Abstract: Cardiac monitoring and/or stimulation methods and systems provide monitoring, defibrillation and/or pacing therapies. A signal processor receives a plurality of composite signals associated with a plurality of sources, separates a signal using a source separation algorithm, and identifies a cardiac signal using a selected vector. The signal processor may iteratively separate signals from the plurality of composite signals until the cardiac signal is identified. The selected vector may be updated if desired or necessary. A method of signal separation involves detecting a plurality of composite signals at a plurality of locations, separating a signal using source separation, and selecting a vector that provides a cardiac signal. The separation may include a principal component analysis and/or an independent component analysis.

Abstract: An exemplary implantable stimulator includes at least one electrode contact array and at least one additional electrode contact. Both the electrode contact array and the additional electrode contact are disposed on an external surface of the stimulator. The electrode contact array includes multiple electrode contacts that are configured to have a first polarity. The additional electrode is configured to have a second polarity. One or more of the electrode contacts disposed on the stimulator are configured to deliver monopolar stimulation and/or multipolar stimulation. Exemplary methods of stimulating a stimulation site within a patient include providing at least one electrode contact array and at least one additional electrode contact. Both the electrode contact array and the additional electrode contact are disposed on an external surface of the stimulator. The electrode contact array includes multiple electrode contacts that are configured to have a first polarity.

Abstract: Methods and apparatus for detection and treatment of respiratory disorders using implanted devices are described. In one form, afferent nerves are electrically or electro-mechanically stimulated to increase the tone of upper airway muscles. Detection of respiratory disorders is carried out using electrodes implanted in sub-pectoral regions. Open and closed airway apneas are distinguished using a combination of acoustic detectors and electrical transducers.

Abstract: An automatic external defibrillator electrode package includes a coded conductive label that uniquely identifies the type of automatic electrode contained therein. Pins on the defibrillator body make electrical contact with the conductive label when the package is attached to the defibrillator. These pins sense the shape of the conductive label to ascertain the electrode type, thereby enabling the AED to automatically set the proper operating mode.

Abstract: A medical device for implantation within a patient comprising a lead body including a conductor within the lead body and a transducer supported by the lead body. The conductor is electrically coupled to the transducer by a conductive fluid, paste or gel. The conductive fluid, paste or gel may be contained within a well in the lead body. The transducer may be a MEMS chip and/or an integrated circuit and may perform any of a variety of functions such as sensing physiological data.

Abstract: One or more sensors sense patient heart rate and patient activity and provide related signals to a processor. The processor is responsive to sensor signals and obtains an activity threshold based on historical patient heart-rate signals and historical patient activity signals. The processor periodically derives a correlation value from current patient heart-rate signals and current patient activity signals and compares the correlation values to the activity threshold. A start of activity is noted when a correlation value exceeds the activity threshold; while an end of activity is noted when a correlation value fails to exceed the activity threshold. Activity is identified as exercise when correlation values continue to exceed the activity threshold for a predetermine amount of time, while an end of exercise is noted when correlation values fall below the activity threshold for a predetermined amount of time.

Abstract: A fixation device for holding stimulating electrodes in electrical contact with the wall of a portion of the gastrointestinal tract is provided. The fixation device includes an expandable member that fixes the electrodes in electrical contact with the gastrointestinal tract wall.

Abstract: A miniature wireless apparatus for collecting physiological signals comprises an electrode pair, an amplifier module, a microcontroller, a wireless module, and a battery. The electrode pair collects a pair of physiological signals of a person under test. The amplifier module amplifies the pair of physiological signals. The microcontroller performs an analog-to-digital conversion and a data compression for an amplified physiological signal generated by the amplifier module. The wireless module modulates a digital physiological signal generated by the microcontroller and transmitting the modulated digital physiological signal to a receiver at the far end. The apparatus can be implemented by a structure of multilayered circuit boards. With the progress of semiconductor technology, all the components of the miniature wireless apparatus can be further integrated to one circuit board, or even one chip.

Abstract: An implantable medical device (IMD) includes a telemetry module to communicate with an external device according to a given protocol. To establish a communication session, the IMD will extend active periods of reception on a given channel when some confirmed data is received from the external device. In addition, once a session has been opened, the programmer transmits a short data set (or preamble) for each cycle which the IMD is set to receive. This data set indicates whether additional data will or will not be sent. If no additional data is to be sent during that cycle, then the IMD powers down the receiver for that cycle.

Abstract: A device, such as an implantable cardiac device, and methods for determining exercise diagnostic parameters of a patient are disclosed. Specifically, a maximum observed heart rate of a patient during exercise can be identified when an activity level and a heart rate measurement of the patient exceed predetermined thresholds. Included are methods for filtering out premature heartbeats or noise from the maximum heart rate determination. Methods of determining other exercise parameters, such as workload are also disclosed. The device includes hardware and/or software for performing the described methods.

Abstract: Displacement or migration of a left ventricular lead located within the coronary sinus or coronary veins of the heart is detected by comparing an electrogram (EGM) waveform pattern from the lead with a stored baseline EGM waveform pattern. Based upon the extent of lead migration, if any, a lead displacement may produce an annunciating response. The patient may be alerted, an electrical stimulus applied through the lead may be adjusted to compensate for lead migration, or an alternative electrode on the lead may be used for EGM sensing and pacing.

Abstract: A system to monitor heart sounds. The system comprises an implantable heart sound sensor operable to produce an electrical signal representative of at least one heart sound, a heart sound sensor interface circuit coupled to the heart sound sensor to produce a heart sound signal, an implantable posture sensor operable to produce an electrical signal representative of a patient's posture, and a controller circuit, coupled to the heart sound sensor interface circuit and the posture circuit. The controller circuit is operable to measure at least one heart sound in correspondence with at least one sensed patient posture.

Abstract: A method and apparatus for detecting atrial arrhythmias include acquiring a cardiac signal comprising R-waves. Differences between pairs of consecutive R-R intervals occurring during a first time interval are computed from the cardiac signal. An atrial arrhythmia is detected subsequent to the first time interval in response to the computed differences. Storage of the cardiac signal is triggered in response to the atrial arrhythmia detection.

Abstract: Techniques are provided for delivering cardiac pacing therapy to the heart of a patient using an epicardial left ventricular satellite pacing device in conjunction with primary pacemaker having at least a right ventricular pacing lead. In one embodiment described herein, right ventricular pulses generated by the primary pacemaker are detected by the satellite pacer and analyzed to determine the timing pattern employed by the primary pacemaker. The timing pattern is then used to specify the delivery times of epicardial left ventricular pulses so as to be synchronized with right ventricular pulses. In another embodiment described herein, the primary pacemaker modulates the right ventricular pulses to encode timing information, which is then detected and decoded by the satellite pacemaker. In this manner, biventricular pacing therapy, such as cardiac resynchronization therapy, may be conveniently delivered using a non-biventricular pacemaker in combination with an epicardial satellite pacer.

Abstract: This document discusses, among other things, a cardiac function management device or other implantable medical device that includes a test mode and a diagnostic mode. During a test mode, the device cycles through various electrode configurations for collecting thoracic impedance data. At least one figure of merit is calculated from the impedance data for each such electrode configuration. In one example, only non-arrhythmic beats are used for computing the figure of merit. A particular electrode configuration is automatically selected using the figure of merit. During a diagnostic mode, the device collects impedance data using the selected electrode configuration. In one example, the figure of merit includes a ratio of a cardiac stroke amplitude and a respiration amplitude. Other examples of the figure of merit are also described.

Abstract: A grooved electrode adapted for interfacing cellular matter is provided. The grooved electrode includes grooves adapted for electrically interfacing the grooved electrode with cellular matter growing along the body of the grooved electrode. Further, the grooved electrode includes a wireless transponder adapted to electrically interface with cellular matter and to relay such interactions via RF signals. The RF signals received by the wireless transponder are modulated in response to electrical signals generated by the cellular matter, which are detected by the transponder. The grooved electrode may be implanted within peripheral nerves for treating various neurological conditions, which may include nerve rehabilitation and prosthetic actuation, severe pain, obstructive sleep apnea and so forth.

Abstract: Methods for performing cardiac signal analysis in an implanted medical device, and devices configured to perform illustrative methods of cardiac signal analysis. A cardiac signal is captured by an implanted device using implanted electrodes and, during at least certain conditions, the cardiac signal undergoes heuristic filtering. In some embodiments, heuristic filtering is achieved by modifying a signal or value that is used as an indicator of received signal amplitude. In an illustrative example, the heuristic filtering includes periodically incrementing or decrementing the signal or value toward a desired quiescent point, where the heuristic filter period is significantly longer than the sampling period for the signal itself. In another illustrative example, the heuristic filter frequency can be adjusted dynamically to keep the signal average near the desired quiescent point.

Abstract: Methods and devices for sensing vector analysis in an implantable cardiac stimulus system. In an illustrative example, a first sensing vector is analyzed to determine whether it is suitable, within given threshold conditions, for use in cardiac event detection and analysis. If so, the first vector may be selected for detection and analysis. Otherwise, one or more additional vectors are analyzed. A detailed example illustrates methods for analyzing sensing vectors by the use of a scoring system. Devices adapted to perform these methods are also discussed, including implantable medical devices adapted to perform these methods, and systems comprising implantable medical devices and programmers adapted to communicate with implantable medical devices, the systems also being adapted to perform these methods. Another example includes a programmer configured to perform these methods including certain steps of directing operation of an associated implanted or implantable medical device.

Abstract: A system is described for detecting and/or treating depression that may be incorporated into an implantable device such as a cardiac rhythm management device. The device may determine that depression is present by analysis of heart rate variability measured using the cardiac sensing channels of the device and/or by detection of blood-borne factors that are associated with depression. If depression is detected, the device may be configured to automatically delivery therapy such as neuromodulation and/or drug delivery.

Abstract: Methods for treating a network of organs including generating a map of at least a portion of the network of organs using a rendering system; selecting at least one treatment location within the luminal passageway of the network of organs; and applying an energy therapy to the treatment location to treat the smooth muscle tissue, where the energy therapy applied to the respective treatment location is defined by a plurality of parameters that are associated with a map. Such a system allows for historical or ideal treatment parameters to be identified, visually or otherwise to actual treatment locations. Also, control systems and methods for delivery of energy that may include control algorithms that prevent energy delivery if a fault is detected and may provide energy delivery to produce a substantially constant temperature at a delivery site. In some embodiments, the control systems and methods may be used to control the delivery of energy, such as radiofrequency energy, to body tissue, such as lung tissue.