System and method for monitoring cardiac function via cardiac sounds using an implantable cardiac stimulation device
First Claim
1. In an implantable cardiac stimulation device for implant within a patient, a method comprising:
- detecting heart sound signals;
determining whether systolic regurgitant murmurs are occurring during an ejection period; and
processing the heart sound signals to derive one or more parameters representative of cardiac function of the patient, wherein the one or more parameters comprise stroke volume, cardiac output, and maximum rate of change of aortic pressure over time.
1 Assignment
0 Petitions
Accused Products
Abstract
Techniques are provided for performing internal measurement of heart sounds to estimate patient cardiac function in terms of stroke volume, cardiac output, or a maximum rate of change of aortic pressure with time (max dP/dt). Control parameters of the medical device are then automatically adjusted so as to optimize overall cardiac function or to provide for ventricular resynchronization therapy. In one example, heart sound signals are derived from acceleration signals received from an accelerometer. The heart sound signals are analyzed to identify S1 and S2 heart sounds as well as ejection period and isovolumic interval (ISOV). Proxies for max dP/dt, stroke volume and cardiac output are then derived from the S1 and S2 heart sounds, the ejection period and the ISOV. Alternative techniques, not requiring detection of ISOV, are employed for use if the patient has heart value regurgitation.
124 Citations
28 Claims
-
1. In an implantable cardiac stimulation device for implant within a patient, a method comprising:
-
detecting heart sound signals; determining whether systolic regurgitant murmurs are occurring during an ejection period; and processing the heart sound signals to derive one or more parameters representative of cardiac function of the patient, wherein the one or more parameters comprise stroke volume, cardiac output, and maximum rate of change of aortic pressure over time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
-
-
27. In an implantable cardiac stimulation device for implant within a patient, a system comprising:
-
means for detecting acceleration signals representative of the acceleration of tissues within the patient; and means for converting the acceleration signals into heart sound signals means for detecting systolic regurgitant murmurs during an ejection period; and means for processing the heart sound signals to derive one or more parameters representative of cardiac function of the patient, wherein the one or more parameters comprise stroke volume, cardiac output, and maximum rate of change of aortic pressure over time. - View Dependent Claims (28)
-
Specification