Source: http://www.google.com/patents/US6577896?dq=60/310,746
Timestamp: 2014-09-16 17:32:42
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Matched Legal Cases: ['art 8', 'art 8', 'art 8', 'art 8', 'art 8', 'art 8']

Patent US6577896 - Single complex electrogram display having a sensing threshold for an ... - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsThe present invention discloses a graphical display method and apparatus relating to an electrogram signal received from at least one lead used in conjunction with an implantable medical device. The present invention provides a time-expanded waveform of a portion of a signal relating to a single heartbeat....http://www.google.com/patents/US6577896?utm_source=gb-gplus-sharePatent US6577896 - Single complex electrogram display having a sensing threshold for an implantable medical deviceAdvanced Patent SearchPublication numberUS6577896 B2Publication typeGrantApplication numberUS 09/780,860Publication dateJun 10, 2003Filing dateFeb 9, 2001Priority dateMay 7, 1998Fee statusPaidAlso published asUS6266555, US20010031927Publication number09780860, 780860, US 6577896 B2, US 6577896B2, US-B2-6577896, US6577896 B2, US6577896B2InventorsRobert Werner, Jack P. Krichen, Deborah SackrisonOriginal AssigneeMedtronic, Inc.Export CitationBiBTeX, EndNote, RefManPatent Citations (56), Non-Patent Citations (2), Referenced by (1), Classifications (15), Legal Events (2) External Links: USPTO, USPTO Assignment, EspacenetSingle complex electrogram display having a sensing threshold for an implantable medical deviceUS 6577896 B2Abstract The present invention discloses a graphical display method and apparatus relating to an electrogram signal received from at least one lead used in conjunction with an implantable medical device. The present invention provides a time-expanded waveform of a portion of a signal relating to a single heartbeat. Sensitivity threshold information is also graphically displayed on the waveform. The programmer assembly of the present invention comprises an analyzer for locating and marking desired characteristics of the electrogram signal with a plurality of markers to produce a marked electrogram signal. A processor receives the electrogram signal from the analyzer and recognizes the marked desired characteristics of the electrogram signal. The processor also receives sensitivity threshold information from a particular lead. A display, controlled by the processor, graphically displays information representing a portion of the electrogram signal immediately adjacent to a single marker and graphically displays a sensitivity threshold superimposed onto the portion of the electrogram signal.
What is claimed is: 1. A system for graphically displaying information received from at least one lead positioned within a passageway of a heart related to an implantable medical device, the system comprising:
an analyzer for receiving the electrogram signal from the electrical lead and for locating and marking desired characteristics of the electrogram signal with a plurality of markers to produce a marked electrogram signal; a processor for receiving the marked electrogram signal from the analyzer, for recognizing the marked desired characteristics of the electrogram signal, and for inserting amplitude information into the marked electrogram signal; a display buffer for momentarily capturing a portion of the electrogram signal adjacent to a single marker; updating means for continuously updating the captured portion of the electrogram signal; a selection switch for selecting a selected signal between the electrogram signal received from the electrical lead and the captured portion of the electrogram signal stored in the display buffer; a sensitivity threshold control for controlling a sensitivity threshold; and a display controlled by the processor for displaying the selected signal and for graphically displaying the sensitivity threshold superimposed on the selected signal. 2. The system of claim 1, wherein the processor centers the selected signal on the display.
3. The system of claim 1, wherein the processor displays the amplitude information on the display.
4. The system of claim 1, wherein the processor further comprises:
monitoring means for monitoring a heart rate; and comparing means for comparing the heart rate to a predetermined set of ranges. 5. The system of claim 4, wherein the updating means updates the captured portion of the electrogram signal with every heartbeat.
6. The system of claim 4, wherein the updating means updates the captured portion of the electrogram signal with every second heartbeat.
7. The system of claim 4, wherein the updating means updates the captured portion of the electrogram signal with every third heart beat.
8. The system of claim 1 and further comprising a hold icon located on the display and controlled by the processor for holding the selected signal and the sensitivity threshold on the display.
9. The system of claim 8 and further comprising a print icon located on the display and controlled by the processor for printing the selected signal and the sensitivity threshold held on the display.
10. The system of claim 1, wherein the display displays the selected signal and the sensitivity threshold in a time-expanded format.
11. A programmer for graphically displaying information received from at least one lead positioned within a passageway of a heart and related to an implantable medical device, the programmer comprising:
an analyzer for receiving an electrogram signal and for locating and marking desired characteristics of the electrogram signal with a plurality of markers to produce a marked electrogram signal; a processor for receiving the electrogram signal from the analyzer and for recognizing the marked desired characteristics of the electrogram signal, the processor also receiving sensitivity threshold information; and a display controlled by the processor for graphically displaying information representing a portion of the electrogram signal immediately adjacent to a single marker and for graphically displaying a sensitivity threshold. 12. The programmer of claim 11, wherein the processor centers the portion of the electrogram signal immediately adjacent to a single marker on the display.
13. The programmer of claim 11, wherein the processor inserts amplitude information onto the electrogram signal.
14. The system of claim 13, wherein the processor displays the amplitude information on the display.
15. The programmer of claim 11, wherein the processor further comprises:
monitoring means for monitoring a heart rate; and comparing means for comparing the heart rate to a predetermined set of ranges. 16. The programmer of claim 15, wherein the display displays an updated portion of the electrogram signal immediately adjacent to a single marker with every heartbeat.
17. The programmer of claim 15, wherein the display displays an updated portion of the electrogram signal immediately adjacent to a single marker with every second heartbeat.
18. The programmer of claim 15, wherein the display displays an updated portion of the electrogram signal immediately adjacent to a single marker with every third heartbeat.
19. The programmer of claim 11, and further comprising a hold icon located on the display and controlled by the processor for holding the electrogram signal immediately adjacent to a single marker and for holding the sensitivity threshold.
20. The programmer of claim 19, and further comprising a print icon located on the display and controlled by the processor for printing the portion of the electrogram signal immediately adjacent to a single marker and for printing the sensitivity threshold.
21. The programmer of claim 11, further comprising a user input, wherein the processor receives updated sensitivity threshold information based upon an input from a user.
22. A method of graphically displaying information relating to an electrogram signal received from at least one lead positioned within a passageway of a heart and related to an implantable medical device, the programmer comprising:
analyzing the electrogram signal to locate desired characteristics of the electrogram signal; inserting a plurality of markers into the electrogram signal at a location of the desired characteristics; filtering a sensitivity threshold signal received from a lead to remove unwanted noise; amplifying the filtered sensitivity threshold signal; and displaying a portion of the electrogram signal immediately adjacent to a single marker and graphically displaying a sensitivity threshold level representing the amplified and filtered sensitivity threshold signal. 23. The method of claim 22, wherein the step of displaying a portion of the electrogram signal further comprises:
centering the portion of the electrogram signal immediately adjacent to a single marker on the display. 24. The method of claim 22 and further comprising:
inserting amplitude information into the electrogram signal. 25. The method of claim 24, wherein the step of displaying a portion of the electrogram signal further comprises:
displaying the amplitude information. 26. The method of claim 22 and further comprising:
monitoring a heart rate; and comparing the heart rate to a predetermined range. 27. The method of claim 26 and further comprising:
displaying the portion of the electrogram signal immediately adjacent to a single marker after each heartbeat. 28. The method of claim 26 and further comprising:
displaying the portion of the electrogram signal immediately adjacent to a single marker after every second heartbeat. 29. The method of claim 26 and further comprising:
displaying the portion of the electrogram signal immediately adjacent to a single marker after every third heartbeat. 30. The method of claim 22 and further comprising:
maintaining the displayed portion of the electrogram signal and the sensitivity threshold level on the display. 31. The method of claim 22 and further comprising:
printing the displayed portion of the electrogram signal and the sensitivity threshold level.
This application is a division of application Ser. No. 09/316,750, filed May 21, 1999, now U.S. Pat. No. 6,266,555. This application claims the benefit of U.S. provisional application Ser. No. 60/084,580, filed May 7, 1998.
FIELD OF THE INVENTION The present invention relates generally to a programmer used in conjunction with an implantable medical device. More specifically, the present invention relates to an improved graphical display of selected information in conjunction with an implantable medical device.
BACKGROUND OF THE INVENTION Implantable medical device systems known in the art comprise several components, including an implantable medical device, such as a pacemaker, pacing and/or sensing leads (leads), and a programmer. The leads connect the implantable medical device to the heart of a patient. The programmer provides multiple functions, including (a) assessing lead performance during a pacemaker or defibrillator implantation, (b) programming the implantable medical device, and (c) receiving feedback information from the implantable medical device for use by a clinician or physician (operator). By measuring the electrical performance of a lead, the programmer aids the operator in selecting an electrically appropriate site for the placement of the lead(s).
In conjunction with programming the implantable medical device system, it is critical for an operator to determine whether the leads are properly positioned within a passageway of a heart, such as an atrium or ventricle of the patient.
A disadvantage of prior art programmers involves the techniques used to display information to the operator during an implant procedure. Most prior art systems graphically display several, continuous-time waveforms, which are constantly scrolling across the screen at a rapid rate. The remaining information is presented to the operator in the form of numerical data. In order to determine if a specific lead is properly positioned within a passageway of the heart, the operator must review not only the graphical display of the continuous-time cardiac waveform scrolling across the display, but also review a variety of numerical data. The operator must then have the ability and understanding to process the various data shown both graphically and numerically in order to determine if the lead is positioned to ensure proper operation of a later attached implantable medical device.
U.S. Pat. No. 5,713,937 to Nappholz et al. discloses a pacemaker programmer menu with selectable real or simulated implant data graphics. This reference discloses a graphical display of two separate characteristics of an implantable medical device system, such as a heartbeat of a patient and a ventricular pacing rate as applied to a medical implant.
Other disclosures relating to the same general issues are listed below in Table 1.
5,833,623
System And Method For Facilitating Rapid Retrieval
And Evaluation Of Diagnostic Data Stored By An
5,782,890
Method For Heart Transplant Monitoring And Analog
Telemetry Calibration
5,724,985
User Interface For An Implantable Medical Device
Using An Integrated Digitizer Display Screen
5,716,384
Method And System For Organizing, Viewing And
Manipulating Information In Implantable Device
5,402,794
Method And Apparatus For Heart Transplant
Monitoring And Analog Telemetry Calibration
5,374,282
Automatic Sensitivity Adjust For Cardiac Pacemakers
5,345,362
Portable Computer Apparatus With Articulating Display
4,809,697
Interactive Programming And Diagnostic System For Use
With Implantable Pacemaker
4,374,382
Marker Channel Telemetry System For A Medical
Portable Computer With An Articulating Display Panel
358,583
The prior art in general, as well as the Nappholz et al. reference in particular, have certain disadvantages. For example, the display units of the prior art patents display a continuous-time cardiac waveform. This waveform is continuously scrolling across the display. Once the continuous-time waveform reaches the end of the display, the waveform disappears and a new continuous-time waveform is generated in real time and scrolls across the screen. Thus, it is virtually impossible for an operator to determine the configuration of the waveform signal, or to determine the amplitude of the signal. Additionally, the operator must evaluate various numerical data in conjunction with the graphical display to determine if a specific lead is properly positioned.
SUMMARY OF THE INVENTION The present invention overcomes the disadvantages of the prior art by providing a method of and apparatus for graphically displaying a visual assessment necessary to determine proper positioning of pacing and/or sensing leads of an implantable medical device system.
The present invention has certain objects. That is, the present invention provides solutions to certain problems existing in the prior art such as: (a) an inability to provide a graphical display of a single cardiac waveform representing a specific portion of the continuous-time waveform corresponding to a single heartbeat, centered on the display; (b) an inability to update the single cardiac waveform based upon a comparison of the heart rate of the patient to specific predetermined rates; (c) an inability to provide a graphical display of the magnitude of the single cardiac waveform; (d) an inability to provide the graphical display of a chosen sensitivity threshold in conjunction with a single cardiac waveform; (e) an inability to provide a graphical display of changes in the sensitivity threshold in conjunction with a single cardiac waveform; (f) an inability to hold the single cardiac waveform, centered on the display; and (g) an inability to print the single cardiac waveform.
The system and method of the present invention provides certain advantages, including: (a) the ability to provide a graphical display of a single cardiac waveform representing a specific portion of the continuous-time waveform corresponding to a single heartbeat centered on the display; (b) the ability to update the cardiac waveform based upon a comparison of the heart rate to specific predetermined rates; (c) the ability to provide a graphical display of the magnitude of the single cardiac waveform; (d) the ability to provide a graphical display of a chosen sensitivity threshold in conjunction with a single cardiac waveform; (e) the ability to provide a graphical display of changes in the sensitivity threshold in conjunction with a single cardiac waveform; (h) the ability to hold the single cardiac waveform centered on the display; and (i) the ability to print the single cardiac waveform.
The system and method of the present invention has certain features, including a graphical display of a single cardiac waveform representing a specific portion of the continuous-time waveform corresponding to a single heartbeat at a time during a pacemaker implant. In addition, the present invention permits selection of the heart passageway from which to view the waveform. Another feature of the present invention is a graphical display of the voltage magnitude of the single cardiac waveform, as well as an expanded version of the single cardiac waveform used to determine the proper position of a lead. Another feature of the present invention is the ability to utilize the heart rate of the patient such that the single cardiac waveform is continuously updated in a manner in which an operator can view the waveform to determine proper location of a pacing or sensing lead. Another feature of the present invention is a graphical representation of a chosen sensing threshold superimposed onto a single cardiac waveform to assist in positioning of a pacing or sensing lead. Another feature of the present invention is the ability to graphically display an updated and modified sensing threshold. Another feature of the present invention is the ability to freeze the single cardiac waveform and superimposed sensing threshold and print a single cardiac waveform and superimposed sensing threshold for further analysis.
FIG. 7 is a block diagram encompassing the present invention.
FIG. 8 is a pictorial representation of a typical display screen during an implant procedure showing a plurality of continuous-time waveforms.
FIG. 9 is a second pictorial representation of a typical display screen during an implant procedure showing a waveform area and waveform control area.
FIG. 10 is a pictorial representation of a display screen during an implant procedure showing a single complex cardiac waveform.
FIG. 11 is a second pictorial representation of a display screen during an implant procedure showing a single complex cardiac waveform.
FIG. 12 is a third pictorial representation of a display screen during an implant procedure showing a single complex cardiac waveform.
FIG. 13 is a flow chart disclosing the steps of the sensitivity threshold feature of the present invention.
DETAILED DESCRIPTION In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
FIG. 1 is a simplified schematic view of one embodiment of implantable medical device (�IMD�) 10 of the present invention. IMD 10 shown in FIG. 1 is a pacemaker comprising at least one of pacing and sensing leads 16 and 18 attached to connector module 12 of hermetically sealed enclosure 14 and implanted near human or mammalian heart 8. Pacing and sensing leads 16 and 18 sense electrical signals attendant to the depolarization and repolarization of the heart 8, and further provide pacing pulses for causing depolarization of cardiac tissue in the vicinity of the distal ends thereof. Leads 16 and 18 may have unipolar or bipolar electrodes disposed thereon, as is well known in the art. Examples of IMD 10 include implantable cardiac pacemakers disclosed in U.S. Pat. No. 5,158,078 to Bennett et al., U.S. Pat. No. 5,312,453 to Shelton et al., or U.S. Pat. No. 5,144,949 to Olson, all hereby incorporated by reference herein, each in its respective entirety.
Switch matrix 166 is used to select which of the available electrodes are coupled to wide band (0.5-200 Hz) amplifier 168 for use in digital signal analysis. Selection of electrodes is controlled by microprocessor 170 via data/address bus 172, which selections may be varied as desired. Signals from the electrodes selected for coupling to bandpass amplifier 168 are provided to multiplexer 174, and thereafter converted to multi-bit digital signals by A/D converter 176, for storage in random access memory 178 under control of direct memory access circuit 180. Microprocessor 170 may employ digital signal analysis techniques to characterize the digitized signals stored in random access memory 178 to recognize and classify the patient's heart rhythm employing any of the numerous signal processing methodologies known to the art.
Detection of atrial or ventricular tachyarrhythmias, as employed in the present invention, may correspond to tachyarrhythmia detection algorithms known in the art. For example, the presence of an atrial or ventricular tachyarrhythmia may be confirmed by detecting a sustained series of short R-R or P-P intervals of an average rate indicative of tachyarrhythmia or an unbroken series of short R-R or P-P intervals. The rate of onset of the detected high rates, the stability of the high rates, and a number of other factors known in the art may also be measured at this time. Appropriate ventricular tachyarrhythmia detection methodologies measuring such factors are described in U.S. Pat. No. 4,726,380 issued to Vollmann, U.S. Pat. No. 4,880,005 issued to Pless et al., and U.S. Pat. No. 4,830,006 issued to Haluska et al., all incorporated by reference herein, each in its respective entirety. An additional set of tachycardia recognition methodologies is disclosed in the article �Onset and Stability for Ventricular Tachyarrhythmia Detection in an Implantable Pacer-Cardioverter-Defibrillator� by Olson et al., published in Computers in Cardiology, Oct. 7-10, 1986, IEEE Computer Society Press, pages 167-170, also incorporated by reference herein in its entirety. Atrial fibrillation detection methodologies are disclosed in Published PCT Application Ser. No. US92/02829, Publication No. WO92/18198, by Adams et al., and in the article �Automatic Tachycardia Recognition�, by Arzbaecher et al., published in PACE, May-June, 1984, pp. 541-547, both of which are incorporated by reference herein in their entireties.
FIG. 6 is a perspective view of programmer unit 200 which includes the present invention. Programmer unit 200 has various features, including outer housing 202, carrying handle 204, articulate display screen 206, RF head or stylus 208, and analyzer 210.
Display unit 206 is disposed on the upper surface of housing 202. Display screen 206 folds down in a closed position when programmer 200 is not in use, thereby reducing the size of programmer 200 and protecting the display surface of display screen 206 during transportation and storage. In the perspective view of FIG. 6, programmer 200 is shown with articulate display screen 206 having been lifted up into one of a plurality of possible open positions such that the display area is visible to a user situated in front of programmer 200. Display screen 206 is preferably an LCD or electroluminescent type, characterized by being relatively thin as compared to a cathode ray tube display, or the like. Display screen 206 is operatively coupled to computer circuitry disposed within housing 202 and is adapted to provide a visual display of graphics and/or numerical and alphanumeric data under control of the computer circuitry.
In accordance with one aspect of the present invention, display screen 206 is provided with touch-sensitivity capability, such that a user can interact with the internal computer by touching the display area of display screen 206 with stylus 208. It is believed that those of ordinary skill in the computer will be familiar with touch-sensitivity display technology, and the details of implementation of such display will not be described further herein. Display screen 206 is the primary input medium for programmer 200, and therefore preferably has sufficient resolution to support operations including selection, gestures, annotation, and character recognition.
FIG. 7 shows block diagram 218 encompassing various features of the present invention. Analyzer 210, as previously discussed, provides a medium for an operator to run a series of diagnostic tests during an implantation procedure of an IMD, such as IMD 10. Analyzer 210 receives a �raw� cardiac electrogram signal from the leads used to later connect IMD 10 to heart 8 of patient 220. Analyzer 210 includes a marker channel telemetry system which utilizes latches to store event information and forms marker codes. The marker codes indicate the occurrence of specific events such as sensed and paced events found in the electrogram signal, for example, the occurrence of a P-wave. Thus, analyzer 210 conditions the electrogram signal received from patient 210 by inserting markers into the electrogram signal. Examples of a marker channel telemetry system are disclosed in U.S. Pat. No. 4,374,382 to Markowitz, hereby incorporated by reference herein in its entirety.
The marker signal is supplied from analyzer 210 to microprocessor 224. Microprocessor 224 performs numerous functions with the received marked electrogram signal. One such function is the addition of amplitude information to the marked electrogram signal. Another function performed by microprocessor 224 is the continual reading of the marked electrogram signal. Microprocessor 224 performs a routine which monitors the content of the continuous electrogram signal for marker information. If a marker is detected that indicates the start of a cardiac waveform complex (P-wave), the information (the �raw� signal accompanied by the additional information) in the continuous signal proceeding the marker and following the marker is captured into a display buffer.
An operator, utilizing programmer unit 200, shown in FIG. 6, has a choice between displaying one or more continuous-time waveforms or displaying a single complex waveform. For purposes of this application, a single complex waveform is defined as a portion of the continuous-time waveform immediately before and after a marker. If a continuous waveform is chosen, microprocessor 224 enables continuous-time waveform display 226. Conversely, if a single complex waveform is desired, microprocessor 224 enables single complex waveform display 228.
When operating in the continuous-time waveform mode, continuous-time waveform display 226 is activated. An example of what is displayed on display screen 206 in this mode is shown in FIGS. 8 and 9.
FIG. 8 shows various signals 242, 244, 246, 248, and 250 which are continuously scrolling across the display screen from left to right. Display 240 of FIG. 8 also shows timing information 252 and 254 to assist an operator in evaluating the various waveforms, as well as toolbar 256. Toolbar 256 includes freeze button 258, continuous-time waveform icon 260, single complex cardiac waveform 262, and other features not relevant to the present invention. While toolbar 256 is shown in FIGS. 8-11 on the right portion of display screen 206, it is done for illustrative purposes only and the location of the toolbar 256 can be altered without deviating from the present invention.
FIG. 9 differs from FIG. 8 in that display screen 206 has been divided into two separate compartments, specifically continuous-time mode display 26A and continuous-time mode control 26B. Through utilization of continuous-time display control 264B, an operator can reprogram various aspects of programmer 200 and view the corresponding change in waveforms via continuous-mode display 264A.
During an implantation procedure, wherein an implantable medical device, such as a pacemaker, is implanted into patient 220, a prior art display screen would display continuous signals, such as those shown in FIGS. 8 and 9, constantly scrolling across display screen 206. Due to the constant movement of the signals across display screen 206, it is extremely difficult for an operator to analyze this information to determine if a pacing or sensing lead is properly positioned within a passageway of a patient.
FIG. 10 discloses display 240A showing a graph of single complex waveform 272 representative of a portion of one of the continuous-time waveforms shown in FIGS. 8 and 9. Waveform 272 is shown in a time-expanded format so that the shape of waveform 272 can be analyzed. Additionally, amplitude information is displayed for greater analysis.
When operating in the single complex waveform mode, single complex waveform display 228 of FIG. 7 is activated and display screen 206 of programmer unit 200 displays a portion of the received electrogram signal corresponding to the information in the stream immediately preceding and following a marker. This information is centered on display screen 206. An example of what is displayed on display screen 206 is shown in FIG. 10. Microprocessor 224 continuously updates displayed waveform 272 at regular intervals. Specifically, microprocessor 224 will provide an updated waveform to display screen 206 stored in a display buffer within microprocessor 224 at regular intervals.
One aspect of the present invention is to provide a readable single complex waveform representing a portion of the received electrogram signal adjacent a marker which can be analyzed by the operator. The single complex waveform must be displayed in a constant location on display screen 206 and updated at a rate which can be processed by the operator. Thus, with the present invention, microprocessor 224 monitors a heart rate of the patient. If the heart rate is less than 90 beats per minute, the single cardiac waveform is updated with each heartbeat. If the heartbeat of the patient is between 90 and 160 heartbeats per minute, the single cardiac waveform is updated every other heartbeat, and if the patient's heartbeat is greater than 160 beats per minute, the single complex waveform is updated every third heartbeat.
Single complex waveform display 228 (of FIG. 7), which is displayed on display screen 206 in FIGS. 10 and 11, provides a means for an operator to evaluate the shape of a waveform, as well as its magnitude, thus enabling an operator to determine if a specific lead is properly positioned within a passageway of heart 8, during an implant procedure.
An additional feature of the present invention includes frozen display 230 (shown in FIG. 7). Frozen display 230 permits a user to �freeze� or hold a particular single complex waveform on display screen 206 for detailed evaluation via freeze button 258 (of FIGS. 10 and 11). The user can also print out the frozen display via printer 232.
With the present invention, the operator may utilize icons 260 and 262, shown in FIGS. 8 and 9, to facilitate a proper reading of the displayed signals. In accordance with the present invention, single complex waveform icon 262 permits a user to view a portion of a single displayed waveform corresponding to a single heartbeat of the patient. By utilizing icon 262, display screen 206 will display the graph shown in FIG. 10. During an implant procedure, it is desirous to view a single waveform corresponding to a single lead in order to determine proper location of the lead. An operator can modify the position of a specific lead and analyze a time, expanded continuously updated waveform. The configuration of the waveform aids the operator in determining the desired location of the lead. Continuous-time waveform icon 260 returns display screen 206 to the continuous-time waveform display.
As shown in FIG. 10, display 240A includes toolbar 256. Toolbar 256 further includes freeze icon 258, continuous-time waveform icon 260, and single complex cardiac waveform 262. As previously discussed, freeze icon 258 permits an operator to continuously view a specific waveform. Continuous-time waveform 260 and single complex waveform 262 act as a toggle switch which permits an operator to display the desired waveform. EGM panel 266 notifies the operator of the source of the signal being viewed, such as a signal from a lead within an atrium or ventricle of the patient, and permits switching between the two signals.
FIGS. 11 and 12 shows display 240B and 240C which is virtually identical to display 240A shown in FIG. 10. However, the display shown in FIGS. 11 and 12 includes heartbeat icon 268 which will appear on display screen 206 each time a marker is sensed by microprocessor 224 representing a heartbeat. As previously discussed, waveform 272 will be updated every first, second, or third heartbeat depending upon the heart rate of the patient. If the heart rate of the patient is less than 90 beats per minute, signal 272 will be updated with each heartbeat. If the heart rate of the patient is between 90 and 160 beats per minute, signal 272 will be updated every other heartbeat. If the heart rate of the patient is greater than 160 beats per minute, waveform 272 will be updated every third heart beat.
An additional feature of the present invention is the ability of an operator to graphically assess the relationship of cardiac events to a sensitivity threshold of IMD 10, thereby providing a means to assess the degree of sensing margin for detected atrial and ventricular events. This feature is also is useful for assessing the degree of margin available for rejecting non-desired events, such as far-field signals and ventricular t-waves. More specifically, the present invention provides a graphical display of the sensitivity threshold, shown in FIGS. 11 and 12 as sensitivity threshold line 270. Sensitivity threshold line 270 is positioned at the graphical location representing a predetermined and adjustable voltage. Prior art references fail in their teachings to disclose a graphical display of the sensitivity threshold positioned across a display screen and in conjunction with a beat of a waveform, as shown in FIGS. 11 and 12.
It is critical that later implanted IMD 10, through its pacing and sensing leads, is capable of properly detecting electrical impulses from heart 8 of a patient, while filtering out unwanted noise, such as far-field signals. Later implanted IMD 10 must sense the intrinsic activity of heart 8 in order to properly operate.
As shown in FIGS. 11 and 12, waveform 272, which represents a simulated electrical signal simulating a heartbeat of a patient, has a positive peak point which is greater than sensitivity threshold line 270. In determining whether the sensitivity threshold of a particular unit is properly set, an operator would review the graphical representation shown in FIGS. 11 and 12. For proper location, the peak of electrical signal 272 must have a voltage greater than sensitivity threshold line 270. However, if sensitivity threshold line 270 is set at too low of a voltage, unwanted noise will be detected and a later implanted IMD may not function properly. The sensitivity threshold can be adjusted to correspond to a desired output through use of a display control, such as display control 264B, shown in FIG. 9. In FIG. 11, the sensitivity threshold is set at 0.50 millivolts, while in FIG. 12, the sensitivity threshold is set at 2.50 millivolts. In both instances (FIGS. 11 and 12), the sensitivity threshold is adequately set since the peak of electrical signal 272 has a voltage greater than sensitivity threshold line 270, but sensitivity threshold line 270 is not positioned to low to allow unwanted noise.
FIG. 13 is a flow chart disclosing the steps encompassing the sensitivity threshold feature of the present invention. The elements shown and described in FIG. 13 are located within a programmer unit 200 (shown in FIG. 6). Electrode 300 would be attached to a specific sensing or pacing lead needing diagnostic evaluation. Filter/protection 302 would receive a signal from sense electrode 300. The purpose of filter/protection 302 is to simulate the characteristics of the input sensing portion of IMD 10. This ensures that the sensing characteristics being analyzed will correspond with the sensing characteristics of later implanted IMD 10. Amplifier 304 receives a signal from filter/protection 302 and provides an amplified signal to either display 206 or rectifier 306. Thus, display 206 can display either a rectified or non-rectified sensitivity threshold.
In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the reciting function and not only structural equivalence but also equivalent structures. For example, although a nail and a screw may not be structurally equivalent in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wood parts, a nail and a screw are equivalent structures.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS2655425 *Feb 25, 1950Oct 13, 1953Cambridge Instr Company IncElectrocardiographUS4316472Aug 9, 1979Feb 23, 1982Mieczyslaw MirowskiCardioverting device with stored energy selecting means and discharge initiating means, and related methodUS4374382Jan 16, 1981Feb 15, 1983Medtronic, Inc.Marker channel telemetry system for a medical deviceUS4375817Dec 22, 1980Mar 8, 1983Medtronic, Inc.Implantable cardioverterUS4379459Apr 9, 1981Apr 12, 1983Medtronic, Inc.Cardiac pacemaker sense amplifierUS4384585Mar 6, 1981May 24, 1983Medtronic, Inc.Synchronous intracardiac cardioverterUS4476868Sep 8, 1980Oct 16, 1984Medtronic, Inc.Body stimulator output circuitUS4483346 *Aug 25, 1983Nov 20, 1984Intech Systems Corp.Electrocardiograph with digitally-printing waveform displayUS4556063Dec 7, 1984Dec 3, 1985Medtronic, Inc.Telemetry system for a medical deviceUS4577633Mar 28, 1984Mar 25, 1986Medtronic, Inc.Rate scanning demand pacemaker and method for treatment of tachycardiaUS4587970Jan 22, 1985May 13, 1986Telectronics N.V.Tachycardia reversion pacerUS4726380Oct 15, 1985Feb 23, 1988Telectronics, N.V.Implantable cardiac pacer with discontinuous microprocessor, programmable antitachycardia mechanisms and patient data telemetryUS4727877Aug 12, 1986Mar 1, 1988Medtronic, Inc.Method and apparatus for low energy endocardial defibrillationUS4779100 *Jul 22, 1987Oct 18, 1988Lafayette Instrument Co., Inc.Polygraph with control adjustment indicatorUS4800883Apr 2, 1986Jan 31, 1989Intermedics, Inc.Apparatus for generating multiphasic defibrillation pulse waveformUS4809697Oct 14, 1987Mar 7, 1989Siemens-Pacesetter, Inc.Interactive programming and diagnostic system for use with implantable pacemakerUS4821723Feb 27, 1987Apr 18, 1989Intermedics Inc.Biphasic waveforms for defibrillationUS4830006Jun 17, 1986May 16, 1989Intermedics, Inc.Implantable cardiac stimulator for detection and treatment of ventricular arrhythmiasUS4880005May 23, 1988Nov 14, 1989Intermedics, Inc.Pacemaker for detecting and terminating a tachycardiaUS4949719Apr 26, 1989Aug 21, 1990Ventritex, Inc.Method for cardiac defibrillationUS4953551Aug 7, 1989Sep 4, 1990Medtronic, Inc.Method of defibrillating a heartUS5099838Dec 15, 1988Mar 31, 1992Medtronic, Inc.Endocardial defibrillation electrode systemUS5117824Nov 14, 1990Jun 2, 1992Medtronic, Inc.Apparatus for monitoring electrical physiologic signalsUS5127404Sep 25, 1991Jul 7, 1992Medtronic, Inc.Telemetry format for implanted medical deviceUS5131388Mar 14, 1991Jul 21, 1992Ventritex, Inc.Implantable cardiac defibrillator with improved capacitorsUS5144949Mar 15, 1991Sep 8, 1992Medtronic, Inc.Dual chamber rate responsive pacemaker with automatic mode switchingUS5158078Aug 14, 1990Oct 27, 1992Medtronic, Inc.Rate responsive pacemaker and methods for optimizing its operationUS5163427Nov 14, 1990Nov 17, 1992Medtronic, Inc.Apparatus for delivering single and multiple cardioversion and defibrillation pulsesUS5188105Nov 14, 1990Feb 23, 1993Medtronic, Inc.Apparatus and method for treating a tachyarrhythmiaUS5199428Mar 22, 1991Apr 6, 1993Medtronic, Inc.Implantable electrical nerve stimulator/pacemaker with ischemia for decreasing cardiac workloadUS5207218Feb 27, 1991May 4, 1993Medtronic, Inc.Implantable pulse generatorUS5269298Oct 23, 1992Dec 14, 1993Incontrol, Inc.Atrial defibrillator and method for providing synchronized delayed cardioversionUS5292343Jun 10, 1992Mar 8, 1994Medtronic, Inc.Hand shake for implanted medical device telemetryUS5312453May 11, 1992May 17, 1994Medtronic, Inc.Rate responsive cardiac pacemaker and method for work-modulating pacing rate decelerationUS5314430Jun 24, 1993May 24, 1994Medtronic, Inc.Atrial defibrillator employing transvenous and subcutaneous electrodes and method of useUS5330507Apr 24, 1992Jul 19, 1994Medtronic, Inc.Implantable electrical vagal stimulation for prevention or interruption of life threatening arrhythmiasUS5331966Dec 16, 1993Jul 26, 1994Medtronic, Inc.Subcutaneous multi-electrode sensing system, method and pacerUS5344431Sep 14, 1992Sep 6, 1994Medtronic, Inc.Method and apparatus for determination of end-of-service for implantable devicesUS5345362Apr 29, 1993Sep 6, 1994Medtronic, Inc.Portable computer apparatus with articulating display panelUS5354316Jan 29, 1993Oct 11, 1994Medtronic, Inc.Method and apparatus for detection and treatment of tachycardia and fibrillationUS5354319Jan 29, 1993Oct 11, 1994Medtronic, Inc.Telemetry system for an implantable medical deviceUS5374282Oct 31, 1991Dec 20, 1994Medtronic, Inc.Automatic sensitivity adjust for cardiac pacemakersUS5402794Jul 1, 1992Apr 4, 1995Medtronic, Inc.Method and apparatus for heart transplant monitoring and analog telemetry calibrationUS5545186Mar 30, 1995Aug 13, 1996Medtronic, Inc.Prioritized rule based method and apparatus for diagnosis and treatment of arrhythmiasUS5620473 *Mar 8, 1995Apr 15, 1997Pacesetter, Inc.Calibration system for pacemaker-generated intracardiac electrogramUS5690686Apr 30, 1996Nov 25, 1997Medtronic, Inc.Method of cardioverting a patient's heartUS5713937Nov 7, 1995Feb 3, 1998Pacesetter, Inc.Pacemaker programmer menu with selectable real or simulated implant data graphicsUS5716384Jul 8, 1996Feb 10, 1998Pacesetter, Inc.Method and system for organizing, viewing and manipulating information in implantable device programmerUS5724985Aug 2, 1995Mar 10, 1998Pacesetter, Inc.User interface for an implantable medical device using an integrated digitizer display screenUS5782890Jan 19, 1995Jul 21, 1998Medtronic, Inc.Method for heart transplant monitoring and analog telemetry calibrationUS5800465Oct 30, 1996Sep 1, 1998Medtronic, Inc.System and method for multisite steering of cardiac stimuliUS5833623May 5, 1997Nov 10, 1998Pacesetter, Inc.System and method for facilitating rapid retrieval and evaluation of diagnostic data stored by an implantable medical deviceUS5836889Mar 3, 1997Nov 17, 1998Biotronik Mess- Und Therapiegeraete Gmbh & Co. Ingenieurbuero BerlinMethod and apparatus for storing signals in an implantable medical deviceUS5891169Jul 28, 1995Apr 6, 1999Biotronik Mess- Und Therapiegeraete GmbhMethod of processing signals characteristic of cardiac activity and an associated deviceUSD358583Apr 29, 1993May 23, 1995Medtronic, Inc.Portable computer with an articulating display panelWO1992018198A2Apr 7, 1992Oct 13, 1992Incontrol IncImproved atrial defibrillator, lead systems, and method* Cited by examinerNon-Patent CitationsReference1Arzbaecher "Automatic Tachycardia Recognition" May-Jun. 1984, pp. 541-547, PACE.2Olson et al "Onset and Stability for Ventricular Tachyarrhythmia Detection in an Implantable Pacer-Cardioverter-Defibrillator" Oct. 7-10, 1986 pp. 167-170 Computers in Cardiology, IEEE, Computer Society Press.Referenced byCiting PatentFiling datePublication dateApplicantTitleWO2012040487A1 *Sep 22, 2011Mar 29, 2012C.R. Bard, Inc.Apparatus and method for catheter navigation using indovascular energy mapping* Cited by examinerClassifications U.S. Classification600/523, 607/27International ClassificationA61N1/372, A61B5/11, A61B5/0424, A61N1/37, A61B5/044Cooperative ClassificationA61B5/7203, A61B5/1107, A61B5/0424, A61N1/37247, A61N1/3702, A61B5/044European ClassificationA61N1/37B, A61N1/372D4ULegal EventsDateCodeEventDescriptionNov 22, 2010FPAYFee paymentYear of fee payment: 8Nov 16, 2006FPAYFee paymentYear of fee payment: 4RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google