Abstract: A differential or relative measurement between an orthogonal measurement vector and another measurement vector can be used to determine the location where fluid accumulation is occurring or the local change in such fluid accumulation. This can help diagnose or treat infection or hematoma or seroma at a pocket of an implanted cardiac rhythm management device, other implanted medical device, or prosthesis. It can also help diagnose or treat pulmonary edema, pneumonia, pulmonary congestion, pericardial effusion, pericarditis, pleural effusion, hemodilution, or another physiological condition.

Abstract: Devices and methods for sleep detection involve the use of an adjustable threshold for detecting sleep onset and termination. A method for detecting sleep includes adjusting a sleep threshold associated with a first sleep-related signal using a second sleep-related signal. The first sleep-related signal is compared to the adjusted threshold and sleep is detected based on the comparison. The sleep-related signals may be derived from implantable or external sensors. Additional sleep-related signals may be used to confirm the sleep condition. A sleep detector device implementing a sleep detection method may be a component of an implantable pulse generator such as a pacemaker or defibrillator.

Abstract: A respiration pattern of a number of respiration cycles is detected and breath intervals (BI) and tidal volume (TVOL) measurements of each of the respiration cycles are respectively determined. An unevenly sampled instantaneous minute ventilation (iMV) signal is produced using the BI and TVOL measurements, and an evenly sampled iMV signal (resampled iMV signal) is produced using the unevenly sampled iMV signal. Disordered breathing is detected based on a comparison between a baseline threshold and the resampled iMV signal.

Abstract: Cardioprotective pre-excitation pacing may be applied to stress or de-stress a particular myocardial region delivering of pacing pulses in a manner that causes a dyssynchronous contraction. Such dyssynchronous contractions are responsible for the desired cardioprotective effects of pre-excitation pacing. A method and device for applying reverse hysteresis and mode switching to the delivery of such cardioprotective pacing are described.

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 synchronizes the delivery of the neural stimulation pulses to the respiratory cycles using a respiratory fiducial point in the respiratory signal and a delay interval. In another embodiment, the neural stimulation system detects a respiratory disorder and, in response, adjusts the delivery of the neural stimulation pulses and/or delivers a respiratory therapy treating the detected respiratory disorder.

Abstract: A sleep quality assessment approach involves collecting data based on detected physiological or non-physiological patient conditions. At least one of detecting patient conditions and collecting data is performed using an implantable device. Sleep quality may be evaluated using the collected data by an implantable or patient-external sleep quality processor. One approach to sleep quality evaluation involves computing one or more summary metrics based on occurrences of movement disorders or breathing disorders during sleep.

Abstract: An inspiratory muscle stimulation system uses an implantable medical device to deliver stimulation to control diaphragmatic contractions for slower and deeper breathing, thereby conditioning and strengthening inspiratory muscles. In various embodiments, respiratory and/or cardiac performance are monitored for controlling parameters of the stimulation.

Abstract: A differential or relative measurement between an orthogonal measurement vector and another measurement vector can be used to determine the location where fluid accumulation is occurring or the local change in such fluid accumulation. This can help diagnose or treat infection or hematoma or seroma at a pocket of an implanted cardiac rhythm management device, other implanted medical device, or prosthesis. It can also help diagnose or treat pulmonary edema, pneumonia, pulmonary congestion, pericardial effusion, pericarditis, pleural effusion, hemodilution, or another physiological condition.

Abstract: A system and method for treating and/or preventing is described for treating periodic breathing characterized by cyclical hyperventilation and hypoventilation, examples of which include Cheyne-Stokes respiration and central sleep apnea. The system could also be used in the treatment of other conditions involving an impairment of respiratory drive.

Abstract: The health state of a subject is automatically evaluated or predicted using at least one implantable device. In varying examples, the health state is determined by sensing or receiving information about at least one physiological process having a circadian rhythm whose presence, absence, or baseline change is associated with impending disease, and comparing such rhythm to baseline circadian rhythm prediction criteria. Other chronobiological rhythms beside circadian may also be used. The baseline prediction criteria may be derived using one or more past physiological process observation of the subject or population of subjects in a non-disease health state. The prediction processing may be performed by the at least one implantable device or by an external device in communication with the implantable device. Systems and methods for invoking a therapy in response to the health state, such as to prevent or minimize the consequences of predicted impending heart failure, are also discussed.

Abstract: A system and method for determining pulmonary performance from transthoracic impedance measures is provided. Transthoracic impedance measures collected by an implantable medical device are correlated to pulmonary functional measures. The pulmonary functional measures are grouped by respiratory pattern. Pulmonary performance is evaluated. Differences are determined by comparing the pulmonary functional measures for each respiratory pattern to the pulmonary functional measures for at least one previous respiratory pattern. A trend is identified from the differences. An alert is generated upon sufficient deviation of the trend from a threshold criteria.

Abstract: An evaluation of heart failure status is provided based on a disordered breathing index. Patient respiration is sensed and a respiration signal is generated. Disordered breathing episodes are detected based on the respiration signal. A disordered breathing index is determined based on the disordered breathing episodes. The disordered breathing index is trended and used to evaluate heart failure status. The disordered breathing index may be combined with additional information and/or may take into account patient activity, posture, sleep stage, or other patient information.

Abstract: Vector selection is automatically achieved via a thoracic or intracardiac impedance signal collected in 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 method, device, and system are provided for accessing metadata in a data storage system. More specifically, a requesting application requests a cache application to allocate a cache page to retrieve metadata from a storage device. After metadata is written to the cache page, the cache page is locked by the requesting application. The cache page is maintained in a locked state by the requesting application. This allows the data stored within the cache page to be quickly accessed and updated by the requesting application without waiting for the cache page to be written back to the storage device after every update to the cache page occurs.

Abstract: Various approaches to detecting arousals from sleep involve generating signals modulated by muscle tone, brainwave activity, and/or other nervous system activity associated with a patient's autonomic arousal response. Generating the signals and/or detecting autonomic arousals from sleep may be performed using an implantable device. Arousal information may be useful to identify sleep disorder events associated with arousals from sleep, for diagnostic purposes, and/or for therapy adjustment.

Abstract: An evaluation of heart failure status is provided based on a disordered breathing index. Patient respiration is sensed and a respiration signal is generated. Disordered breathing episodes are detected based on the respiration signal. A disordered breathing index is determined based on the disordered breathing episodes. The disordered breathing index is trended and used to evaluate heart failure status. The disordered breathing index may be combined with additional information and/or may take into account patient activity, posture, sleep stage, or other patient information.

Abstract: The present disclosure describes methods, devices, and systems for generating, adjusting, and using cardiac waveform morphology templates. The morphology templates include target regions associated with features of cardiac waveforms. The target regions may be adjusted based on relationships between the target regions and features of detected cardiac waveforms associated with the target regions. The templates may be used to analyze cardiac waveforms to classify or monitor various waveform morphologies. Templates may be created or eliminated, for instance, based on a frequency of use. According to one approach, template creation involves providing target regions defined by one or more characteristics. The target regions are adjusted based on detected cardiac waveform features having similar characteristics. A template may be created using the target regions adjusted by this process.

Abstract: Methods and systems for evaluating a pathological condition include acquiring movement information, such as electromyogram (EMG) information, and sleep disordered breathing (SDB) information, and detecting the presence of a pathological condition using both movement and SDB information. Methods may involve sensing physiological signals including at least muscle movement signals. Sleep-related disorders are detected using the sensed physiological signals, the sleep-related disorders including at least an involuntary muscle movement disorder and sleep-disordered breathing. Methods and systems also provide for detecting and treating a sleep-related disorder using movement and SDB information. Cardiac, respiratory, nerve stimulation, drug, or a combination of such therapies may be delivered to treat a detected or diagnosed pathological condition.

Abstract: Methods and systems involve adjusting cardiac pacing based on information acquired via a respiratory therapy device. A medical system includes a respiratory therapy device having one or more sensors and a therapy delivery unit. The one or more sensors are configured to sense respiration cycles. The therapy delivery unit is configured to deliver an external respiratory therapy to the patient. The medical system also includes a pulse generator configured to deliver cardiac pacing pulses to the patient. A controller is coupled to the one or more sensors and the pulse generator. The control unit configured to adjust a cardiac pacing rate based on the patient's respiration cycles.

Abstract: A method and device for cloning snapshots is provided. A new snapshot can be created by cloning an existing snapshot. The clone snapshot may use the preserved data of the existing snapshot, thereby obviating the need to copy the preserved data. Additionally, the clone snapshot may be created with a data structure for storing write data. Since the clone snapshot initially has no write data to store, the creation of the entire clone snapshot can be accomplished without copying any preserved data or write data from the existing snapshot, thereby increasing the efficiency with which a clone snapshot can be created.