262 results about "Fibrillation" patented technology

A cardiac defibrillator includes a fibrillation detector, which determines when a medical patient requires defibrillation at which time a transmitter produces a radio frequency signal. A first stent electrode is implanted into a blood vessel at a first location in the medical patient and a second stent electrode is implanted into a blood vessel at a second location. The first stent electrode contains an electronic circuit that is electrically connected to the second stent electrode. In response to receiving the radio frequency signal, the electronic circuit uses energy from that signal to apply an electric defibrillation pulse between the first and second stent electrodes.

An apparatus and method for treating post-defibrillation electromechanical dissociation ("EMD") or pulseless electrical activity ("PEA"). A first embodiment comprises an implantable defibrillator with the capability of detecting and treating post defibrillation EMD. The stimulator / defibrillator has one or more leads with electrodes and at least one electrode for defibrillation. A sense circuit senses the electrical condition of the heart of the patient. A second sensor senses a parameter correlated to the state of blood flow. The cardiac stimulator / defibrillator detects and terminates ventricular tachyarrhythmia or fibrillation. If the stimulator / defibrillator detects the presence of electrical rhythm in the heart correlated, however, with inadequate blood flow to sustain life (EMD), the device provides an output to stimulate the heart to overcome EMD. The device may also be an external defibrillator. The method for treating the heart to restore blood flow where electromechanical dissociation occurs after termination of a ventricular tachyarrhythmia or ventricular fibrillation comprises identifying electromechanical disassociation after termination of a ventricular tachyarrhythmia or a fibrillation and inducing or re-inducing ventricular fibrillation and subsequently applying defibrillating shocks to terminate the fibrillation.

The invention provides a disposable sensor patch for the non-invasive detection of heart disease. The patch is placed on a person's chest area for automatic analysis of ECG. The heart condition is indicated via an indicator integrated within the patch. The patch is inexpensive and simple for self-administration. In one embodiment, the status of the heart is indicated via multiple LEDs. The detection and indication typically occurs, within 24 hours or sooner if a condition is readily identifiable. The patch is thin, flexible, and incorporates a battery, ECG amplifier, and a processor for analyzing ECG waveform and indicating the heart condition. A software algorithm searches for a cardiac abnormality such as arrhythmia, bradycardia, tachycardia, fibrillation, mycocardial infarction, ischemia, long-QT syndrome, blocks, late potentials, and premature contractions. In another embodiment, results and relevant ECG data are stored in memory for later retrieval.

A skin desensitizing device for temporarily numbing and / or cooling a surface of a subject's skin. The skin desensitizing device comprises a controller, a skin-bracing interface, and at least one overloading-neural source, which includes (i) a transcutaneous electrical nerve stimulator (TENS)-like device capable of electrically stimulating superficial skin neurons of the subject's skin into a state of fibrillation, (ii) a thermoelectric device capable of cooling the subject's skin to approximately 30° F. to 38° F., and (iii) a vibration device capable of vibrating the subject's skin to overload the skin's vibration sensors.

A system and method for detecting and classifying cardiac arrhythmias based on cardiac pressure signals or the combination of cardiac electrical and cardiac pressure signals. A cardiac electrogram signal is sensed to derive a cardiac rate from which an arrhythmia detection is made when the cardiac rate meets arrhythmia detection criteria. An intracardiac pressure signal is sensed to derive an indicator of tachycardia based on an analysis of the pressure signal in either the time domain or frequency domain. The detected arrhythmia is classified as tachycardia or fibrillation based on the tachycardia indicator wherein the tachycardia indicator is compared to tachycardia detection criteria and the arrhythmia is classified as tachycardia if tachycardia detection criteria are met and the arrhythmia is classified as fibrillation if the tachycardia detection criteria are not met.

An apparatus and method for delivering electrical shock therapy in order to treat atrial tachyarrhythmias such as fibrillation in which atrial defibrillation pulses are delivered within a maximum pre-shock R—R synchronization interval. The method has been found to reduce the incidence of early recurrence of atrial fibrillation (ERAF).

An intravascular device for the formation of linear lesions which has particular utility in the treatment of atrial fibrillation and flutter. The intravascular device has an outer delivery member with a distal section which has an elongated opening and a support element coextending with the opening. An EP device having a plurality of electrodes on its distal section is slidably disposed within the inner lumen of the delivery member but it is secured by its distal end within the distal extremity of the delivery member at least while in operation. In this manner an axial force in the proximal direction on the proximal extremity of the EP device, which extends out of the patient during the procedure, will cause the distal shaft section of the EP device to arch outwardly out of and away from the distal section of the delivery shaft along an inner side of the curved distal section and engage the surface of the patient's heart chamber. RF electrical energy delivered to the electrodes on the distal shaft section of the EP device will form a linear lesion which terminates the fibrillation or flutter.

A method of ablating tissue in the heart to treat atrial fibrillation introduces into a selected atrium an energy emitting element. The method exposes the element to a region of the atrial wall and applies ablating energy to the element to thermally destroy tissue. The method forms a convoluted lesion pattern comprising elongated straight lesions and elongated curvilinear lesions. The lesion pattern directs electrical impulses within the atrial myocardium along a path that activates the atrial myocardium while interrupting reentry circuits that, if not interrupted, would cause fibrillation. The method emulates the surgical maze procedure, but lends itself to catheter-based procedures that do not require open heart surgical techniques. A composite structure for performing the method is formed using a template that displays in planar view a desired lesion pattern for the tissue. An array of spaced apart element is laid on the template. Guided by the template, energy emitting and non-energy emitting zones are formed on the elements. By overlaying the elements, the composite structure is formed, which can be introduced into the body to ablate tissue using catheter-based, vascular access techniques.

An implantable medical device such as a defibrillator is described. The device includes an hermetically sealed housing containing a flat electrolytic capacitor and an energy source such as a battery. The battery is connected to the capacitor and provides charge thereto. The capacitor stores the charge at a relatively high voltage. The charge stored in the capacitor is discharged through a defibrillation lead to a site on or in the heart when fibrillation of the heart is detected by the implantable medical device. Methods of making and using the implantable medical device, the capacitor, and their various components are disclosed.

An apparatus and method for delivering electrical shock therapy in order to treat atrial tachyarrhythmias such as fibrillation utilizes a dynamically varying threshold to detect R-waves and synchronously deliver a defibrillation shock.

A medical system includes a housing configured for implantation within a patient's subclavicular region. Detection circuitry provided in the housing is configured to detect cardiac electrical activity. Energy delivery circuitry provided in the housing is configured to deliver therapy to treat a detected tachycardia or fibrillation episode. A lead is coupled to the housing, detection circuitry, and energy delivery circuitry. The lead is configured for subcutaneous, non-intrathoracic placement within the patient, and extends from the subclavicular region to just below the patient's ribs or the subxiphoid process. A defibrillation electrode is provided at a distal end of the lead body. A pair of sensing electrodes is provided on the lead body at locations consistent with positions V2-V5 of surface electrocardiogram electrodes.

An apparatus and method for treating post-defibrillation electromechanical dissociation ("EMD"). A first embodiment comprises an implantable defibrillator, which may include cardioversion and pacemaker capabilities, which has the capability of detecting and treating post defibrillation EMD. The stimulator / defibrillator has one or more leads with electrodes. At least one electrode for defibrillation may be an endocardial or epicardial electrode or other suitable defibrillation electrode. A sense circuit senses the electrical condition of the heart of the patient. A hemodynamic sensor senses a parameter correlated to the state of blood flow. The cardiac stimulator / defibrillator detects ventricular tachyarrhythmia including fibrillation and terminates ventricular tachyarrhythmia. After termination of the ventricular tachyarrhythmia, the stimulator / defibrillator can detect the presence of electrical rhythm in the heart correlated, however, with inadequate blood flow to sustain life. Under such conditions, the device provides an output to stimulate the heart to overcome electromechanical dissociation and restore adequate blood flow. The device may also be an external therapy device, as part of, or in conjunction with an external defibrillator. The method for treating the heart to restore blood flow where electromechanical dissociation occurs after termination of a ventricular tachyarrhythmia or ventricular fibrillation comprises identifying electromechanical disassociation after termination of a ventricular tachyarrhythmia or a fibrillation and providing electrical therapy, the therapy comprising a series of packets of electrical pulses.

An intravascular device for the formation of linear lesions which has particular utility in the treatment of atrial fibrillation and flutter. The intravascular device has an outer delivery member with a distal section which has an elongated opening and a support element coextending with the opening. An EP device having a plurality of electrodes on its distal section is slidably disposed within the inner lumen of the delivery member but it is secured by its distal end within the distal extremity of the delivery member at least while in operation. In this manner an axial force in the proximal direction on the proximal extremity of the EP device, which extends out of the patient during the procedure, will cause the distal shaft section of the EP device to arch outwardly out of and away from the distal section of the delivery shaft along an inner side of the curved distal section and engage the surface of the patient's heart chamber. RF electrical energy delivered to the electrodes on the distal shaft section of the EP device will form a linear lesion which terminates the fibrillation or flutter.

A method and apparatus for cardioverting the atrium of a human heart that includes insertion of first and second elongated electrodes tranvenously into the heart and associated vessels. One electrode is preferably located in the coronary sinus and great vein of the heart. The other electrode is preferably located in the vicinity of the right atrium of the heart, spaced from the electrode located in the coronary sinus. In response to detection of fibrillation or in response to manual triggering, a defibrillation pulse is applied between the first and second electrodes to effect atrial cardioversion. Further, after delivery of a successful defibrillation shock, the width of intrinsic p-waves are monitored and bi-atrial pacing is temporarily initiated if the width exceeds a preset or programmable threshold.

The present invention is directed to a method of forming nonwoven webs comprising coated fibers. The method of forming the nonwoven web generally comprises the steps of forming fibers from a melt fibrillation process, forming at least one fluid stream containing a coating substance, applying the coating substance onto the surface of the fiber, and depositing the coated fibers on a surface to form a web. Typically, the fibers are coated in flight. Preferably, the melt fibrillation process to form the fibers is a melt film fibrillation process. A melt film fibrillation process generally includes the steps of providing a polymeric melt, utilizing a central fluid stream to form an elongated hollow polymeric film tube, and using air to form multiple nanofibers from the hollow tube. The nonwoven web may comprise a layer having a significant number of nanofibers with diameters less than one micron. The layer may comprise two or more pluralities of fiber diameter distributions wherein at least one plurality has an average fiber diameter of less than about one micron.

The invention relates to devices that detect and / or treat tachyarrhythmias. The invention includes software systems that distinguish among various tachyarrhythmias in order to provide treatment for specific tachyarrhythmias. One aspect of the invention employs a methodology to provisionally detect ventricular tachycardia and / or fibrillation and thereafter apply a discrimination function to a series of measured intervals preceding the provisional detection. Discrimination is accomplished by sorting the intervals preceding provisional detection into bins corresponding to interval ranges and examining the relative distribution of the intervals within the bins.

A system and related methods for assisting a user approximate the location of a fibrillation driver within a heart. The system includes an electrode and a computer, which is coupled to the electrode. The electrode is configured to sense a signal emitted from a location in the heart. The computer is configured to calculate a standard deviation of cycle length value for the signal. The user can approximate the location of the fibrillation driver based on a comparison of the standard deviation of cycle length value to other standard deviation of cycle length values that previously have been calculated by the computer for signals emitted from other locations in the heart.

A decorticated bast fiber such as from flax that is particularly suitable as a reinforcement for polymeric resins, thermoplastic, and thermoset composites. The invention specifically overcomes past difficulties involving compounding and injection molding of composite specimens with bast fiber reinforcements. In one form, ultrasonic energy is applied to decorticated bast fibers to cause fibrillation.

A cardiac assist device senses conditions of a heart and controls the generation of various electrical stimuli in response to sense conditions of the heart. The cardiac assist device generates a electrical pulse so as to defibrillate a fibrillated heart when the cardiac assist device determines from the sensed conditions a state of fibrillation. The cardiac assist device generates a chaos control electrical signal so as to bring a pre-fibrillated heart condition back into a normal beating condition when the cardiac assist device determines from the sensed conditions a pre-state of fibrillation. Lastly, the cardiac assist device generates an electrical enhancement signal that causes a threshold of pacing cells in the heart to be exceeded in response to a subthreshold stimulus when the cardiac assist device determines from the sensed conditions a subthreshold pacing signal.

Systems and methods employing a weighted zero crossing sum metric (WZCSM) derived from the EGM that improves the specificity of discriminating between a monomorphic tachyarrhythmia and a polymorphic tachyarrhythmia are provided that examine frequency content and baseline information of the EGM as discriminatory signatures are disclosed. In preferred embodiments, high rate polymorphic QRS complexes are discriminated from high rate monomorphic QRS complexes to increase the specificity of detection of polymorphic VT and VF. Zero crossing points (ZCPs) and weighted ZCP slopes of the high pass filtered EGM signal in baseline and sense event windows are identified. The weighted ZCPs of the baseline window are summed to provide a baseline WZCSB, and the weighted ZCPs of the VSENSE event window are summed to provide a VSENSE event WZCSE. A WZCSM is derived from the VSENSE event WZCSE and the baseline WZCSB that is compared to a threshold.

Methods and apparatus are provided for discriminating high rate polymorphic QRS complexes from high rate monomorphic QRS complexes to increase the specificity of detection of polymorphic VT and VF employing wavelet transform signal processing of the QRS complexes are disclosed. Wavelet transforms are applied to the sampled amplitude values of a sequence of QRS complexes to develop wavelet transform coefficient (WTC) data sets. At least selected ones of the WTC data sets are processed and comparisons are made to determine a wavelet match score. A determination is made as a function of the wavelet match scores of the series of successive QRS complexes that characterizes the most recent QRS complex as more or less likely to signify polymorphic VT or VF.

A biodegradable paper substrate and / or biodegradable fiber (including fiber tow) may be coated with cellulose acetate and / or plasticized cellulose acetate for use in a filter material configured for application in a filter of a smoking article. Flocking and / or fibrillation methods may be used to deposit and / or generate a plurality of fibers that may protrude beyond a surface of the biodegradable substrate material. A filter made in accordance with this design may also include non-biodegradable material.

A decorticated bast fiber such as from flax that is particularly suitable as a reinforcement for polymeric resins, thermoplastic, and thermoset composites. The invention specifically overcomes past difficulties involving compounding and injection molding of composite specimens with bast fiber reinforcements. In one form, ultrasonic energy is applied to decorticated bast fibers to cause fibrillation.

Methods and apparatus for a three-stage ventricular cardioversion and defibrillation therapy that treats ventricular tachycardia and fibrillation at low energy levels. An implantable therapy generator adapted to generate and selectively deliver a three-stage ventricular therapy and at least two leads operably each having at least one electrode adapted to be positioned proximate the ventricle of the patient. The device is programmed to deliver a three-stage therapy via both a far-field configuration and a near-field configuration of the electrodes upon detection of a ventricular arrhythmia. The three-stage therapy includes a first stage for unpinning of one or more singularities associated with the ventricular arrhythmia, a second stage for anti-repinning of the one or more singularities, both of which are delivered via the far-field configuration of the electrodes, and a third stage for extinguishing of the one or more singularities associated delivered via the near-field configuration of the electrodes.

A system and method for selectively treating a ventricular tachycardia based on sensed atrial and ventricular intervals from the patient's heart. A detection window of the ten most recent atrial and ventricular intervals are analyzed for the occurrence of either tachycardia or fibrillation. When a majority of the sensed intervals are satisfied, the apparatus starts a duration time interval. Ventricular intervals and atrial intervals are compare, ventricular interval greater than the atrial interval by a bias factor the system delivers tachycardia therapy to the heart. Alternatively, the method withholds tachycardia therapy to the heart when the atrial rate is classified as atrial fibrillation and the ventricular response is unstable.

A method of applying electrotherapy to the heart of a patient includes positioning electrodes in communication with the heart of the patient; monitoring the patient's heart to determine if its fibrillating; and providing a first signal with a current generator to the heart through the electrodes in response to an indication that the heart is fibrillating. The first stimulus signal reduces the amount of fibrillation.

Systems and methods that improving the specificity of discriminating between a monomorphic tachyarrhythmia and a polymorphic tachyarrhythmia are provided that examine frequency content and baseline information of the EGM as discriminatory signatures are disclosed. Particular algorithms of the present invention that are employed to determine frequency content of the QRS complexes are titled the Slope Distribution Metric (SDM) algorithm and the Slope Distribution Composite (SDC) algorithm.

Systems and methods employing a weighted zero crossing sum metric (WZCSM) derived from the EGM that improves the specificity of discriminating between a monomorphic tachyarrhythmia and a polymorphic tachyarrhythmia are provided that examine frequency content and baseline information of the EGM as discriminatory signatures are disclosed. In preferred embodiments, high rate polymorphic QRS complexes are discriminated from high rate monomorphic QRS complexes to increase the specificity of detection of polymorphic VT and VF. Zero crossing points (ZCPs) and weighted ZCP slopes of the high pass filtered EGM signal in baseline and sense event windows are identified. The weighted ZCPs of the baseline window are summed to provide a baseline WZCSB, and the weighted ZCPs of the VSENSE event window are summed to provide a VSENSE event WZCSE. A WZCSM is derived from the VSENSE event WZCSE and the baseline WZCSB that is compared to a threshold.