Abstract: An exemplary implantable microarray device includes an inlet for a body fluid, a plurality of individual reaction cell arrays where each reaction cell array includes a series of reaction cells configured to receive the body fluid, a sensor array to sense a reaction result for an individual reaction cell array where the reaction result corresponds to a reaction between the body fluid and at least one reagent in each of the reaction cells of the individual reaction cell array and a positioning mechanism to position an individual reaction cell array with respect to the sensor array. Various other exemplary technologies are also disclosed.

Abstract: An exemplary method includes acquiring cardiac electrical activity information; detecting cardiac events within the information including T waves, QRS complexes and/or P waves; and calling for delivery of matter to the heart during a period of time based on the cardiac events. The delivery may occur between a detected T wave and its immediately subsequent QRS complex. The matter being delivered may include stem cells, progenitor cells, nutrients and/or drugs.

Abstract: A medical device is provided that comprises a lead assembly. The lead assembly includes at least one intra-cardiac (IC) electrode, an extra-cardiac (EC) electrode and a subcutaneous remote-cardiac (RC) electrode. The IC electrode is configured to be located within the heart. The EC electrode is configured to be positioned proximate to at least one of a superior vena cava (SVC) and a left ventricle (LV) of a heart. The RC electrode is configured to be located remote from the heart. An arrhythmia monitoring module is configured to analyze intra-cardiac electrogram (IEGM) signals from the at least one IC electrode to identify a potential atrial arrhythmia. An extra-cardiac impedance (ECI) module is configured to measure extra-cardiac impedance along an ECI vector between the EC and RC electrodes to obtain ECI measurements. The hemodynamic performance (HDP) assessment module is configured to determine a hemodynamic performance based on the ECI measurements.

Abstract: A system and method are provided for monitoring ischemic development. The system and method identify a non-physiologic event and obtain cardiac signals along multiple sensing vectors, wherein at least a portion of the sensing vectors extend to or from electrodes located proximate to the left ventricle. The system and method monitor a segment of interest in the cardiac signals obtained along the multiple sensing vectors to identify deviations in the segment of interest from a baseline. The system and method record at least one of timing or segment shift information associated with the deviations in the segments of interest; and identify at least one of size, direction of development or rate of progression of an ischemia region based on the at least one of timing or segment shift information.

Abstract: A method of filtering respiration noise from a localization signal includes acquiring a localization signal from at least one position measurement sensor within a localization field and acquiring an acceleration signal for at least one localization field generator (e.g., a patch electrode). A displacement signal for the field generator is calculated, for example by integrating the acceleration signal twice, and transformed into the frequency domain in order to calculate a fractional power indicative of patient respiration. The fractional power can then be compared to a threshold value, and the localization signal can be filtered if the fractional power exceeds the threshold value. Alternatively, the acquired acceleration signal can be used to gate collection of data points from the localization signal.

Abstract: Techniques are provided for the self-calibration of an implantable blood oxygen saturation sensor. In one example, the pacemaker tracks respiration rate, patient activity level and the degree of pulmonary edema with the patient. The pacemaker identifies periods of time when three conditions are met: the respiration rate is normal, activity is minimal and the degree of pulmonary edema is also minimal. The pacemaker then calibrates the oxygen saturation sensor based on sensor output values detected only when all three conditions are met. By calibrating the sensor only during periods of time when all three conditions are all met, the calibration logic can thereby assume that actual saturation levels within the patient are at a maximum and that any deviation from that maximum is due to changes in blood cell fixation, tissue overgrowth, or other factors unrelated to actual oxygen saturation levels.

Abstract: Techniques are provided for monitoring thoracic fluid levels based on thoracic impedance (ZT) and cardiogenic impedance (ZC). In one example, the implantable device tracks the maximum time rate of change in cardiogenic impedance (i.e. max(dZC/dt)) to detect trends toward hypervolemic or hypovolemic states within the patient based on changes in heart contractility. The detection of these trends in combination with trends in thoracic impedance allows for a determination of whether the thoracic cavity of the patient is generally “too wet” or “too dry,” and thus allows for the titration of diuretics to avoid such extremes. In particular, a decrease in thoracic impedance (ZT) in combination with a decrease in max (dZC/dt) is indicative of the thorax being “too wet” (i.e. a fluid overload). Conversely, an increase in thoracic impedance (ZT) in combination with a decrease in max (dZC/dt) is indicative of the thorax being “too dry” (i.e. a fluid underload).

Abstract: Left atrial pressure and temperature of a patient are monitored to identify a normal wake state, a normal sleep state, and any deviation from those normal states (e.g., an alarm state). In the event an alarm state is identified, a determination is made as to whether to generate an indication of heart failure exacerbation based on a heart failure score. In addition, congestion and perfusion in a patient may be monitored over time to provide a two-dimensional indication of a trend relating to the heart failure status of the patient.

Abstract: An exemplary method includes acquiring cardiac electrical activity information, detecting a T wave and, based on the detecting, calling for delivery of matter to the heart where the matter may include one or more of stem cells, progenitor cells, nutrients and drugs. Another exemplary method includes calling for delivery of electrical energy to cells destined for implantation in the body or cells already implanted in the body. Such delivery may be timed according to cardiac electrical activity and/or delivered at an energy level below a capture threshold of neighboring tissue. Various other exemplary technologies are also disclosed.

Abstract: An exemplary method includes accessing cardiac information acquired via a catheter located at various positions in a coronary sinus of a patient where the cardiac information includes electrical information and mechanical information; calculating scores based on the cardiac information where each of the scores corresponds to the coronary sinus or a tributary of the coronary sinus; and based on the scores, selecting a tributary of the coronary sinus as an optimal candidate for placement of a left ventricular lead. Accordingly, the selected tributary may be relied on during an implant procedure for the left ventricular lead. Various other methods, devices, systems, etc., are also disclosed.

Abstract: Adaptively creating a table of optimal, patient-specific atrioventricular (AV) delays for a an implantable medical device (IMD) begins as the IMD detects the patient entering a target heart rates within a defined range of elevated heart rates. On detection, the device begins testing AV delays by pacing the heart at a number of different AV delays. The IMD selects the optimal AV delay based on a comparison of measurements of cardiac output obtained during each delay's test pacing period. The optimal AV delay corresponds to the one which resulted in the highest cardiac output. The device selects this optimal AV delay and stores it in an AV delay table on the device. The process continues as the device detects the patient entering the other target heart rates in order to complete the table.

Abstract: A cardiac-related signal such as a cardiogenic impedance signal is derived to obtain cardiac information such as stroke volume information that may be used to evaluate cardiac performance and/or other medical conditions. In some aspects detection of the cardiogenic impedance signal involves adaptively cancelling an unwanted component of a sensed signal. For example, in some embodiments a sensed respiratory signal may be subtracted from a thoracic impedance signal to reduce a respiratory component of the thoracic impedance signal. In this way, a more accurate cardiogenic impedance signal may be derived from the resulting signal.

Abstract: A method for use in an implantable medical device comprises the steps of monitoring respiration with an amplifier having a gain, generating a moving apneic threshold based on recent respiration cycles, accumulating differences between amplitudes of respiration cycles and the moving apnea detection threshold and comparing the accumulated differences against an apnea detection threshold to detect the onset of an episode of apnea. The method further comprises measuring respiration levels upon detecting the onset of apnea, confirming the episode of apnea based upon the respiration levels measured upon detecting the onset of apnea; and adjusting one of the gain of the amplifier and the apnea detection threshold so that the time from the detection of onset of apnea to the time of confirmation of the episode of apnea is within a predetermined time range following the detection of the onset of apnea.

Abstract: An exemplary method includes positioning a lead in a patient where the lead has a longitudinal axis that extends from a proximal end to a distal end and where the lead includes an electrode with an electrical center offset from the longitudinal axis of the lead body; measuring electrical potential in a three-dimensional potential field using the electrode; and based on the measuring and the offset of the electrical center, determining lead roll about the longitudinal axis of the lead body where lead roll may be used for correction of field heterogeneity, placement or navigation of the lead or physiological monitoring (e.g., cardiac function, respiration, etc.). Various other methods, devices, systems, etc., are also disclosed.

Abstract: Selection of an appropriate rate programming control (RPC) setting in an implantable medical device (IMD), uses analysis of VA coupling surrogate conditions. The VA coupling surrogate conditions are derived from signals such as cardiogenic impedance, blood pressure, and the pulsatile components of PPG. By analyzing a waveform of the measured surrogate condition, the IMD estimates wall stiffness, through the slope of the waveform, and peripheral arterial pressure, through the reflection time between the main wave and reflection wave of the waveform. These values are plotted against each other on a VA coupling coordinate plane. Based on the location and orientation of the resulting VA coupling plot, the IMD selects an appropriate RPC setting.

Abstract: An exemplary system includes one or more processors; memory; and control logic, of one or more modules operable in conjunction with the one or more processors and the memory, to acquire myocardial potential data associated with position information, acquire myocardial electrical activation data associated with position information, acquire myocardial position data with respect to time, generate isopotential contours based on the potential data, generate isochronal contours based on the electrical activation data, generate isomotion contours based on the position data with respect to time, and overlay the generated isopotential contours, isochronal contours and isomotion contours on a display to indicate a region of myocardial damage or myocardial scarring with respect to a map that comprises anatomical markers. Various other methods, devices, systems, etc., are also disclosed.

Abstract: In specific embodiments, a method to monitor pulmonary edema of a patient, comprises (a) detecting, using an implanted posture sensor, when a posture of the patient changes from a first predetermined posture to a second predetermined posture, (b) determining an amount of time it takes an impedance signal to achieve a steady state after the posture of the patient changes from the first predetermined posture to the second predetermined posture, where the impedance signal is obtained using implanted electrodes and is indicative of left atrial pressure and/or intra-thoracic fluid volume of the patient, and (c) monitoring the pulmonary edema of the patient based on the determined amount of time it takes the impedance signal to achieve the steady state after the posture of the patient changes from the first predetermined posture to the second pre-determined posture.

Abstract: In specific embodiments, a method to monitor left atrial pressure and/or intra-thoracic fluid volume of a patient, comprises (a) monitoring posture of the patient using a posture sensor implanted within the patient, and (b) using portions of an impedance signal, obtained using implanted electrodes, to monitor the left atrial pressure and/or intra-thoracic fluid volume of the patient. Each portion of the impedance signal used to monitor the left atrial pressure and/or intra-thoracic fluid volume of the patient corresponds to a period after which the patient has maintained a predetermined posture for at least a predetermined period of time, and during which the patient has remained in the predetermined posture.

Abstract: A system and method of determining the status of an adverse cardiac condition of a medical patient based on circadian variation of one or more hemodynamic parameters are provided. In some embodiments, the system and method calculate a first average value of a series of first values during a first time period, a second average value of a series of second values during a second time period, and a difference between the first average value and the second average value. The method provides an indication of an adverse cardiac condition when the difference is less than a predetermined threshold.

Abstract: An exemplary method includes selecting a first pair of electrodes to define a first vector and selecting a second pair of electrodes to define a second vector; acquiring position information during one or more cardiac cycles for the first and second pairs of electrodes wherein the acquiring comprises using each of the electrodes for measuring one or more electrical potentials in an electrical localization field established in the patient; and determining a dyssynchrony index by applying a cross-covariance technique to the position information for the first and the second vectors. Another method includes determining a phase shift based on the acquired position information for the first and the second vectors; and determining an interventricular delay based at least in part on the phase shift.