Abstract: A pacemaker, or other implantable medical device, connected to heart tissue, detects atrial and ventricular electrical signals. The pacemaker analyzes the signals to determine whether the signals are representative of P-waves or R-waves according to atrial and ventricular sensitivity threshold values. Signals determined to be P-waves or R-waves are identified as sensed signals. Otherwise the signals are identified as not-sensed signals. The pacemaker further determines whether the sensed signals were detected during a refractory period or an alert period and its current tracking mode (e.g., VDD, DDD vs. DDI, VVI). Information pertaining to these atrial and ventricular signals is transmitted to an external programmer which generates representative histograms. The histograms present the number of counts detected within each of a set of high pass filtered amplitude ranges and further indicate the relative numbers of sensed vs. not-sensed counts.
Type:
Grant
Filed:
December 6, 1999
Date of Patent:
July 24, 2001
Assignee:
Pacesetter, Inc.
Inventors:
Siew Bee Er, Laurence S. Sloman, James E. Tyler
Abstract: An ischemia detector has a patient workload sensor and a patient breathing sensor which emits a signal representing sensed workload, and a patient breathing sensor which emits a signal representing sensed breathing activity of a patient. These signals are supplied to a detector unit which identifies a state of ischemia upon an occurrence of a predetermined relation between the sensed workload and the sensed breathing activity. This predetermined relation is a sensed low workload and a simultaneously sensed high breathing activity.
Abstract: The above objects are achieved in accordance with the principles of the present invention in a female connector part for cooperation with an elongated male connector part, the female connector part being intended for use in a pacemaker housing and having a longitudinal bore adapted to receive the male connector part. An element carrying resilient tongues, disposed at a small inward angle, i.e. inward from the opening of the female connector part, relative to a plane orthogonal to the longitudinal axis of the bore. The tongues are movable between a first position at which the respective tips of the tongues can engage the male connector part in the bore, and a second position at which the tips of the tongues do not engage the male connector part in the bore. The female connector part also includes a sleeve which is movable between two positions respectively corresponding to the first and second positions of the tongues.
Abstract: A pacemaker programmer and diagnostic system retrieves information stored within a pacemaker and analyzes the retrieved data in real time. The stored information can be retrieved by means of a telemetry communication link. The pacemaker automatically lengthens a post-ventricular atrial refractory period (PVARP). The pacemaker determines atrial capture threshold by generating atrial stimulation pulses while maintaining the ventricular stimulation pulse amplitude at a level known to ensure ventricular capture, and by detecting loss of atrial capture. In response to loss of atrial capture, a processor automatically triggers a premature ventricular contraction (PVC) response to prevent a retrograde P-wave from initiating a pacemaker-mediated tachycardia. Also in response to loss of atrial capture, the processor sets the atrial stimulation pulse amplitude to a value above the atrial capture threshold in a subsequent cardiac cycle, and restores the PVARP to its pre-test value.
Type:
Grant
Filed:
September 15, 1999
Date of Patent:
July 17, 2001
Assignee:
Pacesetter, Inc.
Inventors:
Brian M. Mann, Melinda Endaya, Paul A. Levine
Abstract: A system and method for obtaining data from an implantable medical device and delivering the data to a data processing device is disclosed. A portable interrogation device conducts a wireless interrogation of an implantable medical device implanted in a patient, and stores the data received from the implantable device in a memory of the portable interrogation device. At a later time, the portable interrogation device is directly interfaced with a data processing device using a high-speed connection, which provides the data processing device with high speed access to the interrogated data that is stored in the portable interrogation device's memory.
Abstract: A device in the form of a cardiac pacemaker for treating a malfunctioning heart, in which the intrinsic heart rate information is combined with secondary sensor variance information to select an appropriate therapy for the patient. The cardiac pacemaker has operational capability in the sleep mode and includes a hysteresis function. The hysteresis function is disabled during operation in the sleep mode and a pacing therapy is selected based upon the intrinsic heart rate and sleep mode operation.
Type:
Grant
Filed:
November 13, 1998
Date of Patent:
July 10, 2001
Assignee:
Pacesetter, Inc.
Inventors:
Joseph J. Florio, Paul A. Levine, Mark R. Myers
Abstract: A pacemaker programmer and diagnostic system retrieves information stored within a pacemaker and analyzes the retrieved data in real time. The stored information can be retrieved by means of a telemetry communication link. The pacemaker automatically lengthens an AV delay. The pacemaker determines atrial capture by generating atrial stimulation pulses while maintaining the ventricular stimulation pulse amplitude at a level known to ensure ventricular capture, and by detecting loss of atrial capture. In response to the loss of atrial capture, a processor automatically records the atrial capture threshold, and restores the AV delay to its pre-test value. The pulse generator also delivers a backup atrial stimulation pulse concurrent with a ventricular stimulation pulse to reduce the possibility of a retrograde P-wave initiating a pacemaker-mediated tachycardia (PMT).
Type:
Grant
Filed:
September 14, 1999
Date of Patent:
July 10, 2001
Assignee:
Pacesetter, Inc.
Inventors:
Brian M. Mann, Melinda Endaya, Paul A. Levine
Abstract: A method for delivering cardiac therapy, particularly defibrillation therapy, using an implantable cardioverter-defibrillator (ICD) or other cardiac therapy device. The method can be used either alone or in conjunction with any other suitable defibrillation (or other cardiac) therapy regimen. If used in conjunction with a conventional or other suitable defibrillation therapy regimen, the method can be considered to precondition the heart in advance of delivery of the defibrillation shock(s), in order to reduce the defibrillation threshold (DFT), and thus reduce the overall energy required for delivery of effective defibrillation therapy. In either case, in accordance with the method, the voltage gradients (VGs) across a plurality of different regions of the heart are sensed, e.g., using an endocardial sensor array (ESA), and a respective plurality of electrograms (EGMs) are produced in respective EGM channels. The excitable gaps (i.e.
Abstract: An implantable heart stimulator has a control unit which controls the delivery of stimulation pulses to a subject, and an ischemia detector. The control unit is connected to the ischemia detector and reduces the stimulation rate in response to a detection of ischemia.
Abstract: The invention resides in a multi-conductor lead comprising an inner tube containing at least two lumens, the tubing having an outer surface defining an outer diameter thereof. Two coiled conductors are housed within the at least two lumens in the tubing and extend longitudinally therewithin. A third coiled conductor is disposed circumferentially about the outer surface of the tubing. Insulation coating is disposed circumferentially about the outer conductor. Accordingly, the outer coil serves to prevent subclavian crush from causing the inner conductors to short to each other.
Abstract: An accelerometer has a cantilevered beam supported at one end and having an opposite free end, with an inertial, sensing mass mounted at the free end of the beam. The beam is formed of a piezoelectric layer and a supporting layer. The ratio of the thickness of the piezoelectric layer relative to the thickness of the supporting layer is in a range between 2 and 4. The ratio of the modulus of elasticity of the material forming the supporting layer relative to the modulus of elasticity of the material forming the piezoelectric layer is in a range between 8 and 12.
Abstract: A distributed system of network programmers is described for use with implantable medical devices. The system includes a set of network programmers each having a processor for performing functions directed to programming an implantable medical device and having a transceiver for communicating with the implantable medical device in response to those functions. The system also includes a remotely located network server. The network server has a processor for performing additional functions directed to analyzing information received from the network programmers and to transmitting the results of analyses to selected network programmers. By providing network programmers configured to perform only limited functions in conjunction with a network server, the individual network programmers can be considerably less costly to manufacture and maintain.
Abstract: An implantable stimulating device for electrical stimulation of a heart has a stimulus generator which generates electrical stimuli and at least one lead for delivering the stimuli from the generator to the heart. A measurement unit detects spontaneous intervals between successive intrinsic heartbeats, and forms an average of at least five of these spontaneous intervals. A variation with respect to this average for later spontaneous intervals is then identified, and this variation is then used to control a pacing parameter of the stimulus generator.
Abstract: A method of manufacturing a capacitor by highly etching a foil sheet, and at selected relief portions of the sheet, reducing the surface area coefficient. An anode sheet is cut from the foil sheet and assembled with other capacitor components. The surface area coefficient may be reduced by coining or mechanically compressing at the selected relief portions, and an oxide layer may be formed on the sheet after coining.
Abstract: A pacemaker programmer and diagnostic system retrieves information stored within a pacemaker and analyzes the retrieved data in real time. The stored information can be retrieved by means of a telemetry communication link. The pacemaker automatically lengthens a post-ventricular atrial refractory period (PVARP). The pacemaker determines atrial capture by generating atrial stimulation pulses while maintaining the ventricular stimulation pulse amplitude at a level known to ensure ventricular capture, and by detecting loss of atrial capture. In response to loss of atrial capture, a processor automatically records the atrial capture threshold, and restores the PVARP and the atrial pulse amplitude to their pre-test values.
Type:
Grant
Filed:
August 18, 1999
Date of Patent:
June 5, 2001
Assignee:
Pacesetter, Inc.
Inventors:
Brian M. Mann, Melinda Endaya, Paul A. Levine
Abstract: A surface active, viscosity modifying agent is used to promote additional tunnel initiation during the etching of high purity cubicity anode foil, preferably aluminum anode foil, to render it suitable for use in electrolytic capacitors. The anode foil is etched in the electrolyte bath composition by passing a charge rough the bath, resulting in an anode foil having a higher capacitance than foils etched using known methods or etching compositions. The etched anode foil is suitable for use in an electrolytic capacitor.
Type:
Grant
Filed:
April 7, 1999
Date of Patent:
May 29, 2001
Assignee:
Pacesetter, Inc.
Inventors:
Thomas Flavian Strange, Ralph Jason Hemphill
Abstract: A heart stimulating device has the capability of detecting fusion and/or pseudofusion heartbeats by measuring electrical impedance encountered by a delivered stimulation pulse. The device has a pulse generator connected to a lead system for emitting and delivering stimulation pulses, and an impedance measuring arrangement for measuring the impedance. A logic circuit determines that a response by the cardiac tissue to a delivered stimulation pulse includes a fusion or pseudofusion heartbeat if the measured electrical impedance is within a predetermined impedance range, and determines that the response does not include a fusion and/or pseudofusion heartbeat if the measured electrical impedance is outside of the predetermined impedance range.
Abstract: In a method and apparatus for eliminating the influence of double-layer capacitance in electrochemical measurements of the concentration of oxygen in blood using a working electrode, a reference electrode and a counter-electrode in contact with blood, a first potential is applied to the working electrode during a first measurement period and a second potential is applied to the working electrode during a second measurement period, the second potential being equal to a floating potential of the working electrode measured while the working electrode is in an electrically floating state. Charge generated by an output current from the working electrode respectively in the first and second measurement periods is accumulated, and the accumulated charge is used as a proportional representation of the amount of oxygen in the blood.
Abstract: An ischemia detector has a sensor unit which determines the systolic pressure of a subject, a unit wherein a relation is established between the systolic pressure and the subject's heart rate, as the heart rate is varied over a range, and an analyzer which determines the occurrence of ischemia from this relation.
Abstract: In an ICD, a highly efficient biphasic defibrillation pulse is generated by switching at least two charged capacitors, e.g., three capacitors, from a parallel connection to various combinations of a parallel/series connection or a series connection during the first phase of the defibrillation pulse. Such mid-stream parallel/series connection changes of the capacitors steps up the voltage applied to the cardiac tissue during the first phase. A stepped-up voltage during the first phase, in turn, gives an extra boost to, and thereby forces additional charge (current) into, the cardiac tissue cells, and thereby transfers more charge to the membrane of the excitable cardiac cell than if the capacitors were continuously discharged in series. Phase reversal is timed with the cell membrane reaching its maximum value at the end of the first phase.
Type:
Grant
Filed:
May 5, 1998
Date of Patent:
May 15, 2001
Assignee:
Pacesetter, Inc.
Inventors:
James D. Causey, III, Gabriel Mouchawar, Herman L. Renger, Mark W. Kroll