Abstract: A detector for detecting a cardiac event in an IEGM has a bank of digital filters composed of at least two filters with substantially different impulse responses corresponding to different properties of the cardiac event. The filters respectively filter different portions of the IEGM and respectively emit a value per time unit corresponding to the morphological resemblance between the IEGM and the finite impulse response. An analyzing unit combines these output values from the filters in a predetermined manner for comparison with predetermined detection criteria.

Abstract: In a monitor for monitoring diastolic relaxation of a ventricle of a heart, an impedance signal is measured in a ventricle of the heart and the occurrence of a notch in the impedance signal coincident with the entry of blood into the monitored ventricle is detected by forming a time derivative of the impedance signal and generating a loop by plotting impedance values of the impedance signals with respect to related time derivative values to form a loop for each cardiac cycle of the heart, and comparing the generated loop to a loop template representing a normal loop for the subject, to identify deviations in the loop from normal deviations in timing and shape of the notch.

Abstract: In a method for providing software to an implantable medical device system, including an implanted medical device and a presentation unit in communication with each other, a most current version of software for operating one or more of these system units is stored at a server which is remote from the implanted medical device system. Upon each start-up of the presentation unit, a communication link is established between the server and the presentation unit, and information is provided from the presentation unit to the server identifying the software which is respectively currently stored in one or more of the system units. The server determines whether the currently stored software in the system units requires an update and, if so, the server downloads the software version stored at the server to any of the system units which is/are in need of updated software.

Abstract: A multi-chamber pacing system has a pulse generator for successively delivering pacing pulses to chambers of a patient's heart, and IEGM signal detectors, having blanking intervals following the delivery of pacing pulses, including sensing circuits for sensing IEGM-signals from each of the heart chambers. Each of said sensed IEGM signals has a generally known morphology. A signal-reconstructing unit reconstructs the IEGM signal from one of the heart chambers in the blanking interval following delivery of a pacing pulse to another heart chamber.

Abstract: A dual chamber cardiac pacemaker has a pulse controller for delivering stimulation pulses to the ventricle of a heart, a ventricular sensor for sensing ventricular depolarization, and a unit for identifying a beginning of an A-V interval of the heart. The pulse controller causes a ventricular stimulation pulse to be generated at a predetermined energy level after the expiration of a predetermined A-V interval. The controller prolongs the A-V interval under certain circumstances. Upon the expiration of the prolonged A-V interval, the pulse controller causes the ventricular pulse generator to emit a ventricular stimulation pulse at a higher energy level than the predetermined energy level to evoke a response in the ventricle. This allows the intrinsic heart activity to be detected and utilized, while ensuring safe pacing, as well as successful and reliable stimulation and maintaining a low power consumption during normal operation.

Abstract: 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.

Abstract: In a method and apparatus for determining the depleted capacity of a CFx type battery used in an implantable medical device, average values of battery voltage and battery current drawn from the battery are measured during a measurement time, the length of which exceeds a battery voltage recovery time after a load change, and wherein the actual depleted capacity of the battery is determined by predetermined relations between combinations of the average values of voltage and current and depleted battery capacity.

Abstract: In a process for manufacturing a female connector for a pacemaker, a tubular ceramic insert is formed with a longitudinal bore and with two radial holes connecting internal contact surfaces with external contact surfaces. The radial holes are filled with conductive material and the internal and external contact surfaces are metallized. The ceramic insert is covered with a layer of metal except for an area around each of the external contact surfaces.

Abstract: A device for configuring a body insert, such as an electrode lead for a stimulation device, has a wire arrangement adapted to be inserted into the interior of the body insert for stiffening and bending the body insert. The wire arrangement has a tip section which, when the wire arrangement is inserted in the body insert, resides at the distal end thereof. The tip section has a bendable insulating polymer element which contains a number of bending actuators connected in series. The bending actuators are formed by successive silicon sections interconnected by polyimide-filled V-groove joints in thermal communication with a heating element. The operation of the heating element from a regulation unit adapted for access at a proximal end of the body insert controls expansion of the polyimide filling the joints, thereby producing a selected amount of bending at the tip section and the distal end section of the body insert.

Abstract: A heart stimulator has a pulse generator which emits stimulation pulses of different amplitudes, which are delivered to a patient's heart via a lead connected to the pulse generator. The pulse generator is controlled by a control unit, in a procedure for determining a stimulation threshold value, to emit stimulation pulses of successively unidirectionally changing amplitudes. Each stimulation pulse is followed by a test pulse having a predetermined high, constant amplitude delivered in a period corresponding to the refractory period after the preceding stimulation pulse. Each test pulse has an amplitude sufficient to capture a non-refractory heart. A measurement unit is connected to the electrode lead, and measures a signal picked up by the lead after each test pulse. The measured signals are supplied to a comparator, which compares the signals following the test pulses with each other.

Abstract: In a programmer for an implantable medical device, a method for operating and controlling a implantable medical device, and in a computer software product, a graphical representation of a quantity influenced by the operation of the medical device is displayed, and parameters relating to the control of the device are associated with portions of the graphical representation. When an operator selects and alters the shape of the displayed graphical representation to illustrate a desired operational effect of the medical device on the quantity, a value associated with the altered shape is automatically modified and communicated to the implanted medical device. The operator thus is able to select parameters on the basis of the intended effect, rather than setting parameter values and then observing the effect.

Abstract: An implantable cardiac stimulating device has a pacing circuit connected via an electrode lead system to a first electrode which stimulates and detects activity in the left ventricle, a second electrode to stimulate and detect activity in the right atrium, and to a third electrode to detect activity in the left atrium. Upon the occurrence of a paced or sensed depolarization of the right atrium, a first AV-delay is started. When the subsequent left atrial depolarization is detected, a new AV-interval is started that is optimized for the left side of the heart. Either the left ventricle only, or both ventricles, is paced at the optimized left side AV-interval.

Abstract: A heart stimulator has an atrial and ventricular pulse generator for producing atrial and ventricular stimulation pulses, an atrial sensor for sensing atrial signals and an evoked response detector for detecting the occurrence of incipient fusion beats from measured ventricular signals. A determination unit determines an incipient fusion AV-interval from the sensed atrial signals and the detected fusion beats, and a controller controls the pulse generator to deliver stimulation pulses at a controlled AV-interval which is shorter than the incipient fusion AV-interval.

Abstract: A blood flow measuring apparatus has a measuring electrode and a counter-electrode adapted to be brought into contact with the blood of a patient. A measuring unit measures a voltage or a current between the measuring electrode and the counter-electrode and determines the flow of blood therefrom. The measuring electrode is ring-shaped and sized to fit within a blood vessel in the body of the patient. An inner surface of the ring-shaped electrode forms an active measuring electrode surface. The blood flow measuring apparatus is suitable for use in a cardiac pacemaker.

Abstract: The invention relates to the electrode lead connector of a pacemaker. A tubular connector (29) is used for connection to the electrode lead contact plug (10). A transparent component (19) allows for visual confirmation that the electrode lead contact plug (10) is adequately inserted into said tubular connector (29).

Abstract: A programmer for an implantable medical device includes a display which displays a graphical representation of an area of interaction of the medical device within a patient. The graphical representation includes at least one independently selectable graphical object. The programmer includes a unit for associating parameters or functions used in controlling the medical device with the object, so that when an operator, via the programmer, selects an object, the associated parameters or functions are displayed for consultation, modification or execution. By directly linking the programmable parameter or function with an image of the device and the surrounding parts of the patient's body, the clinician is immediately presented with a clear and understandable link between the parameters and a physical entity.

Abstract: A pacemaker has a pulse generator for delivering stimulation pulses to a patient's heart, a sensor for measuring a parameter related to cardiac output, and a control unit for controlling the delivery of stimulation pulses from the pulse generator. The control unit includes an altering unit for altering at least one of the VV delay between consecutive stimulation pulses to the right and left ventricles and the AA delay between consecutive stimulation pulses to the right and left atria. The sensor measures the parameter in various time windows within a time of operation of predetermined VV- or AA-delay values. A determining unit includes a calculation unit for calculating an average value of the measured parameter during each of said time windows and the determining unit uses these average values to determine which one of the VV- and/or AA-delay values results in a higher cardiac output.

Abstract: A rate adaptive pacemaker comprises a means (2) for determining the demand of the patient's organism, a pacing rate controlling means (16) for controlling the pacing rate in response to the patient's demand, and a pacing rate limiting means (20) for preventing the pacing rate from becoming too low. The pacing rate limiting means is adapted to limit the pacing rate downwards such that a first predetermined relation is satisfied between actual cardiac output (CO) and cardiac output (COrest) for the patient in rest conditions and a second predetermined relation is satisfied between actual stroke volume (SV) and rest stroke volume (SVrest).

Abstract: An implantable bi-ventricular heart stimulating device has a control circuit that within a time cycle, delivers pacing pulses with both first and second pacing circuits with a time gap between a pacing pulse delivered by these pacing circuits. The time gap can be such that a pacing pulse delivered by the second pacing circuits falls substantially within a first time interval in which an evoked response can be expected to a pacing pulse delivered by the first pacing circuit. The control circuit performs a temporary modification of the operation of the device such that during at least one time cycle no pacing pulse is delivered by the second pacing circuit during the first time interval.

Abstract: An implantable heart stimulator has a heart signal detector adapted to detect electrical heart signals and to apply the detected signals to at least two detection channels. Each detection channel includes a filter, with each filter having a passband that differs from the passband of the other filters. Each channel also includes a threshold detector and a peak amplitude determining unit connected to the output of the filter in that channel. A heart event identifying unit is connected to the outputs of each channel and unambiguously identifies a type of signal which produced a detected heart event by applying predetermined identifying criteria to the outputs of the threshold detector and the peak amplitude determining unit from each channel.