St. Jude Medical Ab

Pacesetter, Inc.

St. Jude Medical, Inc.

Kjell Norén

Nils Holmström

Anders Björling

Stuart Rosenberg

Kyungmoo Ryu

Karin Ljungström

Michael Xiaoxuan Yang

Wenbo Hou

Kenth A Nilsson

Allen J Keel

Sven Kalling

Steve Koh

Edward Karst

Sven-Erik Hedberg

Tomas Svensson

Malin Öhlander

Thao Thu Nguyen

Karin Järverud

Andreas Blomqvist

Johan Lidman

Stefan Hjelm

Malin Hollmark

Seven-Erik Hedberg

Taraneh G Farazi

Karin Jäverud

Lars Mandal

Anders BJÖRLING

In a system and method for controlling an implantable stimulator capable of producing pacing pulses to be delivered to cardiac tissue, as well as vagal stimulation pulses to be delivered to vagus nerve sites, upon detection of a premature cardiac event, such as a premature ventricular or atrial contraction, a simulated heart rate turbulence (HRT) procedure is applied if the intrinsic heart rate turbulence is weakened or absent. The simulated HRT includes a first phase in which the heart rate is increased, from the existing level, for a number of heart beats, a second phase in which the heart rate is decreased for a number of heart beats, and an optional third phase in which the heart rate is returned to said existing level.

System and method for controlling a heart stimulator

In a method and a device for determining the posture of a patient, a bio-impedance measurement device, having a number of electrodes configured to interact with the patient in a number of different electrode configurations, is operated to initiate a patient posture determining session by measuring an impedance value of the patient with the electrodes in at least one configuration among the number of configurations. A reference impedance value from among a number of stored reference impedance values for the at least one configuration is selected. The number of stored reference impedance values are respectively associated with different postures of the patient, and the posture associated with the selected reference impedance value represents a candidate posture. The measured impedance value is compared with the selected reference impedance value, thereby obtaining a comparison result. Dependent on said comparison result, it is automatically determined whether the current posture of the patient conforms to the candidate posture.

Medical device for determining the posture of patient

An implantable medical device () is configured for generating a cardiogenic impedance signal representative of the cardiogenic impedance of at least a portion of a heart () of a subject () during at least a portion of cardiac cycle. A moment processor () 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 () in order to classify a detected arrhythmia of the heart (), such as discriminate between hemodynamically stable or unstable arrhythmias and/or supraventricular or ventricular tachycardia.

Implantable medical device and method comprising means for detecting and classifying an arrhythmia

A device senses cardioelectrical signals using a right atrial (RA) lead, which might include far-field R-waves as well as near-field P-waves. The device concurrently senses events using a proximal electrode of an LV lead, which can sense both P-waves and R-waves as substantially near-field events. Suitable templates are then applied to the signals sensed via the proximal LV electrode to identify the origin of the signals (e.g. atrial vs. ventricular) so as to properly classify the corresponding events sensed in the RA as near-field or far-field events. In this manner, far-field oversensing is conveniently detected.

Systems and methods for detecting far-field oversensing based on signals sensed by the proximal electrode of a multipolar LV lead

An exemplary method includes accessing cardiac information acquired via a catheter located at various positions in a venous network of a heart of a patient wherein the cardiac information comprises position information with respect to time for one or more electrodes of the catheter; performing a principal component analysis on at least some of the position information; and selecting at least one component of the principal component analysis to represent an axis of a cardiac coordinate system. Various other methods, devices, systems, etc., are also disclosed.

Cardiac coordinate system for motion analysis

A method includes selecting an electrode located in a patient; acquiring position information with respect to time for the electrode where the acquiring uses the electrode for repeatedly measuring electrical potentials in an electrical localization field established in the patient; calculating a stability metric for the electrode based on the acquired position information with respect to time; and deciding if the selected electrode, as located in the patient, has a stable location for sensing biological electrical activity, for delivering electrical energy or for sensing biological electrical activity and delivering electrical energy. Position information may be acquired during one or both of intrinsic or paced activation of a heart and respective stability indexes calculated for each activation type.

Electrode and lead stability indexes and stability maps based on localization system data

An implantable cardiac device has a heart stimulator for electrically stimulating the heart of a patient, detector that measures a physiologic parameter that is affected by the status of a cardiovascular disease associated with sympathetic activation, a signal processor that determines at least one of a low frequency, LF, and a very low frequency, VLF, Mayer wave component in the measured parameter, and analyzer that automatically analyzes the determined Mayer wave component in relation to a predetermined reference value to determine the status of the cardiovascular disease. The detector is a cardio-mechanical parameter detector that measures, as said physiologic parameter, a mechanical change in at least one of the four chambers of the heart. In a corresponding method for monitoring the status of a cardiovascular disease associated with sympathetic activation of a patient having an implantable electric heart stimulator a physiologic parameter affected by the cardiac disease is measured. At least one of a low frequency, LF, and a very low frequency, VLF, Mayer wave component in the parameter is determined, and the wave component is analyzed in relation to a predetermined reference value to determine the status of the cardiovascular disease. A mechanical change in at least one of the four chambers of the heart is measured as the physiologic parameter.

Implantable cardiac device and method for monitoring the status of a cardiovascular disease

An implantable heart stimulating device has a stimulation pulse generator that emits stimulation pulses at an adjustable stimulation rate, an activity sensor that emits an activity signal in response to detected activity of the patient, and a physiological parameter sensor that generates a physiological sensor signal in response to a detected physiological parameter. The activity and physiological sensor signals are supplied to a control arrangement that sets the stimulation rate for the stimulation pulse generator by executing a stimulation rate algorithm dependent on those signals. In the stimulation rate algorithm, if the physiological signal indicates an emotional stress on the part of the patient, the stimulation rate is increased to an adjustable emotional stress rate level, and if no increase in the activity signal occurs during a predetermined time period following the stimulation rate increase, the stimulation rate is decreased.

Implantable heart stimulating device with stimulation rate optimization

In an ischemia detection method, and in an ischemia detector and a cardiac stimulator embodying an ischemia detector, a workload of a patient is measured, as is an ejection fraction (EF) associated with the heart of the patient is determined. A predetermined reference relation between EF and workload for the patient is stored, and an analysis unit detects a state of ischemia of the patient from deviation in the determined EF for various workloads from the stored reference relation.

Detection of ischemia

In a method and apparatus for measuring the ejection fraction in a mammalian heart, the opening and closing of a heart valve is sensed with an implanted sensor, and a pre-ejection period is measured as a function of the sensed opening and closing of the heart valve. The ventricular ejection time also is measured, and the ejection fraction is determined as a function of the measured pre-ejection period and the ejection time.

Method for extracting timing parameters using a cardio-mechanical sensor

In a device and a method for determining a cardiac condition from a detected cardiac signal, an input signal is formed from the detected cardiac signal and supplied to an analysis unit. The analysis unit forms an analysis signal from the input signal, having a real part substantially corresponding to the input signal and an imaginary part that is a predetermined transformation of the input signal. A calculation unit operates on the analysis signal to calculated at least two heart-related parameters therefrom. The heart-related parameters are supplied to a processing unit that combines the heart-related parameters in a predetermined manner for identifying a cardiac condition.

Device and method for determining a cardiac condition using a complex signal formed from a detected cardiac signal

In an implantable heart stimulating device, system and method, electrical stimulation pulses are delivered to first and second ventricles of a heart with a variable time interval therebetween, and signals are sensed at two different positions in the heart, from which an impedance value is derived. A minimum value and a maximum value of the impedance value are determined during a heart cycle, and a relationship between the minimum and maximum values also is determined. The time interval is varied and the relationship is monitored over a number of heart cycles. The time interval is set so that the relationship satisfies a predetermined requirement.

Bi-ventricular heart stimulating device, system and method

A heart stimulator for electric stimulation of a patient's heart has an impedance measuring unit that measures the impedance between at least two measurement electrodes implanted in a patient such that volume changes of at least one of the chambers of the left heart result in changes in the measured impedance. An analyzer analyzes the measured impedance for the control of the stimulation of the heart. A calculation unit calculates an average impedance morphology curve during a time interval of several cardiac cycles. The analyzer analyzes the average impedance morphology curve for use for the control of the stimulation to optimize the patient hemodynamics.

Heart stimulator with stimulation controlled by analysis of an average impedance morphology curve

A valve opening detector for use in an implantable medical device detects opening of at least one valve in the left side of heart, and has an impedance measuring unit for measuring electrical impedance between measuring poles and for generating an impedance signal corresponding thereto, at least one of the poles being arranged in the coronary sinus and/or in the great cardiac vein of the heart. The valve opening detector also includes an impedance signal processor which processes the impedance signal to detect the opening of one or both valves in the left side of the heart.

Implantable medical device with valve opening detector

A dual chamber pacing system normally operates in an atrial synchronized mode, and includes a mode switch that switches the pacing mode to a non-atrial synchronized ventricular stimulating mode in response to the detection of an atrial tachyarrhythmia, and switches the pacing mode back to the atrial synchronized mode in response to, or after a preset time following, detection of cessation of the atrial tachyarrhythmia. A mode switch supervising circuit includes a counter that accumulates an amount of mode switches from a starting point, and supplies the accumulated amount to a comparator, wherein the accumulated amount is compared to a predetermined mode switch amount threshold. The mode switch supervising circuit controls the mode switch to lock the pacing mode to the non-atrial synchronized ventricular stimulating mode for at least a predetermined time period in response to the mode switch amount exceeding the amount threshold.

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Solna, Sweden

Kjell Norén