Abstract: A set of cardiogenic impedance signals are detected along different sensing vectors passing through the heart of the patient, particularly vectors passing through the ventricular myocardium. A measure of mechanical dyssynchrony is detected based on differences, if any, among the cardiogenic impedance signals detected along the different vectors. In particular, differences in peak magnitude delay times, peak velocity delay times, peak magnitudes, and waveform integrals of the cardiogenic impedance signals are quantified and compared to detect abnormally contracting segments, if any, within the heart of the patient. Warnings are generated upon detection of any significant increase in mechanical dyssynchrony. Diagnostic information is recorded for clinical review. Pacing therapies such as cardiac resynchronization therapy (CRT) can be activated or controlled in response to mechanical dyssynchrony to improve the hemodynamic output of the heart.

Abstract: System, assembly and method are provided to facilitate reconstruction of cardiac information representing a complex rhythm disorder associated with a patient's heart to indicate a source of the heart rhythm disorder. The complex rhythm disorder can be treated by application of energy to modify the source of the rhythm disorder.

Abstract: A computer-assisted method for quantitative characterization and treatment of ventricular fibrillation includes preprocessing a time series of an atrial fibrillation signal obtained from a patient, segmenting the time series of the AF signal into activation segments by the computer system, obtaining local activation waveforms (LAW) from the activation segments, determining degrees of similarity between the LAWs, and identifying one or more critical regions in the patient's atria if the LAWs have degrees of similarity exceeding a first threshold value.

Abstract: A cardiac rhythm management (CRM) system includes an implantable medical device that delivers anti-tachyarrhythmia therapies including ATP. When a tachyarrhythmia episode is detected, the implantable medical device analyzes the morphology of a cardiac signal to determine whether and/or when to deliver an ATP therapy. In various embodiments, the implantable medical device produces morphological parameters indicative of the likeliness of success of the ATP therapy and selects an anti-tachyarrhythmia therapy mode based on the morphological parameters. In various embodiments, the implantable medical device also controls the timing of the ATP therapy delivery using morphological features of the cardiac signal to maximize the probability that the ATP therapy is delivered into an ATP window during which a tachyarrhythmia episode can be effectively terminated by pacing.

Abstract: Techniques are described for distinguishing between treatable and non-treatable heart rhythms. A medical device that operates in accordance with the techniques analyzes characteristics over several cardiac event intervals to detect initiation of a sudden rate onset. After detection of the initiation of the sudden rate onset, the IMD analyzes a morphology of an EGM associated with a selected cardiac event within the first several beats after the initiation of sudden rate onset. In one example, the IMD analyzes the morphology of the EGM associated with the first cardiac event immediately subsequent to the initiation of the sudden rate onset. If the morphology of the EGM of the selected cardiac event is abnormal compared to template EGM, the rhythm is classified as treatable. Otherwise, the rhythm is classified as non-treatable.

Abstract: A method and system for determining the mechanism of cardiac arrhythmia in a patient is disclosed. The method basically entails measuring the impedance of cardiac tissue in a portion of the patient's heart using a catheter during an episode of supraventricular tachycardia to produce an iso-impedance map of that cardiac tissue on a video display and analyzing the pattern of the iso-impedance map to differentiate focal arrhythmia caused by a circumscribed region of focal firing and reentrant arrhythmia caused by a macroreentrant circuit. The method can also be used to identify regions of coherent rapidly conducting tissue e.g., Bachman's bundle or the inferoposterior pathway insertion points, to identify focal “mother rotors” throughout the left atrium that may participate in the generation and maintenance of atrial fibrillation and to identify areas of CAFE (complex atrial/fractionated electrograms) that truly reflect these mother rotors.

Abstract: Disclosed herein is a framework for facilitating patient signal analysis. In accordance with one aspect, at least one region of interest within a cycle of a waveform of patient signal data is identified. The identified region of interest may be segmented into portions using amplitude percentage categories. A sequential morphological data series may be generated by compiling time intervals of the segmented portions. One or more sequential signal parameters may be calculated based on the sequential morphological data series. A report may then be generated based at least in part on the one or more sequential signal parameters.

Abstract: Systems, devices and methods described herein can be used to monitor and treat cardiovascular disease, and more specifically, can be used to determine heart rate (HR), determine respiration rate (RR) and classify cardiac rhythms based on atrial intracardiac electrogram (IEGM) and atrial pressure (AP) signals. The atrial IEGM and AP signals are subject to spectrum transforms to obtain an atrial IEGM frequency spectrum and an AP frequency spectrum. Based on peaks in the atrial IEGM and AP frequency spectrums measures of HR and RR are determined, and arrhythmias are detected and/or arrhythmia discrimination is performed.

Abstract: A medical device and associated method for classifying an unknown cardiac signal that includes sensing a cardiac signal over a plurality of cardiac cycles, determining a template of a known cardiac signal in response to the cardiac signal sensed over the plurality of cardiac cycles, sensing an unknown cardiac signal over an unknown cardiac cycle, determining a fourth order difference signal, determining a template alignment point and an unknown cardiac signal alignment point in response to the fourth order difference signal; determining an R-wave onset and an R-wave offset in response to the fourth order difference signal of the unknown cardiac cycle signal, determining an R-wave width as the difference between the R-wave onset and the R-wave offset, determining a morphology analysis window in response to the R-wave width, and determining a first morphology match metric across the morphology analysis window.

Abstract: An example system and method of determining a likely core of a rotational source associated with a heart rhythm disorder are disclosed. A plurality of relative diffusion shapes associated with wave fronts is calculated at a plurality of time points associated with the rotational source. The wave fronts associated with heart signals. A plurality of intersecting points of a smallest relative diffusion shape and other relative diffusion shapes is determined. A bounded polygon of the intersecting points is defined as the likely core.

Abstract: A medical device and associated method for classifying an unknown cardiac signal operate to sense a cardiac signal over known cardiac cycles and generate a template of the known cardiac cycles. An unknown cardiac signal is sensed over an unknown cardiac cycle. A template alignment point and an unknown cardiac signal alignment point are identified by using a fourth order difference signal. The template and the unknown cardiac signal are aligned across an alignment window by aligning the template alignment point and the unknown cardiac signal alignment point. A morphology match metric measuring a similarity between the aligned template and the unknown cardiac signal is computed.

Abstract: A method of treating a complex rhythm disorder of a human heart includes identifying a region of a wall of the heart having an activation trail that is rotational or radially emanating, where the activation trail is indicative of the complex rhythm disorder and is based on activation times associated with one or more activations of the heart. A portion of the region is selected based on the activation trail and modified to affect the activation trail.

Abstract: A system for the detection of cardiac events occurring in a human patient. At least two electrodes are included in the system for obtaining an electrical signal from a patient's heart. An electrical signal processor is electrically coupled to the electrodes for processing the electrical signal. The system receives data regarding the patient's state (e.g. asleep, exercising). Patient state information is stored in a patient state array, thereby enabling the system to track the patient's state over time, and to select an appropriate test for detecting a cardiac event based on both past and present data regarding the patient's state.

Abstract: A personalized real-time automated cardiovascular monitoring system monitors abnormalities in a patient's cardiovascular activity data through the use of individually adjusted electrocardiogram Holter apparatus (Holter/ECG device) that provides an automatic medical diagnosis of cardiac abnormalities and generates abnormality alert signals representative of certain abnormalities in patient's cardiac activities. The signals are transmitted using a wireless network to a medical dispatcher center. A response is generated according to the abnormality detected. Individual parameters indicative of patient's cardio activities are personalized to allow for adjustments of chronic patients. A base Holter/ECG unit, includes the wireless/electric electrodes and their respective wireless/electric connections, and a Holter/ECG recording unit affixed to the base unit. Automatic real-time medical response may be provided based on automatic cardiac abnormality alert detection from the Holter/ECG data.

Abstract: A method of analyzing a complex rhythm disorder in a human heart includes accessing signals from a plurality of sensors disposed spatially in relation to the heart, where the signals are associated with activations of the heart, and identifying a region of the heart having an activation trail that is rotational or radially emanating, where the activation trail is indicative of the complex rhythm disorder and is based on activation times associated with the activations of the heart.

Abstract: The present disclosure provides a system and method of determining a risk score for triage. In particular, a system is provided for providing an assessment of risk of a cardiac event for a patient, for example an incoming patient to a hospital emergency department complaining of chest pain. In the disclosure, the system includes an input device for measuring physiological data based vital signs parameter of the patient, a twelve-lead electrocardiogram (ECG) device for establishing an ECG obtained from results of the electrocardiography procedure, and determining an ECG parameter and a heart rate variability (HRV) parameter therefrom. An ensemble-based scoring system is further provided, establishing weighted classifier based on past patient data and where the vital signs parameter, the ECG parameter and the HRV parameter are compared to corresponding weighted classifiers to determine a risk score. A corresponding method to determine a risk score for triage is also provided.

Abstract: An indication of an actual or potential heart failure condition is computed. One example includes monitoring a first heart rate preceding a first onset of a first sinus tachyarrhythmia episode. Upon detecting the first sinus tachyarrhythmia episode, the indication is automatically provided using information about the first heart rate and how quickly the first onset occurs.

Abstract: A medical device and associated method for classifying an unknown cardiac signal operate to sense a cardiac signal over known cardiac cycles and generate a template of the known cardiac cycles. An unknown cardiac signal is sensed over an unknown cardiac cycle. A template alignment point and an unknown cardiac signal alignment point are identified by using a fourth order difference signal. The template and the unknown cardiac signal are aligned across an alignment window by aligning the template alignment point and the unknown cardiac signal alignment point. A morphology match metric measuring a similarity between the aligned template and the unknown cardiac signal is computed.

Abstract: A method of determining the susceptibility to ventricular arrhythmias in a subject, comprises the steps of: (a) collecting (e.g., by surface EKG or intracardiac EKG) at least one QT and DI interval data set from the subject during a stage of gradually increasing heart rate or a stage of gradually decreasing heart rate; (b) determining (e.g.

Abstract: A system for heart performance characterization and abnormality detection includes an interface for receiving signal data representing an electrical signal indicating electrical activity of a patient heart over multiple heart beat cycles. A filter extracts first signal component data in a first selected bandwidth and first heart cycle portion of the received signal data and second signal component data in a different second selected bandwidth and second heart cycle portion of the received signal data. A signal processor uses the received signal data in calculating a ratio of a first value derived from the first signal component data to a second value derived from the second signal component data. A patient monitor in response to the calculated ratio or value derived from the calculated ratio, generates an alert message associated with the threshold.

Abstract: An implantable heart monitoring device including a sensing unit, a signal quality analysis unit, and an evaluation unit. The sensing unit is connected to at least one electrode that picks up electric potentials. The sensing unit processes electrical signals corresponding to the electric potentials, and generates sense signals including events corresponding to myocardial contractions. The signal quality analysis unit determines whether a noise condition (NC) and/or a low signal indication is present for an event and generates an indication signal. The evaluation unit evaluates the sense signals and the indication signals, treats a detected event as non-valid if a NC and/or low signal indication signal is present for that event, and uses only intervals defined by two consecutive events which do not have a NC and/or a low signal indication to determine a rate of events of the sense signal.

Abstract: An apparatus comprises a cardiac signal sensing circuit, a physiologic sensor circuit configured to provide a physiologic sensor signal representative of mechanical cardiac activity, a therapy circuit, and a control circuit. The control circuit includes a cardiac depolarization detection circuit, a tachyarrhythmia detection circuit, and a timer circuit. A time interval between a mechanical cardiac event and a detected fiducial electrical cardiac event is monitored. The control circuit is configured to correct the monitored time interval for variation with heart rate to form a corrected electromechanical time interval, initiate anti-tachyarrhythmia therapy when the corrected electromechanical time interval satisfies a specified time interval threshold value during a detected episode of tachyarrhythmia, and withhold anti-tachyarrhythmia therapy otherwise.

Abstract: An electrocardiogram analyzer has a measurement section for measuring an electrocardiographic signal; a determination unit for determining, from arrhythmia determination reference information that is information pertinent to arrhythmia, whether or not an electrocardiogram multiplex, which includes a first predetermined number of heart beats, in the thus-measured electrocardiographic signal is arrhythmia; a reference waveform determination unit that determines a reference waveform from the electrocardiogram complex including the first predetermined number of heart beats when the determination unit has determined that the electrocardiogram complex is not arrhythmia, storing the thus determined reference waveform; and an analysis unit that performs an analysis as to whether or not an electrocardiogram complex being measured is arrhythmia by use of the stored reference waveform.

Abstract: Embodiments of the present invention relate to implantable systems, and methods for use therewith, for monitoring myocardial electrical stability. A patient's heart is paced for a period of time using a patterned pacing sequence that repeats every N beats, and an electrical signal is obtained that is representative of a plurality of consecutive beats of the patient's heart while it is being paced using the patterned pacing sequence that repeats every N beats. Myocardial electrical stability is then analyzed using time domain techniques that are tailored to the patterned pacing sequence used to pace the patient's heart. In other embodiments, the patient's heart need not be paced. This abstract is not intended to be a complete description of, or limit the scope of, the invention.

Abstract: A method, system, and device for detection of an arrhythmia, and discrimination between different types of arrhythmia, for example to determine whether to administer an electric shock to the heart, the device comprising a wearable monitor with electrodes that detect the electrical activity of a beating heart, attached to an embedded monitoring system having an amplifier, a microprocessor, a data storage device, and a power supply, all disposed on a substrate having large distal end portions that attach to the electrodes and a narrow intermediate portion that attaches to the monitoring system.

Abstract: Described herein are implantable systems and devices, and methods for use therewith, that can be used to perform arrhythmia discrimination based on activation times. A plurality of different sensing vectors are used to obtain a plurality of IEGMs that collectively enable electrical activations to be detected in the left atrial (LA) chamber, the right atrial (RA) chamber, and at least one ventricular chamber of a patient's heart. For each of a plurality of cardiac cycles, there is a determination, based on the plurality of obtained IEGMs, of an LA activation time, an RA activation time, and a ventricular activation time. Arrhythmia discrimination is then performed based on the determined activation times.

Abstract: A method is disclosed for displaying patient ECG data. The method includes receiving ECG data including an ECG waveform; receiving analyzed ECG data including arrhythmic events; generating an indicia of the detected arrhythmic event; and displaying the indicia of the detected arrhythmic event in relation to the ECG waveform at a position associated with a time of the detected arrhythmic event. A system for displaying patient ECG data is also disclosed.

Abstract: A system for measuring heart rate variability (HRV) comprising 3 sub-systems: a data collection sub-system, a data analysis sub-system, and an output sub-system. A patient is connected to a heart monitoring device such as an ECG and the data collection sub-system records the patients heart beats, and an ECG chart is produced from which the patient's HRV value is derived by the data analysis sub-system. The present invention obtains the HRV value through calculation of a new parameter called relative density (RD). In accordance with the inventive method, data points are generated from the peak interval data of measured heart beats and the HRV relative density parameter (RD) is calculated by correlation between two subsets of data points.

Abstract: System, assembly and method are provided to facilitate reconstruction of cardiac information representing a complex rhythm disorder associated with a patient's heart to indicate a source of the heart rhythm disorder. The complex rhythm disorder can be treated by application of energy to modify the source of the rhythm disorder.

Abstract: A method for identifying oversensing in implantable medical devices (IMDs), such as implantable cardioverter defibrillators (ICDs), is described. A near-field electrogram signal and a far-field electrogram signal are obtained via a near-field electrode pair and a far-field electrode pair. The near-field electrogram signal is compared to the far-field electrogram signal and a determination of whether oversensing exists is made based on the comparison. In some instances, a scheduled therapy is withheld in response to determining that oversensing exists.

Abstract: The present technology describes various embodiments of systems and methods for analyzing electrocardiograms to detect ventricular fibrillation. In several embodiments, systems for detecting ventricular fibrillation can be implemented without interrupting cardiopulmonary resuscitation. In one embodiment, a method of identifying a cardiac rhythm in a person includes recording an electrocardiogram signal of the person and stratifying the signal. A signal having a parameter value within a pre-determined range is categorized as a shockable ventricular fibrillation signal while a signal having a parameter value outside the pre-determined range is categorized as a non-shockable signal.

Abstract: An implantable medical device is provided for detecting transportless ventricular rhythm of a heart lacking atrial transport and comprises a housing, sensors configured to be located proximate to a heart, a sensing module to sense cardiac signals representative of a rhythm originating from the heart and a rhythm detection module. The rhythm detection module determines a change in AV association and identifies a potential ventricular complex with loss of atrial transport (VCLAT) based on the change in AV association.

Abstract: The type of arrhythmia in a patient's heart can be determined by monitoring the atrial and ventricular rate of the heart; detecting a pathological initial ventricular and/or atrial rate during a first time period; if a pathological initial rate is detected, then administering at least one antiarrhythmic cardioactive drug over a short second time period; detecting the heart's response to the administered drug(s), as by comparing the responsive ventricular and atrial rates with the initial ventricular and atrial rates, respectively, within a third time period; and determining the type of atrial or ventricular arrhythmia from the presence or absence of differences, and the type of differences, between the responsive atrial and ventricular rates compared with the initial atrial and ventricular rates. The invention further involves a related device which includes an implantable cardiac device (10) and a drug delivery device (20).

Abstract: A method is disclosed for displaying patient ECG data. The method includes receiving ECG data including an ECG waveform; receiving analyzed ECG data including arrhythmic events; generating an indicia of the detected arrhythmic event; and displaying the indicia of the detected arrhythmic event in relation to the ECG waveform at a position associated with a time of the detected arrhythmic event. A system for displaying patient ECG data is also disclosed.

Abstract: A TWA measuring apparatus includes: a T-wave feature quantity measuring section; a classifying section classifying T-wave feature quantities into groups of odd and even electrocardiogram waveforms; a reliability index calculating section calculating: first and second representative values and first and second dispersion values of the T-wave feature quantities in the odd and even group; a difference between the first and second representative values, to obtain a TWA feature quantity; and an adjustment value between the first representative value and the first dispersion value, and an adjustment value between the second representative value and the second dispersion value, to obtain a reliability index; and a reliability recognizing section recognizing: when the reliability index exceeds a threshold, that reliability of the TWA feature quantity is high; and when the reliability index does not exceed the threshold, that the reliability is low.

Abstract: Systems and methods define an index of risk for cardiac disease by detecting cellular derangements that may lead to cardiomyopathy, heart rhythm disorders or ischemic heart disease. The markers include fluctuations or abnormal rate-behavior of electrical, mechanical or other measurable biosignals. The invention operates in modes that can be applied to prevent atrial fibrillation or the risk for ventricular arrhythmias. Alternative embodiments are applied to tissue outside the heart such as skeletal muscle, smooth muscle, the central nervous system, the respiratory system, the urogenital system and the gastrointestinal system.

Abstract: Electrical crosstalk between two implantable medical devices or two different therapy modules of a common implantable medical device may be evaluated, and, in some examples, mitigated. In some examples, one of the implantable medical devices or therapy modules delivers electrical stimulation to a nonmyocardial tissue site or a nonvascular cardiac tissue site, and the other implantable medical device or therapy module delivers cardiac rhythm management therapy to a heart of the patient.

Abstract: Systems and devices to gather data from a subject's heart, analyze said data to determine whether the subject is experiencing cardiac arrhythmia, and display results of said determining. Use, and display of cardiac condition information, are preferably simple and unambiguous to untrained users.

Abstract: The invention provides a sensor for measuring both impedance and ECG waveforms that is configured to be worn around a patient's neck. The sensor features 1) an ECG system that includes an analog ECG circuit, in electrical contact with at least two ECG electrodes, that generates an analog ECG waveform; and 2) an impedance system that includes an analog impedance circuit, in electrical contact with at least two (and typically four) impedance electrodes, that generates an analog impedance waveform. Also included in the neck-worn system are a digital processing system featuring a microprocessor, and an analog-to-digital converter. During a measurement, the digital processing system receives and processes the analog ECG and impedance waveforms to measure physiological information from the patient. Finally, a cable that drapes around the patient's neck connects the ECG system, impedance system, and digital processing system.

Abstract: A system and method for determining atrial arrhythmia burden is provided. Consecutive sets of parametric data regularly obtained from an implantable medical device through remote interrogation are centrally maintained. An atrial arrhythmia burden is determined. A cumulative atrial tachyarrhythmia (AT) duration is identified for each atrial arrhythmia episode recorded in the parametric data over a fixed look back period. One of an AT mode switch time and maximum atrial tachyarrhythmia AT duration are evaluated respectively subject to the duration between the consecutive sets being of sufficient length and a change having occurred to the maximum AT duration.

Abstract: An implantable medical device senses a plurality of electrograms from substantially different atrial locations, detects regional depolarizations from the electrograms, and analyzes timing relationships among the regional depolarizations. The timing relationships provide a basis for effective therapy control and/or prognosis of certain cardiac disorders. In one embodiment, an atrial activation sequence is mapped to show the order of occurrences of the regional depolarizations during an atrial depolarization for classifying a detected tachyarrhythmia by its origin. In another embodiment, conduction time between two atrial locations is measured for monitoring the development of an abnormal atrial conditions and/or the effect of a therapy.

Abstract: One or more embodiments of the present disclosure relates to a method and/or system for classifying and/or treating heart rhythms. The present disclosure involves sensing electrical signals associated with depolarizations of a patient's heart. The sensed electrical signals are converted to digital values and storing the digital values. Normalizing solely a maximum and a minimum value of the stored digital values associated with a depolarization of the patient's heart without normalizing other stored digital values of the depolarization is another aspect of the present disclosure. The maximum and minimum values associated with the depolarization are compared to maximum and minimum values associated with a template derived from signals indicative of a heart depolarization of known type. A determination is made as to whether a match exists between the maximum and minimum values associated with the depolarization to the maximum and minimum values associated with a template.

Abstract: The invention discloses a method, a system, a computer program and a device for determining the surface charge and/or dipole densities on heart walls. Using the foregoing, a table of dipole densities ?(P?, t) and/or a table of surface charge densities ?(P?, t) of a given heart chamber can be generated.

Abstract: Arrhythmia may impact the determination of physiological information from a physiological signal. A patient monitoring system may detect the presence of arrhythmia based on changes in the physiological signal. Derived value data sets may be extracted from the physiological signal and calculations performed to generate arrhythmia features. The arrhythmia features may be used to generate an arrhythmia indicator that may indicate the presence of arrhythmia in the physiological signal.

Abstract: In an implantable medical device such as an implantable cardiac defibrillator, and a method for classifying arrhythmia events, IEGM signals are analyzed to detect an arrhythmia event and a respiratory pattern of the patient is sensed. At least one respiratory parameter reflecting characteristics of the respiratory pattern of the patient is determined based on the sensed respiratory pattern and a respiratory measure corresponding to a change of a rate of change of the at least one respiratory parameter is calculated. The detected arrhythmia event is classified based on the respiratory measure and the IEGM signals, wherein arrhythmia events that satisfy at least a first criterion is classified as an arrhythmia event requiring therapy.

Abstract: An implantable medical device acquires a first cardiac signal in a first heart chamber and a second cardiac signal in a second heart chamber. The device determines if the first signal is unreliable. In response to determining the first signal to be unreliable, the device switches from a first cardiac arrhythmia detection mode of operation to a second cardiac arrhythmia detection mode of operation, the first detection mode requiring the use of both the first cardiac signal and the second cardiac signal and the second detection mode requiring the use of the second cardiac signal and not requiring the use of the first cardiac signal.

Abstract: An implantable heart stimulating device for indicating congestive heart failure (CHF) has a processor and a sensor combination that senses at least two heart events during one heart cycle at different locations of the heart. The processor is supplied with signals from the sensor combination relating to the sensed events, and determines therefrom at least one heart time interval between the sensed events in the same heart cycle. The processor determines a CHF indicator value representing a degree of CHF based on a variability measure calculated from at least two heart time intervals from at least two different heart cycles. The processor determines the CHF indicator value in relation to previous CHF indicator values.

Abstract: Methods and systems are provided for determining an increased likelihood of the occurrence of a cardiac arrhythmia, myocardial ischemia, congestive heart failure and other diseased conditions of the heart associated with elevated sympathetic neural discharges in a patient. The methods and systems comprise monitoring the sympathetic neural discharges of a patient from the stellate ganglia, the thoracic ganglia, or both, and detecting increases in the sympathetic neural discharges. The methods and systems may further comprise delivering therapy to the patient in response to a detected increase in the sympathetic neural discharge, such as delivering one or more pharmacological agents; stimulating myocardial hyperinnervation in the sinus node and right ventricle of the heart of the patient; and applying cardiac pacing, cardioversion or defibrillation shocks.

Abstract: A resuscitation system that includes at least two defibrillation electrodes configured to be applied to the exterior of the chest of a patient for delivering a defibrillation shock, a source of one or more ECG signals from the patient, a defibrillation circuit for delivering a defibrillation shock to the defibrillation electrodes, a control box that receives and processes the ECG signals to determine whether a defibrillation shock should be delivered or whether CPR should be performed, and that issues instructions to the user either to deliver a defibrillation shock or to perform CPR, wherein the determination of whether CPR should be performed and the instructions to perform CPR can occur at substantially any point during a rescue. The control box may include a user operable control for initiating delivery of a defibrillation shock, and the instructions to deliver a defibrillation shock include instructions to activate the user operable control.

Abstract: A medical device system that includes a brain monitoring element, cardiac monitoring element and a processor. The processor is configured to receive a brain signal from the brain monitoring element and a cardiac signal from the cardiac monitoring element. The processor is further configured to compare the brain signal to the cardiac signal. A method of comparing a brain signal to a cardiac signal is also provided.