Implantable cardiac stimulation device and method that monitors displacement of an implanted lead
First Claim
1. In an implantable cardiac stimulation device that monitors displacement of a cardiac lead implanted in a heart, the device comprising:
- an impedance measurement circuit that generates an impedance measurement signal representing impedance measured using the implanted lead over a discrete time period;
a memory for storing the impedance measurement signal to provide an impedance template, wherein the impedance measurement circuit periodically generates subsequent impedance measurement signals; and
a processor programmed to compare the subsequent impedance measurement signals to the impedance template and to generate comparison factor values from the comparisons, the comparison factor values being indicative of relative displacement of the implanted cardiac lead.
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Abstract
An implantable cardiac stimulation device and method that monitors displacement of a cardiac lead implanted in a heart. The device includes an impedance measurement circuit that generates a template representing the impedance measured using the lead over a cardiac cycle of the patient'"'"'s heart. The impedance measurement circuit generates subsequent impedance measurement signals, which are then compared to the template to derive a comparison factor. The comparison factors are stored in a memory and are indicative of lead displacement. A telemetry circuit transmits the comparison factors to a non-implanted receiver for analysis of lead displacement.
155 Citations
29 Claims
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1. In an implantable cardiac stimulation device that monitors displacement of a cardiac lead implanted in a heart, the device comprising:
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an impedance measurement circuit that generates an impedance measurement signal representing impedance measured using the implanted lead over a discrete time period;
a memory for storing the impedance measurement signal to provide an impedance template, wherein the impedance measurement circuit periodically generates subsequent impedance measurement signals; and
a processor programmed to compare the subsequent impedance measurement signals to the impedance template and to generate comparison factor values from the comparisons, the comparison factor values being indicative of relative displacement of the implanted cardiac lead. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. In an implantable cardiac stimulation device for monitoring displacement of a cardiac lead implanted in a heart, the device comprising:
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impedance template means for providing a template representing variations in impedance measured using the implanted lead over a predefined time period;
impedance measurement means for generating impedance signals representing impedance measured using the implanted lead;
comparison means for comparing each of the impedance signals to the template and for providing corresponding comparison values, the comparison values being indicative of lead displacement;
memory means for storing at least selected ones of the comparison values; and
telemetry means for transmitting the comparison values to a non-implanted receiver. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. In an implantable cardiac stimulation device, a method of monitoring displacement of a cardiac lead implanted in a heart, the method comprising the steps of:
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generating and storing a template representing impedance of the implanted lead at a predetermined time;
at spaced apart times, providing an impedance signal representing impedance of the implanted lead;
comparing each impedance signal to the template to generate a corresponding comparison value;
storing in a memory at least selected ones of the comparison values, the comparison values be related to lead displacement; and
conveying the comparison measures to an external receiver for analysis. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29)
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Specification