Abstract: Improved pacing thresholds for capturing the heart are achieved by forming a discontinuity in the cardiac tissue of the heart chamber, disposing a pacing electrode at a distance less than a space constant of the cardiac tissue from the discontinuity in the cardiac tissue, and applying a stimulus of a first polarity at an energy insufficient to cause the directly stimulated tissue adjacent to the pacing electrode to propagate a depolarization wave through the cardiac tissue mass of the heart chamber but sufficient to induce a transmembrane potential change at the tissue adjacent to the discontinuity that results in a propagated wave front. Thus, pacing energy is advantageously reduced.
Abstract: A medical device and more particularly a drug delivery pump has an hydraulic reservoir, a metering device, a displacement reservoir, a drug reservoir, and a drug infusion port all contained in a housing that can either be attached to or implanted into a patient. The hydraulic reservoir contains an hydraulic fluid that is under compression and flows through the metering device at an hydraulic rate. The hydraulic metering is isolated from the drug, and the metering device does not contain moving parts. The hydraulic fluid then flows into the displacement reservoir that applies pressure to the drug reservoir. The drug reservoir is compressible and adapted to contain a drug. As the drug reservoir is compressed, drug egresses through the drug infusion port at an infusion rate that is controlled by hydraulic rate. A method for filling the drug pump and a method for infusing drug from the drug pump are also disclosed.
Abstract: A method of measuring a source impedance of at least one cardiac electrical signal in a mammalian heart is provided. A first amplifier system is operated. A first signal from a chamber of the heart is received. The first signal is passed through a first amplifier. A second amplifier system is then operated. A second signal from the chamber of the heart is received. The second signal is passed through a second amplifier. Finally, the source impedance of at least one cardiac electrical signal is calculated. The source impedance is based on the amplified first signal and the amplified second signal.
Abstract: Heparin-polyoxyalkylenepolyamine adducts, and methods of making and using such adducts are disclosed. Compositions including a quaternary ammonium heparin complex, a moisture curable polysiloxane, and an organic solvent are also disclosed, along with methods of making and using such compositions.
Abstract: An implantable pacemaker is provided with cardiac depolarization sensing electrodes welded into the case along a peripheral edge surface thereof. The electrodes are coupled to signal processing circuitry within the case to provide leadless acquisition of electrocardiographic data for telemetry to a programmer. Each electrode is a thin film, multilayer ceramic structure mounted in a welding ring. Each electrode is substantially flat and is disposed within a recess in the peripheral edge surface of the case. Each electrode is a sandwich structure comprising a thin film layer, first and second ceramic layers, and a ground plane layer between the ceramic layers.
Abstract: An apparatus for treatment of Ménière's disease by intermittently increasing air (gas) pressure, in an air (gas) pressure chamber in communication with an outwardly sealed external ear volume bordering the tympanic membrane, comprises a peripherally fixed flexible circular diaphragm forming a wall of the chamber and being displaceable in a perpendicular direction essentially without being tensioned. Displacement of the diaphragm away from the chamber is effected by air pressure built up in the chamber, not by a separate displacement device. The apparatus further comprises a linear electromagnetic device for displacing the diaphragm. The apparatus may include systems for gas pressure sensing; chamber pressure equalizing; and microprocessor control, for controlling the displacement of the diaphragm and the pressure equalizing device by a signal input from the pressure sensing device.
Abstract: An electrochemical cell including a cell enclosure, a fill tube, a ball, a closing button, an anode, a cathode, and an electrolyte. The cell enclosure defines an internal volume and includes a cover forming a fillport through hole. The fill tube is separately formed, and defines a leading section, a trailing section, and a passageway. The leading section is secured within the fillport through hole. The ball is sealingly secured within the passageway. The closing button is also separately formed, and is sealingly secured within the fillport through hole adjacent the leading section of the fill tube. The anode, cathode, and electrolyte are maintained within the internal volume. By configuring the fill tube such that the leading section thereof is secured within the fillport through hole, an overall extension of the fill tube relative to the internal volume is greatly reduced, thereby maximizing a volumetric efficiency.
Abstract: A prosthesis for implantation in a blood vessel includes struts with a cross-section having a flat base with angled edges on the inner surface and chamfered edges on the outer or exterior surface. The base angled edge is substantially a right angle, while the outer or exterior surface has edges that are chamfered with either round or angled chamfers. The chamfers could be manufactured by either machining the chamfer into the stock material, or by tumbling the stent in a tumbler to abrasively wear the edges to form a chamfer.
Abstract: Methods and apparatus for burn-in of integrated circuit (IC) dies at the wafer level. In one embodiment, a wafer is fabricated having an array of dies formed thereon wherein the dies are separated by scribe areas. Surrounding each die is one or more ring conductors which are electrically coupled to various circuits on the die via die bond pads. The wafer further includes a series of conductive pads located in an inactive region of the wafer. Electrically connecting the conductive pads to the ring conductors is a series of redundant scribe conductors. During burn-in, a burn-in indicating apparatus located on each die monitors burn-in parameters such as elapsed burn-in time. The indicating apparatus further records the elapsed burn-in time (or other parameter). The indicating apparatus may be subsequently interrogated to verify the burn-in time.
Type:
Grant
Filed:
April 25, 2000
Date of Patent:
September 30, 2003
Assignee:
Medtronic, Inc.
Inventors:
Andreas A. Fenner, Lary R. Larson, Paul F. Gerrish, Daniel E. Fulton, James W. Bell, James Thomas May
Abstract: An implantable medical device having reduced volume includes a high voltage die mounted to a substrate and assembled into a device body. The die is flip chip mounted, reducing the size of the substrate and of the device. A high voltage implantable medical device such as an implantable cardio defibrillation device or a hybrid device has a high voltage flip chip die mounted to a substrate containing implantable medical device circuitry to operate with the high voltage flip chip.
Abstract: An implantable drug infusion device includes a pump tube for holding a liquid to be pumped. A race is configured to support the tube. A roller assembly is configured to compress the tube against the race at one or more points along the path, and the roller assembly includes at least one roller. A tube guide is operably connected to the roller assembly to align the pump tube with respect to a corresponding roller.
Type:
Grant
Filed:
April 28, 2000
Date of Patent:
September 30, 2003
Assignee:
Medtronic, Inc.
Inventors:
Steven R. Christenson, Reginald D. Robinson, James M. Haase, Manfred K. Lüedi
Abstract: A system of performing a medical procedure, such as surgery, is provided. The system comprises a sensor to sense a state of cardiac tissue, such as an impending contraction and an indicator to indicate the state of the cardiac tissue. Methods and devices for performing the medical procedure are also provided.
Type:
Grant
Filed:
September 26, 2000
Date of Patent:
September 30, 2003
Assignee:
Medtronic, Inc.
Inventors:
Michael R. S. Hill, Scott E. Jahns, James R. Keogh
Abstract: A slitting tool for severing a tubular body includes a body portion, extending along a first axis, joined to a nose portion extending along a second axis, the second axis extending at an angle between approximately 5 degrees and approximately 90 degrees with respect to the first axis.
Type:
Application
Filed:
February 14, 2003
Publication date:
September 25, 2003
Applicant:
Medtronic, Inc.
Inventors:
Kenneth C. Gardeski, Jeff J. Jannicke, Stanten C. Spear, David A. Schuelke, Debbie L. Kirihara, Elizabeth A. Ellingson, Jeremy J. Odegard, Richard P. Manahan, Andrzej M. Malewicz
Abstract: An electrocautery device is disclosed. In accordance with one aspect of the invention, the electrocautery electrode/tip is provided with a hollow, conductive tube terminating at its distal end in a ball point type tip. Fluid, preferably conductive fluid, is applied to the proximal end of the hollow electrode/tip, and expelled from the distal end thereof during electrocautery. The ball point distal tip allows the distal tip to be directly applied to the tissue and “rolled” or slid along the tissue. This allows the distal tip to be moved across the tissue without dragging or snagging on the tissue. In addition, the conductive fluid expelled from the distal tip further lubricates the distal tip as it moves across the tissue. If conductive fluid is used, the conductive fluid emanating from the electrode/tip conducts the RF electrocautery energy away from the distal tip so that it is primarily the fluid, rather than the distal tip that actually accomplishes the cauterizing of tissue.
Abstract: A stacked die package is formed by stiffening a flexible substrate, arranging a chip mounting pattern on one side of the substrate, and mounting chips according to the arranged pattern. A solder ball array on the opposite side of the substrate is routed to the chips, and the flexible substrate and stiffener are folded to align the chips in the stacked die package. The stiffener is removed by a single saw cut.
Abstract: A system and method for predicting the likelihood of occurrence of an impending neurological episode. Electrical stimuli are delivered to a structure of the brain. Response field potentials evoked by the stimuli are sensed. Analysis of these field potentials allows for predictions as to the occurrence of an impending, but not yet occurring, neurological disorder. In one example, a measurement of change in response pulses is used to determine a level of interconnectivity in the structures of the brain. The level of functional interconnectivity is used in predicting the occurrence of the neurological event. An example of such a neurological event includes an epileptic seizure.
Abstract: Electrostatic Discharge (ESD) protection scheme includes a divided rail structure to route damaging ESD away from sensitive circuitry. Specifically, Vdd and Vss rails are divided to segregate the ESD current within a circuit, thus isolating the sensitive circuitry from ESD exposure. In an exemplary embodiment, Vdd is divided into Vdd-esd and Vdd core, while Vss is divided into Vss-esd and Vss core. The structure in cooperation with diodes, clamps and resistors enables to isolate the rails (Vdd core and Vss core) associated with sensitive circuitry from ESD current.
Abstract: A surgical apparatus for delivering a conductive fluid to a target site for ablating bodily tissue. The apparatus includes a tube fluidly connected to a source of conductive fluid. The tube defines a proximal portion, a distal portion and a central pathway. The central pathway extends from the proximal portion to the distal portion and is configured to direct flow of conductive fluid to the distal portion. The distal portion is configured for placement at a target site of bodily tissue and forms a helical slot. The helical slot is configured to allow flow of conductive fluid from the central pathway. Following delivery of the conductive fluid, an electrical current is applied to create a virtual electrode for ablating bodily tissue at the target site.
Abstract: The invention is directed to pacing techniques designed to avoid competitive atrial pacing. In particular, the techniques dynamically adjust a non-competitive atrial pacing (NCAP) interval based on sensed cardiac conditions. An apparatus capable of delivering pacing stimuli, such as a pacemaker or an implantable cardioverter/defibrillator (ICD), is described that inhibits delivery of an atrial pacing stimulus for an NCAP interval having a duration that is adjusted according to sensed cardiac conditions. The apparatus may adjust the duration of the NCAP interval when sensing, for example, premature ventricular contraction (PVC), pacemaker mediated tachycardia (PMT), or atrial arrhythmia (AA).