FIG. 1 ), a temperature sensor (e.g., a thermocouple), a blood pressure sensor, a blood glucose sensor, a blood oxygen sensor, a pH sensor, an accelerometer, and a microphone.

[0051] In executing the calibration engine 101, the processor 222 may be configured to receive, process, and manage biometric data acquired by the biometric sensor 221 and communicate the biometric data to the memory 224 for storage and / or across the network 210 via the transceiver 225. Biometric data from one or more other devices 204 may also be received by the processor 222 via the transceiver 225. Additionally, as described in more detail below, the processor 222 may be configured to selectively respond to different tapping patterns (e.g., single tap or double tap) received from the UI sensor 223 such that different tasks of the patch (e.g., acquiring, storing, or transmitting data) are initiated based on the detected pattern. In some embodiments, the processor 222 may generate audible feedback regarding the detection of the gesture.

[0052] The UI sensor 223 includes, for example, a piezoelectric or capacitive sensor configured to receive user input, such as a tap or touch. For example, the UI sensor 223 may be controlled to perform capacitive coupling in response to the patient 202 tapping or touching the surface of the device 204. Gesture recognition may be implemented via any one of a variety of capacitive types, such as resistive-capacitive, surface-capacitive, projected-capacitive, surface ultrasonic, piezoelectric, and infrared touch. The capacitive sensor may be positioned over a small area or the length of the surface, such that a tap or touch on the surface activates the monitoring device.

[0053] The memory 224 is any non-transitory, tangible medium, such as magnetic, optical, or electronic memory (e.g., any suitable volatile and / or non-volatile memory, such as random access memory or a hard disk drive). The memory 224 stores computer instructions that are executed by the processor 222.

[0054] The transceiver 225 may include a separate transmitter and a separate receiver, or alternatively, the transceiver 225 may include a transmitter and receiver integrated into a single device.

[0055] During operation, the device 204 utilizing the calibration engine 101 observes / acquires biometric data of the patient 202 via the biometric sensor 221, stores the biometric data in memory, and shares this biometric data throughout the system 200 via the transceiver 225.

[0056] 3, a method 300 (e.g., performed by the calibration engine 101 of FIGS. 1 and / or 2) is illustrated, according to one or more exemplary embodiments. Method 300 addresses the need for on-site or in-situ catheter calibration by generating an automatic calibration during navigation of the catheter 110 within the patient 125 (e.g., across a mapping volume) during an ongoing clinical procedure.

[0057] The method begins at block 320, where the calibration engine 101 recalls first calibration data stored in memory of the catheter 110 during use (e.g., in the current clinical procedure). The first calibration data can be stored during catheter manufacture or during the last calibration activity, either before the current clinical procedure.

[0058] Typically, the calibration data includes one or more parameters such as sensitivity and angle (e.g., direction). The sensitivity can be the coil sensitivity of each component of the catheter 110 (e.g., the sensitivity of each sensing coil in terms of how many volts per gauss it produces). The angle can be the angle between pairs of components of the catheter 110.

[0059] At block 340, the calibration engine 101 captures one or more voltage measurements from the catheter 110. Each of the one or more voltage measurements may be captured by one or more components of the catheter 110. More specifically, the one or more voltage measurements may be voltage readings obtained by each or a particular set of components (e.g., electrodes 111, sensors, etc.) of the catheter 110 at one or more points as the catheter 110 is navigated within the patient 125 (e.g., across a mapping volume). According to an embodiment, the one or more voltage measurements may originate from one or more transmitters. In this regard, the one or more voltage measurements are known to the system 100.

[0060] At block 360, the calibration engine 101 estimates second calibration data based on the one or more voltage measurements. According to one or more embodiments, the calibration engine 101 uses each voltage reading obtained by each component to determine a real-time sensitivity and a real-time angle of the second calibration data.

[0061] In block 380, the calibration engine 101 outputs the second calibration data to the catheter 110 (e.g., overwriting the first calibration data in the memory of the catheter 110) so that the second calibration data is applied to the catheter 110. In this manner, the first calibration data of block 320 can be modified by the second calibration data (e.g., real-time sensitivity and real-time angle) estimated in block 360.

[0062] At arrow 390, method 300 loops. In this regard, calibration engine 101 can repeat method 300 to further refine or adjust any stored calibrations. That is, if any online calibration data (estimated in block 360) differs from the stored calibration data (recalled in block 320), calibration engine 101 can use the online calibration data to procure better performance from catheter 110 (which may, for example, perform differently over time due to aging).

[0063] 4, a method 400 (e.g., performed by calibration engine 101 of FIGS. 1 and / or 2) is illustrated according to one or more exemplary embodiments. The method begins at block 410, where calibration engine 101 captures one or more voltage measurements at a current position during a clinical procedure. According to one or more embodiments, calibration engine 101 collects measurements (e.g., voltage readings) at a sensing coil of catheter 110 from one or more points in space (each current position as catheter 110 is advanced), which values ​​may then be used by calibration engine 101 to estimate parameters.

[0064] In an exemplary embodiment, system 100 can be, or be part of, an electrophysiology system (e.g., a CARTO® system). Additionally, catheter 110 can include a SAS sensor. The SAS sensor includes one axial sensor (sensing coil) with one calibration parameter (e.g., coil sensitivity). Each sensing coil can collect voltage measurements from each of nine (in this embodiment) transmitters at a single point. That is, the total number of measurements (T) is equal to the number (M) of transmitter calibrations for each axial sensor (S) per point (X) (e.g., (M * S) * X=T). At maximum collection, the SAS sensor collects nine measurements at a single point (e.g., 9 * 1) * 1=9).

[0065] Additionally, the catheter 110 can include a DAS sensor. The DAS sensor includes two axial sensors. The DAS sensor has three calibration parameters (e.g., two coil sensitivities and the angle between them). In a system with nine transmitters, the DAS sensor collects 18 voltage measurements at a single point (e.g., 9 * 2) * 1=18).

[0066] Additionally, the catheter 110 can include a TAS sensor. The TAS sensor includes three axial sensors. The TAS sensor has six calibration parameters (e.g., three coil sensitivities and three angles between the coil pairs). A total of 27 voltage measurements (if nine transmitters are present) are then captured at a single point (e.g., 9 * 3) * 1=27).

[0067] At decision block 420, calibration engine 101 determines whether additional voltage measurements for calibration are required. If additional voltage measurements for calibration are required, method 400 proceeds to block 430 (indicated by a YES arrow). Method 400 then proceeds via block 410 to decision block 420. If additional voltage measurements for calibration are not required, method 400 proceeds to block 460 (indicated by a NO arrow).

[0068] To determine that additional voltage measurements are needed, the catheter engine 101 may utilize a minimum threshold number associated with the type of catheter being used and compare the minimum threshold number to the number of one or more voltage measurements captured. In this manner, the calibration engine 110 and system 100 may implement a rule that the number of voltage measurements is greater than or equal to the number of unknown parameters. The number of coils and / or transmitters then drives the minimum threshold number.

[0069] According to one or more embodiments, calibration engine 101 can calibrate SAS, DAS, and / or TAS sensors of catheter 110. To calibrate a SAS sensor (i.e., one axial sensor), the minimum threshold number is six voltage measurements from six transmitters to ensure that calibration engine 101 has enough measurements to estimate calibration data from a single point. To calibrate a DAS (i.e., two axial sensors), the minimum threshold number is ten voltage measurements from five transmitters (e.g., 10=5) to ensure that calibration engine 101 has enough measurements to estimate calibration data from a single point. * 2). To calibrate a TAS sensor (i.e., three axial sensors), the minimum threshold number is 12 voltage measurements (e.g., 12 = 4) from four transmitters to ensure that the calibration engine 101 has enough measurements to estimate calibration data from a single point. * 3). If calibration engine 110 and system 100 collect from more than a single point, the minimum threshold number can be four transmitters for DAS sensors and three transmitters for TAS. Thus, one or more technical effects, advantages, and benefits is that calibration engine 110 and system 100 are adaptable to existing surgical / mapping systems to work with any catheter.

[0070] At block 430, the catheter 110 is advanced along the path to change the current position to the next position. Note that if the calibration engine 101 is calibrating on a path, the catheter 110 can move between (e.g., predetermined) positions. According to one embodiment, the path can be approximately the size of the expected working volume (e.g., a sweep from one side of the ventricle to another).

[0071] According to one or more embodiments, as catheter 110 is steered or advanced, additional points may be collected within a short period of time. As shown in chart 500 of FIG. 5, if catheter 110 is steered and 10 points are collected, 270 voltage measurements will be taken. Similarly, if catheter 110 is steered and 100 points are collected, 2700 voltage measurements will be taken.

[0072] At block 460, the calibration engine 101 estimates calibration data (e.g., at least 12 parameters) based on one or more voltage measurements. Examples of parameters include, but are not limited to, the position, the orientation angle, the sensitivity of each sensor, and the mutual angle between each sensor.

[0073] According to one or more embodiments, the at least 12 parameters may include, for a TAS sensor, six location / orientation parameters and six calibration parameters. Note that a TAS sensor, as discussed herein, generally includes three coil sensitivities and three angles between coil pairs (e.g., six calibration parameters).

[0074] As shown in chart 500 of FIG. 5 , if 270 voltage measurements are made, 60 location / orientation parameters and six calibration parameters can be estimated (e.g., 66 parameters). Similarly, if 2700 voltage measurements are made, 600 location / orientation parameters and six calibration parameters can be estimated (e.g., 606 parameters). Note that each of the location / orientation parameters depends on the TAS position, and therefore the number of location / orientation parameters increases to correspond to the number of positions (from blocks 410 and 420). Also note that each of the calibration parameters does not depend on the TAS position, so the number of calibration parameters remains at six. One or more advantages, technical effects, and / or benefits of calibration engine 101 and the online magnetic calibration system include the ability to estimate calibration data from several points across the mapping volume, so that the estimates are more robust with respect to local field distortions.

[0075] For example, for a TAS sensor, note that a total of 27 measurements are taken at one point. It is further noted that as more points are collected to increase the number of measurements, catheter calibration improves (e.g., the more measurements taken during the procedure, the more robust the estimates for calibration data). As shown in chart 500, at 10 points, 270 measurements can be used to estimate 66 parameters, of which 6 are calibration parameters. At 100 points, 2700 measurements can be used to estimate 606 parameters (again, 6 of which are calibration parameters). The estimated calibration parameters can then be combined with the previously known geometric relationship between the sensor and catheter, which ultimately provides the location and orientation of the catheter during the steering procedure. Thus, the resulting location may be as accurate, if not better, than the calibration provided by the current calibration chamber.

[0076] At block 480, the calibration engine 101 applies the calibration data to the catheter 110. Additionally, according to one or more embodiments, the estimated calibration parameters can be combined with a known prior relationship between the sensor and the catheter 110. For example, the TAS sensor is aligned with the shaft 112.

[0077] According to one or more embodiments, the calibration engine 101 in the magnetic location system utilizes a mathematical model (e.g., a set of equations) that takes in several inputs. The number of inputs may include, but is not limited to, a magnetic field model (e.g., magnetic field values ​​at each point in the mapping volume), calibration data as described herein, and sensor position and orientation in the mapping volume. The model output is a prediction of the voltage value generated by each sensing coil. When the calibration engine 101 operates in normal mode, the magnetic field is known because it is stored in the field generator's memory, the calibration data is known because it is stored in the catheter's memory, and the sensor position and orientation are estimated by finding the position and orientation values ​​that best match the model-predicted voltages to the actual measured voltages. When the calibration engine 101 operates in calibration mode, the magnetic field is known because it is stored in the field generator's memory, but the calibration data and sensor position and orientation are estimated by finding the calibration data values ​​and the position and orientation values ​​that best match the model-predicted voltages to the actual measured voltages. Furthermore, in calibration mode, the location estimation does not need to be as robust as in normal mode (because calibration engine 101 has more parameters to estimate). Furthermore, using many points, calibration engine 101 can robustly estimate calibration data (e.g., because it is not dependent on the points selected). Note that calibration engine 101 can start in calibration mode until calibration data is estimated, and then switch to normal mode (e.g., using any estimated calibration data instead of stored data).

[0078] Additionally, calibration engine 101 can utilize the calibration data to determine the life cycle of catheter 110, along with electrode / coil degradation since the previous calibration. For example, calibration engine 101 can set and check a threshold for the difference between stored calibration parameters and online estimated calibration parameters, thereby preventing use (e.g., by shutting down catheter 110) if catheter 110 is excessively degraded (e.g., greater than the threshold). Because catheter 110 may still be usable (e.g., despite exceeding the threshold), calibration engine 101 and system 100 can provide a notification to physician 115 (or medical professional or clinician) according to the threshold, and physician 115 can decide to use catheter 110 in any way (e.g., based on the knowledge that the risk of use is not too high).

[0079] The flowcharts and block diagrams in the figures illustrate the structure, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of instructions, including one or more executable instructions for implementing the depicted logical function(s). In some alternative implementations, the functions shown in the blocks may occur out of the order shown in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending on the functionality involved. It should also be noted that each block of the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified function or operation, or may operate or be executed by a combination of dedicated hardware and computer instructions.

[0080] While features and elements are described above in particular combinations, those skilled in the art will understand that each feature or element can be used alone or in combination with other features and elements. Additionally, the methods described herein may be implemented in a computer program, software, or firmware embodied in a computer-readable medium for execution on a computer or processor. As used herein, computer-readable medium should not be construed as being a transitory signal itself, such as an electric wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse passing through a fiber optic cable), or an electrical signal transmitted through a current line.

[0081] Examples of computer-readable media include electrical signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, optical media such as compact disks (CDs) and digital versatile disks (DVDs), random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), and memory sticks. A processor together with software may be used to implement a radio frequency transceiver for use in a terminal, base station, or any host computer.

[0082] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural unless the context clearly dictates otherwise. It should be understood that the terms "comprise" and / or "comprising," as used herein, indicate the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0083] The description of different embodiments herein is provided for illustrative purposes, but is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terms used herein are selected to best explain the principles, practical applications, or technical improvements of the embodiments compared to technologies found on the market, or to enable those skilled in the art to understand the embodiments disclosed herein.

[0084] [Embodiment] (1) A method for calibrating a medical device, comprising: capturing, by a calibration engine executed by one or more processors, one or more voltage measurements by one or more components of the catheter; estimating, by the calibration engine, calibration data based on the one or more voltage measurements; outputting, by the calibration engine, the calibration data to the catheter. (2) The method of embodiment 1, wherein the one or more voltage measurements include voltage readings obtained by each or a specific set of the one or more components. (3) The method of embodiment 2, wherein the voltage readings are obtained at one or more points as the catheter is maneuvered within the patient. (4) The method of embodiment 1, wherein the calibration data includes one or more parameters including sensitivity and angle. (5) The method of embodiment 4, wherein the sensitivity includes a coil sensitivity for each of the one or more components of the catheter.

[0085] (6) The method of embodiment 4, wherein the angle includes an angle between at least one pair of the one or more components of the catheter. (7) The method of embodiment 1, wherein the one or more components include at least one axial sensor. (8) The method of embodiment 7, wherein the one or more voltage measurements by the at least one axial sensor are from at least three transmitters. (9) The method of embodiment 1, wherein the catheter includes at least one of a single-axis sensor, a two-axis sensor, and a three-axis sensor. (10) The method of embodiment 1, wherein the calibration data includes location / orientation and calibration parameters.

[0086] (11) A system for calibrating a medical device, comprising: a memory storing processor executable code for a calibration engine; one or more processors communicatively coupled to the memory, the one or more processors executing the processor executable code to provide the system with: capturing, by the calibration engine, one or more voltage measurements by one or more components of a catheter; estimating, by the calibration engine, calibration data based on the one or more voltage measurements; and outputting, by the calibration engine, the calibration data to the catheter. (12) The system of embodiment 11, wherein the one or more voltage measurements include voltage readings obtained by each or a specific set of the one or more components. (13) The system of embodiment 12, wherein the voltage readings are obtained at one or more points as the catheter is maneuvered within the patient. (14) The system of embodiment 11, wherein the calibration data includes one or more parameters including sensitivity and angle. (15) The system of embodiment 14, wherein the sensitivities include coil sensitivities for each of the one or more components of the catheter.

[0087] (16) The system of embodiment 14, wherein the angle includes an angle between at least one pair of the one or more components of the catheter. (17) The system of embodiment 11, wherein the one or more components include at least one axial sensor. (18) The system of embodiment 17, wherein the one or more voltage measurements by the at least one axial sensor are from at least three transmitters. (19) The system of embodiment 11, wherein the catheter includes at least one of a single-axis sensor, a two-axis sensor, and a three-axis sensor. (20) The system of embodiment 11, wherein the calibration data includes location / orientation and calibration parameters.

Claims

1. A system for calibrating a medical device, including a catheter, comprising: A memory, processor-executable code for a calibration engine; a memory for storing the first calibration data; one or more components of the catheter, the one or more components including at least one axial sensor; one or more processors communicatively coupled to the memory, the one or more processors executing the processor executable code to provide the system with: predicting, by the calibration engine using a mathematical model, voltage values ​​generated by the at least one axial sensor, wherein inputs taken by the mathematical model include a magnetic field model including magnetic field values ​​at each point in a mapping volume; receiving, by the calibration engine, one or more voltage measurements from the at least one axial sensor within the mapping volume; estimating, by the calibration engine, second calibration data based on the one or more voltage measurements by finding second calibration data values ​​and position and orientation values ​​that best match a model-predicted voltage to an actual measured voltage; and one or more processors configured to cause the calibration engine to output the second calibration data to the memory and overwrite the first calibration data with the second calibration data for use in estimating third calibration data.

2. The one or more processors execute the processor executable code to provide the system with: recalling, by the calibration engine, an nth calibration data item (where n is an integer equal to or greater than 2) stored in the memory; receiving, by the calibration engine, one or more voltage measurements from the catheter; estimating, by the calibration engine, an (n+1)th calibration data item based on the one or more voltage measurements; 2. The system of claim 1, further configured to repeatedly cause the calibration engine to overwrite the nth calibration data in the memory with the n+1th calibration data for use in estimating the n+2th calibration data.

3. The one or more processors execute the processor executable code to provide the system with: receiving, by the calibration engine, the one or more voltage measurements at a current location; The system of claim 1 , further configured to cause the calibration engine to determine whether additional voltage measurements are needed for calibration.

4. If the determination is "YES", the one or more processors execute the processor executable code to provide the system with: the calibration engine causes the catheter to advance along a path to change the current position to a next position; receiving, by the calibration engine, one or more additional voltage measurements at the next location; 4. The system of claim 3, further configured to cause the calibration engine to repeatedly determine whether additional voltage measurements for calibration are needed until the determination is "NO."

5. If the determination is "NO", the one or more processors execute the processor executable code to provide the system with: estimating, by the calibration engine, calibration data based on the one or more voltage measurements and the further one or more voltage measurements; The system of claim 3 or 4, further configured to cause the calibration engine to apply the calibration data to the catheter.

6. The system of claim 1 , wherein the one or more voltage measurements include voltage readings taken by each or a particular set of the one or more components.

7. The system of claim 6 , wherein the voltage readings are taken at one or more points as the catheter is maneuvered within the patient.

8. The system of claim 1 , wherein the first calibration data and the second calibration data include one or more parameters including sensitivity and angle.

9. The system of claim 8 , wherein the sensitivities include coil sensitivities for each of the one or more components of the catheter.

10. The system of claim 8 , wherein the angle comprises an angle between at least one pair of the one or more components of the catheter.

11. The system of claim 1 , wherein the one or more voltage measurements by the at least one axial sensor are from at least three transmitters.

12. The system of claim 1 , wherein the catheter includes at least one of a single-axis sensor, a dual-axis sensor, and a triple-axis sensor.

13. The system of claim 1 , wherein the first and second calibration data include location / orientation and calibration parameters.

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