Abstract: In a method and a system for organizing not yet implanted implantable medical devices, each having a telemetry unit associated therewith, a local administration unit transmits an inquiry signal to at least one of the telemetry units and receives a return signal therefrom in response to the inquiry signal. The return signal establishes the existence of the medical device, and the local administration unit, or a remote external unit in communication with the local administration unit, can then determine a course of action to be taken, such as a recall procedure, invoicing or taking inventory, based on the return signal from the medical device.

Abstract: 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.

Abstract: An implantable medical device is operable in a normal mode of operation, including a test mode, as well as in at least one other mode of operation outside of the normal mode. The device has a signal detector that is responsive to an external activation and a timer that can be programmed with a specified time period. If the external activation is detected by the signal detector during the programmed time period, the medical device is operated in a mode outside of the normal mode. The medical device enters into the test mode, within the normal mode, if the external activation is detected by the signal detector outside of the time period.

Abstract: In a cardiac stimulating device, an infection control current is generated and applied to a subject in whom a medical device is implanted by completing a circuit including an entirely electrically conductive exterior of a housing of the device, an electrode carried by an electrode lead of the device, and an electrically conductive surface of a proximal portion of the electrode lead, extending from the housing to a location, after implantation, situated beyond entry of the electrode lead into the venous system and before entry of the electrode lead into the superior vena cava. The infection control current can be a current with a square waveform, and the circuit can be completed at selected times, such as only during the refractory period of the subject's heart.

Abstract: A stylet unit has a flexible tubular stylet sleeve, a flexible inner stylet wire inserted into a channel of the stylet sleeve with at a least a portion of the stylet wire and at least a portion of the channel each having a non-circular cross section for preventing rotation of the wire inside the sleeve. The stylet unit has a handle with which the sleeve and the stylet wire are movable relative to each other in a longitudinal direction. The sleeve and the wire are connected at one end thereof to the handle, with the sleeve being rotationally arranged within the handle.

Abstract: In a cardiac stimulating device for biventricular stimulation, an intracorporeal ECG signal obtained from measuring electrode leads located outside of the heart is used for monitoring capture of the right and left ventricles. If loss of capture is detected in any of the ventricles then the pacing pulse energy will be adjusted to obtain complete biventricular capture.

Abstract: A sealing plug having a self-sealing access slit is provided in a medical implant. An insert is inserted into the self-sealing access slit to preserve the slit during storage.

Abstract: A monitor for early detection of an ischemic heart disease of a patient has an impedance measurement unit including an electrode arrangement for measuring an intracardiac impedance and generating a corresponding impedance signal, a notch detector connected to the impedance measurement unit for detecting the occurrence of a notch in the impedance signal coincident with the entry of blood into the ventricle, and a pattern recognition unit which compares the measured post-notch impedance curve with a stored predetermined reference impedance curve template to detect an ischemic heart disease from the result of the comparison.

Abstract: A fixation arrangement on the outer surface of an electrode head at distal end of a pacing lead includes an attachment mechanism having at least one tine, the tine being connected to the electrode head by a tine base portion that includes an electrically controlled heat-responsive positioner. The electrically controlled heat responsive positioner allows the angular position of the tine relative to the electrode head to be selective adjusted by a temperature change in the positioner.

Abstract: In an implantable heart stimulating device, system and method, a control circuit has first and second circuits for sensing and pacing. The first circuit can be connected to a first electrode member suited to be positioned in or at a first ventricle of the heart. The second circuit can be connected to a second electrode member suited to be positioned in or at a second ventricle of the heart. The control circuit is able to detect whether signals sensed by the second circuit are likely to be far field signals. The control circuit performs this detection by at least determining whether, during a predetermined time (length, more signals are sensed by the second circuit than by the first circuit.

Abstract: An implantable bi-ventricular heart stimulating device and system operate, within a time cycle, to deliver pacing pulses with both a first and a second pacing circuit with a first time delay between these pacing pulses. The device employs a criterion with which a signal typical for a premature ventricular contraction is detected. The device also operates with a second time delay and/or with a third time delay, and, if a predefined pacing rule is fulfilled, to deliver a pacing pulse with the second time delay or said third time delay. The risk for arrhythmia in connection with a PVC is reduced.

Abstract: A cardiac pacemaker has an algorithm for dynamic overdrive of a patient's atria in order to suppress atrial tachyarrhythmias. The device further has circuitry for adapting the AV-delay during dynamic overdrive of the atria to a value adapted to the patient's needs.

Abstract: 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.

Abstract: An implantable medical device has a conductive housing, electronic circuitry for the operation of the implantable medical device, and radio frequency circuitry for transmitting and/or receiving radio frequency signals, the electronic circuitry and the radio frequency circuitry being interconnected and arranged within in the housing. The housing has at least one slot therein, and a slot feed operatively interconnected between the radio frequency circuitry and the slot. The electrically conductive housing provided with the at least one slot is operable as an antenna for the radio frequency signals. The electric circuitry, the radio frequency circuitry, and the interconnection can be enclosed by the housing so that they are shielded from external radiation in any direction.

Abstract: A heart monitoring device has a control circuit, the control circuit being adapted to be electrically connected to electrode surfaces arranged at two different positions of the heart. The control circuit derives an impedance value indicative of the impedance between the electrode surfaces. Furthermore, the control circuit is arranged to determine and monitor a relationship between a positive rate of change and a negative rate of change of the impedance value. The device can, in particular, be used to detect and treat a systolic dysfunction of a heart.

Abstract: In a method for operating a system having an implantable medical device that communicates by wireless telemetry data exchange with an external unit, an algorithm is employed, selecting either an internal calculation processor in the implantable device or an external calculation processor in the external unit for accomplishing a given data processing. If the sum of an estimated amount of energy to process the data in the internal calculation processor and an estimated amount of energy required to then transmit an expected amount of result data to the external unit exceeds an estimated amount of energy required to transmit the source data to the external unit, the external calculation processor is selected. Otherwise, the internal calculation processor is selected. The method thereby results in a minimal energy consumption in the implantable medical device. This, in turn, allows for a device with a long battery lifetime and thus an improved patient comfort.

Abstract: 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.

Abstract: In a compression and decompression coding method, arrangement and computer program product, a data signal containing a number of symbols is converted into a series of codewords. A set of codewords is established and the data signal is monitored to determine the most frequently occurring symbols therein and/or sequences of symbols therein containing at least two symbols. A codeword is then allocated to each of the most frequently occurring of the symbols and/or symbol sequences. At least one codeword is reserved for indicating uncompressed data. When compressing a signal, the incoming symbols are first checked to determine if they correspond to a codeword. If a symbol corresponds to more than one codeword, further symbols are read until a symbol occurs which corresponds to one codeword only. That codeword is then transmitted. Any symbol that does not correspond to a codeword is supplemented with a codeword indicative of no compression and is then transmitted.

Abstract: A multi-chamber pacing system has a pulse generator for successively delivering pacing pulses to chambers of a patient's heart. Evoked response detectors having blanking intervals following the delivery of pacing pulses include sensing elements for sensing IEGM-signals from each of the heart chambers and an integrating unit that integrates the IEGM-signal within evoked response detection time windows after delivery of pacing pulses for detecting evoked response. The evoked response detection time window for a heart chamber contain at least one blanking interval resulting from delivery of a pacing pulse to another chamber and each of the sensed IEGM signals having a generally known morphology. An integral reconstructing unit reconstructs the time integral of the IEGM signal from one of the heart chambers in the blanking interval following delivery of a pacing pulse to another heart chamber.

Abstract: An implantable bi-ventricular heart stimulating device (10) has a control circuit with first and second sensing circuits for respectively sensing in the two ventricles and first and second stimulation circuits for respectively stimulating the two ventricles. The control circuit determines whether a signal, sensed by said second sensing circuit, occurs essentially simultaneously with a signal sensed by the first sensing circuit. Furthermore, the control circuit determines whether a further signal is sensed by said second sensing circuit within a predetermined time interval which follows after the signal sensed by the second sensing circuit but within the same time cycle as that signal. If this occurs, the control circuit determines whether the sensed signals represent actual cardiac events, or are likely the result of far field detection.