System and method for discriminating hypervolemia, hypervolemia and euvolemia using an implantable medical device

摘要

Techniques are provided for use by an implantable medical device or diagnostic sensor for detecting and discriminating euvolemia, hypervolemia and hypovolemia. In one example, the device detects a pressure signal within the patient representative of changes in cardiac pressure overall several cardiac cycles. The device generates separate time-domain and frequency-domain representations of the pressure signal and then discriminates among euvolemia, hypervolemia and hypovolemia within the patient based on an analysis of the time-domain and the frequency-domain representations of the signal. Depending upon the capabilities of the device, suitable warnings may be generated to alert the patient or caregiver. Diuretics or other medications can be titrated to address abnormal fluid conditions such as a fluid overload during hypervolemia. Techniques for detecting a pressure alternans pattern indicative of imminent decompensation are also described.

主权项

1. A method for use with an implantable medical device for implant within a patient, the method comprising:
applying a cardiac pressure detector to detect a pressure signal within the patient representative of changes in cardiac pressure during at least one cardiac cycle; applying a time-domain and frequency-domain processor to generate separate time-domain and frequency-domain representations of the pressure signal; applying a discrimination system to discriminate among euvolemia, hypervolemia and hypovolemia within the patient based on the time-domain and the frequency-domain representations of the pressure signal; wherein applying a discrimination system to discriminate euvolemia, hypervolemia and hypovolemia comprises:
identifying an ejection period of the cardiac cycle within the time-domain representation of the pressure signal;assessing a shape of the time-domain representation of the pressure signal during the ejection period; anddiscriminating hypervolemia from hypovolemia and euvolemia based on the shape of the time-domain representation of the pressure signal during the ejection period; and applying a controller unit to control at least one implantable medical device therapeutic function in response to applying a discrimination system to discriminate among euvolemia, hypervolemia and hypovolemia.