Surgery: light – thermal – and electrical application – Light – thermal – and electrical application – Electrical therapeutic systems
Reexamination Certificate
1999-05-21
2001-07-24
Evanisko, George R. (Department: 3737)
Surgery: light, thermal, and electrical application
Light, thermal, and electrical application
Electrical therapeutic systems
C607S059000
Reexamination Certificate
active
06266566
ABSTRACT:
THE FIELD OF THE INVENTION
The present invention generally relates to data normalization, and more particularly to user selectable normalization of individual waveforms displayed on a medical device.
BACKGROUND OF THE INVENTION
Programmers are used to initialize and service various implanted devices for cardiac therapy. These devices include pacemakers, cardioversion/defibrillator devices, and so on. Presently, typical programmers provided to the physician are generally the size and shape of a portable or laptop computer. Communication with an implanted device is accomplished through inductive coupling by using an accessory connected to the programmer, commonly called a “wand”. The programmers further include a screen for displaying alphanumeric information, and, optionally, to display graphic information such as an electrogram (EGM) or an electrocardiogram (ECG). The programmer may also include a printer for printing information, such as the programming parameters set for a particular pacemaker, data logged by the pacemaker for a pre-selected period, or an ECG.
Programmers may also contain an analyzer which is used to assess pacing lead performance during a pacemaker or defibrillator implantation or during lead system troubleshooting. By measuring a lead's electrical performance, the analyzer aids the implanting physician in selecting an electrically appropriate site for the placement of the implanted device.
Pacing leads are insulated wires that carry precisely controlled electrical impulses from a pacemaker implanted in the upper chest to the inner wall of the heart. The analyzer utilizes software to provide an implanting physician with a dynamic display of key pacing and sensing measurements, and a display of waveform which enable the physician to rapidly select an appropriate site for lead placement.
When viewing waveform information on the programmer/analyzer display, variations in the signal gain of the displayed waveform can cause wide variations in the height of the displayed waveform, creating legibility problems. Signal gain variations are typically encountered when the device operator switches display modes (e.g., switching between pacing and sensing modes). In such a mode switch, the polarization following pacing pulses is large and can infringe on other waveforms on the display.
Controls are typically provided on the programmer/analyzer for incrementally adjusting the height of the waveform on the display. However, such controls require frequent adjustments, and it often takes an unacceptably long period of time to adjust the waveform to an optimal size, resulting in the potential loss of critical display data.
Another approach to the problem of waveforms exhibiting different amplitude characteristics is the use of a “normalize all waveforms” control on the programmer. While the “normalize all waveforms” control provides a quick method of normalizing all waveforms on a programmer/analyzer display to a predefined height, this “all or nothing” approach to waveform normalization is not acceptable for applications where individual leads (e.g., EGM and ECG) may be attached, repositioned, or unattached during a lead test.
Other disclosures relating to the same general problem include the U.S. Patents listed below in Table 1.
TABLE 1
Prior Art Patents
Patent No.
Title
5,033,623
System and Method for Facilitating Rapid Retrieval and
Evaluation of Diagnostic Data Stored by an Implantable
Medical Device
5,402,794
Method and Apparatus for Heart Transplant Monitoring
and Analog Telemetry Calibration
5,716,384
Method and System for Organizing, Viewing and
Manipulating Information in Implantable Device
Programmer
5,724,985
User Interface for an Implantable Medical Device Using
an Integrated Digitizer Display Screen
5,782,890
Method for Heart Transplant Monitoring and Analog
Telemetry Calibration
At least some of the devices and methods disclosed in the patents of Table 1 may be modified advantageously in accordance with the teachings of the present invention.
SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages of the prior art by providing an apparatus and method for automatically adjusting the display height of an individually selectable cardiac waveform to a predetermined nominal size on a programmer/analyzer display.
The present invention has certain objects. That is, the present invention provides solutions to certain problems existing in the prior art such as the display of waveform data from implantable medical devices wherein: (a) the height of displayed waveforms is difficult to control due to changes in the signal gain upon mode change operations; (b) adjusting the height of an individual waveform with existing incremental sizing controls is cumbersome and time consuming; and (c) concurrently adjusting the height of all waveforms in a display through a single normalization operation becomes impracticable when individual leads (e.g., EGM and ECG) corresponding to a single waveform may be attached, repositioned, or unattached during a lead test.
At least some embodiments of the present invention include one or more of the following advantages: (a) increased flexibility in that each waveform is independently adjustable through its own corresponding normalization function; (b) operational simplicity and efficiency in that a user need only activate one button to normalize an individual waveform, and the normalize button is positioned adjacent its corresponding waveform; and (c) expanded usability in that the normalization function is available in a number of different display modes, including: a waveform adjust screen, a lead analysis screen, a threshold test screen, and an advanced test mode screen.
The present invention has certain features, including a programmer/analyzer including a user interface consisting of a display and means for displaying several graphic elements. The graphic elements include at least one waveform element showing a time dependent parameter related to a cardiac function, such as an ECG or EGM. The programmer/analyzer further includes a user selectable waveform normalization graphic element associated with each displayed waveform element which, upon activation, adjusts the waveform to a predetermined nominal size on the display. In a display having two or more adjacent waveforms, each user selectable waveform normalization graphic element operates only on its associated waveform.
The user selectable waveform normalization graphic element is available within several display modes of the programmer/analyzer, including: a live waveform adjust screen, a lead analysis screen, a threshold test screen, and an advanced test screen.
Other features, advantages, and objects of the invention will become apparent by referring to the appended drawings, detailed description, and claims.
REFERENCES:
patent: 5345362 (1994-09-01), Winkler
patent: 5402794 (1995-04-01), Wahlstrand et al.
patent: 5578063 (1996-11-01), Bocek et al.
patent: 5716384 (1998-02-01), Snell
patent: 5724985 (1998-03-01), Snell et al.
patent: 5782890 (1998-07-01), Wahlstrand et al.
patent: 5833623 (1998-11-01), Mann et al.
Blowers Paul
Bradley A. Martin
Nichols Timothy J.
Werner Robert
Evanisko George R.
McMahon Beth L.
Medtronic Inc.
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