Abstract: Techniques are provided for estimating left atrial pressure (LAP) or other cardiac performance parameters based on measured conduction delays. In particular, LAP is estimated based interventricular conduction delays. Predetermined conversion factors stored within the device are used to convert the various the conduction delays into LAP values or other appropriate cardiac performance parameters. The conversion factors may be, for example, slope and baseline values derived during an initial calibration procedure performed by an external system, such as an external programmer. In some examples, the slope and baseline values may be periodically re-calibrated by the implantable device itself. Techniques are also described for adaptively adjusting pacing parameters based on estimated LAP or other cardiac performance parameters. Still further, techniques are described for estimating conduction delays based on impedance or admittance values and for tracking heart failure therefrom.

Abstract: In a method and an implantable medical device for assessing a degree of pulmonary edema of a patient, at least two specific body patients of the patent are detected and at least one impedance sensing session is initiated to sense trans-thoracic impedance signals from the patient when the patient is in one of the at least two specific positions. Impedance values are obtained from the impedance signals, and a relation between respective impedance values at the at least two positions is determined. This relation is then used as a metric of pulmonary edema to assess the degree of pulmonary edema, and is provided as an output.

Abstract: An analyte measuring system has an implantable medical device having a signal source arranged for generating a current signal and electrodes for applying the current signal to a surrounding tissue in a subject body. The device measures a resulting voltage signal with the electrodes and calculates an impedance signal therefrom. The system comprises a signal processor arranged for generating an estimate of a concentration of an analyte in the tissue based on a spectrum analysis of the determined impedance signal.

Abstract: An implantable medical device (100) is configured for generating a cardiogenic impedance signal representative of the cardiogenic impedance of at least a portion of a heart (10) of a subject (20) during at least a portion of cardiac cycle. A moment processor (132) calculates a moment parameter value based on the cardiogenic impedance signal. The moment parameter is representative of a weighted sum of impedance amplitudes within a time window centered at defined time instance within the cardiac cycle. The weights of the impedance amplitudes are further dependent on the length in time between the defined time instance and the point of time of the associated impedance amplitude. The moment parameter is of high diagnostic value and is employed by an arrhythmia classifier (132) in order to classify a detected arrhythmia of the heart (10), such as discriminate between hemodynamically stable or unstable arrhythmias and/or supraventricular or ventricular tachycardia.

Abstract: Disclosed herein are systems and methods for automatically determining ST windows for ischemia detection. In one example, an R-wave is identified in a signal derived from an IEGM and the derivative signal data following the identified R-wave is analyzed so as to find portions of the derivative signal comprising samples having lower values than a predetermined threshold. Further, a portion of the derivative signal including samples having lower values than the threshold is determined to correspond to a ST window for that cardiac cycle if that portion fulfills predetermined requirements. A reference ST window based on a number of determined ST windows is determined. Using the reference ST window, ischemia can be detected by comparing IEGM data in the reference ST window with current IEGM data from a segment of the IEGM signal corresponding to the reference ST window.

Abstract: CRT settings for an implantable medical device are determined by applying pacing pulses to heart chambers of a scheme of different combinations of interchamber delays. A respective width parameter value representing an R or P wave width is determined for each such delay combination based on an ECG representing signal and the width parameter values are employed to estimate a parametric model defining the width parameter as a function of interchamber delays. Candidate interchamber delays that minimize the width parameter are determined from the parametric model and employed to determine optimal CRT settings. The technique provides an efficient way of finding optimal CRT settings when multiple pacing sites are available in a heart chamber.

Abstract: The invention relates to a medical implantable lead for monitoring and/or controlling an organ inside a human or animal body. The lead comprises a conducting arrangement having a first conducting coil of at least one electrically conducting wire for connecting a first electrode electrically to a connector to receive and/or transmit electric signals from and to the tissue, respectively. The lead is tapered in a distal portion and has a smaller cross sectional dimension at the distal portion than at the rest of the lead. The first conducting coil is terminated at a termination point on a distance from the distal end. The conducting arrangement has a first end conductor in the form of a non-coiled electric conductor or an eccentrically positioned small diameter coil which connects the first electrode electrically with the coil.

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: In response to local or systemic inflammation in a patient, photobiomodulation therapy is applied to a cardiac location to reduce the risk and/or occurrence of cardiac arrhythmia. Once inflammation is identified, photobiomodulation therapy can be applied in any suitable fashion (e.g., via a catheter- or transesophageal probe-mounted photoemitter, via an externally-applied photoemitter, or via photoemitter incorporated into an implantable medical device). Photobiomodulation therapy can also be employed to good advantage in conjunction with non-photobiomodulation therapy (e.g., traditional cardiac rhythm management therapies).

Abstract: In an implantable heart stimulator and a method for operation thereof, stimulation pulses are delivered to a heart. The amplitude of the delivered stimulation pulses can be selectively set. For setting the amplitude, threshold searches are performed at selected time intervals. Each threshold search determines a threshold value required for achieving capture. The amplitudes of the respective stimulation pulses are set to a value that exceeds the determined threshold value by a safety margin. The safety margin is selected as a function of the selected time intervals.

Abstract: The present invention generally relates to an implantable medical device and method for detecting and monitoring cardiac status of a patient using simultaneous multisite measurements of the intracardiac impedance and in particular to ischemia detection using the simultaneous multisite measurements. The device comprises an impedance measuring unit being connectable to a plurality of electrode configurations including a current generating device adapted to generate a current and apply the current between two electrodes of a current injecting electrode configuration of the electrode configurations and a voltage sensing device including a plurality of voltage sensing circuits arranged in parallel.

Abstract: The present invention relates to an improved medical device and method for accurately and reliably determining a cardiac status of a patient. An implantable medical device, IMD, comprises a sensor arrangement adapted to sense signals related to mechanical activity of the heart and an activity level sensor arrangement adapted to sense an activity level of the patient. Further, the IMD calculates a percentage of left ventricular diastolic time (PLVDT) for a cardiac cycle corresponding to a relation between a diastolic time interval and a cardiac cycle time interval using the determined systolic and diastolic time intervals or a percentage of left ventricular systolic time (PLVST) for a cardiac cycle corresponding to a relation between a systolic interval time interval and a cardiac cycle time interval. A cardiac status is determined based on the calculated PLVDT (or PLVST) and on an activity level of the patient.

Abstract: Implantable systems, and methods for use therewith, for monitoring arterial blood pressure on a chronic basis are provided herein. A first signal indicative of electrical activity of a patient's heart, and a second signal indicative of mechanical activity of the patient's heart, are obtained using implanted electrodes and an implanted sensor. By measuring the times between various features of the first signal relative to features of the second signal, values indicative of systolic pressure and diastolic pressure can be determined. In specific embodiments, such features are used to determine a peak pulse arrival time (PPAT), which is used to determine the value indicative of systolic pressure. Additionally, a peak-to-peak amplitude at the maximum peak of the second signal, and the value indicative of systolic pressure, can be used to determine the value indicative of diastolic pressure.

Abstract: Implantable systems, and methods for use therewith, for monitoring arterial blood pressure on a chronic basis are provided herein. A first signal indicative of electrical activity of a patient's heart, and a second signal indicative of mechanical activity of the patient's heart, are obtained using implanted electrodes and an implanted sensor. By measuring the times between various features of the first signal relative to features of the second signal, values indicative of systolic pressure and diastolic pressure can be determined. In specific embodiments, such features are used to determine a peak pulse arrival time (PPAT), which is used to determine the value indicative of systolic pressure. Additionally, a peak-to-peak amplitude at the maximum peak of the second signal, and the value indicative of systolic pressure, can be used to determine the value indicative of diastolic pressure.

Abstract: In a biventricular heart stimulator and a method for controlling such a biventricular heart stimulator, successive stimulation pulses are delivered to the ventricles of a heart such that stimulation pulses in a single heartbeat cycle are respectively first delivered to the first ventricle and then to the second ventricle. Capture or loss of capture in response to stimulation pulses delivered to one ventricle is detected. As a result of a detected loss of capture, preventative measures are taken for preventing loss of capture in the other ventricle.

Abstract: In a device and method in a dual chamber pacing system operating in an atrial synchronized mode, the cardiac stimulator is connectable to a lead arrangement arranged for sensing atrial electrical and mechanical activity. Upon detection of an atrial arrhythmia based on either of sensed atrial mechanical activity, atrial electrical activity, or a combination thereof, a mode switch from an atrial synchronized ventricle stimulating mode to a non-atrial synchronized mode is triggered.

Abstract: An implantable medical device is connected to a cardiomechanic sensor implanted in or in connection with a cardiac ventricle. The sensor generates a deformation signal representative of the myocardial deformation. The implantable medical device processes the deformation signal by calculating the derivative thereof to generate a deformation rate signal representative of the rate of myocardial deformation. The deformation rate signal is filtered and respective maximum deformation rate values are identified for multiple cardiac cycles in the filtered deformation rate signal. A value representative of the systemic blood pressure is calculated based on a combination of the respective maximum deformation rate values.

Abstract: An implantable medical device, is designed to collect a signal representative of the electric activity of the heart and determine a cardiogenic impedance signal for at least a portion of the heart. An R-wave detector of the IMD detects the timing of an R-wave during a cardiac cycle based on the signal representative of the electric activity. A minimum detector detects the timing of a cardiogenic impedance minimum in the cardiogenic impedance signal and within a systolic time window of the cardiac cycle. A detected arrhythmia is then classified by the IMD based on the timing of the R-wave detected by the R-wave detector and the timing of the cardiogenic impedance minimum detected by the minimum detector.

Abstract: An implantable cardiac stimulation device has an atrial detector that detects atrial events of a patient's heart, and a memory in which sequences of IEGM signals are stored, having a predetermined length, and an analyzing unit that analyzes the sequences to determine if the stored sequences contain atrial events having a lower amplitude than the current sensitivity setting of the atrial detector. A control unit is connected to the atrial detector to adjust the sensitivity setting thereof to a threshold that is determined based on the aforementioned analysis of the IEGM signals.

Abstract: In an implantable biventricular heart stimulating device, and a biventricular heart stimulating method, wherein operation takes place normally with a time VV between a pacing pulse delivered, or inhibited, by a first ventricular pacing circuit and a pacing pulse delivered, or inhibited, by a second ventricular pacing circuit, and wherein a time VVcts is determined that is to be used instead of VV during a capture threshold search.