Method and apparatus for reconstructing electrocardiogram (ECG) data

Abstract

Systems and devices for synthesizing (generating) a 12-lead ECG dataset from 3-lead ECG data. In particular, one or more transformation parameters may be determined that may be applied to the 3-lead ECG dataset to generate the 12-lead ECG data at a particular speed and accuracy. The transformation parameters, including a number of matrices, may be determined from the 12-lead ECG dataset and the 3-lead ECG data of a synchronized patient. The 12-lead ECG dataset may be collected at a different time than the 3-lead ECG data. In some embodiments, the 12-lead ECG dataset and / or the 3-lead ECG dataset may be resampled prior to determining the transformation parameters.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. patent application Ser. No. 17 / 948,099, entitled "METHOD AND APPARATUS FOR RECONSTRUCTING ELECTROCARDIOGRAM (ECG) DATA," filed on September 19, 2022, which claims priority as a continuation of U.S. patent application Ser. No. 17 / 494,806, entitled "METHOD AND APPARATUS FOR RECONSTRUCTING ELECTROCARDIOGRAM (ECG) DATA," filed on October 5, 2021 (now U.S. Patent No. 11,445,963), each of which is incorporated by reference in its entirety herein.

[0002] Incorporation by Reference All publications and patent applications mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

[0003] Technical Field Described herein are methods and apparatus for generating electrocardiogram display data. More particularly, described herein are methods and apparatus (devices and systems) for generating a 12-lead ECG display data set based on acquired 3-lead ECG data. [Background technology]

[0004] Acute myocardial infarction (AMI, also known as heart attack) remains the leading cause of death in developed countries. Finding an accurate and cost-effective solution for AMI diagnosis is crucial. The survival of patients suffering from AMI critically depends on reducing delays in treatment, especially the time between the onset of symptoms and medical treatment. Technologies that allow the diagnosis of AMI early after the onset of AMI symptoms, for example in the patient's home or wherever the patient may be, could significantly reduce mortality from AMI.

[0005] Twelve-lead electrocardiogram (ECG) is a widely adopted tool in cardiac diagnostics. Typically, before an ECG data set is acquired, characteristic points on the patient's body are identified and electrodes are placed relative to these points. During acquisition of the ECG data set, voltages between two or more electrodes are measured and the corresponding ECG signals are called ECG leads. A conventional 12-lead ECG uses ten electrodes to generate twelve ECG signals or leads.

[0006] Recent advances in the treatment of AMI and other cardiac conditions may include the use of portable ECG devices. In contrast to traditional ECG devices, portable ECG devices may generate substantially fewer leads. For example, some portable ECG devices may provide three leads.

[0007] However, due to the widespread adoption of the traditional 12-lead ECG, it can be difficult for clinicians to analyze ECG datasets other than the 12-lead ECG, and therefore it may be beneficial to convert ECG datasets other than the traditional 12-lead ECG format to the traditional 12-lead ECG format. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made to solve the problems in the conventional techniques described above. [Means for solving the problem]

[0009] The systems, methods, and devices of the present disclosure each have several innovative aspects, no single one of which is responsible for the desirable properties disclosed herein.

[0010] One innovative aspect of the subject matter described in this disclosure can be implemented as a method for synthesizing electrocardiogram (ECG) data, which may include receiving a first 12-point ECG dataset for a patient associated with a first dataset collection time, receiving a first 3-point ECG dataset for the patient associated with a second dataset collection time different from the first dataset collection time (e.g., more than an hour, more than a day, more than a week, etc.), determining a set of linear transformation parameters for synthesizing the 12-point ECG dataset based at least in part on the first 12-point ECG dataset and the first 3-point ECG data, and synthesizing a second 12-point ECG dataset from a second 3-point ECG dataset associated with a third collection time based at least in part on the set of linear transformation parameters.

[0011] A method of generating electrocardiogram (ECG) data may include receiving current 3-lead ECG data recorded from a patient, the current 3-lead ECG data including three orthogonal or quasi-orthogonal leads; generating a derived 12-lead ECG data set from the current 3-lead ECG data by applying a set of linear transformation parameters, the set of linear transformation parameters being determined based at least in part on a previous 12-lead ECG data recorded from the patient at a first previous acquisition time and a previous 3-lead ECG data set recorded from the patient at a second previous acquisition time different from the first previous acquisition time; the previous 3-lead ECG data set is synchronized with the previous 12-lead ECG data set by determining a representative heart beat for both the previous 3-lead ECG data set and the previous 12-lead ECG data set, the set of linear transformation parameters including a set of transformation matrices that combine the previous 12-lead ECG data set from the previous 3-lead ECG data set; and outputting the derived 12-lead ECG data set.

[0012] The previous 3-lead ECG data set may be synchronized with the previous 12-lead ECG data set by determining a representative heart beat that applies to both the previous 3-lead ECG data set and the previous 12-lead ECG data set. The representative heart beat may represent both the 12-lead ECG data set and the 3-lead ECG data set, or may be an average heart beat waveform (e.g., components of the P, Q, R, S, T segments, etc. (e.g., all or a portion of the PR interval, all or a portion of the QRS complex, all or a portion of the ST segment, etc.). The representative heart beat may be determined as described herein, such as an arithmetic mean or average value.

[0013] For example, a method of generating electrocardiogram (ECG) data may include receiving current 3-lead ECG data recorded from a patient, the current 3-lead ECG data including three orthogonal or quasi-orthogonal leads, and generating a 12-lead ECG data set derived from the current 3-lead ECG data by applying a set of linear transformation parameters based at least in part on a previous 12-lead ECG data set recorded from the patient at a first previous acquisition time and a previous 3-lead ECG data set recorded from the patient at a second previous acquisition time different from the first previous acquisition time. the previous 3-lead ECG dataset and the previous 12-lead ECG dataset by determining a central heart rate for both the previous 3-lead ECG dataset and the previous 12-lead ECG dataset; segmenting the previous 12-lead ECG dataset and each lead of the previous 3-lead ECG dataset, wherein the set of linear transformation parameters includes a set of transformation matrices that combine segments of the previous 12-lead ECG dataset from segments of the previous 3-lead ECG dataset; and outputting the derived 12-lead ECG dataset.

[0014] The previous 3-lead ECG dataset may be synchronized with the previous 12-lead ECG dataset by further determining a cross-correlation between the previous 3-lead ECG dataset and the previous 12-lead ECG dataset. The previous 3-lead ECG dataset may be synchronized with the previous 12-lead ECG dataset by further aligning features of a QRS complex of the previous 12-lead ECG dataset with features of a QRS complex of the previous 3-lead ECG dataset. The previous 3-lead ECG dataset may be synchronized with the previous 12-lead ECG dataset by further resampling at least one of the previous 12-lead ECG dataset and the previous 3-lead ECG dataset. The resampling may be performed in the frequency domain.

[0015] The previous 3-lead ECG data set may be synchronized with the previous 12-lead ECG data set by further determining the center heart beat for both the previous 3-lead ECG data set and the previous 12-lead ECG data set based on a plurality of heart beats.The previous 3-lead ECG data set may be synchronized with the previous 12-lead ECG data set by further determining the center heart beat for both the previous 3-lead ECG data set and the previous 12-lead ECG data set by selecting a representative heart beat from each of the previous 12-lead ECG data set and the previous 3-lead ECG data set.

[0016] Outputting the derived 12-lead ECG data set may include displaying the derived 12-lead ECG data set.As previously mentioned, the 3-lead ECG leads may be orthogonal or quasi-orthogonal.

[0017] A method of generating electrocardiogram (ECG) data includes receiving current 3-lead ECG data recorded from a patient, the current 3-lead ECG data including three orthogonal or quasi-orthogonal leads, and generating a 12-lead ECG data set derived from the current 3-lead ECG data by applying a set of linear transformation parameters that are at least partially related to a previous 12-lead ECG data set recorded from the patient at a first previous acquisition time and a previous 3-lead ECG data set recorded from the patient using orthogonal or quasi-orthogonal leads at a second previous acquisition time different from the first previous acquisition time. wherein the previous 3-lead ECG dataset is determined based on a representative heart beat for both the previous 3-lead ECG dataset and the previous 12-lead ECG dataset, synchronizing the previous 3-lead ECG dataset with the previous 12-lead ECG dataset by determining a representative heart beat for both the previous 3-lead ECG dataset and the previous 12-lead ECG dataset; segmenting the previous 12-lead ECG dataset and each lead of the previous 3-lead ECG dataset, wherein the set of linear transformation parameters includes a set of transformation matrices that combine segments of the previous 12-lead ECG dataset from segments of the previous 3-lead ECG dataset; and outputting the derived 12-lead ECG dataset.

[0018] Also described herein is a method of generating electrocardiogram (ECG) data that may include accessing a first 12-point ECG dataset for a patient associated with a first dataset collection time; accessing a first 3-point ECG dataset for the patient associated with a second dataset collection time different from the first dataset collection time; determining a set of linear transformation parameters based at least in part on the first 12-point ECG dataset and the first 3-point ECG dataset; receiving a second 3-point ECG dataset from a third data collection time; and outputting a second 12-point ECG dataset synthesized from the second 3-point ECG dataset using the set of linear transformation parameters.

[0019] In some variations, determining the set of linear transformation parameters may include synchronizing the first 3-point ECG data set with the first 12-point ECG data. In some embodiments, the synchronizing may include determining a cross-correlation between the first 3-point ECG data set and the first 12-point ECG data. In some other embodiments, the synchronizing may include resampling at least one of the first 12-point ECG data set and the first 3-point ECG data. The resampling may be performed in the frequency domain.

[0020] In some variations, the synchronizing step may include determining a central heart beat of the first 12-lead ECG data set and the first 3-lead ECG data. In some cases, determining the central heart beat may include determining an average or median value of the first 12-lead ECG data set and the first 3-lead ECG data set based on a plurality of heart beats. In other aspects, determining the central heart beat may include selecting a representative heart beat from each of the first 12-lead ECG data set and the first 3-lead ECG data.

[0021] In some variations, determining the set of linear transformation parameters may include segmenting each lead of the first 12-point ECG data set and the first 3-point ECG data set, and determining a set of transformation matrices for synthesizing segments of the first 12-point ECG data set from segments of the first 3-point ECG data.

[0022] In some variations, the method may include displaying the second 12-point ECG data. In some other variations, determining the set of linear transformation parameters may include pre-processing the first 12-point ECG data set and the first 3-point ECG data. In yet other variations, the first 3-point ECG may be orthogonal or quasi-orthogonal. The resulting orthogonal or quasi-orthogonal data set may include a data set sufficient to determine associated conventional 12-point ECG data.

[0023] Also described herein are ECG systems configured to perform any of these methods. These systems may be configured to determine the transformation matrix and / or generate a 12-point ECG either locally (with respect to the patient), remotely, or a combination of locally and remotely from a currently recorded 3-lead (e.g., orthogonal or quasi-orthogonal) ECG. For example, the ECG system may include a computational node configured to receive a first 12-point ECG dataset for a patient associated with a first dataset acquisition time, receive a first 3-point ECG dataset for a patient associated with a second dataset acquisition time that is different from the first dataset acquisition time, and determine a set of linear transformation parameters for synthesizing a 12-point ECG dataset based at least in part on the first 12-point ECG dataset and the first 3-lead ECG data. The ECG system may also include a portable ECG device configured to provide a second 3-point ECG dataset from the patient, the computational node further configured to synthesize a second 12-point ECG dataset from the second 3-point ECG dataset associated with a third acquisition time based at least in part on the set of linear transformation parameters.

[0024] An electrocardiogram (ECG) system includes a portable ECG device configured to record a current 3-lead ECG dataset from a patient; and a non-transitory computer readable storage medium including instructions that, when executed by one or more processors, cause the one or more processors to: access a first 12-point ECG dataset for the patient associated with a first dataset acquisition time; access a first 3-lead ECG dataset for the patient associated with a second dataset acquisition time that is different from the first dataset acquisition time; and generate linear transformation parameters for synthesizing a 12-lead ECG dataset based at least in part on the first 12-point ECG dataset and the first 3-lead ECG data. receiving the current 3-lead ECG dataset from the portable ECG device; synthesizing a second 12-lead ECG dataset from the current 3-lead ECG dataset based at least in part on the set of linear transformation parameters; and outputting the second 12-lead ECG dataset.

[0025] In some variations, the computing node may be further configured to synchronize the first 3-lead ECG data set to the first 12-lead ECG data. The synchronization may include determining a cross-correlation between the first 3-lead ECG data set and the first 12-lead ECG data. In some other variations, the synchronization may include matching a QRS complex feature of the first 12-lead ECG data set with a QRS complex feature of the first 3-lead ECG data. In yet other variations, the synchronization may include resampling at least one of the first 12-lead ECG data set and the first 3-lead ECG data. The resampling may be performed in the frequency domain.

[0026] In some variations, the synchronization may include determining a central heart beat of the first 12-lead ECG data set and the first 3-lead ECG data. In some cases, determining the central heart beat may include determining an average or median value of each of the first 12-lead ECG data set and the first 3-lead ECG data set based on a plurality of heart beats. In other aspects, determining the central heart beat may include selecting a representative heart beat from each of the first 12-lead ECG data set and the first 3-lead ECG data.

[0027] In some variations, the one or more processors (sometimes referred to herein as “computational nodes”) may be further configured to determine a set of transformation matrices for segmenting each lead of the first 12-point ECG data set and the first 3-point ECG data set and synthesizing segments of the first 12-point ECG data set from segments of the first 3-point ECG data.

[0028] In some variations, the computing node may be further configured to generate a display data set based on the second 12-point ECG data. In some other variations, the computing node may be further configured to pre-process the first 12-point ECG data set and the first 3-point ECG data. In some variations, the first 3-point ECG data set may be an orthogonal or quasi-orthogonal data set to the first 12-point ECG data. In some cases, the orthogonal or quasi-orthogonal data set may include a data set sufficient to determine associated conventional 12-point ECG data.

[0029] Another innovative aspect of the subject matter described in this disclosure can be implemented as a non-transitory computer-readable storage medium including instructions that, when executed by one or more processors (e.g., computing nodes), cause the computing nodes to perform operations including receiving a first 12-point ECG dataset for a patient associated with a first dataset acquisition time; receiving a first 3-point ECG dataset for the patient associated with a second dataset acquisition time different from the first dataset acquisition time; determining a set of linear transformation parameters for combining the 12-point ECG dataset based at least in part on the first 12-point ECG dataset and the first 3-point ECG dataset; and combining a second 12-point ECG dataset from a second 3-point ECG dataset associated with a third acquisition time based at least in part on the set of linear transformation parameters.

[0030] For example, a non-transitory computer readable storage medium, when executed by one or more processors, may cause the one or more processors to: receive a first 12-point ECG dataset for a patient associated with a first dataset acquisition time; receive a first 3-point ECG dataset for the patient associated with a second dataset acquisition time that is different from the first dataset acquisition time; and determine a set of linear transformation parameters based at least in part on the first 12-point ECG dataset and the first 3-point ECG data, wherein the first 3-lead ECG dataset is a set of linear transformation parameters based at least in part on the first 12-point ECG dataset and the first 3-lead ECG data. receiving a second 3-lead ECG dataset corresponding to the patient; synthesizing a second 12-lead ECG dataset from the second 3-lead ECG dataset based at least in part on the set of linear transformation parameters; and outputting the second 12-lead ECG dataset.

[0031] In some variations, execution of the instructions for determining the set of linear transformation parameters may cause the computational node to perform operations further including synchronizing a first 3-lead ECG data set with a first 12-lead ECG data set. In some aspects, the synchronizing may include determining a cross-correlation between the first 3-lead ECG data set and the first 12-lead ECG data. In some other aspects, the synchronizing may include aligning a QRS complex feature of the first 12-lead ECG data set with a QRS complex feature of the first 3-lead ECG data. In some embodiments, the synchronizing may include resampling at least one of the first 12-lead ECG data set and the first 3-lead ECG data. In some aspects, the resampling may be performed in the frequency domain.

[0032] In some variations, the synchronizing step may include determining a median heart rate of the first 12-lead ECG data set and the first 3-lead ECG data. [Brief description of the drawings]

[0033] The novel features of the embodiments described herein are set forth with particularity in the appended claims. A better understanding of the features and advantages of the embodiments can be obtained by reference to the following detailed description and the accompanying drawings which set forth illustrative embodiments. [Figure 1] FIG. 1 illustrates a variation of an ECG system according to some embodiments. [Diagram 2] 1 is a simplified flow chart illustrating the generation of a 12-lead ECG data set from 3-lead ECG data. [Diagram 3] 1 illustrates a process flow for synthesizing a 12-lead ECG data set based on 3-lead ECG data. [Figure 4] 5 is a flowchart illustrating an example method for determining a linear transformation matrix in accordance with some embodiments. [Diagram 5]FIG. 13 is a lead diagram including lead I from a 12-lead ECG and lead X1 from a 3-lead ECG according to some embodiments. [Figure 6] FIG. 1 illustrates some reference points for exemplary ECG leads. [Figure 7] 1 is a flow chart illustrating an exemplary method for synthesizing a 12-lead ECG data set from 3-lead ECG data, according to some embodiments. [Figure 8] 1 is a graph of an exemplary 12-lead ECG, according to some embodiments. [Figure 9] 1 is a graph of exemplary three-lead ECG data, according to some embodiments. [Figure 10] 1 is a graph of exemplary synthesized 12-lead ECG data, according to some embodiments. [Figure 11] 2 is a block diagram of a computing node according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] An electrocardiogram (ECG) can graphically represent the detected voltages associated with the contraction of the myocardium. Contractions resulting from depolarization and repolarization of the myocardium can be examined by examining the ECG graph. The 12-lead ECG graph is a widely adopted tool that provides 12 different voltage captures of the detected cardiac voltages. Clinicians are widely trained to infer the state of the heart by examining a patient's 12-lead ECG data.

[0035] Portable ECG devices have been developed that allow for the collection of electrocardiogram data outside of a clinic or doctor's office. However, many portable ECG devices do not capture enough information to generate traditional 12-lead ECG data. For example, some portable ECG devices only generate or capture 3-lead ECG data. In fact, in some cases, patient records only contain 12-lead ECG data, making interpretation of non-12-lead ECG data difficult.

[0036] Implementations of the subject matter described in this disclosure may be used to generate (synthesize) 12-point ECG data from non-12-point ECG data. More specifically, the subject matter may describe the synthesis of conventional 12-point ECG data from three-point ECG data, such as orthogonal or quasi-orthogonal three-point ECG data. In some variations, the synthesis / generation of the 12-point ECG data may be based on applying transformation parameters to the three-point ECG data. The transformation parameters may be determined based on previously captured (recorded) 12-point ECG data of the patient and the three-point ECG data of the patient. In particular, the 12-point ECG data may be captured at a different time relative to the three-point ECG data. In some variations, the transformation parameters may include one or more matrices that may be applied to the three-point ECG data to synthesize the associated 12-point ECG data. In this manner, a clinician may advantageously review the three-point ECG data that may be presented as conventional 12-point ECG data. In some cases, the 3-lead ECG data may be provided by a portable ECG device that may be used in environments other than a clinic, hospital, doctor's office, etc. For example, the 3-lead ECG data may be captured by the patient at home, transmitted to a remote computing node, and converted to conventional 12-lead ECG data that may be transmitted to and displayed by a clinician.

[0037] The transformation parameters may be determined by synchronizing and segmenting the previously captured 12-lead ECG data and the 3-lead ECG data. A least squares analysis may then be performed to deterministically determine a set of transformation matrices that may be used to synthesize the 12-lead ECG data from the 3-lead ECG data. Once determined, the transformation parameters may be stored. In some cases, the transformation parameters may be stored remotely in a cloud-based storage system. The 12-lead ECG data may be synthesized from the 3-lead ECG data using these remotely stored transformation parameters.

[0038] FIG. 1 illustrates one variation of an ECG system 100 according to some embodiments. The ECG system 100 may include a small, portable ECG device 110 and a display device 140. The ECG device 110 may generate three-lead ECG data for a patient 120. In some cases, the patient 120 may place the ECG device 110 on the chest while touching one or more contact electrodes with a hand. Additionally, the ECG device 110 may have multiple electrodes on a surface that contacts the patient 120. Thus, the ECG device 110 may contact the patient 120 with multiple electrodes via the patient's fingers and / or chest. The ECG device may generate three-lead ECG data via the electrodes. One example of an ECG device 110 is described in commonly owned U.S. Patent No. 10,433,744, entitled "MOBILE THREE-LEAD CARDIAC MONITORING DEVICE AND METHOD FOR AUTOMATED DIAGNOSTICS," filed April 11, 2016, which claims priority to U.S. Provisional Patent Application No. 62 / 145,431, entitled "MOBILE THREE-LEAD CARDIAC MONITORING DEVICE AND METHOD FOR AUTOMATED DIAGNOSTICS," filed April 9, 2015. These applications are incorporated herein by reference in their entireties.

[0039] In some variations, the leads generated by the ECG device 110 may be orthogonal or quasi-orthogonal. The three-lead ECG data from the ECG device 110 may contain some or all of the information contained in traditional 12-lead ECG data. However, some clinicians may be unfamiliar with interpreting cardiac data from orthogonal or quasi-orthogonal leads from the ECG device 110.

[0040] Data from the ECG device 110 may be transmitted to a network 130. The network 130 may include remote (cloud-based) storage and / or one or more remote computing nodes (not shown). In some variations, the 12-lead ECG data may be synthesized from the 3-lead ECG data provided by the ECG device 110 in the network 130. The 12-lead ECG data may be displayed on a display device 140. In this manner, a clinician may advantageously review the patient's ECG data in a traditional 12-lead format. Furthermore, the patient 120 may be located outside of a doctor's office or examination room. Thus, the ECG device 110 may enable a clinician to diagnose and treat the patient 120 in a remote location.

[0041] In some variations, the display device 140 may include one or more processors capable of synthesizing 12-lead ECG data from the 3-lead ECG data. For example, the display device 140 may be a laptop computer, a smart display or monitor, a mobile phone, or other available device. Thus, in some variations, the network 130 may transmit the 3-lead ECG data from the ECG device 110 to the display device 140. The display device 140 may convert the 3-lead ECG data to 12-lead ECG data and then display this data.

[0042] 2 is a simplified flowchart 200 illustrating the generation of 12-point ECG data 210 from 3-point ECG data 220. In some variations, the 3-point ECG data 220 may be provided by the ECG device 110 of FIG. 1. Although illustrated here as X1, X2, and X3, the three leads from the ECG device 110 may have any viable label and may include more than three leads in some variations. The leads from the ECG device 110 may be orthogonal or quasi-orthogonal to a lead space encompassing a conventional 12-point ECG, such as the 12-point ECG data 210. Thus, most or all of the information that may be included in a conventional 12-point ECG may be included (encoded) in the orthogonal or quasi-orthogonal leads from the ECG device 110. In other words, the orthogonal or quasi-orthogonal data includes sufficient data to determine the conventional 12-point ECG data. The twelve leads are labeled I, II, III, aVR, aVL, aVF, V1, V2, V3, V4, V5, and V6, although the leads of the 12-lead ECG data 210 may have any feasible label. In some variations, more or fewer leads may be generated from the 3-lead ECG data 220.

[0043] In some embodiments, the 3-lead ECG data 220 may be processed with a linear transform 240 to generate or synthesize 12-lead ECG data 210. In this manner, the 3-lead ECG data 220 from the ECG device 110 may be converted into 12-lead ECG data 210 that may be more easily interpreted by a clinician due to the widely adopted and understood nature of traditional 12-lead ECG data. In some cases, the synthesized 12-lead ECG data 210 may be displayed as a traditional 12-lead ECG chart for analysis and review by a clinician.

[0044] In some variations, the linear transform 240 may be based, at least in part, on previously captured (recorded) and stored 12-lead ECG data of the patient (not shown). The relationship of the linear transform 240 to the patient's previous 12-lead ECG data is illustrated in FIG.

[0045] 3 illustrates a process flow 300 for determining or synthesizing 12-lead ECG data based on 3-lead ECG data. Although described with respect to 3-lead ECG data, the process described herein may be adapted for use with any available ECG data other than conventional 12-lead ECG data.

[0046] The process flow 300 may use previously recorded and / or captured 12-lead ECG data 310 of the patient and 3-lead ECG data 320 of the patient. The 12-lead ECG data 310 may be from an available ECG device capable of generating and / or recording 12-lead ECG data. In some variations, the 12-lead ECG data 310 may be a baseline ECG recording for a known physical condition of the patient. In some cases, the 12-lead ECG data 310 may be from a health record associated with the patient. For simplicity, the 12-lead ECG data 310 is shown to include leads I, II, III, aVR, aVL, aVF, V1, V2, V3, V4, V5, and V6, although in other embodiments, the 12-lead ECG data 310 may include any available leads.

[0047] The three-lead ECG data 320 may include any available three-lead orthogonal or quasi-orthogonal ECG data. In some variations, the three-lead ECG data 320 may be provided by a small / portable ECG device, such as the ECG device 110 of FIG. 1. For simplicity, the three-lead ECG data 320 is shown to include leads X1, X2, and X3, but any available three-lead ECG data may be included. In particular, the 12-lead ECG data 310 and the three-lead ECG data 320 may be collected (e.g., captured or recorded) at different times. In other words, the 12-lead ECG data 310 may be collected / recorded at a first time, and the three-lead ECG data 320 may be collected / recorded at a second time that is different from the first time.

[0048] The 12-lead ECG data 310 and the 3-lead ECG data 320 may be subjected to analysis 330 to determine a relationship therebetween. In some cases, the analysis 330 may determine a linear relationship between the 3-lead ECG data 320 and the 12-lead ECG data 310. In some variations, the linear relationship may include one or more linear transformation matrices 340 (not shown) that may be used to transform the 3-lead ECG data 320 into 12-lead ECG data. In other words, the linear transformation matrices 340 may be used to synthesize and / or display the 12-lead ECG data derived from the 3-lead ECG data 320. In this manner, the patient's 3-lead ECG data 320 may be displayed as traditional 12-lead ECG data to enable a clinician to diagnose the patient's cardiac health. In some cases, the 3-lead ECG data 320 may be provided by the patient from a home environment or other location away from traditional medical facilities. For example, a patient may collect three-lead ECG data 320 at home using ECG device 110. In this manner, extensive cardiac care may be provided to patients who are far from or remote from specialized cardiac care facilities.

[0049] 4 is a flow chart illustrating an example method 400 for determining a linear transformation matrix, according to some embodiments. Some examples may perform the operations described herein, including additional operations, fewer operations, operations in a different order, operations in parallel, and some different operations. Method 400 may be performed by a processor or computer, such as a cloud-based processing node, locally (with respect to the patient) or remotely in cooperation with one or more processors. In other variations, method 400 may be performed by any other suitable system or device.

[0050] Method 400 may optionally be associated with a "calibration phase" in which a linear transformation matrix is ​​"calibrated" to convert the 3-lead ECG data to 12-lead ECG data. As an overview of the process, 12-lead ECG data recorded / captured at a first time is aligned with 3-lead ECG data recorded / captured at a second time. After alignment, the ECG data is segmented and transformation matrices associated with the ECG data segments are determined.

[0051] Method 400 begins at block 402, where 12-point ECG data of a patient associated with a first acquisition time (e.g., a data collection time) is received. The 12-point ECG data may be collected and / or recorded using any available ECG device. In some variations, the 12-point ECG data may be received from a medical record, including an electronic medical record. In some cases, the 12-point ECG data may be stored in one or more remote file systems, such as a cloud-based system. Thus, the 12-point ECG data may be accessed via one or more networks, including, for example, the Internet. As discussed above, the 12-point ECG data may be associated with a first acquisition time. That is, the 12-point ECG data may be captured and / or recorded for a first time or time period.

[0052] Next, in block 404, three-lead ECG data for the patient associated with a second acquisition time is received. The three-lead ECG data may be captured and / or recorded by any available ECG device, such as ECG device 110 of FIG. 1. The three-lead ECG data may be orthogonal or quasi-orthogonal ECG data and may be collected and / or recorded for a second time or time period. In particular, the first time or time period may be different from the second time or time period. In some cases, the three-lead ECG data may be stored in a remote file system and accessed over one or more networks.

[0053] Next, in block 406, the 12-lead ECG data and the 3-lead ECG data may be pre-processed. As indicated by the dashed lines in FIG. 4, this operation may be optional. Signal pre-processing may include noise filtering, baseline wandering removal, or any other possible pre-processing operation. For example, pre-processing of the 12-lead ECG data and / or the 3-lead ECG data may include low pass filtering to band limit the respective data signals and remove out-of-band noise.

[0054] Next, at block 408, a median beat is generated for the 3-lead ECG data and the 12-lead ECG data. In some embodiments, a median beat may be generated for each lead of associated ECG data. To generate the median beat, different beats of a particular lead of ECG data are aligned. In some cases, the alignment is determined by cross-correlation of the QRS complexes of the beats of the selected lead. After the ECG data of the selected lead is aligned, a median value associated with the particular ECG lead may be determined to determine the median beat. Although described herein as a median operation, in other embodiments, any other viable selection operation may be used, including but not limited to an average operation, a mode operation, etc. In some variations, instead of determining a median beat for each ECG data lead, a representative lead (e.g., a representative beat) may be selected.

[0055] Next, in block 410, the center heart rate of the 3-lead and 12-lead ECG data is synchronized. Because the 12-lead ECG data may have been acquired at a different time than the 3-lead ECG data, the duration of the 12-lead ECG data may differ from the duration of the 3-lead ECG data. Therefore, the 3-lead ECG data needs to be synchronized and / or normalized to the 12-lead ECG data before any ECG data relationship can be determined. In some variations, the ECG data may be synchronized with respect to an interval. For example, the ECG data may be synchronized with respect to a depolarization interval and with respect to a repolarization interval.

[0056] 5 is a lead diagram 500 including lead I 510 from a 12-lead ECG and lead X1 520 from a 3-lead ECG, according to some embodiments. A depolarization interval 530 may begin with an atrial depolarization (e.g., the beginning of a heartbeat when the atrium contracts) and end after the QRS complex (depicted as point J in lead diagram 500). In some embodiments, synchronization of the ECG data for the depolarization interval may include cross-correlation of a first ECG data lead with a second ECG data lead. For example, cross-correlation may be used to align lead I 510 with lead X1 520 by using distinct features of the QRS complexes included in each ECG data lead. In some variations, synchronization may include determining a time shift between lead I 510 and lead X1 520. After determining the time shift, other leads of the 3-lead ECG (e.g., X2, X3, not shown here for simplicity) may be shifted by the same or a similar amount.

[0057] The repolarization interval 535 may begin at point J and extend to the end of the heartbeat. Synchronization during the repolarization interval 535 may include resampling the short ECG leads (in time) to lengths closer to the long ECG leads. The portion of the ECG leads from point J onwards may be divided into two sections. The first section begins at point J and ends at T max (T max (may be a relative maximum after point J). The second interval is T max Starting from the end of the heartbeat, T end It extends to.

[0058] First, the length of X1 lead 520 is from point J to point T max The length of lead I 510 in the interval from point J to point T is compared to the length of lead I 510 in the interval from point J to point T. The shorter ECG is resampled such that its length is expanded to approximately match the length of the longer ECG. In the example of FIG. max The length of lead I 510 from point J to point T is longer than the length of lead X1 520. Therefore, lead X1 520 is max 5. The signal may be resampled to approximately match the length of the I lead 510 up to the

[0059] In some variations, resampling of the ECG leads may be done in the frequency domain by adding zero samples to the short leads. For example, points J and T max If a section of the I-lead 510 between has M samples and the equivalent section of the X1-lead 520 has N samples, then M zero-valued samples may be added to the center of the frequency spectrum of the X1-lead 520 before transforming back to the time domain. In other variations, the resampling may be performed in the time domain.

[0060] The second section of X1 lead 520 (T max and T end The second interval of lead X1 510 (between X1 and X2) may also be resampled in a similar manner. The resampled ECG leads may be filtered by fitting a polynomial, such as a 10th order polynomial, to reduce noise. The resulting resampled and filtered lead X1 540 is shown in FIG. 5 for reference. Similar resampling operations can be performed for ECG leads X2 and X3.

[0061] Returning to FIG. 4, at block 412, the central heart beats of the 12-lead ECG data and the synchronized 3-lead ECG data are divided into a number of segments. In some variations, the 12-lead ECG data and the 3-lead ECG data may be divided into three segments, although other numbers of segments are possible. The segments may be based on fiducial points identified on each ECG lead. In some variations, P start , Q, J, and T end may be used.

[0062] FIG. 6 is a diagram 600 showing some reference points for exemplary ECG leads. start may refer to the starting point of an ECG lead. In particular, P startThe fiducial points occur before the P wave, which is the first positive ECG deflection within the cardiac period shown in FIG. 6. The Q fiducial point is associated with the beginning of the QRS complex portion of the ECG lead. The QRS complex includes the Q, R and S waves and is associated with the contraction of the ventricles of the heart. The J fiducial point is associated with the end of the QRS complex. end The reference point is the end point of the ECG lead.

[0063] In some variations, the fiducial points may be determined automatically, for example, by a computer algorithm or program executed by one or more processors. Exemplary methods are described in Sun, Y. et al. (2005) "Characteristic wave detection in ECG signal using morphological transform," BMC Cardiovasc Disord, Sept. 20, 5:28, and Rakshit et al. (2015) "EKF with PSO technique for delineation of P and T wave in electrocardiogram (ECG) signal," Second International Conference on Signal Processing and Integrated Networks, 2015. nd International Conference on Signal Processing and Integrated Networks (SPIN), IEEE.

[0064] Additionally, a PQ fiducial point may be determined. The PQ fiducial point is located between [Q-60 milliseconds (ms), Q-20 ms]. Note that Q is associated with the beginning of the Q wave of the QRS complex described above. The PQ fiducial point is based on a minimum of the three-lead ECG data during the [Q-60 ms, Q-20 ms] interval. The minimum may be based on a vector magnitude of the orthogonal or pseudo-orthogonal leads;

number

[0065] Based on the determined fiducial points, three segments may be determined for each ECG lead. Examples of segments include [P start The first segment (T P ), the second segment (T QRS ), [J-20ms, T end The third segment (T T ) may be included. Example of segment T P , T QRS , and T T is shown in Figure 6 for reference. In some embodiments, the three segments may overlap. Overlapping the segments may allow for smoothing of discontinuities between the segments by a later determined transformation function and / or matrix.

[0066] Next, in block 414, patient-specific transformation parameters are determined for the determined segments. In some variations, the transformation parameters may be expressed as linear transformation matrices (e.g., linear transformation parameters). Four transformation matrices may be defined, one for each segment defined in block 412 (e.g., T P , T QRS , and T T The first matrix is ​​associated with the QRS complex (the first segment) and the second matrix is ​​associated with the transition region between the QRS complex and the T wave.

[0067] In some variations, T P , T QRS , and T T The matrix associated with the segment is T P , T QRS , T T These matrices may be written as:

number

number

number

[0068] In some embodiments, the Y vector may include eight independent leads based on the Y1 and Y2 limb leads and four other leads. In other embodiments, the transformation matrix may be calculated using a least squares method. For example,

number

number

number

[0069] In some variations, the heart rates of each lead heart beat may be concatenated and the above formula (Equation 2) may be applied. For example, five or more heart beats may be concatenated, but any number of heart beats including one may be used.

[0070] In another variant, the matrix {T P,j}, {T QRS,j} and {TT,j}, and then calculate the median of each set of respective coefficients in each set of matrices.

[0071] A fourth matrix may be used to synthesize the region between the QRS complex and the T wave. This region is sometimes called the "ST segment," which refers to the segment between the conventional S wave and the T wave on the ECG tracing. In some variations, the transient matrix T transient is expressed as follows in Equation 3: QRS and T T It may also be a weighted combination of matrices.

number

number

[0072] Therefore, the linear transformation T P , T QRS , T T and T transient may generate 12-point ECG data (as output) based on 3-point ECG data (as input). In particular, the linear transformation may generate / synthesize segments of 12-point ECG data based on the segments of 3-point ECG data. In some embodiments, the segments of 12-point ECG data may overlap. The overlap may help to smooth discontinuities in the generated (synthesized) 12-point ECG data.

[0073] Linear transformation T P , T QRS , T T and T transient may be stored for later use. For example, the linear transform may be used to synthesize 12-lead ECG data based on 3-lead ECG data recorded / captured at a later time relative to the 3-lead ECG data used to determine the linear transform. In some embodiments, the transform may be stored in cloud storage or any executable medium.

[0074] The combined 12-lead ECG data may include ECG display data. Thus, in some embodiments, the 12-lead ECG display data may be displayed to a clinician to enable the clinician to perform a cardiac examination and diagnosis of the patient based on the three-lead ECG data. In other words, the three-lead ECG data may be advantageously converted to conventional 12-lead ECG data to enable the cardiac examination.

[0075] 7 is a flow chart illustrating an exemplary method 700 for synthesizing 12-lead ECG data from 3-lead ECG data, according to some embodiments. In some variations, the 3-lead ECG data may include orthogonal or quasi-orthogonal ECG lead data. Method 700 may be referred to as a "monitoring phase" in which a transformation matrix (determined with respect to method 400) is used to synthesize 12-lead ECG data that may be displayed and reviewed by a clinician.

[0076] Method 700 begins at block 702 where three-lead ECG data is received. In some variations, the three-lead ECG data may be provided by (received from) the ECG device 110 of FIG. 1 . In other variations, the three-lead ECG data may be provided from a remote server, such as a cloud-based storage device. In some variations, the three-lead ECG data may be orthogonal or quasi-orthogonal ECG data (as described with respect to FIG. 2 ). Next, at block 704, fiducial points and fiducial-related segments are determined for the three-lead ECG data. In some embodiments, the fiducial points are P start , Q, J, and T end Based on these reference points, four composite segments may be defined. The four segments are the T P , T QRS , T T and T transient It may correspond to a segment.

[0077] Next, in block 706, the 12-point ECG data is synthesized from the received 3-point ECG data for each of the defined segments. In some embodiments, the linear transformation (e.g., linear transformation matrix T) described with respect to FIG. 4 is used to synthesize each segment of the 12-point ECG data. P , T QRS , T T and T transient ) may be used. For example, T P The segment is composed of the received three-lead ECG data and the T P It may be synthesized (e.g., determined or reconstructed) by matrix multiplication with a matrix T QRS The segment is composed of the received three-lead ECG data and the T QRS They may be combined by matrix multiplication with matrices. T The segment is composed of the received three-lead ECG data and the T T The ST segment may be synthesized by matrix multiplication with the T transient , T QRS and T TThey may be combined by a weighted combination of matrices.

number

[0078] In some embodiments, the ST segment may be defined within the interval [J-20ms, J+80ms]. In some cases, with some weighting factors, the reconstruction matrix is ​​a single matrix T single , matrix T T and matrix T QRS In another embodiment, the ST segment may be simplified to the population matrix T POP may be reconstructed using

[0079] Next, discontinuities between the combined segments are smoothed in block 708. In some cases, the smoothing is accomplished by transitioning between matrices rather than making an abrupt change between the matrices used in block 706. An example is shown below in Equation 6:

number

[0080] In some variations, discontinuities occurring between segments of the combined 12-lead ECG signal may be smoothed using one or more cubic spline functions. Additionally, although described as combining 12 leads of a 12-lead ECG, the method of FIG. 7 may be used to combine fewer than 12 leads. For example, the method of FIG. 7 may be used to combine a subset of the 12 traditional ECG leads. In yet another variation, the methods described herein may be used to combine or reconstruct missing leads of any well-defined set of ECG leads. In this case, the base or orthogonal / quasi-orthogonal lead may be any lead to which the missing ECG lead may be associated.

[0081] 8 is a graph of exemplary 12-lead ECG data 800, according to some embodiments. The 12-lead ECG data 800 may be captured (recorded) during a first acquisition. As shown, the 12-lead ECG data 800 may include twelve conventional leads: I, II, III, aVR, aVL, aVF, V1, V2, V3, V4, V5, and V6. The 12-lead ECG data 800 may be used to determine linear transformation parameters, as described with respect to FIG.

[0082] 9 is a graph of exemplary three-lead ECG data 900 according to some embodiments. In some variations, the three-lead ECG data 900 may be captured at a first acquisition time relative to the 12-lead ECG data 800. For example, the three-lead ECG data 900 may represent ECG data captured by a patient with a portable ECG device 110 for analysis by a clinician. The three-lead ECG data 900 may include three leads, such as X1, X2, and X3, as described herein. Leads X1, X2, and X3 may be labeled a, b, and c in FIG. 9.

[0083] FIG. 10 is a graph of an exemplary combined 12-lead ECG data 1000 according to some embodiments. For example, the combined 12-lead ECG data 1000 may be based on the 3-lead ECG data 900 of FIG. 9. In some variations, the combined 12-lead ECG data 1000 may be combined using a set of transformation parameters based on previously recorded 12-lead ECG data (not shown). A visual comparison of the 12-lead ECG data 800 and the combined 12-lead ECG data 1000 reveals that the combined 12-lead ECG data 1000 may be relatively similar to the 12-lead ECG data 800. Table 1 below shows the average difference and associated standard deviation between the 12-lead ECG data 800 and the combined 12-lead ECG data 1000. A relatively large average value (e.g., a value closer to 1.0) indicates a greater similarity between the 12-lead ECG data 800 and the combined 12-lead ECG data 1000.

[0084] [Table 1]

[0085] FIG. 11 is a block diagram of a computing node 1100 according to some embodiments. The computing node 1100 may include a device input / output (I / O) interface 1120, a processor 1130, and a memory 1140. The device I / O interface 1120, which may be coupled to a network (not shown), may transmit signals to and receive signals from other wired or wireless devices. For example, the device I / O interface 1120 may send and receive data to and from a portable device, such as the ECG device 110 of FIG. 1 or any available display for displaying ECG data. In some embodiments, the device I / O interface 1120 may transmit data to a portable device, such as a smartphone, a computing table, a laptop, or any other available device. Although not shown for simplicity, a transceiver controller may be implemented within the processor 1130 and / or memory 1140 to control the transmit and receive operations of the device I / O interface 1120, including, for example, receiving 3-lead ECG data and 12-lead ECG data, and transmitting composite 12-lead ECG data and associated images.

[0086] The processor 1130, which is also coupled to the device I / O interface 1120 and the memory 1140, may be any suitable processor or processors capable of executing scripts or instructions of one or more software programs stored within the computing node 1100 (such as in the memory 1140).

[0087] The memory 1140 may include a transformation parameter database 1142. The transformation parameter database 1142 may include one or more transformation parameters for one or more patients. In some embodiments, the one or more transformation parameters may include a linear transformation matrix that may be used to synthesize 12-point ECG data from the 3-point ECG data, for example as described with respect to FIGS. 4 and 7. For example, the computing node 1100 may receive the 3-point ECG data via the device I / O interface 1120 and synthesize (generate) 12-point ECG data based on the 3-point ECG data and one or more transformation parameters stored in the transformation parameter database 1142. The synthesized 12-point ECG data may then be transmitted to other available devices via the device I / O interface 1120.

[0088] The memory 1140 may also include a non-transitory computer-readable storage medium (eg, one or more non-volatile memory elements, such as an EPROM, an EEPROM, a flash memory, a hard drive, etc.) that may store the following software modules: A conversion parameter determination software (SW) module 1144 for generating conversion parameters; a lead synthesis SW module 1146 for synthesizing ECG leads; and · Lead Display SW module 1147 which generates displayable ECG lead data.

[0089] Each software module includes program instructions that, when executed by the processor 1130, may cause the computing node 1100 to perform a corresponding function. Thus, the non-transitory computer-readable storage medium of the memory 1140 may include instructions for performing all or a portion of the operations recited herein.

[0090] The processor 1130 may execute a transformation parameter determination SW module 1144 to determine transformation parameters including a linear transformation matrix for generating (synthesizing) 12-lead ECG data from the 3-lead ECG data. In some variations, the transformation parameter determination SW module 1144 may include instructions for determining a transformation matrix as described with respect to FIG. 4. In some embodiments, the determined transformation parameters may be stored in memory 1140, such as in a transformation parameter database 1142.

[0091] The processor 1130 may execute the lead synthesis SW module 1146 to synthesize ECG leads based at least in part on the transformation parameters. For example, execution of the lead synthesis SW module 1146 may generate 12-point ECG data based on the received 3-point ECG data and the transformation parameters. The transformation parameters may be determined using the transformation parameter determination SQ module 1144 and / or stored in the transformation parameter database 1142. In some variations, the lead synthesis SW module 1146 may include instructions to synthesize ECG data as described with respect to FIG. 7.

[0092] The processor 1130 may execute the lead display SW module 1147 to generate ECG data that may be displayed to a clinician. For example, execution of the lead display SW module 1147 may generate 12-lead ECG data that may be displayed, the displayed data being based on ECG data synthesized based on the lead synthesis SW module 1146.

[0093] In this specification, when a feature or element is referred to as being "on" another feature or element, it may be directly on the other feature or element, or intervening features and / or elements may also be present. In contrast, when a feature or element is referred to as being "directly" on another feature or element, there are no intervening features or elements. Also, when a feature or element is referred to as being "connected," "attached," or "coupled" to another feature or element, it will be understood that it may be directly connected, attached, or coupled to the other feature or element, or there may be intervening features or elements present. In contrast, when a feature or element is referred to as being "directly connected," "directly attached," or "directly coupled" to another feature or element, there are no intervening features or elements present. Although described or illustrated with respect to one embodiment, the features and elements so described or illustrated may be applied to other embodiments. Also, when referring to a structure or feature that is disposed "adjacent" to another feature, one skilled in the art will understand that it may have overlapping or underlying portions with the adjacent feature.

[0094] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the present invention. For example, as used herein, the singular forms "a", "an" and "the" are intended to include the plural unless the context clearly indicates otherwise. Furthermore, as used herein, it will be understood that the terms "comprise" and / or "comprising" specify the presence of stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any combination of one or more of the associated listed items and may be abbreviated as " / ".

[0095] For ease of description, spatially relative terms such as "below," "down," "lower," "upper," "upper" and the like may be used herein to describe the relationship of one element or feature to another element or feature as depicted in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, an element described as "below" or "below" the other element or feature would be oriented "above" the other element or feature. Thus, the exemplary term "below" may encompass both an orientation of "up" and "down." The device may be in other orientations (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein will be interpreted accordingly. Similarly, terms such as "upward," "downward," "vertically," "horizontally," and the like are used herein for descriptive purposes only, unless specifically indicated otherwise.

[0096] In this specification, the terms "first" and "second" may be used to describe various features / elements (including steps), but these features / elements should not be limited by these terms unless the context indicates otherwise. These terms may be used to distinguish one feature / element from another. Thus, a first feature / element described below can be referred to as a second feature / element, and similarly, a second feature / element described below can be referred to as a first feature / element without departing from the teachings of the present invention.

[0097] Throughout this specification and the claims that follow, unless the context otherwise requires, the word "comprises" and variations such as "comprises" and "comprising" mean that various components may be employed jointly in methods and articles (e.g., apparatus and compositions and apparatuses that include methods). For example, the term "comprising" is understood to mean the inclusion of any described element or step, but not the exclusion of other elements or steps.

[0098] In general, any apparatus and methods described herein should be understood to be inclusive, although all or a subset of the components and / or steps may alternatively be exclusive and may be expressed as "consisting of" or alternatively "consisting essentially of" various components, steps, subcomponents or substeps.

[0099] As used in the present specification and claims, including as used in the examples, unless expressly specified otherwise, all numerical values ​​may be read as being preceded by the word "about" or "approximately", even if the term does not explicitly appear. The phrase "about" or "approximately" may be used in describing a size and / or location to indicate that the stated value and / or location is within a reasonable expected range of value and / or location. For example, a numerical value may have a value of ±0.1% of the stated value (or numerical range), ±1% of the stated value (or numerical range), ±2% of the stated value (or numerical range), ±5% of the stated value (or numerical range), ±10% of the stated value (or numerical range), etc. Additionally, numerical values ​​provided herein should be understood to include about or approximately that value, unless the context indicates otherwise. For example, if the value "10" is disclosed, "about 10" is also disclosed. Numeric ranges referred to herein are intended to include all subranges subsumed therein. It is also understood that when a value is disclosed, "less than or equal to the value," "greater than or equal to the value," and possible ranges between the values ​​are also disclosed, as would be well understood by one of ordinary skill in the art. For example, when a value "X" is disclosed, not only "less than or equal to X" but also "greater than or equal to X" (e.g., X is a numeric value) are disclosed. It is also understood that throughout this application, data is provided in many different formats, and this data represents endpoints and starting points, and ranges for any combination of data points. For example, when a specific data point "10" and a specific data point "15" are disclosed, it is understood that values ​​greater than 10, greater than or equal to 10, less than 10, less than or equal to 10, and equal to 10 and 15 are considered to be disclosed, as well as values ​​between 10 and 15. It is also understood that each unit between two particular units is also disclosed. For example, when 10 and 15 are disclosed, 11, 12, 13, and 14 are also disclosed.

[0100] Although various exemplary embodiments have been described above, any of a number of modifications may be made to the various embodiments without departing from the scope of the invention as set forth in the claims. For example, the order in which the various described method steps are performed may often be changed in alternative embodiments, and in other alternative embodiments, one or more method steps may be skipped entirely. Any feature of the various apparatus and system embodiments may be included in some embodiments and not included in other embodiments. Thus, the foregoing description has been provided primarily for illustrative purposes and should not be construed as limiting the scope of the invention as defined in the claims.

[0101] The examples and illustrations contained herein are illustrative and not limiting, showing specific embodiments in which the subject matter may be practiced. As mentioned, other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of the present disclosure. Such embodiments of the subject matter of the present invention may be referred to herein, individually or collectively, by the term "invention" for convenience only, and there is no intention to spontaneously limit the scope of the present application to any single invention or inventive concept when more than one invention is actually disclosed. Thus, while specific embodiments have been shown and described herein, any arrangement calculated to achieve the same purpose may be substituted for the specific embodiment shown. The present disclosure is intended to cover any adaptations or variations of the various embodiments. Combinations of the above embodiments, as well as other embodiments not specifically described herein, will be apparent to those skilled in the art upon reviewing the above description.

Claims

1. 1. A method for synthesizing electrocardiogram (ECG) data, comprising: receiving current three-lead ECG data recorded from a patient, the current three-lead ECG data including three orthogonal or quasi-orthogonal leads; generating a derived 12-point ECG data set from the current 3-lead ECG data by applying a set of linear transformation parameters, the set of linear transformation parameters being determined based at least in part on a previous 12-lead ECG data set recorded from the patient at a first previous acquisition time and a previous 3-lead ECG data set recorded from the patient at a second previous acquisition time different from the first previous acquisition time, the previous 3-lead ECG data set being synchronized with the previous 12-point ECG data set by determining representative heartbeats for both the previous 3-lead ECG data set and the previous 12-lead ECG data set, the set of linear transformation parameters including a set of transformation matrices that combine the previous 12-lead ECG data set from the previous 3-lead ECG data set, and the previous 3-lead ECG data set being synchronized with the previous 12-lead ECG data set by further resampling at least one of the previous 12-lead ECG data set and the previous 3-lead ECG data set; outputting the derived 12-lead ECG data set; A method comprising:

2. 2. The method of claim 1, wherein generating the derived 12-lead ECG data set comprises segmenting each lead of the previous 12-lead ECG data set and the previous 3-lead ECG data set, and wherein the set of linear transformation parameters comprises a set of transformation matrices that combine segments of the previous 12-lead ECG data set from segments of the previous 3-lead ECG data set.

3. 2. The method of claim 1, wherein the previous 3-lead ECG data set is synchronized with the previous 12-lead ECG data set by further determining a cross-correlation between the previous 3-lead ECG data set and the previous 12-lead ECG data set.

4. 2. The method of claim 1, wherein the previous 3-lead ECG data set is synchronized with the previous 12-lead ECG data set by further aligning QRS complex features of the previous 12-lead ECG data set with QRS complex features of the previous 3-lead ECG data set.

5. The method of claim 1 , wherein the resampling is performed in the frequency domain.

6. 2. The method of claim 1, wherein the previous 3-lead ECG data set is synchronized with the previous 12-lead ECG data set by further determining the representative heart beat for both the previous 3-lead ECG data set and the previous 12-lead ECG data set based on a median heart beat or an average heart beat from multiple heart beats.

7. 2. The method of claim 1, wherein the previous 3-lead ECG data set is synchronized with the previous 12-point ECG data set by further determining the representative heart beat for both the previous 3-lead ECG data set and the previous 12-lead ECG data set by selecting a median heart beat from each of the previous 3-lead ECG data set and the previous 12-lead ECG data set.

8. The method of claim 1 , wherein outputting the derived 12-lead ECG data set comprises displaying the derived 12-lead ECG data set.

9. The method of claim 1 , wherein the leads of the three-lead ECG are orthogonal or quasi-orthogonal.

10. 1. A method for generating electrocardiogram (ECG) data, comprising: receiving current three-lead ECG data recorded from a patient, the current three-lead ECG data including three orthogonal or quasi-orthogonal leads; generating a derived 12-point ECG data set from the current 3-lead ECG data by applying a set of linear transformation parameters, the set of linear transformation parameters being determined based at least in part on a previous 12-point ECG data set recorded from the patient at a first previous acquisition time and a previous 3-lead ECG data set recorded from the patient at a second previous acquisition time different from the first previous acquisition time using orthogonal or quasi-orthogonal leads; and generating a derived 12-point ECG data set from the current 3-lead ECG data by determining a representative heartbeat for both the previous 3-lead ECG data set and the previous 12-lead ECG data set. a step of synchronizing the previous 12-lead ECG dataset with the previous 12-lead ECG dataset; and a step of segmenting each lead of the previous 12-lead ECG dataset and the previous 3-lead ECG dataset, wherein the set of linear transformation parameters includes a set of transformation matrices that combine segments of the previous 12-lead ECG dataset from segments of the previous 3-lead ECG dataset, and the previous 3-lead ECG dataset is synchronized with the previous 12-lead ECG dataset by further resampling at least one of the previous 12-lead ECG dataset and the previous 3-lead ECG dataset; outputting the derived 12-lead ECG data set; A method comprising:

11. 1. An electrocardiogram (ECG) system comprising: a portable ECG device configured to record a current three-lead ECG data set from a patient; a non-transitory computer-readable storage medium containing instructions that, when executed by one or more processors, cause the one or more processors to: accessing a first 12-lead ECG dataset for the patient associated with a first dataset acquisition time; accessing a first three-lead ECG data set for the patient associated with a second data set acquisition time that is different from the first data set acquisition time; determining a set of linear transformation parameters for synthesizing a 12-point ECG data set based at least in part on the first 12-point ECG data set and the first 3-point ECG data, wherein the first 3-point ECG data set is synchronized to the first 12-point ECG data set by determining representative heartbeats for the first 3-point ECG data set and the first 12-point ECG data set, and the set of linear transformation parameters includes a set of transformation matrices for synthesizing the first 12-point ECG data set from the first 3-point ECG data set; receiving the current three-lead ECG data set from the portable ECG device; synthesizing a second 12-lead ECG data set from the current 3-lead ECG data set based at least in part on the set of linear transformation parameters; synchronizing the first 3-lead ECG data set to the first 12-lead ECG data set, the synchronizing including resampling at least one of the first 12-lead ECG data set and the first 3-lead ECG data set; outputting the second 12-lead ECG data set; A system that causes an operation including

12. The system of claim 11 , wherein the synchronization includes determining a cross-correlation between the first 3-lead ECG data set and the first 12-lead ECG data.

13. 12. The system of claim 11, wherein the synchronization comprises matching QRS complex features of the first 12-lead ECG data set with QRS complex features of the first 3-lead ECG data.

14. The system of claim 11 , wherein the resampling is performed in the frequency domain.

15. The system of claim 11 , wherein the synchronizing includes determining a representative heart beat for the first 12-lead ECG data set and the first 3-lead ECG data set.

16. 16. The system of claim 15, wherein determining the representative heartbeat comprises determining a mean or median value of each of the first 12-lead ECG data set and the first 3-lead ECG data set based on a plurality of heartbeats.

17. 16. The system of claim 15, wherein determining the representative heart beat includes selecting a median heart beat from each of the first 12-lead ECG data set and the first 3-lead ECG data set.

18. The non-transitory computer-readable storage medium further comprises: segmenting each lead of the first 12-lead ECG data set and the first 3-lead ECG data set; determining a set of transformation matrices for synthesizing a segment of the first 12-lead ECG data set from a segment of the first 3-lead ECG data set; The system of claim 11 configured to:

19. The system of claim 11 , wherein the non-transitory computer-readable storage medium is further configured to generate a display data set based on the second 12-lead ECG data set.

20. 12. The system of claim 11, wherein the leads of the first three-lead ECG data set are orthogonal or quasi-orthogonal.

Images