Patent ID: 12232877

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that these are specific embodiments and that the present invention may be practiced also in different ways that embody the characterizing features of the invention as described and claimed herein.

The present invention will be more fully understood from the following detailed description of the preferred embodiments thereof, taken together with the drawings. Reference is now made toFIGS.2A-2C, which are schematic system diagrams and a flow diagram showing a system and method for diagnosis of arrhythmia focus according to some embodiments of the present invention.

As inFIG.2C, in stage1electrode stickers202are affixed to a patient. Most preferably ten stickers202are affixed to the patient. The sticker placement is as known in the art for 12-lead ECG recording. In stage2, twelve electrode cables203are connected to the stickers202. Electrode cables203are connected to a wearable recorder204worn by the patient. Wearable recorder204is adapted for 12-lead ECG recording. Recorder204then records heart activity as an ECG waveform206for an extended period of time typically varying between 24 hours and 72 hours. During this time the patient is outside the EP lab and goes about daily activities.

The output of recorder204is herein referred to as wearable ECG waveform (WF)206. ECG WF206preferably comprises 12 channels. Optionally, any number of channels may be recorded that provides sufficient data for arrhythmia diagnosis as described herein. ECG WF206is stored in recorder204on a recording medium. A non-limiting example of a recording medium is flash memory, but other forms of storage may be used. Non-limiting examples of ECG storage formats include SCP-ECG, DICOM-ECG, and HL7 aECG, but other formats may be used. Recorder204uses filters207to enhance the signal received from electrode stickers202and cables203. Non limiting examples of filters207include low pass, high pass, band pass, and notch filters or a combination of these. Filters207are configurable and comprise settings that can be duplicated in the same filters used in other ECG recorders. In stage3, once sufficient ECG waveform data has been gathered or after completion of the monitoring period, electrode stickers202remain affixed to the patient and electrode cables203are disconnected from stickers202and the recorder204is returned to the EP lab for analysis. Analysis may be optionally be performed in a clinic or lab associated with EP lab. Alternatively, stickers202are removed and their exact positioning on the patient is marked, such as with a non-limiting example of a marker pen. Alternatively and preferably stickers202are provided with a dye or ink which marks the skin of the patient such that a mark indicating the position of sticker202is left on the patient from the dye after sticker202is removed.

In stage4, ECG waveform206is imported from recorder204into waveform analyzer210. The importing of ECG WF206is performed by wired or wireless connection of recorder204to analyzer210followed by interaction by an operator with analyzer210to initiate the importing. Alternatively the storage media is extracted from recorder204and inserted into a storage media reader connected wired or wirelessly to analyzer210. Alternatively, the importing comprises exporting from the recorder204by interaction with the recorder204. Analyzer210is adapted to process the ECG WF206in the ECG storage format used by recorder204. Alternatively, recorder204stores ECG WF206in an ECG storage format that can be processed by analyzer210. Alternatively, analyzer210translates the ECG WF206ECG format provided by recorder204into a format that it can process using a translation module211(shown inFIG.2Aas xlator211). Processing includes manipulation and analysis as described below.

In the embodiment ofFIG.2A, waveform analyzer210runs on a standalone computer. Alternatively, in the embodiment ofFIG.2B, analyzer210is a software module running on the same computational hardware as pace mapping system220described below.

Analyzer210preferably comprises a screen (not shown) and interaction means such as a keyboard and mouse (not shown) for viewing and manipulating wearable ECG waveform206.

ECG waveform206is then analyzed optionally using ECG analysis software to detect arrhythmia waveform patterns. The operator/practitioner now interacts with analyzer210to define at least one of the identified waveforms as an arrhythmia template waveform222for later use during pace mapping of arrhythmia focus.FIG.3Aprovides an illustration of an identified arrhythmia template waveform ready to be exported from analyzer210.

In stage5, for the embodiment ofFIG.2A, the arrhythmia template waveform222is exported from analyzer210using wired or wireless means into pace mapping system220. The export format is preferably adapted to suit the mapping system220used. Optionally, analyzer210connects to system220via the ECG input port (not shown) of system220and mimics the signal that an ECG device would provide such that system220displays the received template waveform222which can then be saved in system220as the template waveform222. Alternatively, template waveform222may be saved and exported by analyzer210as any standard image file type not limited to jpeg, BMP, PNG, or similar for use by system220.

Alternatively, as in the embodiment ofFIG.2Bwhere analyzer210is a software module of system220, the template222is stored in the internal storage of system220for use during the pace mapping. Alternatively, the template is stored in a separate file store (not shown).

The patient will now return to the EP lab for diagnosis (mapping) of the arrhythmia focus within the heart. Electrode stickers202are still affixed to the patient from stage1. Alternatively, new stickers202are affixed at exactly the previously marked positions. In stage6electrode stickers202are connected to electrode cables211of EP lab recorder212. EP Lab recorder212refers to an ECG recorder preferably for 12 channel recording. EP lab recorder212comprises filters213which are the same as filters207and are configured with the same filter settings that were used by filters207on wearable recorder204for recording wearable ECG WF206. Optionally, translation module211also comprises a filter adaptor module (not shown) for adjusting the ECG WF206to match lab ECG WF214based on the filters213used in EP lab recorder212. Optionally, wearable recorder204is used as EP lab recorder212, and electrodes202optionally remain connected to recorder204or are reconnected in the EP lab.

EP lab recorder212produces EP lab ECG waveform214. ECG waveform214is provided to pace mapping system220. System220comprises a visual display (not shown) for viewing the lab ECG waveform214of recorder212. The use of the same sticker positions, number of leads, channels and filters ensures that wearable ECG WF206and lab ECG WF214are compatible and that template waveform222can be used as a basis for comparison with paced waveform224as described below.

In stage7, pacing is now performed by probing areas of the heart with pacer catheter230. ECG waveform214is now used by system220to provide and display paced waveform224which changes as pacer catheter230is moved to different positions in the heart. Paced waveform224is compared to arrhythmia template waveform222, defined in stage4and exported in stage5, until the waveforms sufficiently match and arrhythmia focus is diagnosed at stage8. Preferably, the comparison is performed by system220which provides a numeric percentage match indication on a screen (not shown), such that the medical practitioner can determine the arrhythmia focus based on a high percentage match indication, preferably above 95%. Preferably comparison comprises display of the template and paced waveforms overlapped on the screen (not shown) as illustrated inFIGS.3B and3C. Following diagnosis, curative therapy by ablation or other means known in the art may then be performed.

Reference is now made toFIGS.3A-3Cwhich are exemplary ECG waveforms according to some embodiments of the present invention.FIG.3Ashows a twelve lead ECG waveform with 12 channels. As shown, an arrhythmia event is defined by definition lines312. The arrhythmia event as defined by lines312is used as an arrhythmia template waveform such as waveform222described above.

FIG.3Bshows visual comparison of the template waveform ofFIG.3Awith a paced ECG waveform such as waveform224described above. Comparison is performed by superimposing template channels310on top of paced waveform channels330. As inFIG.3A, the arrhythmia event area is defined by lines312. In the exemplary comparison ofFIG.3B, the template and paced waveforms do not match to a sufficient percentage since the pacer catheter is not close enough to the arrhythmia focus in the heart.

In the exemplary comparison ofFIG.3Cthe template and paced waveforms match well to a high percentage since the pacer catheter is close to the arrhythmia focus in the heart and a successful diagnosis of the arrhythmia focus is accomplished.

Reference is now made toFIGS.4A-4C, which are schematic system diagrams and a flow diagram showing a system and method for diagnosis of arrhythmia focus according to some embodiments of the present invention.

As inFIG.4C, in stage1electrode stickers402are affixed to a patient. Most preferably ten stickers402are affixed to the patient. The sticker placement is as known in the art for 12-lead ECG recording. In stage2, twelve electrode cables403are connected to the stickers402. Electrode cables403are connected to a wearable recorder404worn by the patient. Wearable recorder404is adapted for 12-lead ECG recording. Recorder404then records heart activity as an ECG waveform406for an extended period of time typically varying between 24 hours and 72 hours as known in the art. During this time the patient is outside the EP lab and goes about daily activities.

The output of recorder404is herein referred to as wearable ECG waveform (WF)406. ECG WF406preferably comprises 12 channels. Optionally, any number of channels may be recorded that provides sufficient data for arrhythmia diagnosis as described herein. ECG WF406is stored in recorder404on a recording medium. A non-limiting example of a recording medium is flash memory, but other forms of storage may be used. Non-limiting examples of ECG storage formats include SCP-ECG, DICOM-ECG, and HL7 aECG, but other formats may be used. Recorder404uses filters407to enhance the signal received from electrode stickers402and cables403. Non limiting examples of filters407include low pass, high pass, band pass, and notch filters or a combination of these. Filters407are configurable and comprise settings that can be duplicated in the same filters used in other ECG recorders.

In stage3, once sufficient ECG waveform data has been gathered or after completion of the monitoring period, electrode stickers402remain affixed to the patient and electrode cables403are disconnected from stickers402and the recorder404is returned to the EP lab for analysis. Analysis may be optionally be performed in a clinic or lab associated with EP lab. Alternatively, stickers402are removed and their exact positioning on the patient is marked, such as with a non-limiting example of a marker pen. Alternatively and preferably stickers402are provided with a dye or ink which marks the skin of the patient when sticker402is applied or removed such that a mark indicating the position of sticker402is left on the patient from the dye after sticker402is removed.

In stage4, ECG waveform406is imported from recorder404into waveform analyzer410. The importing of ECG WF406is performed by wired or wireless connection of recorder404to analyzer410followed by interaction by an operator with analyzer410to initiate the importing. Alternatively the storage media is extracted from recorder404and inserted into a storage media reader connected wired or wirelessly to analyzer410. Alternatively, the importing comprises exporting from the recorder404by interaction with the recorder404. Analyzer410is adapted to process the ECG WF406in the ECG storage format used by recorder404.

Alternatively, recorder404stores ECG WF406in an ECG storage format that can be processed by analyzer410. Alternatively, analyzer410translates the ECG WF406ECG format provided by recorder404into a format that it can process using a translation module411(shown inFIG.4Aas xlator411). Processing includes manipulation and analysis as described below.

In the embodiment ofFIG.4A, waveform analyzer410runs on a standalone computer. Alternatively, in the embodiment ofFIG.4B, analyzer410is a software module running on the same computational hardware as pace mapping system420described below.

Analyzer410preferably comprises a screen (not shown) and interaction means such as a keyboard and mouse (not shown) for viewing and manipulating wearable ECG waveform406.

ECG waveform406is then analyzed to detect arrhythmia waveform patterns. The operator/practitioner now interacts with analyzer410to identify waveforms indicating arrhythmia. The arrhythmia waveform portions (such as422-A and422-B) are preferably automatically identified by arrhythmia waveform detection software. Alternatively arrhythmia waveform portions are identified by waveform detection software and the identified waveform portions are confirmed by the operator of analyzer410. Alternatively the operator of analyzer410identifies arrhythmia waveform portions. Preferably arrhythmia waveform portions are identified using a combination of the above. Preferably the patient has indicated arrhythmia episodes while wearing Wearable Recorder404and operator or software use these indications to locate arrhythmia waveform portions using analyzer410.

Arrhythmia waveform portions are indicated by operator or software on analyzer410based on the start and stop times of the waveform of interest on the recorded timeline.FIG.4Dshows a non-limiting exemplary wearable WF406as viewed in analyzer410. Arrhythmia waveforms422-A and422-B have been indicated by operator or software in analyzer410. Although two portions (422-A and422-B) are described herein, this is for the sake of simplicity and preferably any number of arrhythmia waveform portions may be indicated and extracted from waveform406. Therefore at the end of stage4, arrhythmia waveform portions will have been identified.

In stage5, for the embodiment ofFIG.4A, the arrhythmia waveforms422are exported from analyzer410. The waveforms portions, as indicated by the timestamp data from stage4, are each extracted and then preferably concatenated together to form a composite arrhythmia waveform422.FIG.4Eshows an exemplary, non-limiting composite arrhythmia waveform422comprising indicated waveforms422-A and422-B which were extracted from ECG WF406.

Composite arrhythmia waveform422is now exported from analyzer410and imported using wired or wireless means into pace mapping system420. Preferably waveform422is exported from analyzer410onto removable storage media421such as but not limited to a USB storage drive. Preferably drive421is adapted for one-time usage to prevent mixing up of patient arrhythmia waveforms422. Preferably drive421comprises encryption mechanisms to prevent patient data stored on drive421from being read by systems aside from analyzer410and pace mapping system420. Drive421is then connected to mapping system420for importing of arrhythmia WF422into system420.

Optionally wearable ECG406is in a digital format. Optionally wearable ECG406is in an analog format. Optionally composite arrhythmia waveforms422are in analog format. Optionally composite arrhythmia waveforms422are in digital format. Where wearable WF406and composite WF422are in different formats (analog or digital), analyzer410converts between these formats.

The format of arrhythmia WF422is preferably adapted to suit the mapping system420used. Optionally, analyzer410connects to system420via the ECG input port (not shown) of system420and mimics the signal that an ECG device would provide to “play back” WF422such that system420imports, stores and displays constructed arrhythmia waveform422. Optionally drive421is plugged into ECG input port (not shown) of system420and mimics the signal that an ECG device would provide to “play back” WF422such that system420imports, stores and displays constructed arrhythmia waveform422. Alternatively drive421or analyzer410are plugged into a data input port (not shown) of system420such that system420imports, stores and displays constructed arrhythmia waveform422.

Alternatively, waveform422may be saved and exported by analyzer410as any standard image file type not limited to jpeg, BMP, PNG, or similar for use by system420.

Alternatively, as in the embodiment ofFIG.4Bwhere analyzer410is a software module of system420, the arrhythmia waveform422is stored in the internal storage of system420for use during the pace mapping. Alternatively, arrhythmia WF422is stored in a separate file store (not shown).

In the final part of stage5, arrhythmia WF422is analyzed using pace mapping system420to create a template waveform423for comparison to Lab ECG WF414.

In stage6the patient will return to the EP lab for diagnosis (mapping) of the arrhythmia focus within the heart. Electrode stickers402are still affixed to the patient from stage1. Alternatively, new stickers402are affixed at exactly the previously marked positions. In stage6electrode stickers402are connected to electrode cables411of EP lab recorder412. EP Lab recorder412refers to an ECG recorder preferably for 12 channel recording. EP lab recorder412comprises filters413which are the same as filters407and are configured with the same filter settings that were used by filters407on wearable recorder404for recording wearable ECG WF406. Optionally, translation module411also comprises a filter adaptor module (not shown) for adjusting the ECG WF406to match lab ECG WF414based on the filters413used in EP lab recorder412. Optionally, wearable recorder404is used as EP lab recorder412, and electrodes402optionally remain connected to recorder404or are reconnected in the EP lab.

EP lab recorder412produces EP lab ECG waveform414. ECG waveform414is provided to pace mapping system420. System420comprises a visual display (not shown) for viewing the lab ECG waveform414of recorder412. The use of the same sticker positions, number of leads, channels and filters ensures that wearable ECG WF406and lab ECG WF414are compatible and that template waveform423extracted from arrhythmia WF422can be used as a basis for comparison with paced waveform424as described below.

In stage7, pacing is now performed by probing areas of the heart with pacer catheter430. ECG waveform414is now used by system420to provide and display paced waveform424which changes as pacer catheter430is moved to different positions in the heart. Paced waveform424is compared to the template WF423derived from arrhythmia waveform422until the waveforms sufficiently match and arrhythmia focus is diagnosed at stage8. Preferably, the comparison is performed by system420which provides a numeric percentage match indication on a screen (not shown), such that the medical practitioner can determine the arrhythmia focus based on a high percentage match indication, preferably above 95%. Preferably comparison comprises display of the template and paced waveforms overlapped on the screen (not shown) as illustrated inFIGS.3B and3C. Following diagnosis, curative therapy by ablation or other means known in the art may then be performed.

It is to be understood that the invention is not limited in its application to the details set forth in the description contained herein or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Those skilled in the art will readily appreciate that various modifications and changes can be applied to the embodiments of the invention as hereinbefore described without departing from its scope, defined in and by the appended claims.