摘要:
An implantable medical device system and method in which the implantable device is adapted to operate in a minimum ventricular pacing mode. The device delivers cardiac pacing pulses in a first pacing mode during a normal mode of operation and upon detecting myocardial ischemia alters the first pacing mode in response to the myocardial ischemia detection.
摘要:
Techniques 'AND SYSTEM (10)' for detection and treatment of myocardial ischemia are described that monitor both the electrical and dynamic mechanical activity of the heart to detect and verify the occurrence of myocardial ischemia in a more reliable manner. The occurrence of myocardial ischemia can be detected by monitoring changes in an electrical signal such as an ECG or EGM, and changes in dynamic mechanical activity of the heart. Dynamic mechanical activity can be represented, for example, by a heart acceleration signal or pressure signal. The electrical signal can be obtained from a set of implanted or external electrodes (16,18,20;22,24,26)' . The heart acceleration signal can be obtained from an single- or multiple-axis accelerometer (88,108)' and/or a pressure sensor deployed within or near the heart. The techniques correlate contractility changes detected by an accelerometer or pressure sensor with changes in the ST electrogram segment detected by the electrodes (16,18,20;22,24,26)' to increase the reliability of ischemia detection.
摘要:
An implantable barometric pressure sensor (220) coupled with an implantable medical device (IMD) provides a barometric pressure related, referenced pressure value for use in combination with an absolute pressure value measured by an implantable absolute pressure sensor (20) coupled to the IMD. In one embodiment, the barometric pressure sensor (220) is formed as part of a connector module (180) of the IMD or extends from the connector module (180). A percutaneous access device (360) is implanted to extend through the skin and subcutaneous tissue layer of the patient and is coupled with the barometric pressure sensor (220). The barometric pressure sensor (220) is preferably enclosed within an air chamber (170) of the implantable medical device, and a catheter (310) extends between the air chamber (170) of the implantable medical device and the percutaneous access device (360). Or the barometric pressure sensor (220) is enclosed within an air chamber (368) of the percutaneous access device, and a lead extends between the barometric pressure sensor (220) and the implantable medical device.
摘要:
Techniques 'AND SYSTEM (10)' for detection and treatment of myocardial ischemia are described that monitor both the electrical and dynamic mechanical activity of the heart to detect and verify the occurrence of myocardial ischemia in a more reliable manner. The occurrence of myocardial ischemia can be detected by monitoring changes in an electrical signal such as an ECG or EGM, and changes in dynamic mechanical activity of the heart. Dynamic mechanical activity can be represented, for example, by a heart acceleration signal or pressure signal. The electrical signal can be obtained from a set of implanted or external electrodes (16,18,20;22,24,26)' . The heart acceleration signal can be obtained from an single- or multiple-axis accelerometer (88,108)' and/or a pressure sensor deployed within or near the heart. The techniques correlate contractility changes detected by an accelerometer or pressure sensor with changes in the ST electrogram segment detected by the electrodes (16,18,20;22,24,26)' to increase the reliability of ischemia detection.
摘要:
In determining whether a patient has ischemia or other conditions discernible in the variation occurring in the ST portion of the electrocardiogram signal, we filter out bad ST change parameters that are not changing at a rate representative of human ischemia ST change parameter rates of change. This can be used for driving therapy systems to alleviate cardiac ischemia. This filtering can be enhanced by using multiple cardiac electrical vectors for the electrogram signal vectors, and using a determination of Axis shift to modify filter parameters and the expected ranges of precursors to the ST change parameter (an ST change variable) to eliminate bad cardiac cycles, that is cardiac cycle information that may be misleading.
摘要:
A system for chronically measuring a physiologic parameter by an implantable device with has several forms is described. At its core a fixture for holding on to a blood vessel and forcing a sensor against a surface of the vessel is taught. Numerous adaptations and uses with various sensors are described.
摘要:
A device and method for measuring and communicating parameters of a brain, tissue or other organs is disclosed. The invention includes a sensor to sense the parameter of interest and then communicate the sensed parameter to an activation system. The activation system may cause the parameter to be displayed, processes or cause action to be taken. The activation system may be entirely or partially implanted or entirely external to the patient.
摘要:
A device and method for measuring and communicating parameters of a brain, tissue or other organs is disclosed. The invention includes a sensor to sense the parameter of interest. The sensor is preferably located at the distal end of a probe. In the preferred embodiment, the sensor is part of a passive system that allows pressure or temperature measurements to be made and communicated to an attending practitioner when the passive system receives power from an external source. In an alternate embodiment, the sensor is part of a system having a long-term energy source and storage system that allows pressure or temperature measurements to be taken periodically or upon demand, stored and then communicated to an attending practitioner as desired. The invention also includes, in one embodiment, a method for measuring and communicating parameters of a brain, tissue or other organs. The method includes the steps of providing a sensor to sense the parameter of interest, implanting the sensor in or near a target in the brain, tissue or other organ where the parameter of interest may be sensed, providing a reaction device where the parameter may be displayed, processed or cause action to be taken, sensing the parameter or interest, communicating the sensed parameter to the reaction device and displaying or processing the parameter or causing action to be taken in response to the parameter.
摘要:
Adaptations to an intra-thoracic fluid-status-trend indication and/or alert algorithm are disclosed. Some embodiments monitor fluid levels in heart failure patients and others suffering from pulmonary edema and the like. Some embodiments reset a cumulative fluid index when a short-term intra-thoracic impedance value exceeds a baseline impedance value minus a predetermined positive hysteresis value. Many device, system, and method embodiments hereof serve to reduce the number of false positive alerts while retaining the desired sensitivity.