Vitafin N.v.

Vitatron Medical B. V.

Frederik H Wittkampf

Kornelis A Mensink

Gerrit W Van Arragon

Willem Boute

Hendrik L Brouwer

Wim Boute

Alexis C Renirie

Frits M Van Krieken

Vincent Giele

Anthony F Rickards

Guillaume L Cals

A pacing lead is disclosed having folded tine elements in a first normal state, the tine elements being adapted to be unfolded by insertion of a stylet. In the second unfolded state, the tine elements are stretched to conform closely to the outer diameter of the lead casing, providing a reduced cross-section that facilitates introduction of the lead, and repositioning of the lead tip. A telescoping arrangement of inner and outer tubing elements is used to enable the stretching of the tine elements.

Pacing lead with improved anchor mechanism

A pacemaker and method of cardiac pacing employing the Tx mode of rate control, having means for automatically terminating the refractory period after sensing of an evoked T wave following a delivered stimulus. The pacemaker also is capable of overriding a natural rate and delivering one or more stimulus pulses so as to obtain a Tx rate determination during what would otherwise be inhibited pacer operation.

Rate adaptive pacemaker apparatus and method

Apparatus and method for treatment of tachycardia, wherein when tachycardia is determined a portion of a patient T-wave is sensed and utilized as indicating the end of the cardiac refractory interval. One or more anti-tachycardia stimuli are delivered in timed relation to the sensed T-wave. The initial T-wave from which the first A-T stimulus is timed may be evoked by delivery of an early stimulus.

Pacemaker with improved tachycardia treatment means and method

A programmable dual chamber cardiac pacemaker is provided which provides improved means for responding to sensed high atrial rates. The pacemaker monitors the sensed high atrial rates and determines whether they are physiological or not, and automatically controls the operative atrial refractory period as a function of whether or not the atrial rate is physiological. The pacemaker is permitted to go into a Wenckebach mode of operation only when it is determined that a sensed high atrial rate is physiological, and that under other conditions will automatically go into a block mode of operation.

Dual chamber pacemaker with automatic high rate limit mode determination

A pacemaker system incorporates an implantable pacemaker and a plurality of electrodes, electrodes preferably being on a pacing lead for a single chamber pacemaker, or a pair of such leads for a dual chamber pacemaker. Programmable connection means are provided for connecting the pacemaker output to a selected combination of lead electrodes, the selection being changed during each pacer cycle to optimize the choice of unipolar and bipolar operation for given pacemaker events. In one mode, the system employs bipolar QRS sensing and unipolar pacing and T-wave sensing. In another mode, the system employs bipolar QRS sensing and pacing, and unipolar T-wave sensing.

Pacemaker system with automatic event-programmed switching between

An improved cardiac pacemaker adapted to be programmed into one of a plurality of given modes of operation, including dual chamber modes, and in particular synchronous operation for pacing the patient's ventricle following detection of natural atrial heartbeats. The pacemaker has means for monitoring the time relationship between delivered ventricular stimulus pulses and next succeeding atrial heartbeats, for determining the occurrence of pacemaker induced retrograde P waves, or pacemaker caused tachycardia. The timing, and thus the rate of sensed P signals is processed to determine the desirability of establishing a special P sense window for looking for the occurrence of P signals at rates above a normal maximum operating rate, in which event the stability of the V-A timing is monitored in accordance with predetermined criteria to determine the existence of pacemaker mediated tachycardia, which may be broken up by skipping a ventricular stimulus. During detection of atrial beats at a rate higher then the predetermined maximum operating rate, the synchronous ventricular stimulus rate is maintained at an average at or below the maximum rate, while maintaining a substantially constant A-V interval.

Dual chamber pacemaker

A dual chamber pacemaker having means for operating in different pacing modes, including dual chamber modes, contains the capability of switching into a fixed rate ventricular pacing mode and of sensing early atrial signals without affecting the ventricular pacing timing. The timing of a plurality of such sensed early atrial signals is analyzed to determine if they represent retrograde P waves and, if so, the indicated V-A conduction time. The pacemaker atrial refractory time is adjusted so that, during dual chamber operation, the atrial refractory time extends past the time of anticipated retrograde P waves, thereby optimizing the setting of the atrial refractory period for avoidance of pacemaker mediated tachycardia. Other pacing conditions may also be adjusted in response to the determined patient V-A time.

Dual chamber pacemaker system with V-A time measurement apparatus and

A physiological device adapted for implantation in a human patient, e.g. a cardiac pacemaker or muscle stimulator, characterized by having programmable means for generating data and assembling same for presentation of one or more histograms. The implanted device has circuitry for registering the occurrence of sensed or evoked events, as well as device operating events such as cycles of operation, and means, preferably software control of a microprocessor, for classifying registered events into respective classes of one or more parameters associated with the events and for accumulating counts of events for each such class. The system also includes external apparatus for communicating programmed instructions to the device, whereby histogram selection and histogram classes are programmed, and for receiving the histogram data transmitted from the implanted device and displaying it in a convenient histogram form. Time based histograms are also generated, utilizing a software clock for continuously tracking time.

Physiological devices such as pacemakers and method for providing

A programmable pacemaker apparatus having a microprocessor and means for receiving program information from an external source, means for generating and delivering stimulus signals and means for sensing the occurrence of natural heartbeats in a patient, and having a battery source powering the apparatus, said microprocessor being combined with program instructions stored in memory for controlling the operation of said pacemaker, comprising controller circuit means external to said microprocessor and interconnected therewith for controlling the operating state of said microprocessor, said controller means having occurrence means for determining the occurrence of given events. The controller means further comprises means for stopping operation of the microprocessor on command from the microprocessor and for starting operation of the microprocessor upon determination of one of said events, whereby the microprocessor normally is on less than about 25% of the time. The pacemaker provides for at least two modes of pacing rate control, whereby the patient's heartbeat can be overdriven, or abrupt changes in rate are not followed beyond a selected rate change limit. Means are provided for microprocessor control of testing of pacemaker conditions, and for limiting current to the pacemaker output circuit when the battery voltage drops below a predetermined value.

Programmable cardiac pacemaker with microprocessor control of pacer rate

A pacing system and method of programming the rate of said system is disclosed, wherein the pacemaker comprises circuitry for receiving a first group of simple on-off magnetic pulses which are accumulated and translated into the decades portion of the desired heartbeat rate (in bpm), and also for receiving a second group of pulses which are translated into the units count of the desired pacing rate in bpm. The circuitry provides that an initial portion of the programming signal is inspected relative to predetermined criteria, so that such initial portion acts also as an enabling key for accepting the overall programming signal. The doctor simply applies a simple hand held magnet t times according to the desired tens component of the programmed rate in bpm, maintains the magnet applied for at least a predetermined number of pacer intervals, and then applies the magnet u times corresponding to the units component of the desired heart rate, thereby programming the pacer to operate at tu bpm.

Programmable pacer and method of external programming

A physiological stimulating system includes improved means for minimizing the polarization that results at the stimulus site, thereby enabling enhanced detection of evoked responses. In the pacemaker embodiment, the stimulus signal comprises positive recharge pulses immediately before and immediately after the negative stimulus signal, the recharge pulses being adapted in a time duration and amplitude such that the total current delivered to the stimulus site, (e.g., a patient's heart) by the stimulus signal is substantially zero.

Apparatus for physiological stimulation and detection of evoked response

Pacemaker output circuit

An improved automatically rate adaptive pacemaker, wherein the rate of delivered stimulus pulses is controlled as a function of sensed hearbeat characteristics and/or patient threshold. The pacemaker analyzes different characteristics or parameters of the detected heartbeat signal, and the rate of delivered stimulus pulses is controlled as a function of predetermined correlation factors. The pacemaker includes means for automatic threshold tracking, and also for adjusting the rate of delivered stimulus pulses as a continuous function of the patient threshold.

Rate adaptive pacemaker and method of cardiac pacing

An epicardial lead is disclosed having plural electrode tips adapted for securing to the epicardium while moving the electrode at a small angle with respect to the external surface of the heart. At least 2 electrode tips are provided which are curved downward from the bottom surface of the electrode head and backward toward the proximal end of the electrode, so that they can be hooked into the epicardium while pulling the entire lead in a generally backward direction along the surface of the heart. Anchor means are provided at the forward or distal tip of the electrode head, with means for projecting the anchor out of the bottom surface and forward so as to anchor the electrode head against forward movement thereof. The result is a lead which can be firmly secured to the epicardium by two quick movements while maintaining the lead in close proximity to the heart surface, such that minimum access to the heart surface is required.

Epicardial lead

An atrial lead assembly is provided which is adapted for curving into position within the atrium, the lead having a flexible length without any preset curve, and comprising stylet means for introducing a curve into the distal end of the lead. The stylet enables the operator to set the axis of the lead along a curvilinear path adjustable by the operator. The lead has a tip of a continuous helical type adapted to be rotated into contact with the trabeculae, the lead being rotatable about the stylet while the stylet maintains the lead axis in a desired position, whereby the tip is caused to engage the trabeculae. After such engagement, the stylet can be removed, leaving the lead tip in good fixation with the atrial wall.

Growing community of inventors

Brummen, Netherlands

Frederik H Wittkampf