System and method for deriving a virtual ECG or EGM signal
First Claim
1. A system for having at least three electrode for measuring voltage signals S1 and S2 between a first and second pair of the at least three electrodes, respectively, and wherein one of the at least three electrodes is a common electrode used in both said first and second pairs, the system for automatically deriving an approximation of a voltage signal S existing between the common electrode and a selected point, the system comprising:
- a user interface to allow a user to select a value for an angle θ
, wherein the angle θ
is the angle measured between a directional vector associated with a predetermined one of the first and second pair of the at least three electrodes and a directional vector U associated with the voltage signal S; and
a processing circuit coupled to the user interface to derive the amplitude of the voltage signal S as a function of S1, S2, θ
, an angle β
between the first and second pairs.
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Accused Products
Abstract
A system and method for obtaining a virtual physiologic voltage signal between a first predetermined point in a second selected point in the body is disclosed. At least three electrodes are used to measure two voltage signals S1 and S2 in a body. In one embodiment, the signal S1 is measured between a first electrode and a common electrode, and the signal S2 is measured between a second electrode and the common electrode. A selected point within the body may be chosen to define a pair of virtual electrodes existing between this selected point and the common electrode. An approximation of the voltage signal S as could be measured between electrodes positioned at these virtual electrode locations may be derived as a function of S1, S2, and θ, wherein θ is the angle between the directional vector U1 for the signal S1 and the directional vector U for the signal S. According to the inventive system and method, the signal value for S is also dependent on the distances between the electrode pairs, on the angle β between directional vectors U1 and U2, and on the distance between the virtual electrodes. The current invention may be utilized with electrodes that are positioned either externally on the surface of, or implanted within, a body. According to one aspect of the invention, a user may employ a user interface to select the values of θ, β, and the electrode spacings. Alternatively, ones of these parameters may be predetermined by the system. In another embodiment, the system could derive the signal S over a predetermined range of values for the angle θ. The system may then select the angle of θ resulting in the derived signal S that exhibits a desired waveform morphology.
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Citations
35 Claims
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1. A system for having at least three electrode for measuring voltage signals S1 and S2 between a first and second pair of the at least three electrodes, respectively, and wherein one of the at least three electrodes is a common electrode used in both said first and second pairs, the system for automatically deriving an approximation of a voltage signal S existing between the common electrode and a selected point, the system comprising:
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a user interface to allow a user to select a value for an angle θ
, wherein the angle θ
is the angle measured between a directional vector associated with a predetermined one of the first and second pair of the at least three electrodes and a directional vector U associated with the voltage signal S; and
a processing circuit coupled to the user interface to derive the amplitude of the voltage signal S as a function of S1, S2, θ
, an angle β
between the first and second pairs.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A system for generating a derived signal S indicative of a time-varying voltage signal that would be measured between electrodes positioned at first and second points within a body, the system comprising:
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at least three electrodes to provide a first predetermined electrode pair and a second predetermined electrode pair, the first predetermined electrode pair to measure a time-varying signal S1 having a directional vector U1, and the second predetermined electrode pair to measure a time-varying signal S2 having a directional vector U2; and
a processing circuit coupled to receive the time-varying voltage signals S1 and S2, and to derive the signal S along a directional vector U that is an approximation of a signal that would be measured between the first point defined by the intersection of directional vectors U1 and U2, and the second point, the signal S being derived as a function of an angle θ
that is the angle measured between the directional vector U1 and the directional vector U.- View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. A method executed by a processing circuit for approximating a physiologic voltage signal S between two points within a body spaced a distance D apart from one another, the method comprising the methods of:
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a.) measuring two signals S1 and S2 having directional vectors U1 and U2, respectively;
b.) determining an angle θ
measured between the directional vector U1 and a directional vector U of the voltage signal S; and
c.) approximating the physiologic voltage signal S as a function of the angle θ
.- View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35)
c1.) performing one or more of the multiple processing steps to obtain intermediate processing results;
c2.) transferring the intermediate processing results to the second processing portion via the communication circuit; and
c3.) executing remaining ones of the multiple processing steps by the second portion to obtain the physiologic voltage signal S.
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30. The method of claim 27, wherein the processing circuit includes at least a first and second processing portion, the first processing portion being located inside the body and the second processing portion being located outside the body, wherein the first processing circuit further includes a communication circuit, wherein step c.) further including the methods of:
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c1.) transferring signals S1 and S2 to the second processing portion via the communication circuit; and
c2.) approximating, by the second processing portion, the physiologic voltage signal S as a function of the angle θ
.
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31. The method of claim 27, wherein the processing circuit includes at least a first and second processing portion, the first processing portion being located inside the body and the second processing portion being located outside the body, wherein the first processing circuit further includes a communication circuit, wherein step c.) further including the methods of:
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c1.) approximating, by the first processing portion, the physiologic voltage signal S as a function of the angle θ
; and
c2.) transferring signals S1 and S2 to the second processing portion via the communication circuit.
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32. The method of claim 26, and further including the steps of
d.) repeating steps a.) through c.) for all values of the angle θ - existing at predetermined increments within a predetermined range of angles to generate respective physiologic voltage signals, and
e.) selecting an optimal physiologic voltage signal from among all of the respective physiologic voltage signals based on predetermined criterion.
- existing at predetermined increments within a predetermined range of angles to generate respective physiologic voltage signals, and
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33. The method of claim 32, wherein step e.) is performed using criterion describing waveform morphology of an ECG signal.
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34. The method of claim 32, wherein step a.) includes selecting directional vectors U1 and U2, and wherein the function of step c.) is further a function of β
- , a selectable angle between directional vectors U1 and U2.
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35. The method of claim 26, wherein step c.) includes the step of approximating the physiologic voltage signal S as a function of a selectable value provided for the distance D.
Specification