Abstract: An exemplary method includes performing a capture threshold assessment using a bipolar electrode configuration, deciding if capture occurred for a maximum energy value of the capture threshold assessment and, if capture did not occur, then performing a lead impedance test for the lead associated with the bipolar electrode configuration. Such a test may aim to detect an insulation defect and/or a conductor defect. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: Detection of atrial fibrillation involves detecting a plurality of ventricular events and obtaining a series of probabilities of AF, each corresponding to a probability of AF for a different beat window having a plurality of ventricular events. AF onset is detected when one or each of a plurality of consecutive AF probabilities satisfies an AF trigger threshold. AF termination is detected when one or each of a plurality of consecutive AF probabilities does not satisfy the AF trigger threshold. Upon detection of AF onset, ventricular events are processed to detect for a sudden onset of irregularity of the ventricular events. AF onset is confirmed when sudden onset is detected and overturned when sudden onset is not detected.

Abstract: Embodiments include strain sensor devices for detecting movement, morphological changes or other physical parameters within a patient's body tissue. Some embodiments are directed specifically to measuring parameters within a patient's heart and may also be configured to communicate with an implantable stimulation device and associated external programming device.

Abstract: An implantable medical device system that senses physiologic processes via multiple sensor signal configurations. The device can further process the sensor configurations to obtain additional processed signal configurations. The device can utilize the processed configurations for ongoing sensing of the physiologic process. The device can also automatically evaluate the multiple sensor configurations as well as the processed configurations and select the configuration offering the best signal discrimination to reduce oversensing or erroneously interpreting secondary characteristics of the physiologic process as corresponding to primary characteristics of the process as in double-counting. The signal discrimination can be evaluated as an absolute margin and/or a ratio between amplitudes of the primary and secondary characteristics. The signal discrimination can also be evaluated based at least in part on a calculated mean and standard deviation according to each configuration.

Abstract: Pattern classification techniques are provided for use with an implantable medical device for detecting cardiac ischemia substantially in real-time. Values representative of morphological features of electrical cardiac signals are detected by the implantable medical device. Then, a determination is made as to whether the patient is subject to an on-going episode of cardiac ischemia by applying the values to a pattern classifier configured to identify patterns representative of cardiac ischemia. In one example, the determination is made substantially in real-time by the device itself based on the IEGM signals it detects. In other examples, the IEGM signals are relayed promptly to a bedside monitor or other external device, which analyzes the signals using the pattern classifier to detect ischemia. Therapy may be applied in response to cardiac ischemia. For example, if the implanted device is equipped with a drug pump, appropriate medications may be administered such as anti-thrombolytics.

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: An implantable medical device includes a first, short-range telemetry circuit; a second, long-range telemetry circuit; a first power system that powers the first telemetry circuit; and a second power system that powers the second telemetry circuit. The second power system includes an internal charging system and a rechargeable battery coupled to the internal charging system. The internal charging system may be configured for electromagnetic-inductive or RF-transmission coupling with an external charging system. A controller monitors the energy level of the rechargeable battery and provides an signal indicative of the level.

Abstract: An implantable medical device with a notification system. The device monitors itself and an implantee for one or more condition indicating notification and delivers the notification at a time the patient is determined to be wakeful and, optionally, at relative rest. The notification can be repeated periodically until acknowledged by the user or the system is evaluated and reprogrammed by the physician. A user input can be included to provide the device confirmation of receipt of the notification as well as to delay delivery of any indicated subsequent notifications. The notification is provided without requiring any additional or special dedicated hardware.

Abstract: Techniques are described for use by an implantable medical device equipped to use trim values, which allow the device to continue to use trim values despite certain memory errors such as parity errors. Briefly, optimal trim values are stored within RAM. Nominal trim values are stored within ROM. Device functions are then performed using the trim values stored within RAM. If an error is detected indicative of possible corruption of RAM, then the trim values from ROM are loaded into RAM to enable continued operation of the device using the nominal trim values despite the error. In a preferred implementation, the optimized trim values are initially stored at two separate locations within RAM. A procedure is described herein for allowing the device to continue to use the optimized trim values following a device reset if no parity error is detected. If a parity error occurred, the device instead uses the nominal trim values from ROM.

Abstract: A method of fabricating an implantable medical device having a receptacle adapted to receive a connector assembly attached to a proximal end of an implantable lead. A distal end portion of the implantable lead carries at least one electrode electrically connected with a terminal contact on the connector assembly. The receptacle contains at least one internal insulative sealing surface. An anti-static coating comprising carbon nanotubes is applied to the at least one internal insulative sealing surface.

Abstract: An exemplary method includes providing at least two-dimensional position information, for at least two points in time, for an electrode located in a cardiac space; determining a local estimator based on the position information; and, based at least in part on the determined local estimator, selecting a configuration for delivering a cardiac pacing therapy or diagnosing a cardiac condition. Exemplary methods for regional estimators and exemplary methods for global estimators are also disclosed along with devices and systems configured to perform various methods.

Abstract: Embodiments of the present invention relate to implantable systems, and methods for use therewith, for monitoring myocardial electrical stability. A patient's heart is paced for a period of time using a patterned pacing sequence that repeats every N beats, and an electrical signal is obtained that is representative of a plurality of consecutive beats of the patient's heart while it is being paced using the patterned pacing sequence that repeats every N beats. Myocardial electrical stability is then analyzed using frequency domain techniques that are tailored to the patterned pacing sequence used to pace the patient's heart. In other embodiments, the patient's heart need not be paced. This abstract is not intended to be a complete description of, or limit the scope of, the invention.

Abstract: System and methods for assessing sensed signals for determining a reliability measure of their accuracy with respect to a patient's true physiological status. As one example, the signals can include multiple, independently obtained signals, such as an electro-chemically based measure of cardiac activity and a plethysmography based measure of hemodynamic output which typically exhibit different morphologies and varying phase shifts with respect to each other. One manner of assessing the signals is to transform them into the frequency domain, such as via a Fast Fourier Transform (FFT), and evaluate them, such as by a coherence determination, to determine the degree of their mutual agreement. This can be used to assess the reliability of the sensing. Therapy can be delivered under certain observed conditions, such as a condition of hemodynamic insufficiency where anti-tachycardia pacing and/or shocking therapy can be delivered.

Abstract: An implantable cardiac stimulation and rhythm management device includes an impedance measuring circuit which determines a patient's intra-thoracic impedance and the resistance and reactance components of the impedance. The device includes a microcontroller which calculates a ratio (Z/R) which equals the reactance (Z) divided by the resistance (R). The microcontroller is configured to use the calculated ratios to establish a baseline intra-thoracic fluid level, an upper bound relative to the baseline, and a lower bound relative to the baseline, and to monitor the Z/R ratio relative to the baseline and upper and lower bounds. When the Z/R ratios are outside of the established bounds, operating parameters of the stimulation and rhythm management may be altered by the microcontroller.

Abstract: An implantable system applies tiered antitachycardia pacing (ATP) that may be combined with pre-pulsing therapy in order to reduce pain. In one implementation, an exemplary system applies a progression of increasingly potent pacing vectors, progressing in an initial tier from small electrodes inside the heart to later tiers that increasingly use a large electrode surface outside the heart. In the latter tiers, a pre-pulse may be added prior to each ATP pulse to reduce the sensation of pain.

Abstract: A device and methods for automatically evaluating one or more patient physiological parameters and, upon determination that certain therapies are indicated, delivering therapeutic mechanical stimulations to tissue of the patient. The mechanical stimulations generally include vibrations delivered at frequencies somewhat higher or lower than an intrinsic frequency and the therapeutic vibrations are delivered to drive the intrinsic frequency towards a desired value. The device and methods more closely emulate natural physiologic feedback mechanisms and can reduce undesired side effects of other known therapies. The device can include a small and efficient electrical motor which is interconnected with a crank and link mechanism to generate oscillatory motion which is conducted to a flexible wall of a bio-compatible housing of the device.

Abstract: An exemplary method includes determining an atrial to ventricular activation time for a right ventricle; determining an atrial to ventricular activation time for a left ventricle; and determining a pacing sequence that paces the right ventricle prior to activation of the left ventricle if the time for the right ventricle exceeds the time for the left ventricle or that paces the left ventricle prior to activation of the right ventricle if the time for the left ventricle exceeds the time for the right ventricle, wherein, in the pacing sequence, pacing of the prior, paced ventricle occurs at a time based at least in part on a difference between the time for the right ventricle and the time for the left ventricle and an atrio-ventricular delay limit. Various other exemplary methods, devices and/or systems are also disclosed.

Abstract: Techniques are provided for use with an implantable medical device such as a pacemaker or implantable cardioverter/defibrillator (ICD) for predicting and detecting hypoglycemia. In one example, the device tracks changes in a paced depolarization integral (PDI). A significant increase in PDI over a relatively short period of time indicates the onset of hypoglycemia (this can also be confirmed with QT changes). Upon detection of hypoglycemia, appropriate warning signals are generated to alert the patient. Certain therapies automatically provided by the implantable device may also be controlled in response to hypoglycemia. For example, if the patient is an insulin-dependent diabetic and the implantable device is equipped with an insulin pump capable of delivering insulin directly into the bloodstream, insulin delivery is automatically suspended until blood glucose levels return to acceptable levels.

Abstract: A conductive electrolyte comprises an indicator dye for facilitating detection of electrolyte leakage in a high voltage electrolytic capacitor as well as for facilitating the determination as to when an electrolyte has reached a desired pH range. In a method for detecting electrolyte leakage, a capacitor comprising a flat stack of anodes enclosed in a housing with a lid and an electrolyte comprising an indicator dye is inspected for the presence of electrolyte leaking out of the capacitor. The indicator dye facilitates viewing leaking electrolyte. The indicator dye can be a coloring agent that changes the color of the electrolyte or can be a fluorescent that fluoresces when exposed to ultraviolet light. The indicator dye is also utilized as a pH indicator during the manufacture of electrolytic capacitors, wherein a base is introduced into an electrolyte having an indicator dye that changes pH when the electrolyte turns basic.

Abstract: An implantable cardiac lead comprises a lead body having a proximal end and a distal end, the proximal end of the lead body carrying a connector assembly connectable to an implantable medical device, and the distal end of the lead body carrying a distal electrode, a proximal electrode and an intermediate electrode positioned between the distal and proximal electrodes. The distal and proximal electrodes are connected together at a node point located within the distal end of the lead body, the node point being electrically connected to a first terminal contact on the connector assembly and the intermediate electrode being electrically connected to a second terminal contact on the connector assembly. Preferably, the intermediate electrode is positioned approximately midway between the distal and proximal electrodes.