Abstract: An implantable system includes terminals, a pulse generator, a sensing circuit, separate signal processing channels, and first, second and third multiplexers. The terminals are connected to electrodes via conductors of leads. Different subsets of the electrodes are used to define different electrical pulse delivery vectors, and different subsets of the electrodes are used to define different sensing vectors. The pulse generator produces electrical pulses, and the sensing circuit senses a signal indicative of an impedance associated with a selected sensing vector. The first multiplexer selectively connects outputs of the pulse generator to a selected one of the different electrical pulse delivery vectors at a time. The second multiplexer selectively connect inputs of the sensing circuit to a selected one of the different sensing vectors at a time. The third multiplexer selectively connects an output of the sensing circuit to one of the plurality of separate signal processing channels at a time.

Abstract: Techniques are provided for use with an implantable cardiac stimulation device equipped with a multi-pole left ventricular (LV) lead and a right ventricular (RV) lead for identifying suitable pacing vectors. In one example, RV-LV delay times are measured while using different electrodes of the LV lead as cathodes for sensing. The LV electrode having the longest RV-LV delay time is identified and LV capture thresholds and diaphragmatic stimulation thresholds are measured for pacing vectors that employ that LV electrode as a cathode. Assuming at least one vector employing the selected LV electrode is found to have acceptable thresholds, the vector is selected for use in delivering pacing therapy with the selected LV electrode. If none of the pacing vectors employing the selected LV electrode has acceptable thresholds, another LV electrode is selected and the procedure is repeated. Examples with a multi-pole RV lead are also described.

Abstract: Methods, systems and devices efficiently identify cardiac resynchronization therapy (CRT) pacing parameter set(s) that provide improved hemodynamic response relative to an initial CRT pacing parameter set, wherein each CRT pacing parameter set includes at least two CRT pacing parameters. User input(s) are accepted that specify a maximum amount of time and/or parameter sets that can be used to perform testing, and specify relative importance of parameters within the sets. Based on the accepted user input(s), there is a determination of how many different variations of each of the CRT pacing parameters can be tested, and based on this determination different CRT pacing parameter sets are selected and tested to obtain a hemodynamic response measure corresponding to each of the different sets tested. Additionally, one or more of the tested CRT pacing parameter sets, if any, that provide improved hemodynamic response relative to the initial CRT pacing parameter set is/are identified.

Abstract: Methods and systems described herein are especially useful wherein monitoring for atrial fibrillation (AF) is based on RR interval variability as measured from an electrocardiogram (ECG) signal. An activity threshold, which can be patient specific, is obtained. Patient activity is monitored. Based on the monitored patient activity and the activity threshold, there is a determination of when it is likely that AF monitoring based on RR interval variability is adversely affected by patient activity. When it has been determined that it is likely that AF monitoring based on RR interval variability is adversely affected by patient activity, whether and/or how AF monitoring is performed is modified.

Abstract: Methods, systems and devices efficiently identify cardiac resynchronization therapy (CRT) pacing parameter set(s) that provide improved hemodynamic response relative to an initial CRT pacing parameter set, wherein each CRT pacing parameter set includes at least two CRT pacing parameters. User input(s) are accepted that specify a maximum amount of time and/or parameter sets that can be used to perform testing, and specify relative importance of parameters within the sets. Based on the accepted user input(s), there is a determination of how many different variations of each of the CRT pacing parameters can be tested, and based on this determination different CRT pacing parameter sets are selected and tested to obtain a hemodynamic response measure corresponding to each of the different sets tested. Additionally, one or more of the tested CRT pacing parameter sets, if any, that provide improved hemodynamic response relative to the initial CRT pacing parameter set is/are identified.

Abstract: An implantable system includes terminals, a pulse generator, a sensing circuit, separate signal processing channels, and first, second and third multiplexers. The terminals are connected to electrodes via conductors of leads. Different subsets of the electrodes are used to define different electrical pulse delivery vectors, and different subsets of the electrodes are used to define different sensing vectors. The pulse generator produces electrical pulses, and the sensing circuit senses a signal indicative of an impedance associated with a selected sensing vector. The first multiplexer selectively connects outputs of the pulse generator to a selected one of the different electrical pulse delivery vectors at a time. The second multiplexer selectively connect inputs of the sensing circuit to a selected one of the different sensing vectors at a time. The third multiplexer selectively connects an output of the sensing circuit to one of the plurality of separate signal processing channels at a time.

Abstract: Techniques are provided for controlling spinal cord stimulation (SCS) or other forms of neurostimulation. In one example, SCS treatment is delivered to a patient and nerve impulse firing signals are sensed along the spinal cord following the SCS treatment. The nerve impulse signals are analyzed to determine whether the signals are associated with effective SCS and then the delivery of additional SCS is controlled to improve SCS efficacy. For example, the nerve impulse signals can be analyzed to determine whether the signals are consistent with a positive patient mood associated with pain mitigation and, if not, SCS control parameters are adjusted to improve the efficacy of the SCS in reducing pain. In other examples, heart rate variability (HRV) is also used to control SCS. Still further, adjustments may be made to SCS control parameters to improve antiarrhythmic or sympatholytic effects associated with SCS. Techniques employing baseline/target calibration procedures are also described.

Abstract: A nerve stimulation system includes a pulse generator and implantable lead. The pulse generator includes a sensing module and a pace circuit. The lead has an electrode array near the distal end and a connector at the proximal end for connection to the pulse generator. Conductors in the lead electrically connect the electrode array with the sensing module and pace circuit. The electrode array includes a first pair of small electrodes and a large electrode close to each other. The small electrodes and large electrode are physically separated from each other by insulative spaces extending generally transversely to a longitudinal axis of the lead. When the conductors are in electrical communication with the sensing module and pace circuit, the first pair of small electrodes are in electrical communication with both the sensing module and the pace circuit and the large electrode is in electrical communication with the pace circuit only.

Abstract: An implantable system includes terminals, a pulse generator, a sensing circuit, separate signal processing channels, and first, second and third multiplexers. The terminals are connected to electrodes via conductors of leads. Different subsets of the electrodes are used to define different electrical pulse delivery vectors, and different subsets of the electrodes are used to define different sensing vectors. The pulse generator produces electrical pulses, and the sensing circuit senses a signal indicative of an impedance associated with a selected sensing vector. The first multiplexer selectively connects outputs of the pulse generator to a selected one of the different electrical pulse delivery vectors at a time. The second multiplexer selectively connect inputs of the sensing circuit to a selected one of the different sensing vectors at a time. The third multiplexer selectively connects an output of the sensing circuit to one of the plurality of separate signal processing channels at a time.

Abstract: Methods and systems are provided to control a configuration of a neural stimulation (NS) system having an NS device coupled to an NS lead. The methods and systems change between configurations of the NS system and collect cardiac signals from a patient that are representative of cardiac rhythms experienced by the patient over a period of time and in connection with multiple NS configurations. The methods and systems derive, from the cardiac signals, characteristic values for at least one physiologic characteristic indicative of at least one of normal and abnormal cardiac rhythms in connection with the multiple NS configurations; and select, from the multiple NS configurations, an NS operating configuration to be used by the NS system based on the characteristic values.

Abstract: Techniques are provided for use with an implantable medical device for assessing left ventricular (LV) sphericity and atrial dimensional extent based on impedance measurements for the purposes of detecting and tracking heart failure and related conditions such as volume overload or mitral regurgitation. In some examples described herein, various short-axis and long-axis impedance vectors are exploited that pass through portions of the LV for the purposes of assessing LV sphericity. In other examples, impedance measurements taken along a vector between a right atrial (RA) ring electrode and an LV electrode implanted near the atrioventricular (AV) groove are exploited to assess LA extent, biatrial extent or mitral annular diameter. The assessment techniques can be employed alone or in conjunction with other heart failure detection techniques, such as those based on left atrial pressure (LAP.

Abstract: Techniques are provided for use by implantable medical devices such as cardiac resynchronization therapy (CRT) devices for detecting pulmonary edema based on transthoracic impedance sensed using cardiac pacing/sensing leads, wherein detection can be performed while lead maturation occurs. Briefly, the implantable device determines whether the leads are within an initial post-implant interval following implant during which lead maturation generally occurs. The device then detects pulmonary edema or related medical conditions within the patient based on transthoracic impedance using a set of detection parameters adjusted for use during the post-implant interval. Thus, rather than “blanking” impedance data during lead maturation, the device instead detects and processes impedance during this period to identify possible episodes of pulmonary edema so that appropriate measures can be undertaken, such as delivery of warnings or titration of appropriate medications.

Abstract: A nerve stimulation system includes a pulse generator and implantable lead. The pulse generator includes a sensing module and a pace circuit. The lead has an electrode array near the distal end and a connector at the proximal end for connection to the pulse generator. Conductors in the lead electrically connect the electrode array with the sensing module and pace circuit. The electrode array includes a first pair of small electrodes and a large electrode close to each other. The small electrodes and large electrode are physically separated from each other by insulative spaces extending generally transversely to a longitudinal axis of the lead. When the conductors are in electrical communication with the sensing module and pace circuit, the first pair of small electrodes are in electrical communication with both the sensing module and the pace circuit and the large electrode is in electrical communication with the pace circuit only.

Abstract: A method for trending heart failure measures cardiogenic impedance (CI) and obtains signals representing estimates for or direct measurements of at least one of cardiac volume and pressure of the heart when the CI measurements were obtained. The method identifies correction factors based on the signals and applies the correction factors to the contractility estimates. A system for trending heart failure includes a contractility module to determine contractility estimates from CI measurements taken along at least a first vector through a heart, and a collection module to receive signals representing estimates for or direct measurements of at least one of cardiac volume and pressure of the heart when the CI measurements were obtained. The system further includes a factor module to identify correction factors based on the signals and a correction module to apply the correction factors to the contractility estimates.

Abstract: An implantable system includes terminals, a pulse generator, a sensing circuit, separate signal processing channels, and first, second and third multiplexers. The terminals are connected to electrodes via conductors of leads. Different subsets of the electrodes are used to define different electrical pulse delivery vectors, and different subsets of the electrodes are used to define different sensing vectors. The pulse generator produces electrical pulses, and the sensing circuit senses a signal indicative of an impedance associated with a selected sensing vector. The first multiplexer selectively connects outputs of the pulse generator to a selected one of the different electrical pulse delivery vectors at a time. The second multiplexer selectively connect inputs of the sensing circuit to a selected one of the different sensing vectors at a time. The third multiplexer selectively connects an output of the sensing circuit to one of the plurality of separate signal processing channels at a time.

Abstract: Methods, systems and devices efficiently identify cardiac resynchronization therapy (CRT) pacing parameter set(s) that provide improved hemodynamic response relative to an initial CRT pacing parameter set, wherein each CRT pacing parameter set includes at least two CRT pacing parameters. User input(s) are accepted that specify a maximum amount of time and/or parameter sets that can be used to perform testing, and specify relative importance of parameters within the sets. Based on the accepted user input(s), there is a determination of how many different variations of each of the CRT pacing parameters can be tested, and based on this determination different CRT pacing parameter sets are selected and tested to obtain a hemodynamic response measure corresponding to each of the different sets tested. Additionally, one or more of the tested CRT pacing parameter sets, if any, that provide improved hemodynamic response relative to the initial CRT pacing parameter set is/are identified.

Abstract: Methods and systems are provided to control a configuration of a neural stimulation (NS) system having an NS device coupled to an NS lead. The methods and systems change between configurations of the NS system and collect cardiac signals from a patient that are representative of cardiac rhythms experienced by the patient over a period of time and in connection with multiple NS configurations. The methods and systems derive, from the cardiac signals, characteristic values for at least one physiologic characteristic indicative of at least one of normal and abnormal cardiac rhythms in connection with the multiple NS configurations; and select, from the multiple NS configurations, an NS operating configuration to be used by the NS system based on the characteristic values.

Abstract: Techniques are provided for controlling spinal cord stimulation (SCS) or other forms of neurostimulation. In one example, SCS treatment is delivered to a patient and nerve impulse firing signals are sensed along the spinal cord following the SCS treatment. The nerve impulse signals are analyzed to determine whether the signals are associated with effective SCS and then the delivery of additional SCS is controlled to improve SCS efficacy. For example, the nerve impulse signals can be analyzed to determine whether the signals are consistent with a positive patient mood associated with pain mitigation and, if not, SCS control parameters are adjusted to improve the efficacy of the SCS in reducing pain. In other examples, heart rate variability (HPV) is also used to control SCS. Still further, adjustments may be made to SCS control parameters to improve antiarrhythmic or sympatholytic effects associated with SCS. Techniques employing baseline/target calibration procedures are also described.

Abstract: A nerve stimulation system includes a pulse generator and implantable lead. The pulse generator includes a sensing module and a pace circuit. The lead has an electrode array near the distal end and a connector at the proximal end for connection to the pulse generator. Conductors in the lead electrically connect the electrode array with the sensing module and pace circuit. The electrode array includes a first pair of small electrodes and a large electrode close to each other. The small electrodes and large electrode are physically separated from each other by insulative spaces extending generally transversely to a longitudinal axis of the lead. When the conductors are in electrical communication with the sensing module and pace circuit, the first pair of small electrodes are in electrical communication with both the sensing module and the pace circuit and the large electrode is in electrical communication with the pace circuit only.

Abstract: Techniques are provided for use by implantable medical devices such as cardiac resynchronization therapy (CRT) devices for detecting pulmonary edema based on transthoracic impedance sensed using cardiac pacing/sensing leads, wherein detection can be performed while lead maturation occurs. Briefly, the implantable device determines whether the leads are within an initial post-implant interval following implant during which lead maturation generally occurs. The device then detects pulmonary edema or related medical conditions within the patient based on transthoracic impedance using a set of detection parameters adjusted for use during the post-implant interval. Thus, rather than “blanking” impedance data during lead maturation, the device instead detects and processes impedance during this period to identify possible episodes of pulmonary edema so that appropriate measures can be undertaken, such as delivery of warnings or titration of appropriate medications.