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AssigneePacesetter, Inc.
InventorsLaurence S. Sloman, Kerry A. Bradley, Joseph J. Florio
Estimating the term…
An implantable cardiac stimulation device with automatic threshold testing capabilities. The device utilizes an algorithm for measuring a first and a second threshold settings. The first threshold setting is determined by decreasing the stimulation energy from an initially high, supra-threshold value until loss of capture is detected, and is set as the pulse energy at which capture is still detected. The second threshold setting is determined by increasing the stimulation energy from an initially low, sub-threshold value until capture is detected, and is set as the stimulation energy at which capture is regained. The algorithm further determines if the threshold test results are reliable by comparing the difference between the first and second threshold settings to an expected difference, known as the Wedensky Effect value. A deviation from the Wedensky Effect value which is known for a given patient, indicates a discrepancy in the threshold test result. Such a deviation could be used to indicate when a threshold test is suspected of being erroneous, for example, due to fusion. During a subsequent threshold test, the stimulation parameters are adjusted so that the likelihood of fusion is minimized. Once a threshold test result is evaluated and found to be consistent with the expected Wedensky Effect value, the stimulation energy is automatically adjusted to a level safely above the threshold value.
A method of automatically performing a threshold test, comprising:
A method of automatically determining the occurrence of fusion, comprising:
A cardiac stimulation device for automatically performing a threshold test, comprising:
A cardiac stimulation device for automatically determining the occurrence of fusion, comprising:
Dependencies are inferred from the claim text.