Abstract: A system and method for managing preload reserve and tracking the inotropic state of a patient's heart. The S1 heart sound is measured as a proxy for direct measurement of stroke volume. The S3 heart sound may be measured as a proxy for direct measurement of preload level. The S1-S3 pair yield a point on a Frank Starling type of curve, and reveal information regarding the patient's ventricular operating point and inotropic state. As an alternative, or in addition to, measurement of the S3 heart sound, the S4 heart sound may be measured or a direct pressure measurement may be made for the sake of determining the patient's preload level. The aforementioned measurements may be made by a cardiac rhythm management device, such as a pacemaker or implantable defibrillator.

Abstract: Atrial capture threshold testing is performed in accordance with an atrial capture threshold testing schedule. Monitoring for retrograde P-waves occurs at least during times other than times during which scheduled atrial capture threshold testing is performed. In response to detecting a retrograde P-wave indicative of sub-threshold atrial pacing during monitoring, an unscheduled atrial capture threshold test is performed and pacing of the atrium is adjusted based on the unscheduled atrial capture threshold test.

Abstract: An embodiment of a baroreflex stimulator comprises a pulse generator to provide a baroreflex stimulation signal through an electrode, and a modulator to modulate the baroreflex stimulation signal based on a circadian rhythm template. According to an embodiment of a method for operating an implantable medical device, comprising a baroreflex stimulation therapy is applied at a stimulation intensity using a baroreflex stimulator in the implantable medical device, and the baroreflex stimulation therapy is modulated based on a circadian rhythm template stored within the implantable medical device. Modulating the baroreflex stimulation therapy includes using the circadian rhythm template to change the stimulation intensity to mimic natural blood pressure fluctuations during the day.

Abstract: In a medical implantable device having a hermetically sealed, radio shielded encapsulations containing an RF circuit therein and having an antenna located outside of the encapsulation, and in a method for connecting the RF circuit to the antenna, at least one hermetical feedthrough connection is provided in the form of at least one conductor passing through a wall portion of the encapsulation in a liquid-tight and gas-tight manner, with the feedthrough being electrically insulated from the encapsulation. At least one connector pin is provided on an RF circuit board, which is resiliently mounted on the RF circuit board. The RF circuit is mounted in the encapsulation so as to cause the connector pin to resiliently engage the conductor and to electrically connect the conductor with the RF circuit board.

Abstract: Cardiac monitoring and/or stimulation methods and systems that provide one or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac signal separation is employed for automatic capture verification using cardiac activation sequence information. Devices and methods sense composite cardiac signals using implantable electrodes. A source separation is performed using the composite signals. One or more signal vectors are produced that are associated with all or a portion of one or more cardiac activation sequences based on the source separation. A cardiac response to the pacing pulses is classified using characteristics associated with cardiac signal vectors and the signals associated with the vectors. Further embodiments may involve classifying the cardiac response as capture or non-capture, fusion or intrinsic cardiac activity. The characteristics may include an angle or an angle change of the cardiac signal vectors, such as a predetermined range of angles of the one or more cardiac signal vectors.

Abstract: A therapeutic device and therapeutic method for delivering electrical energy or a medicament to a body tissue or organ utilizing ultrasonic vibration to cause a device implanted in the body tissue or organ to be treated to discharge an electrical current or medicament to the target area.

Abstract: A medical device measures an impedance associated with one or more electrodes, e.g., the impedance presented to the medical device by a total electrical circuit that includes the one or more electrodes, the conductors associated with the electrodes, and tissue proximate to the electrodes. The medical device stores at least one patient-specific relationship between impedance and a stimulation parameter, and adjusts the value of the stimulation parameter based on the measured impedance according to the relationship. The medical device may store multiple relationships, and select one the relationships based on, for example, an activity level of the patient, posture of the patient, or a current stimulation program or electrode combination used to deliver stimulation. By adjusting a stimulation parameter, such as amplitude, according to such a relationship, the stimulation intensity as perceived by the patient may be kept substantially constant.

Abstract: A method that electrically stimulates a heart muscle to alter the ejection profile of the heart, to control the mechanical function of the heart and reduce the observed blood pressure of the patient. The therapy may be invoked by an implantable blood pressure sensor associated with a pacemaker like device. In some cases, where a measured pretreatment blood pressure exceeds a treatment threshold, a patient's heart may be stimulated with an electrical stimulus timed relative to the patient's cardiac ejection cycle. This is done to cause dyssynchrony between at least two cardiac chambers, which alters the patient's cardiac ejection profile from a pretreatment cardiac ejection profile. This has the effect of reducing the patient's blood pressure from the measured pretreatment blood pressure.

Abstract: The disclosed method analyzes cardiac electrophysiological signals, including ECG and internal cardiac electrograms, based on multi-level symbolic complexity calculation and multi-dimensional mapping. The results may be used to objectively identify cardiac disorders, differentiate cardiac arrhythmias, characterize pathological severities, and predict life-threatening events. Multi-level symbolization and calculation of the electrophysiological signal is used provide better reliability and analysis resolution for identifying and characterizing cardiac disorders. Adaptive analysis of the cardiac signal complexity enables calculation efficiency and reliability with high SNR, and with low calculation volume and power consumption. One dimension (time or frequency domain) and multi-dimension symbolic analysis is used to provide more information of cardiac pathology and high risk rhythm transition to doctors.

Abstract: A physiological power source is coupled to a signal coupler/decoupler through a conductive line. The signal coupler/decoupler includes a proximal signal port, connected to the physiological power source through the first conductive line, and separate distal signal ports. The signal coupler/decoupler combines signals flowing to the physiological power source through the distal signal ports and separates a signal flowing away from it through the proximal signal port.

Abstract: A method of transitioning stimulation energy (e.g., electrical stimulation pulses) between a plurality of electrodes implanted within a patient is provided. The method comprises selecting a plurality of stimulation output values (e.g., electrical current amplitude values) for each of the electrodes. The method further comprises selecting a plurality of different modification values for at least one of the electrodes, respectively multiplying the stimulation output values and the modification values to determine modified stimulation output values for the electrode(s), which may optionally be stored in a steering table, and incrementally transitioning the stimulation energy to or from the electrode(s) in accordance with the modified stimulation output values. The modified stimulation output values are stored in a steering table. The modification values may be selected in a manner that maintains paresthesia when transitioning the stimulation energy between the electrodes.

Abstract: Method and apparatus that uses dual-chamber (RA-RV), three-chamber (BiA-RV, or RA-BiV), or four-chamber (BiA-BiV) implantable cardiac devices including pacemakers, defibrillators and cardioverters, which stimulate cardiac tissue electrically to control the patient's heart rhythm. The method and apparatus are further configured to create a far-field intra-atrial electrogram (AEGM) and a far-field intra-ventricular electrogram (VEGM) that are independently filtered, scaled, and then summed to form a composite far-field electrogram.

Abstract: A wireless cardiogram signal diagnostic instrument includes a band, a signal transmitting device, two sets of connecting pieces, and a conductive assembly. The band has two opposite mounting portions separated by a distance. The two mounting portions are provided with the conductive assembly having a first conductive piece and a second conductive piece. The signal transmitting device is provided with a third conductive piece. The two sets of connecting pieces each have a first connecting piece that is conductive provided on the mounting portion of the band and a second connecting piece that is conductive provided on the signal transmitting device. The first connecting piece is correspondingly assembled with the second connecting piece, so that the signal transmitting device can be detachably assembled on the band. Via the above arrangement, the instrument can be worn on a user's chest to collect and measure the variation values of cardiogram voltages.

Abstract: A method and apparatus for prevention and treatment of nausea and vomiting by the simultaneous electrical stimulation of the pericardium meridian six point and pericardium meridian seven point on the ventral side of the wrist of a patient. The meridian stimulator comprises a wrist-band like housing that is worn on the ventral side of the human wrist and contains a circuitry means included within the said housing and electrically coupled to the electrodes. A negative electrode is positioned on the pericardium meridian six point and a positive electrode is placed on the pericardium meridian seven point and a low amperage current is passed through these points via electrodes positioned at these points. A liquid crystal display unit reads the current supplied to the electrodes and indicates via an indicator light when current is being supplied to the meridian stimulator and further comprises a touch screen for a power on and off button and for increasing the rate of electrical stimulations.

Abstract: A neural stimulation system controls the delivery of neural stimulation using a respiratory signal as a therapy feedback input. The respiratory signal is used to increase the effectiveness of the neural stimulation, such as vagal nerve stimulation, while decreasing potentially adverse side effects in respiratory functions. In one embodiment, the neural stimulation system detects apnea and, in response, adjusts the delivery of the neural stimulation pulses and/or delivers a respiratory therapy treating the detected apnea.

Abstract: Device data is generated at each medical device in a system including a plurality of medical devices. Priority information is dynamically assigned to the device data at each medical device based on the character of the device data. The device data and the priority information are transmitted from each medical device. Interfering communications of device data and priority information from multiple medical devices are processed successively based on the priority information.

Abstract: A cardiac rhythm management device predicts defibrillation thresholds without any need to apply defibrillation shocks or subjecting the patient to fibrillation. Intravascular defibrillation electrodes are implanted in a heart. By applying a small test energy, an electric field near one of the defibrillation electrodes is determined by measuring a voltage at a sensing electrode offset from the defibrillation electrode by a known distance. A desired minimum value of electric field at the heart periphery is established. A distance between a defibrillation electrodes and the heart periphery is measured, either fluoroscopically or by measuring a voltage at an electrode at or near the heart periphery. Using the measured electric field and the measured distance to the periphery of the heart, the defibrillation energy needed to obtain the desired electric field at the heart periphery is estimated. In an example, the device also includes a defibrillation shock circuit and a stimulation circuit.

Abstract: A system evaluates the performance of an implantable medical device, such as by using a remote external server and a user interface and stored historical physiological data of a population of congestive heart failure (CHF) patients. A processor is coupled to a patient data storage device to apply multiple algorithm variations against the same implantable physiological data from the patient to produce corresponding resulting CHF indicators. The user interface includes a display that is configured to display to a user information allowing comparison between the resulting CHF indicators from the multiple algorithm variations. The display also includes a population data selector to permit the user to select physiological data from a population that includes a different set of one or more patients or physiological data collected over a period of time from the patient. This permits optimization of an algorithm parameter or selection of a best performing algorithm.

Abstract: Systems and methods are provided for estimating a patient's ventricular defibrillation threshold (VDFT). Stimulation pulses, which are of at least three different energy levels up to 2 Joules, are delivered to the patient's right ventricle during a window defined between an R-wave and a vulnerable period that follows the R-wave. Voltage potentials, induced in response to the delivered RV stimulation pulses, are measured at a location of the patient's left ventricle (LV) where it is predicted that potential gradients induced in response to RV stimulation pulses will be lowest. Potential gradients are computed using the measured voltage potentials. The patient's VDFT can then be estimated by estimating, based on the computed potential gradients, the RV stimulation energy level that would be required to achieve a minimum acceptable potential gradient at the location of the patient's LV where it is predicted that potential gradients induced in response to RV stimulation pulses will be lowest.

Abstract: A method and system for verifying capture in the heart involves the use of pacing artifact templates. One or more pacing artifact templates characterizing a post pace artifact signal associated with a particular pace voltage or range of voltages are provided. A pacing artifact template is canceled from a cardiac signal sensed following a pacing pulse. Capture is detected by comparing the pacing artifact canceled cardiac signal to an evoked response reference. Fusion/pseudofusion detection involves determining a correlation between a captured response template and a sensed cardiac signal.