Abstract: An exemplary device includes a processor, one or more communication interfaces, memory and one or more modules stored in the memory that comprise processor executable instructions to receive data from an implantable device via at least one of the one or more communication interfaces, to interrogate the data for one or more particular types of data, to process one or more particular types of data and to transmit information via at least one of the one or more communication interfaces. Various other exemplary devices, methods, systems, etc., are also disclosed.

Abstract: Techniques are described for detecting changes in posture; detecting cardiac ischemia while accounting for changes in posture; and delivering therapy or warning signals in response thereto using the implantable medical device. In one example, the device detects variations in the electrical cardiac signals indicative of a possible episode of cardiac ischemia. Changes in patient posture are detected as well using an accelerometer or similar device. Then, an episode of cardiac ischemia is detected based on the variations in the cardiac signals while distinguishing variations due to changes in posture. In another example, the device instead detects changes in posture based on transient changes in morphological features of electrical cardiac signals.

Abstract: Methods and systems may identify a vector or a vector configuration, such as a combination of electrodes, for monitoring ischemia. The method may include: selecting a first combination of sensors as a first candidate to be used for monitoring ischemia; detecting a shift in a ST segment of one of an electrocardiogram and a cardiac electrogram using the first candidate; selecting a second combination of sensors as a second candidate to be used for monitoring ischemia; detecting a shift in a ST segment of one of an electrocardiogram and a cardiac electrogram using the second candidate; comparing the ST shifts for the first and second candidates; and identifying one of the first and second candidates for monitoring ischemia based on the comparison. A multi-electrode implantable cardiac device may include a controller configured to effectuate such functions.

Abstract: An implantable medical lead for active fixation to cardiac tissue is disclosed herein. The lead may include a lead body distal end, a tissue fixation helical anchor and a structure. The tissue fixation helical anchor may be coupled to the lead body distal end and include a distal tip. The structure may be coupled to the lead body distal end and include a structure distal end including a first radiopaque marker. The structure may be biased to project the structure distal end near the distal tip. When the tissue fixation helical anchor is progressively embedded in the cardiac tissue, the cardiac tissue progressively displaces the structure distal end proximally.

Abstract: Implantable medical leads have reduced diameter while providing for optimized mechanical and electrical properties, by reducing the diameters of the conducting cables used within the leads for sensing and delivery of therapeutic electrical stimulation. In an embodiment, conducting filaments within a cable have oval cross-sectional areas. Suitably orienting the oval filaments increases the contact surface between adjacent filaments, broadly distributing the pressure between filaments and reducing fretting fatigue, while the oval cross-sectional area also increases conductivity. In an embodiment, non-conducting coatings around filaments within a cable, or around groups of filaments organized into cable-layers, reduce fretting fatigue. In an embodiment, the cross-sectional area of filaments decreases as the filaments are positioned at increasing radial distances from the center of the cable.

Abstract: An implantable medical lead configured for improved MRI safety and heating reduction performance is disclosed herein. In one embodiment, the lead includes a tubular body having a proximal end and a distal end with a lead connector near the proximal end. In this embodiment the lead further includes a conductor extending longitudinally within the tubular body and having a proximal end that is electrically coupled to the connector and a distal end electrically coupled to a contact pin. The lead in this embodiment further includes a filter element electrically coupled to a distal end of the contact pin and a flange electrically coupled between a proximal end of the filter element and a proximal portion of an electrode. In this embodiment the flange and the proximal portion of the electrode form at least a first part of a hermetic chamber enclosing the filter element.

Abstract: An implantable medical lead for coupling to an implantable pulse generator may be configured for improved safety. The lead may include: a first electrode; a second electrode in electrical communication with the first electrode; and an active circuit element in electrical communication with the first electrode and the second electrode. The active circuit element may be configured to change an impedance of the lead. The active circuit element may be configured to change the impedance of the lead in response to a pacing signal or a signal having opposite polarity to a pacing signal. A method of using an implantable medical lead for improved safety may include changing an impedance of an implantable medical lead from a relatively high impedance to a relatively low impedance and/or changing an impedance of an implantable medical lead from a relatively low impedance to a relatively high impedance.

Abstract: Techniques are provided for the self-calibration of an implantable blood oxygen saturation sensor. In one example, the pacemaker tracks respiration rate, patient activity level and the degree of pulmonary edema with the patient. The pacemaker identifies periods of time when three conditions are met: the respiration rate is normal, activity is minimal and the degree of pulmonary edema is also minimal. The pacemaker then calibrates the oxygen saturation sensor based on sensor output values detected only when all three conditions are met. By calibrating the sensor only during periods of time when all three conditions are all met, the calibration logic can thereby assume that actual saturation levels within the patient are at a maximum and that any deviation from that maximum is due to changes in blood cell fixation, tissue overgrowth, or other factors unrelated to actual oxygen saturation levels.

Abstract: An implantable cardiac stimulation device provides stimulation therapy from within the left ventricle of a heart. The device includes a pulse generator adapted to be coupled to an implantable cardiac stimulation electrode and a power supply that provides the stimulation electrode with a positive voltage. The positive voltage promotes coating of the electrode through a body coating process. The coating serves to repel formation of clots on the electrode.

Abstract: A set of cardiogenic impedance signals are detected along different sensing vectors passing through the heart of the patient, particularly vectors passing through the ventricular myocardium. A measure of mechanical dyssynchrony is detected based on differences, if any, among the cardiogenic impedance signals detected along the different vectors. In particular, differences in peak magnitude delay times, peak velocity delay times, peak magnitudes, and waveform integrals of the cardiogenic impedance signals are quantified and compared to detect abnormally contracting segments, if any, within the heart of the patient. Warnings are generated upon detection of any significant increase in mechanical dyssynchrony. Diagnostic information is recorded for clinical review. Pacing therapies such as cardiac resynchronization therapy (CRT) can be activated or controlled in response to mechanical dyssynchrony to improve the hemodynamic output of the heart.

Abstract: An implantable stimulation system includes a stimulation current generator encased in an implantable housing, one or more stimulation leads to deliver therapeutic stimulation from the generator to target patient tissue, and inductive elements arranged to condition the stimulation for delivery to the target tissue with increased efficiency and reduced pain sensation. The inductive elements are arranged external to the housing and integral with one or more of a stimulation lead or an external component of the housing, such as a header. The inductive elements serve to condition therapeutic stimulations such that varying the output of the generator allows the system to deliver arbitrary effective waveforms to the target tissue.

Abstract: An enhanced intraluminal flow measurement system and method is conducive for a low-power ultrasonic system that can use continuous-wave (CW) Doppler sensing and wireless RF telemetry. Applications include measurement of blood flow in situ in living organisms. Implementations include an extraluminal component located outside of a body, such as a human or animal body, containing a lumen. The extraluminal component can be wirelessly coupled via an RF magnetic field or other RF field to an implantable intraluminal component. The intraluminal component (i.e. implant) is implanted inside of the lumen of the body such as a heart or elsewhere in a vasculature (such as in a dialysis shunt). The intraluminal component can telemeter, via RF electromagnetic signals, flow data directly out of the body housing the intraluminal component to be received by the extraluminal component.

Abstract: In an implantable medical device for monitoring blood-glucose concentration in the blood, metabolic oxygen consumption is derived by measuring physiological metrics related to mixed venous oxygen concentration. Blood-glucose concentration is determined using correlations of blood-glucose concentration with measures of metabolic oxygen consumption including oxymetric, temperature, and electrocardiographic data. Additional physiological sensor measurements may be used to enhance the accuracy of the analysis of blood-glucose concentration. By using a combination of oxymetric and other physiological metrics, blood-glucose concentration can be reliably calculated over a wide range. The device compares the blood-glucose concentration with upper and lower acceptable bounds and generates appropriate warning signals if the concentration falls outside the bounds. The device may also control a therapeutic device to maintain blood-glucose concentration within an acceptable range.

Abstract: Techniques are described for detecting ischemia, hypoglycemia or hyperglycemia based on intracardiac electrogram (IEGM) signals. Ischemia is detected based on a shortening of the interval between the QRS complex and the end of a T-wave (QTmax), alone or in combination with a change in ST segment elevation. Alternatively, ischemia is detected based on a change in ST segment elevation combined with minimal change in the interval between the QRS complex and the end of the T-wave (QTend). Hypoglycemia is detected based on a change in ST segment elevation along with a lengthening of either QTmax or QTend. Hyperglycemia is detected based on a change in ST segment elevation along with minimal change in QTmax and in QTend. By exploiting QTmax and QTend in combination with ST segment elevation, changes in ST segment elevation caused by hypo/hyperglycemia can be properly distinguished from changes caused by ischemia.

Abstract: An exemplary method includes delivering stimulation energy via a right ventricular site; sensing an evoked response caused by the delivered stimulation energy at the right ventricular site; calculating a paced propagation delay for the right ventricular site (PPDRV); delivering stimulation energy via a left ventricular site; sensing an evoked response caused by the delivered stimulation energy at the left ventricular site; calculating a paced propagation delay for the left ventricular site (PPDLV); and determining an interventricular delay time (VV) for delivery of a bi-ventricular pacing therapy based in part on the paced propagation delay for the right ventricular site (PPDRV) and the paced propagation delay for the left ventricular site (PPDLV). Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: An exemplary method includes, based on metrics available as input to a chronic phase optimization algorithm for selecting an optimal electrode configuration for delivery of a cardiac pacing therapy, executing the chronic phase optimization algorithm during an acute phase to select an optimal electrode configuration for delivery of a cardiac pacing therapy; during the acute phase, acquiring position information with respect to time for electrodes implanted in a body; determining one or more acute phase metrics based on the acquired position information; and validating the chronic phase optimization algorithm based at least in part on the one or more acute phase metrics.

Abstract: Systems and methods are provided for use by implantable medical devices equipped to deliver multi-site left ventricular (MSLV) pacing. MSLV is associated with a relatively long post-ventricular atrial blanking (PVAB) period that might limit the detection of pathologic rapid organized atrial tachycardias (OAT). In one example, MSLV cardiac resynchronization therapy (CRT) pacing is delivered within a tracking mode. A possible atrial tachycardia is detected based on the atrial rate exceeding an atrial tachycardia assessment rate (ATAR) threshold. The device then switches to single-site LV pacing, thereby effectively shortening the PVAB to detect additional atrial events that might otherwise be obscured, and thereby permitting the device to more reliably distinguish organized atrial tachycardias (such as atrial flutter) from sinus tachycardia.

Abstract: Systems and methods are provided for use by implantable medical devices equipped to deliver multi-site left ventricular (MSLV) pacing. Sequential MSLV is associated with a relatively long post-ventricular atrial blanking (PVAB) period that might limit the detection of pathologic rapid organized atrial tachycardias (OAT). In one example, sequential MSLV cardiac resynchronization therapy (CRT) pacing is delivered within a tracking mode. A possible atrial tachycardia is detected based on the atrial rate exceeding an atrial tachycardia assessment rate (ATAR) threshold. The device then switches to either single-site LV pacing or simultaneous MSLV pacing, thereby effectively shortening the PVAB to detect additional atrial events that might otherwise be obscured, and thereby permitting the device to more reliably distinguish OATs (such as atrial flutter) from sinus tachycardia.

Abstract: A lead includes a lead body with a stylet receiving lumen, a distal tip, and a distal portion proximal of the distal tip that is biased to assume a non-linear configuration. Insertion of a stylet into the lumen causes the distal portion to transition from the non-linear configuration to a generally linear configuration. The lead also includes a first arm member having a distal end and a proximal end coupled to the lead body proximal of the distal tip; and a nosepiece, at least a portion of which is biodegradable. The nosepiece is configured to receive the distal tip of the lead body and the distal end of the first arm member such that the lead body, first arm member and nosepiece form a closed arrangement prior to biodegradation of the nosepiece and an open arrangement after biodegradation of the nosepiece.

Abstract: An implantable medical device is provided that comprises a pulse generator that provides atrial and ventricular pacing pulses on demand. The pulse generator times delivery of the ventricular pacing pulses based on an AV pacing interval. The device also includes an AV hysteresis module that extends the AV interval from a base AV interval to an extended AV interval to promote intrinsic heart activity. A refractory module establishes a PVARP interval equal to base PVARP interval following at least one of the ventricular pacing pulses. The refractory module lengthens the PVARP interval by adding a PVARP extension to a base PVARP interval to provide an extended PVARP interval.