Abstract: The invention is directed to structure and methods for coordinating the operation of an implantable medical device (IMD) with magnetic resonance imaging (MRI) techniques. For example the IMD can be made to activate a blanking period during the time when the electromagnetic radiation bursts occur. Blanking an IMD at times when MRI electromagnetic radiation bursts occur can prevent an undesirable action or incorrect sensing by the IMD while under the influence of the electromagnetic radiation bursts.

Abstract: An implantable medical device provides ventricular pacing capabilities and optimizes AV intervals for multiple purposes. In general, intrinsic conduction is promoted by determining when electromechanical systole (EMS) ends and setting an AV interval accordingly. EMS is determined utilizing various data including QT interval, sensor input, and algorithmic calculations.

Abstract: Various device embodiments comprise a pulse generator, a signal processing module and a controller. The pulse generator is adapted to provide a neural stimulation signal to be applied at a neural simulation site within an autonomic nervous system (ANS). The signal processing module is adapted to receive and process sensed neural traffic at a neural sensing site within the ANS. The controller is connected to the pulse generator and adapted to provide a neural stimulation control signal to the pulse generator to generate the neural stimulation signal, and to the signal processing module to receive a feedback control signal indicative of the sensed neural traffic. The controller is adapted to adjust the neural stimulation control signal to adjust at least one parameter of the neural stimulation signal to converge on desired sensed neural traffic at the neural sensing site. Other aspects and embodiments are provided herein.

Abstract: A device for delivering pacing therapy includes an atrial and ventricular leads, sensing circuitry connected to the leads for detecting depolarizations, and pulse generation circuitry for delivering ventricular pacing pulses based on sensed atrial depolarizations. The device includes control circuitry for controlling the pulse generation circuitry in a first mode in which the pulse generation circuitry delivers atrial synchronized pulses to both the right and left ventricular leads in response to each atrial depolarization sensed. In response to a detected atrial arrhythmia, the control circuitry causes the pulse generation circuitry to deliver atrial synchronized ventricular pacing pulses in response only to selected atrial depolarizations.

Abstract: An exemplary method includes accessing cardiac information acquired via a catheter located at various positions in a venous network of a heart of a patient where the cardiac information comprises position information, electrical information and mechanical information; mapping local electrical activation times to anatomic positions to generate an electrical activation time map; mapping local mechanical activation times to anatomic positions to generate a mechanical activation time map; generating an electromechanical delay map by subtracting local electrical activation times from corresponding local mechanical activation times; and rendering at least the electromechanical delay map to a display. Various other methods, devices, systems, etc., are also disclosed.

Abstract: Methods and apparatus for treatment, such as skin rejuvenation treatment, using non-uniform laser radiation. An output beam from a laser source is coupled into an optical system that modifies the beam to provide a large-diameter beam having a non-uniform energy profile, comprised of a plurality of high-intensity zones surrounded by lower-intensity zones within the treatment beam. A large area of tissue, preferably 7-10 mm in diameter, can be treated simultaneously, while minimizing the risk of burning or other damage to the skin.

Abstract: An exemplary includes acquiring an electroneurogram of the right carotid sinus nerve or the left carotid sinus nerve, analyzing the electroneurogram for at least one of chemosensory information and barosensory information and calling for one or more therapeutic actions based at least in part on the analyzing. Therapeutic actions may aim to treat conditions such as sleep apnea, an increase in metabolic demand, hypoglycemia, hypertension, renal failure, and congestive heart failure. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: Method and apparatus for modifying gene expression in cardiac muscle cells, by the application of electric fields. In some embodiments, the modification provides treatment of heart failure. Optionally, the treatment also provides an immediate improvement in cardiac function.

Abstract: A medical system comprises a plurality of electrodes; at least one sensor configured to output at least one signal based on at least one physiological parameter of a patient; and a processor. The processor is configured to control delivery of stimulation to the patient using a plurality of electrode configurations. Each of the electrode configurations comprises at least one of the plurality of electrodes. For each of the electrode configurations, the processor is configured to determine a first response of target tissue to the stimulation based on the signals, and a second response of non-target tissue to the stimulation based on the signals. The processor is also configured to select at least one of the electrode configurations for delivery of stimulation to the patient based on the first and second responses for the electrode configurations. As examples, the target tissue may be a left ventricle or vagus nerve.

Abstract: A stimulation system, an implantable electrode device and a method for operating an implantable electrode device are proposed. A simplified implantation, a simple construction and reliable control are made possible by the electrode device being supplied with energy, and controlled, in an exclusively wireless manner via a time-variable magnetic field. The magnetic field is generated by an implanted control device.

Abstract: Systems and methods for pacing the heart using resynchronization pacing delays that achieve improvement of cardiac function are described. An early activation pacing interval is calculated based on an optimal AV delay and an atrial to early ventricular activation interval between an atrial event and early activation of a ventricular depolarization. The early activation pacing interval for the ventricle is calculated by subtracting the measured AVEA from the calculated optimal AV delay. The early activation pacing interval is initiated responsive to sensing early activation of the ventricle and pacing is delivered relative to expiration of the early activation pacing interval.

Abstract: A method of modifying the force of contraction of at least a portion of a heart chamber is provided. A non-excitatory electric field of given duration is applied, at a delay after an activation of the heart, which increase the force of contraction by at least 5%. Apparatus is also provided for pacing with hemodynamic improvement. Circuitry applies an extended pacing signal to electrodes to pace the heart, the extended pacing signal having an overall duration greater than 8 ms from a time of initiation of application of that portion of the signal that initiates action potential propagation. The signal includes a train of biphasic pulses having pulse durations of at least 1 ms, and the signal has an amplitude that is at least three times as great as a threshold for pacing the heart and that is sufficient neither for cardioversion nor for defibrillation. Other embodiments are also described.

Abstract: A method for operating an implantable medical device includes delivering a plurality of pacing pulses to an atria of a patient's heart and monitoring intrinsic atrial activity to detect intrinsic atrial contractions between one or more of the plurality of pacing pulses. The method further includes detecting atrial undersensing as a function of the detection of intrinsic atrial contractions.

Abstract: Systems including an implantable receiver-stimulator and an implantable controller-transmitter are used for leadless electrical stimulation of body tissues. Cardiac pacing and arrhythmia control is accomplished with one or more implantable receiver-stimulators and an external or implantable controller-transmitter. Systems are implanted by testing external or implantable devices at different tissue sites, observing physiologic and device responses, and selecting sites with preferred performance for implanting the systems. In these systems, a controller-transmitter is activated at a remote tissue location to transmit/deliver acoustic energy through the body to a receiver-stimulator at a target tissue location. The receiver-stimulator converts the acoustic energy to electrical energy for electrical stimulation of the body tissue. The tissue locations(s) can be optimized by moving either or both of the controller-transmitter and the receiver-stimulator to determine the best patient and device responses.

Abstract: Described here are devices, systems, and methods for improving left ventricular function in a patient with systolic heart failure with left ventricular dysfunction using baroreflex activation therapy. In general the systems have at least one electrode and a control system in communication with the electrode, the control system including a processor and memory, wherein the memory includes software defining a stimulus regime configured to effect improvement in left ventricular function. The methods for improving left ventricular function in a subject typically include identifying a patient in need of left ventricular function improvement and stimulating a baroreceptor with a baroreceptor activation device to improve left ventricular function.

Abstract: The invention provides a cardiac rhythm management system which includes a tachyarrhythmia detection and classification circuit programmed to detect and classify a tachyarrhythmia, a biologic therapy delivery device configured to deliver or regulate an expression cassette suitable for terminating or preventing atrial fibrillation (AF), and a control circuit coupled to the tachyarrhythmia detection and classification circuit and the biologic therapy delivery device. Also provided is an implantable medical device for use in a body having a cardiovascular system, which includes an implantable device body including at least a cardiovascular portion configured to be in the cardiovascular system, and an expression cassette incorporated into the cardiovascular portion of the implantable device body, the expression cassette selected to express a gene product that terminates or prevents AF. Further provided are methods which employ particular expression cassettes to prevent, inhibit or treat AF.

Abstract: An implantable pacing device for delivering ventricular pacing may be configured to intermittently reduce the AVD interval for beneficial effect in patients with compromised ventricular function (e.g., HF patients and post-MI patients). The AVD interval may be reduced in an AVD reduction mode, by shortening the AVD in an atrial triggered ventricular pacing mode or by switching to a non-atrial triggered ventricular pacing mode (e.g., VVI) and delivering paces at a rate above the intrinsic rate. The physiological effects of AVD reduction may be either positive or negative on cardiac output, depending upon the individual patient.

Abstract: Adaptive rate pacing for improving heart rate kinetics in heart failure patients involves determining onset and sustaining of patient activity. The patient's heart rate response to the sustained activity is evaluated during a time window defined between onset of the activity and a steady-state exercise level. If the patient's heart rate response to the sustained activity is determined to be slow, a pacing therapy is delivered at a rate greater than the patient's intrinsic heart rate based on a profile of the patient's heart rate response to varying workloads. If determined not to be slow, the pacing therapy is withheld. Monitoring-only configurations provide for acquisition and organization of physiological data for heart failure patients. These data can be acquired on a per-patient basis and used to assess the HF status of the patient.

Abstract: A system and method for generating baseline data for automated management of cardiovascular pressure is disclosed. Collected device measures are accumulated to record raw physiometry for a patient, wherein the patient is regularly monitored by an implantable medical device, beginning with an initial observation period. Derived device measures are generated to provide derivative physiometry determined at least in part from the collected device measures. A patient status indicator is determined by analyzing the collected and derived device measures to diagnose a pathophysiology indicative of an absence, onset, progression, regression, and status quo in cardiovascular pressure, wherein the collected and derived device measures and the patient status indicator originating from the initial observation period include baseline data.

Abstract: A method of modifying the force of contraction of at least a portion of a heart chamber, including providing a subject having a heart, comprising at least a portion having an activation, and applying a non-excitatory electric field having a given duration, at a delay after the activation, to the portion, which causes the force of contraction to be increased by a least 5%.

Abstract: An implantable cardiac rhythm management (CRM) device delivers a chronic therapy while detecting an ischemic state. When the ischemic state indicates the occurrence of an ischemic event, the implantable CRM device delivers a post-ischemia therapy. The post-ischemia therapy and the chronic therapy are adjusted using feedback control with the ischemic state and parameters indicative of the effectiveness of the post-ischemic therapy and the effectiveness of the chronic therapy as inputs.

Abstract: An implantable system acquires intracardiac impedance with an implantable lead system. In one implementation, the system generates frequency-rich, low energy, multi-phasic waveforms that provide a net-zero charge and a net-zero voltage. When applied to bodily tissues, current pulses or voltage pulses having the multi-phasic waveform provide increased specificity and sensitivity in probing tissue. The effects of the applied pulses are sensed as a corresponding waveform. The waveforms of the applied and sensed pulses can be integrated to obtain corresponding area values that represent the current and voltage across a spectrum of frequencies. These areas can be compared to obtain a reliable impedance value for the tissue. Frequency response, phase delay, and response to modulated pulse width can also be measured to determine a relative capacitance of the tissue, indicative of infarcted tissue, blood to tissue ratio, degree of edema, and other physiological parameters.

Abstract: A method of modifying the force of contraction of at least a portion of a heart chamber, including providing a subject having a heart, comprising at least a portion having an activation, and applying a non-excitatory electric field having a given duration, at a delay after the activation, to the portion, which causes the force of contraction to be increased by a least 5%.

Abstract: A cardiac medical device and associated method control delivery of dual chamber burst pacing pulses in response to detecting tachycardia. In one embodiment, a single chamber pacing pulse is delivered in response to detecting a tachycardia. Dual chamber pacing pulses are delivered subsequent to the single chamber pacing pulse. An intrinsic depolarization is sensed subsequent to delivering the dual chamber pacing pulses. The tachycardia episode is classified in response to the sensed intrinsic depolarization.

Abstract: A method of modifying the force of contraction of at least a portion of a heart chamber, including providing a subject having a heart, comprising at least a portion having an activation, and applying a non-excitatory electric field having a given duration, at a delay after the activation, to the portion, which causes the force of contraction to be increased by a least 5%.

Abstract: A method of detecting a cardiac event that includes sensing cardiac signals from a plurality of electrodes, determining rates of change of the sensed cardiac signals, and determining a range of the sensed cardiac signals. The sensed cardiac signals are detected as being associated with the cardiac event in response to the determined rates of change and the determined range.

Abstract: An implantable medical system may include an implantable medical lead including at least one electrode and an implantable medical device. The implantable medical device comprises an electromagnetic interference (EMI) detection module that monitors for one or more particular characteristics of EMI. A control module is configured to control a therapy module to generate monophasic stimulation pulses while operating the IMD in a first operating mode. In response to detecting the condition indicative of the presence of EMI, the control module switches the IMD from the first operating mode to a second operating mode and generates at least one multiphasic stimulation pulses while operating the IMD in the second operating mode.

Abstract: A method is disclosed that includes selecting an electrode configuration from a plurality of electrode configurations associated with electrodes of an implantable lead, sensing activity of the right ventricle and the left ventricle, determining an interval between sensed activity of the right ventricle and sensed activity of the left ventricle and determining whether the selected electrode configuration is suitable based at least in part on the interval. In one embodiment, an implantable device performs such a method to improve patient response to the CRT therapy, for example, by selecting a different electrode configuration if the current configuration is not suitable. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: A patient's ejection fraction is maximized through simultaneous sensing and stimulating across multiple electrodes. In one exemplary embodiment, a catheter or lead having multiple electrodes connected to a pulse generator is used. The pulse generator provides individual current control of the stimulus applied to each electrode, and further includes the ability to sense intrinsic and evoked depolarization through multiple electrodes. In another exemplary embodiment, a multiplicity of individual implantable microstimulators, each having its own current source and/or sensor and electrodes, cooperate in concert to provide multi-site stimulation and sensing.

Abstract: An adaptive CRT control system that achieves optimal AV delay and VV pacing intervals associated with temporal patterns of stroke volumes that represent internally the heart conditions is disclosed.

Abstract: Systems and methods are provided for reducing heating within pacing/sensing leads of a pacemaker or implantable cardioverter-defibrillator that occurs due to induced radio frequency (RF) currents during a magnetic resonance imaging (MRI) procedure, or in the presence of other sources of strong RF fields. For example, bipolar coaxial leads are described wherein the ring conductor of the lead is disconnected from the ring electrode via a switch in response to detection of MRI fields to convert the ring conductor into an RF shield for shielding the inner tip conductor of the lead so as to reduce the strength of RF currents induced therein and hence reduce tip heating. Other exemplary leads are described wherein a band stop filter is instead used to block RF signals to likewise convert the ring conductor into an RF shield. The switches and band stop filters also help to prevent MRI-induced stimulation.

Abstract: Various system embodiments comprise a medical device, comprising a flexible tether, a neural stimulation circuit, and a controller. The flexible tether is adapted to be fed into a patient's throat. The flexible tether includes a plurality of electrodes. The neural stimulation circuit is adapted to deliver neural stimulation. The controller is adapted to control the neural stimulation circuit to provide a neural stimulation therapy using at least one electrode from the plurality of electrodes, and to implement a neural stimulation test routine. The neural stimulation test routine is adapted to assess neural stimulation efficacy for electrode subsets of the plurality of electrodes to identify a desired electrode subset for use in delivering the neural stimulation therapy to elicit a desired response.

Abstract: A method of modifying the force of contraction of at least a portion of a heart chamber, including providing a subject having a heart, comprising at least a portion having an activation, and applying a non-excitatory electric field having a given duration, at a delay after the activation, to the portion, which causes the force of contraction to be increased by a least 5%.

Abstract: This document discusses, among other things, systems, devices, and methods measure an impedance and, in response, adjust an atrioventricular (AV) delay or other cardiac resynchronization therapy (CRT) parameter that synchronizes left and right ventricular contractions. A first example uses parameterizes a first ventricular volume against a second ventricular volume during a cardiac cycle, using a loop area to create a synchronization fraction (SF). The CRT parameter is adjusted in closed-loop fashion to increase the SF. A second example measures a septal-freewall phase difference (PD), and adjusts a CRT parameter to decrease the PD. A third example measures a peak-to-peak volume or maximum rate of change in ventricular volume, and adjusts a CRT parameter to increase the peak-to-peak volume or maximum rate of change in the ventricular volume.

Abstract: Augmentation of electrical conduction and contractility by biphasic cardiac pacing. A first stimulation phase is administered to the cardiac blood pool. This first stimulation phase has a predefined polarity, amplitude and duration. A second stimulation phase is then administered to the cardiac blood pool. This second phase also has a predefined polarity, amplitude and duration. The two phases are applied sequentially. Contrary to current thought, anodal stimulation is first applied and followed by cathodal stimulation. In this fashion, pulse conduction through the cardiac muscle is improved together with the increase in contractility.

Abstract: System and methods provide pacing therapy that modulates the atrioventricular (AV) delay to control ventricular interval variability. A base AV delay is determined as a function of heart rate. For each cardiac cycle, the base AV delay is modulated to reduce beat-to-beat variability of successive ventricular beats. The modulated AV delay compensates for variability of successive atrial beats. For example, modulation of the base AV delay may involve varying the AV delay inversely with a change in atrial interval.

Abstract: Various embodiments of the present invention are directed to systems, methods and devices for cardiac applications including those relating to pacing devices. One such device is directed to a cardiac rhythm therapy (CRT) device designed for dual chamber pacing using two pacing signals each having a positive and negative component that has been modified for single chamber pacing. The device comprises a first output that connects to a pacing lead; a second output that connects to the pacing lead; a third output that connects to a reference point; and electrical circuitry connecting the second electrical connection to the first output, the third electrical connection to the second output, and the first and fourth electrical connections to the third output.

Abstract: A method and apparatus are disclosed for treating a condition of a patient's heart includes placing a first electrode and/or a second electrode in a right ventricle of the heart. In one example, a reference electrode is placed within the patient and internal or external to the heart. A pacing signal is generated including a first signal component, a second signal component and a reference component with the first and second signal components having opposite polarity and with both of the first and second components having a potential relative to the reference component. The pacing signal and the placement of the electrodes are selected to alter a contraction of a left ventricle of the heart.

Abstract: A system and a method for estimating changes in cardiac pumping capacity in response to an intervention from data recorded by an accelerometer positioned on an outer surface of the heart. Interventions such as intravenous administration of nitroprusside, betablocker, epinephrine (adrenaline), or changes in the intravascular volume such as by fluid filling, are considered. It is shown that it is possible to directly correlate changes in cardiac pumping capacity to changes in parameters or graphical representation derived from signals characteristic to the acceleration an outer surface of the heart. In particular, it is shown how the effect of the interventions can be directly read from these parameters or graphical representations, and can thereby assist in decisions regarding the treatment of a cardiac surgery patient. The invention is preferably used in a post-surgery monitoring unit for surveillance of cardiac surgery patients.

Abstract: The disclosure includes methods and systems for treating ventricular arrhythmias. Embodiments include an implantable cardiac device or system including a determining module that determines a value of a parameter indicative of a rate of an intrinsic pacemaker of a heart of a patient experiencing fast ventricular arrhythmia (FVA) and a delivery module, programmed to deliver therapy for ventricular arrhythmias to a patient. Some methods include determining a value of a parameter indicative of a rate of an intrinsic pacemaker of a heart of a patient experiencing an FVA; if the value indicates the rate is about equal to or higher than a threshold, delivering a first therapy to the patient for terminating the FVA, and if the value indicates the rate is lower than the threshold, delivering a second therapy, different from the first therapy, to the patient for terminating the FVA.

Abstract: An implanted electrical signal generator delivers a novel exogenous electrical signal to a vagus nerve of a patient. The vagus nerve conducts action potentials originating in the heart and lungs to various structures of the brain, thereby eliciting a vagal evoked potential in those structures. The exogenous electrical signal simulates and/or augments the endogenous afferent activity originating from the heart and/or lungs of the patient, thereby enhancing the vagal evoked potential in the various structures of the brain. The exogenous electrical signal includes a series of electrical pulses organized or patterned into a series of microbursts including 2 to 20 pulses each. No pulses are sent between the microbursts. Each of the microbursts may be synchronized with the QRS wave portion of an ECG. The enhanced vagal evoked potential in the various structures of the brain may be used to treat various medical conditions including epilepsy and depression.

Abstract: Heart rate variability metrics are derived from the intervals between successive heart beats, referred to as BB intervals. A method implementable by an implantable cardiac device for excluding BB intervals due to ectopic beats based on a function of preceding BB intervals is presented. It is desirable to remove such BB intervals from a BB interval time series used to calculate a heart rate variability metric.

Abstract: An implantable monitoring device includes a flexible lead body that includes at least one sensing element. The device also includes a rigid main body connected to the flexible lead body at an attachment point. The rigid main body is generally centered about a longitudinal axis defined by the flexible lead body when the lead body is unflexed. The device further includes a measurement circuit, which is housed within the rigid main body and electrically coupled to the at least one sensing element of the flexible lead body and at least another sensing element on an outside surface of the rigid main body. The measurement circuit is configured to measure a potential difference between the at least one sensing element of the flexible lead body and the at least another sensing element of the main body.

Abstract: Techniques are provided for detecting heart failure or other medical conditions within a patient using an implantable medical device, such as pacemaker or implantable cardioverter/defibrillator, or external system. In one example, physiological signals, such as immittance-based signals, are sensed within the patient along a plurality of different vectors, and the amount of independent informational content among the physiological signals of the different vectors is determined. Heart failure is then detected by the implantable device based on a significant increase in the amount of independent informational content among the physiological signals. In response, therapy may be controlled, diagnostic information stored, and/or warning signals generated. In other examples, at least some of these functions are performed by an external system.

Abstract: For a sampled signal, storing characteristic points generated based on parameters corresponding to curvature of the signal. The characteristic points include a time of occurrence of a lobe in a curvature series based on the signal and a corresponding amplitude of the signal. The characteristic points provide a compressed version of the sampled signal. The signal is reconstructed by establishing a function between a chronological sequence of characteristic points. For a repetitive signal, the stored data includes a code to indicate a time of reoccurrence of a previous cycle or data corresponding to differences between a previous cycle and a current cycle.

Abstract: Systems and methods provide for selection of automatic capture verification modes. A number of capture verification modes are evaluated, wherein at least one of the capture verification modes has a distinct temporal relationship between delivery of a pacing pulse and detection of capture of heart tissue by the pacing pulse than the other capture verification modes. One or more capture verification modes are selected based on the evaluation. Capture verification is implemented using the selected one or more capture verification modes.

Abstract: A system and method for contactless power transfer in implantable devices for charging rechargeable batteries disposed within the implantable devices are provided. The system includes a first coil electrically couplable to a power source, wherein the first coil is configured to produce a magnetic field. The system further includes a second coil electrically coupled to the rechargeable battery disposed within the implantable device and configured to receive power from the first coil via the magnetic field and to transfer the power to the rechargeable battery. The system also includes a field focusing element disposed between the first coil and the second coil and configured as a self resonant coil having a standing wave current distribution to focus the magnetic field onto the second coil and enhance the coupling between the first coil and the second coil.

Abstract: A device for detecting cardiac ischemia is disclosed. The device includes a processor that is configured to distinguish between two different heart beats types such as ventricularly paced beats and supraventricular beats. The processor applies different ischemia tests to the two different beat types, and generates alert when it detects ischemia.

Abstract: An implantable medical device, IMD, (100) is connectable to at least one ventricular lead (210) having a ventricular basal electrode (214) and a ventricular apical electrode (212). The IMD (100) comprises a pulse generator (120) for generating pacing pulses applied to a heart (10) through the ventricular lead (210). The operation of this pulse generator (120) is controlled by a controller (130) that is configured to control the pulse generator to first deliver a pacing pulse to the ventricular basal electrode (214) to stimulate the basal portion of the ventricle (12, 14) before a pacing pulse is delivered to the apical portion of the ventricle (12, 14) by the ventricular apical electrode (212). This pulse sequence achieves a biologically more correct cardiac stimulation and a contraction pattern that reduces the risk for valvular regurgitation.

Abstract: A method and medical device for delivering an atrial pacing pulse to an atrial chamber to generate an evoked atrial depolarization, delivering a stimulation pulse to an atrioventricular node during a stimulation window to increase a PR interval of the heart, the stimulation window having a start time corresponding to the delivered atrial pacing pulse so that the stimulation pulse is delivered during a refractory period corresponding to the evoked atrial depolarization, and delivering a ventricular pacing pulse to a first ventricular chamber during the increased PR interval to cause a contraction of the first ventricular chamber to occur prior to a contraction of a second ventricular chamber to increase dyssynchrony between the contraction of the first ventricular chamber and the contraction of the second ventricular chamber.