Abstract: A helical winding formed by a wound ribbon and having a length considerably exceeding its diameter, is adapted for implantation into a patient's body. Adjacent turns of the winding partially overlap each other and overlapping portions of the ribbon engage each other to limit the relative axial motion of adjacent turns. At least a portion of the overlapping structure is oriented non-parallel to the longitudinal axis of the winding. In a method of manufacturing such a winding a ribbon is formed to a desired cross-sectional shape with a longitudinally expanding engagement structure. The ribbon is then wound on a mandrel to produce a winding of desired length, with adjacent turns partially overlapping each other and the engagement structure causing overlapping portions of the ribbon to be mechanically engaged so as to limit the relative axial motion of adjacent turns of the winding. Finally the mandrel is removed out of the wound winding.

Abstract: An implantable electrode for stimulating tissue has a piezoelectric electrode for electrically and mechanically stimulating tissue and for detecting electrical and mechanical evoked response of the stimulated tissue. An implantable lead and an implantable stimulation device employing such an electrode are described including diagnostic circuitry for making a diagnosis of the heart condition using such an electrode.

Abstract: An implantable detection and therapy device allow prediction of the vasovagal syncope for use in administering therapy to a subject, the therapy including pacing pulses or drug delivery, or a combination thereof. The detection and therapy device includes a sensor which obtains blood flow velocity data or blood pressure data either in the area of the tricuspid valve or in the superior vena cava. The data are utilized in a control unit to identify the occurrence of venous pooling, which is recognized by the occurrence of a sudden reduction of the peak values of blood flow velocity waves or blood pressure waves. If this sudden reduction of the blood flow velocity waves or blood pressure waves is preceded by a sudden increase in the sinus heartbeat rate, the reduction is identified as being caused by venous pooling. The sudden increase in sinus heartbeat rate is caused by the increased sympathetic activity preceding the vasovagal syncope.

Abstract: In a method and apparatus for removing data outliers in measured signals in an implanted medical apparatus, such as data outliers produced by GSM disturbance picked up by an implanted cardiac stimulator lead and superimposed on the sensed cardiac activity signal, the signal from the implanted lead is subjected to median filtering. The median filtering minimizes, or eliminates, the effect of highly aberrational data points in the incoming signal, without the necessity of actually removing the components in the signal produced by the disturbance from the incoming signal itself. Since no portion of the actual incoming signal is removed by the median filtering, the data integrity of the sensed cardiac signal is preserved.

Abstract: A heart stimulator, operable for single-chamber and/or dual-chamber pacing, includes a first unipolar electrical lead placeable in the atrium of a heart, and a second unipolar electrical lead placeable in the ventricle of the heart. In the heart stimulator, a differential detector is connected to each of these unipolar leads and detects a differential signal representative of cardiac activity between the atrial electrode and the ventricular electrode. The differential signal is supplied to decision logic which evaluates each of those outputs including using a morphology analysis, if necessary. Depending on the type of cardiac activity identified as a result of the evaluation, the decision logic supplies a signal to a control unit in the heart stimulator to cause the therapy administered by the heart stimulator to be altered as warranted. The decision logic may also derive a respiration signal from the differential signal, which can also be used to modify the administered therapy.

Abstract: In an apparatus for terminating atrial fibrillation using pulses having an energy content which is the same as the energy content of conventional pacing pulses, stimulation pulses are respectively emitted by a number of electrodes disposed at different sites in or on a heart experiencing atrial fibrillation. When atrial fibrillation is detected, waveforms are measured at each of the electrodes, and the electrode having the waveform exhibiting the shortest interval between successive identifiable, cyclical waveform characteristics, such as successive P-waves, is selected as a first electrode for beginning an atrial defibrillation attempt. Stimulation pulses are emitted from the first electrode at a stimulation rate which is slightly shorter than the aforementioned shortest interval and the other electrodes are stimulated at a rate which is slightly shorter than the rate for the first electrode. All of the stimulation pulses are delivered starting at the latest local detection point in time.

Abstract: In a system for detecting changes in body posture, electrocardiograms are recorded. The recorded electrocardiograms analyzed are to determine changes in the body posture of a patient from changes in the morphology of the recorded electrocardiograms. The electrocardiogram analysis can be augmented by obtaining and analyzing an accelerometer signal as well.

Abstract: A heart stimulating device has pulse generators which can operate in either a first mode wherein the stimulation pulse energy is adjusted to a capture threshold of a patient's heart, or a second mode wherein the stimulation pulse energy is fixed. An evoked response detector senses IEGM signals to detect capture or non-capture subsequent to an emitted stimulation pulse. A noise detector detects as noise IEGM signals having predetermined signal characteristics. The noise detector, after having detected noise, sets the pulse generators to operate in the second mode. A lead arrangement connects the pulse generators, the evoked response detector, and the noise detector to a patient's heart.

Abstract: A back-up pulse generator for a pacemaker having a first energy storing component for storing energy to be delivered in a stimulation pulse and connectable to means for conducting the stimulation pulse to the heart, the back-up pulse generator including a back-up pulse energy storing component for emitting a back-up pulse after a failure to sense an evoked response from a preceding stimulation pulse. The back-up pulse energy storing component substantially permanently stores energy at a higher voltage than the energy stored in the first energy storing component.

Abstract: A heart stimulating device for avoiding problems related to fusion beats contains a pulse generator for delivering stimulation pulses to a patient's heart and having a basic escape interval, a detector with a filter which senses QRS characteristics in IEGM signals, a logic stage which controls the pulse generator, and a detector without a filter which senses QRS characteristics in IEGM signals. The logic stage activates the detector without a filter preceding an end of the basic escape interval and prolongs the basic escape interval by a predetermined extension interval if the detector without a filter senses a QRS indication.

Abstract: An implantable medical device has a pulse generator for generating electrical pulses, an electrical energy storage element connectable to an output stage, and an electrode arrangement for conducting the electrical pulses to tissue, the electrode arrangement having an input end and an output end. The output means of the pulse generator is connectable to the input end of the electrode arrangement, and the capacitance of the output stage is less than 1 .mu.F and the electrode arrangement has a capacitor with a capacitance greater than 1 .mu.F.

Abstract: A tachycardia eliminating apparatus includes a heartbeat detector which detects heartbeats in an input heart activity signal which delivers an output heartbeat signal indicating each detected heartbeat, a tachycardia detector coupled to the output of the heartbeat detector which generates a tachycardia indication signal in response to a detected tachycardia status of a heart as reflected in the heartbeat signal, and a respiratory system stimulator coupled to the output of the tachycardia detector and generating an output respiratory system stimulation signal for stimulating a respiratory system to achieve a stimulated breathing rate, with the ratio of the detected heartbeat rate to the stimulated breathing rate corresponding to a predetermined value.

Abstract: An active medical implant has a hermetically sealable capsule formed by a first part and a second closing part, the capsule being devised to hold a battery unit, an electronics unit, conductors for electrically connecting the battery to the electronics unit, and contacts arranged on the exterior of the capsule for connection to electrodes. The first part is made, at least in part, of a rolled, multi-layer composite sheet or plate, one layer of which is made of a biocompatible material and a second layer of which is made of a diffusion-proof material which is essentially resistant to corrosive chemicals. The two layers are joined by rolling, with the layer made of biocompatible material constituting the outer wall of the capsule.

Abstract: A stylet unit which can be introduced into a narrow, hollow, flexible component, such as a hollow electrode cable for a heart stimulator, to stiffen the component and bend its distal end section, is in the form of a double stylet combination with a flexible stylet shell and an internal stylet, movably arranged inside the shell, with a pre-curved distal end section, whose radius of curvature is on a first side of the stylet. In an area before the pre-curved end section, the stylet has a pre-shaped stylet section with a pre-shaped stylet section whose radius of curvature is on the side of the stylet opposite the first side on which the end section's radius of curvature lies.

Abstract: A device for affixing an elongate contact pin on an electrode lead for connection to a medical implant, such as a heart stimulator, contains an elongate connector part with an opening at one end into which the contact pin can be inserted. The connector part has an affixing part which, when acted on by the contact pin, can move in the connector part's longitudinal direction between a contact pin-affixing position and a contact pin-release position.

Abstract: A pacemaker system includes an electrode lead having a distal tip electrode for supplying stimulation pulses to cardiac tissue and a ring electrode, the electrode lead being connected to a cardiac stimulator. A detector is contained in a stimulator housing and is connected to the electrode lead for detecting electrical cardiac activity between said ring electrode and said tip electrode.

Abstract: An intracardiac blood flow velocity measurement device has a catheter adapted to be inserted through a blood vessel into the heart, at least two electrodes made of two different biocompatible materials mounted on the catheter at a detecting position which is located in a selected detecting area when the catheter is inserted into the heart for detecting blood flow velocity, with at least one of the electrodes being formed as a polarizable electrode and being disposed in the detecting position, and another of the electrodes being located on the catheter at an axially spaced distance from the polarizable electrode. Variation in an over-voltage or in a galvanic voltage is detected, and is used as a blood flow velocity signal.

Abstract: An electrical connector jack has at least one disk-shaped element made of an elastic, conductive material which has one or more contact surfaces arranged to come into contact with the corresponding contact surfaces on a contact pin. A layer of insulating, elastic material is provided on both sides of the electrically conductive material. The disk-shaped element is elastically deformed by the contact pin when the pin is inserted into the connector jack, so the contact surfaces of the electrically conductive material and the insulating material are pressed against the corresponding contact surfaces on the contact pin, the contact surfaces being protectively sealed by the contact surfaces of the insulating material.

Abstract: A blood flow velocity measurement device is devised where there exist such entities within the fluid which are detectable when axially flowing (passing by) an appropriate detector of known and well defined dimensions mounted onto a catheter. The entities produced for instance by a generator, when flowing by the detector, induced a known single response, the response bearing direct correlation to the flow velocity, in the form of direct reciprocity to the velocity and direct proportion to the length of the sensitive length of the detector. Autocorrelation of the function obtained by the overlap and pile-up of successive events is calculated and from the characteristic points in the autocorrelation function the axial velocity is inferred. The measurement is best when the probing beam is perpendicular to the flow.

Abstract: A heart stimulator, with verification of capture in the atrium of a heart, contains an atrial pulse generator which, via an atrial electrode, emits stimulation pulses in the atrium and a ventricular detector which senses depolarization signals in the ventricle via a ventricular electrode. The time which elapses between two consecutive stimulation pulses emitted in the atrium can be varied, and variation in ventricular events associated with the stimulation pulses is studied. If the ventricular events vary in time in the same way stimulation pulses emitted in the atrium vary, AV conduction is functional, and capture is present in the atrium.