176 results about "Ventricular fibrillation" patented technology

A cardiac monitor is provided that monitors the condition of the heart of a cardiac patient and generates signals indicating one of several conditions, such as supraventricular tachycardia, ventricular tachycardia and ventricular fibrillation. In order to generate these signals, the ECG from the patient is analyzed to determine a cardiac interval and heart rate, as well as a waveform factor and a waveform factor irregularity. The waveform factor is derived from the average of the ECG amplitudes during a cardiac interval and the peak value of the ECG during the same interval. Preferably, a running average is calculated over several intervals. This waveform factor is then used to detect shockable ventricular arrhythmia. The waveform factor irregularity is indicative of the variability of the waveform factor and is used to differentiate between ventricular tachycardia and ventricular defibrillation.

Transcutaneous electrical and magnetic nerve stimulation devices are disclosed, along with methods of averting imminent medical attacks using energy that is delivered noninvasively by the devices. The attacks comprise asthma attack, epileptic seizure, attacks of migraine headache, transient ischemic attack or stroke, onset of atrial fibrillation, myocardial infarction, onset of ventricular fibrillation or tachycardia, panic attack, and attacks of acute depression. The imminence of an attack is forecasted using grey-box or black-box models as used in control theory. In preferred embodiments of the disclosed methods, a vagus nerve in the neck of a patient is stimulated noninvasively to avert the attack.

Transcutaneous electrical and magnetic nerve stimulation devices are disclosed, along with methods of averting imminent medical attacks using energy that is delivered noninvasively by the devices. The attacks comprise asthma attack, epileptic seizure, attacks of migraine headache, transient ischemic attack or stroke, onset of atrial fibrillation, myocardial infarction, onset of ventricular fibrillation or tachycardia, panic attack, and attacks of acute depression. The imminence of an attack is forecasted using grey-box or black-box models as used in control theory. In preferred embodiments of the disclosed methods, a vagus nerve in the neck of a patient is stimulated noninvasively to avert the attack.

A basic life support system (BLSS) includes a processing element and an output element, such as a display screen or an audio output element, for providing an individual with real-time instructions on providing emergency medical care to a patient until paramedics or other healthcare professionals arrive to take over care for the patient. The instructions may be provided as graphics, including animations, as text, audibly, or as a combination of visible and audible elements. The BLSS may be configured for providing emergency medical care to individuals who have suffered from ventricular fibrillation. Accordingly, the BLSS may also include a defibrillation apparatus, an air or oxygen supply, a respiratory interface, one or more sensors, or a combination thereof.

An implantable medical device and method are provided for assessing autonomic tone and risk factors associated with arrhythmias and, based on this assessment, an early recurrence of ventricular tachycardia or ventricular fibrillation is predicted. Specifically, changes in R—R interval, heart rate variability, patient activity, and myocardial ischemia are measured prior to and after a detected an arrhythmia episode. A recurrence score is calculated as a weighted sum of measured parameters and compared to a prediction criterion. The prediction criterion may be a preset threshold score or an individualized episode template based on previously calculated recurrence scores associated with recurring episodes. Stored parameters and episode-related data may be downloaded for offline analyses for optimizing prediction criteria and monitoring patient status.

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.

Techniques are provided for use with an implantable medical device such as a pacemaker or implantable cardioverter / defibrillator (ICD) for predicting and detecting hypoglycemia. In one example, the device tracks changes in a paced depolarization integral (PDI). A significant increase in PDI over a relatively short period of time indicates the onset of hypoglycemia (this can also be confirmed with QT changes). Upon detection of hypoglycemia, appropriate warning signals are generated to alert the patient. Certain therapies automatically provided by the implantable device may also be controlled in response to hypoglycemia. For example, if the patient is an insulin-dependent diabetic and the implantable device is equipped with an insulin pump capable of delivering insulin directly into the bloodstream, insulin delivery is automatically suspended until blood glucose levels return to acceptable levels. If the device is an ICD, it may be controlled to begin charging defibrillation capacitors upon detection of hypoglycemia so as to permit prompt delivery of a defibrillation shock, which may be needed if hypoglycemia triggers ventricular fibrillation. The detection techniques may be used in conjunction with other hypoglycemia detection techniques to improve detection specificity.

A system and method based on electrocardiogram (ECG) complexity analysis for real-time detecting shockable ventricular fibrillation (VF) and ventricular tachycardia (VT), and discriminating them from non-shockable tachyarrhythmia (e.g. supraventricular tachycardia (SVT) and atrial fibrillation (AF)) and high-frequency noise. In the disclosed invention, complexity measure CM (0 to 100), quantitatively characterizing the complexity nature of the non-linear dynamics underlying cardiac arrhythmia, is extracted from the sensed patient ECG signal using ECG complexity analysis. From the calculated complexity measure, by three thresholds (low complexity threshold (LCT), mediate complexity threshold (MCT), and high complexity threshold (HCT)), different kinds of tachyarrhythmia (i.e. heart rate (HR) above a preset rate threshold) and high-frequency noise are discriminated from each other: for non-shockable tachyarrhythmia, CM<=LCT; for VT, LCT<CM<=MCT; for VF, MCT<CM<=HCT; and for high-frequency noise, HCT<CM. The disclosed system and method can be used as a primary cardiac tachyarrhythmia detection scheme or as a backup system to reconfirm arrhythmia detection using conventional techniques.

In some embodiments, a wearable cardioverter defibrillator (“WCD”) system may output an opening human-perceptible indication, after detecting a shockable cardiac arrhythmia but before validating it. This may succeed in informing the patient that the WCD system is working, and in particular analyzing a just-detected cardiac arrhythmia. The information may give comfort and confidence to the patient who may be conscious, and be experiencing only ventricular tachycardia but not ventricular fibrillation.

A basic life support system (BLSS) includes a processing element and an output element, such as a display screen or an audio output element, for providing an individual with real-time instructions on providing emergency medical care to a patient until paramedics or other healthcare professionals arrive to take over care for the patient. The instructions may be provided as graphics, including animations, as text, audibly, or as a combination of visible and audible elements. The BLSS may be configured for providing emergency medical care to individuals who have suffered from ventricular fibrillation. Accordingly, the BLSS may also include a defibrillation apparatus, an air or oxygen supply, a respiratory interface, one or more sensors, or a combination thereof.

The present invention is directed to an electromechanical pumping system for simulating the beating of heart in a cardiac surgery training environment. A computer-controllable linear actuator is used to control the electromechanical pumping system.In a preferred embodiment, the electromechanical pumping system is linked to a porcine heart. The heart is made to beat by inserting intra-ventricular balloons placed inside the heart and connected to the pumping system. When controlled by the electromechanical pumping system, the porcine heart is able to display normal and abnormal beating rhythms, as well as ventricular fibrillation.In addition, an electronic pressure sensor incorporated into the pumping system can be used to trigger a ventricular fibrillation mode when the porcine heart attached to the pumping system is handled by a trainee surgeon.

Implantable defibrillators are implanted into the chests of patients prone to suffering ventricular fibrillation, a potentially fatal heart condition. A critical component in these devices is an aluminum electrolytic capacitors, which stores and delivers one or more life-saving bursts of electric charge to a fibrillating heart. These capacitors make up about one third the total size of the defibrillators. Unfortunately, conventional manufacturers of these capacitors have paid little or no attention to reducing the size of these capacitors through improved capacitor packaging. Accordingly, the inventors contravened several conventional manufacturing principles and practices to devise unique space-saving packaging that allows dramatic size reduction. One embodiment of the invention uses thinner and narrower separators and top and bottom insulative inserts to achieve a 330-volt operating, 390-volt surge, 190-microfarad, 30-Joule aluminum electrolytic capacitor which is 33 percent smaller than conventional capacitors having similar electrical traits.

An apparatus and method is presented for improving cardiac function after successful termination of a tachyarrhythmia such as ventricular fibrillation. A series of electrical stimulation pulses are delivered prior to a defibrillation shock if one or more specific criteria are met.

A method of determining a state of ventricular fibrillation from a waveform, includes: performing calculations on the Fourier transform of the waveform voltage values by using the quotient of the power in a high frequency band and of the power in a low frequency band; and determining the state of ventricular fibrillation by relating this ratio to the state of ventricular fibrillation. A defibrillation system for use in treatment of ventricular fibrillation includes at least one sensor to measure heart rhythm and at least one applicator to apply a defibrillation shock to a patient. The system further includes at least one processor which is adapted to calculate the ratio and also to obtain user input regarding survival of subgroups and average response times in the user's domain which allows calculation of an estimated maximum overall survival and selection of an optimum threshold for the ratio measure based on this maximum. The system further includes a user interface system in operative connection with the processor to provide information related to the ratio to a user.

A method is provided for analyzing the condition of a patient to determine whether or not a defibrillation shock should be applied, without stopping CPR (primarily chest compressions). While chest compressions continue to be applied to the victim, the system differentiates between (1) a perfusing rhythm that has the capability of leading to a beating heart without a shock and (2) ventricular fibrillation (VF) which sometimes occurs in the presence of ventricular tachycardia (VT), in which there is no capability for leading to a beating heart without a shock. Defibrillation shocks should be applied only when needed and that is in the presence of VF and sometimes in the presence of VT. Electrocardiographic (ECG or EKG) signals obtained from electrodes applied to the patient's chest are analyzed so that the presence of a QRS signal characteristic of a rhythm which has the potential of supporting a beating heart, or the absence of a QRS signal which indicates ventricular fibrillation, may be detected in the presence of artifacts resulting from chest compressions.

A method of determining a state of ventricular fibrillation from a waveform, includes: performing calculations on the Fourier transform of the waveform voltage values by using the quotient of the power in a high frequency band and of the power in a low frequency band; and determining the state of ventricular fibrillation by relating this ratio to the state of ventricular fibrillation. A defibrillation system for use in treatment of ventricular fibrillation includes at least one sensor to measure heart rhythm and at least one applicator to apply a defibrillation shock to a patient. The system further includes at least one processor which is adapted to calculate the ratio and also to obtain user input regarding survival of subgroups and average response times in the user's domain which allows calculation of an estimated maximum overall survival and selection of an optimum threshold for the ratio measure based on this maximum. The system further includes a user interface system in operative connection with the processor to provide information related to the ratio to a user.

The present invention relates to a preventive and / or therapeutic agent for hyperkalemia, and a potassium excretion promoter containing EP4 agonist. Since EP4 agonist promotes potassium excretion, it is useful as a preventive and / or therapeutic agent for hyperkalemia. In addition, if selective EP4 agonist uses, it is a preventive and / or therapeutic agent for hyperkalemia without side effects. Further, if EP4 agonist is used, it is useful as improving agent for various symptoms (e.g. paresthesia, error of perception, weakness, myoparalysis, nausea, vomit, abdominal pain, diarrhea, arrhythmia, atrioventricular block, ventricular fibrillation, atrial fibrillation, cardiac arrest, asphyxia and / or dyspnoea etc.).

Methods are provided for treating arrhythmias including tachycardias, such as idiopathic ventricular tachycardia, ventricular fibrillation, and Torsade de Pointes (TdP) in a manner that minimizes undesirable side effects.

A method is provided for controlling an automatic external defibrillator without stopping CPR (primarily chest compressions). While chest compressions continue to be applied to the victim, the system differentiates between (1) a perfusing rhythm that has the capability of leading to a beating heart without a shock and (2) ventricular fibrillation (VF) which sometimes occurs in the presence of ventricular tachycardia (VT), in which there is no capability for leading to a beating heart without a shock. Defibrillation shocks should be applied only when needed and that is in the presence of VF and sometimes in the presence of VT. Electrocardiographic (ECG or EKG) signals obtained from electrodes applied to the patient's chest are analyzed so that the presence of a QRS signal characteristic of a rhythm which has the potential of supporting a beating heart, or the absence of a QRS signal which indicates ventricular fibrillation, may be detected in the presence of artifacts resulting from chest compressions.

An implantable cardiac stimulation device applies defibrillating electrical energy to the atria of a heart at a time which avoids inducing ventricular fibrillation of the heart. The device includes an atrial fibrillation detector that detects atrial fibrillation of the heart, a pacing pulse generator that applies a ventricular pacing pulse to the heart responsive to detection of atrial fibrillation, a timer that times a time period through an evoked response and a T-wave caused by the pacing pulse, and a defibrillation pulse generator that applies defibrillating electrical energy to the atria of the heart after the timer completes the timing of the time period.

A technique is provided for detecting episodes of cardiac ischemia based on an examination of post-T-wave signal segments. Since cardiac ischemia is often a precursor to acute myocardial infarction (AMI) or ventricular fibrillation (VF), the technique thereby provides a method for predicting the possible onset of AMI or VF so that a warning may be delivered to the patient. The warning preferably includes both a perceptible electrical notification signal applied directly to subcutaneous tissue and a warning signal delivered via short range telemetry to a handheld warning device external to the patient. In one example, the onset of cardiac ischemia is identified by detecting a sharp falling edge within post-T-wave signals by filtering the signals using a high-pass filter having a cutoff frequency of at least 1 Hz. The total amount of energy in the filtered signal is calculated and compared against various thresholds.

A technique is provided for detecting episodes of cardiac ischemia based on an examination of the total energy of T-waves. Since cardiac ischemia is often a precursor to acute myocardial infarction (AMI) or ventricular fibrillation (VF), the technique thereby provides a method for predicting the possible onset of AMI or VF. Briefly, the technique integrates internal electrical cardiac signals occurring during T-waves and then compares the result against a running average. If the result exceeds the average by some predetermined amount, ischemia is thereby detected and a warning signal is provided to the patient. The maximum slope of the T-wave is also exploited. Techniques are also set forth herein for reliably detecting T-waves, which help prevent P-waves from being misinterpreted as T-waves on unipolar sensing channels. The T-wave detection technique may be used in conjunction with ischemia detection or for other purposes.

A composition is provided which contains policosanol and omega-3 fatty acids and which may be used for treating and or reducing hypercholesterolemic diseases, total cholesterol, LDL-cholesterol, LDL / HDL ratio, triglycerides, coronary heart disease (heart attacks and strokes), sudden cardiac death, ventricular fibrillation, tachycardia, hypertension, inflammation, thrombosis, deep-vein thrombosis, stroke, macular degeneration, autoimmune and / or immunoregulatory diseases, cardiovascular diseases, anxiety, depression and / or neurodegenerative disorders, and / or raise HDL cholesterol in humans and animals. The method comprises administering policosanol and omega-3 fatty acids which together effectively lower the LDL / HDL cholesterol ratio. Typically, the administered composition includes about 0.1-10:1 parts by weight of policosanol to omega-3 fatty acids.

A method is provided for analyzing the condition of a patient to determine whether or not a defibrillation shock should be applied, without stopping CPR (primarily chest compressions). While chest compressions continue to be applied to the victim, the system differentiates between (1) a perfusing rhythm that has the capability of leading to a beating heart without a shock and (2) ventricular fibrillation (VF) which sometimes occurs in the presence of ventricular tachycardia (VT), in which there is no capability for leading to a beating heart without a shock. Defibrillation shocks should be applied only when needed and that is in the presence of VF and sometimes in the presence of VT. Electrocardiographic (ECG or EKG) signals obtained from electrodes applied to the patient's chest are analyzed so that the presence of a QRS signal characteristic of a rhythm which has the potential of supporting a beating heart, or the absence of a QRS signal which indicates ventricular fibrillation, may be detected in the presence of artifacts resulting from chest compressions.

The present invention provides a cell phone and a case, wherein the case includes a external system and a internal system, wherein the external system includes a signal receive part, a cell phone case, a connector and a defibrillator part, wherein the internal portion includes an power supply part, a amplifying part and a signal processing part; the present invention also provides a method for removal of cardiac ventricular fibrillation.

A method of determining a state of ventricular fibrillation from waveform obtained at sampling rates and with filtering typical of current clinical devices, includes: performing calculations to produce the autocorrelation function of the measured ventricular fibrillation heart rhythm over a given range of lags; determining a first value related to the sum of the absolute values of the series of values forming the autocorrelation function over the given range of lags over the period of time; and determining the state of ventricular fibrillation by relating the first value or the logarithm of the first value to the state of ventricular fibrillation. A defibrillation system for use in treatment of ventricular fibrillation includes at least one sensor to measure heart rhythm and at least one applicator to apply a defibrillation shock to a patient. The system further includes at least one processor in communication with the sensor and the applicator which is adapted to calculate the first value related to the sum of the absolute values of the values in the autocorrelation function over the given range of lags over the period of time. The system further includes a user interface system in operative connection with the processor to provide information related to the first value to a user.

Techniques are provided that identify and localize on to reentrant and ectopic patterns of electrical activation in the heart wall. These patterns may correspond to atrial fibrillation, ventricular fibrillation, or other heart arrhythmia conditions. The techniques detect these patterns of electrical activity using a multi-lead an intra-cavitary catheter that, along with a controller, is able to track, over a multi-dimensional cubic space, reentrant activity and identify filaments in the heart cavity. The intra-cavitary catheter includes multiple conducting poles positioned in a configuration relative to each other and functioning as either or both sensing and active poles for measuring electrical pathways in the heart wall and over the multi-dimensional space.