Histogram-based thoracic impedance monitoring

摘要

Systems and methods for monitoring pulmonary edema or other thoracic fluid status in a subject use thoracic impedance histogram information. An internal or external processor circuit receives the thoracic impedance histogram information and uses it to compute and provide a lung fluid status indication. The thoracic impedance histogram information can include a count, mean or median of a histogram bin or subrange of bins within the histogram range.

主权项

1. A system comprising:
an implantable medical device including,
an electrical impedance measurement circuit configured to measure one or more thoracic impedance-indicating signal characteristics, including at least a liquid status component, using information about electrical energy injected between two or more electrodes and a potential difference created thereby between the same or different two or more electrodes; anda memory circuit including a number of histogram bins, each bin representing a subrange of thoracic impedance-indicating signal characteristic values, including values indicative of a liquid status, the memory circuit configured for storing a count representative of the one or more thoracic impedance-indicating signal characteristics, including at least the liquid status component, into a histogram bin having a numerically inclusive subrange; and a processor circuit including an input to receive and use information about the count representative of the one or more thoracic impedance-indicating signal characteristics, including at least the liquid status component, stored in the histogram to provide a lung edema status indication.