166 results about "Cardiac monitoring" patented technology

Methods and apparatus for gathering and processing data sensed on an individual from portable heart monitors and accelerometers aligned along three orthogonal axes determine substantially equivalent oxygen consumption information during an individual's physical activities without requiring gas-flow or gas-analysis equipment. Such information promotes calculations of physiological energy expenditures, and analyses of the accelerometer data associated with a specific sensing location on an individual's body provide indication of the particular physical activity for selecting appropriate scaling factors and filtering requirements in analyzing the data to determine various parameters indicative of the individual's expenditure of physiological energy, and other health-oriented factors.

Embodiments of the invention provide methods of obtaining continuous cardiac information from a mammal. First, attach a self-contained, wearable, portable continuous cardiac monitor to the mammal to create a chamber containing electrodes used to detect cardiac signals from the mammal. Next, continuously detect without analyzing the cardiac signals from the mammal for at least 24 hours. Next, store information related to substantially all detected cardiac signals in the cardiac monitor.

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.

One embodiment of the invention is a cardiac monitor having a housing; a plurality of electrodes within and extending from the housing; a state machine within the housing configured to digitialize and store in memory signals from the plurality of electrodes; a sealing surface and an adhesive on the sealing surface configured to form a watertight perimeter around the plurality of electrodes when the housing is affixed to a mammal. Another embodiment of the invention provides a continuous cardiac monitor having a housing; a surface on the housing adapted to be sealably engaged to a mammal; an adhesive on the surface that is adapted to remain affixed to the mammal for at least 7 days; at least two electrodes within the housing positioned to detect a cardiac information of the mammal while the surface is sealably engaged to the mammal; an electronic memory within the housing wherein, the electronic memory is sized to store at least 24 hours of continuous cardiac information; and wiring within the housing connecting the electronic memory to the electrodes.

A system for long-term non-invasive heart monitoring includes (1) a disposable unit that has built-in electrodes, a built-in wire antenna, a watertight chamber that can be opened and closed, and an adhesive surface for cutaneous mounting; (2) an electronic controller that can acquire, process and store physiological signals, and can be fitted into the disposable unit to establish electrical contact with the built-in electrodes; and (3) a portable communication unit that can wirelessly communicate bi-directionally with the electronic controller, and further communicate bi-directionally with a remote service center.

Embodiments of the present invention provide a method of analyzing cardiac information by collecting a plurality of self-contained, wearable, portable cardiac monitors each of the cardiac monitors electronically storing at least 24 hours of continuously detected and unanalyzed cardiac signals from a mammal. Next, retrieving cardiac information stored in each of the plurality of self-contained portable cardiac monitors. Next, forwarding retrieved cardiac information.

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.

Cardiac monitoring and / or stimulation methods and systems that provide one or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac signal separation is employed to detect, monitor, track and / or trend ischemia using cardiac activation sequence information. Ischemia detection may involve sensing composite cardiac signals using implantable electrodes, and performing a signal separation that produces one or more cardiac activation signal vectors associated with one or more cardiac activation sequences. A change in the signal vector may be detected using subsequent separations. The change may be an elevation or depression of the ST segment of a cardiac cycle or other change indicative of myocardial ischemia, myocardial infarction, or other pathological change. The change may be used to predict, quantify, and / or qualify an event such as an arrhythmia, a myocardial infarction, or other pathologic change. Information associated with the vectors may be stored and used to track the vectors.

Disclosed are systems and methods which provide a relatively small, preferably easily transportable, interpretive biotelemetric monitor, such as may utilize platforms developed for use as personal digital assistants, adapted for use by non-health care personnel. A preferred embodiment biotelemetric monitor comprises a self-contained EKG monitor providing ICU cardiac monitoring with accurate real-time diagnostic heart rhythm analysis directly to the wearer. Preferred embodiment biotelemetric monitors implement multiple interactive screens to guide a user through a series of screens to help understand the monitored conditions. Moreover, the biotelemetric monitor may operate to analyze and interpret the monitored data to thereby present information with respect to the probable implications of the monitored condition and / or make recommendations which may be useful to the patient at that time. Preferably, communications functionality is included to facilitate communication between the biotelemetric monitor and a host system.

Cardiac monitoring and / or stimulation methods and systems that provide one or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac signal separation is employed for automatic capture verification using cardiac activation sequence information. Devices and methods sense composite cardiac signals using implantable electrodes. A source separation is performed using the composite signals. One or more signal vectors are produced that are associated with all or a portion of one or more cardiac activation sequences based on the source separation. A cardiac response to the pacing pulses is classified using characteristics associated with cardiac signal vectors and the signals associated with the vectors. Further embodiments may involve classifying the cardiac response as capture or non-capture, fusion or intrinsic cardiac activity. The characteristics may include an angle or an angle change of the cardiac signal vectors, such as a predetermined range of angles of the one or more cardiac signal vectors.

This invention provides methods and systems for extracting cardiac parameters, including ventricular wall motion, from a plethysmographic signal is provided. Additionally, the invention provides a wide range of uses and system configurations for cardiac monitoring, including ambulatory uses, uses for stress testing, uses for monitoring first responder personnel, and the like.

A monitor includes cardiac and movement sensors 36, 34 responsive to a user's heart beat and a user's movement. The monitor includes a processor coupled to the sensors for generating heart-rate or other cardiac data and user movement or activity data. These data can be stored in a memory and used to analyse the relationship between heart rate and physical exertion.

Cardiac monitoring and / or stimulation methods and systems provide for monitoring, diagnosing, defibrillation and pacing therapies, or a combination of these capabilities, including cardiac systems incorporating or cooperating with neuro-stimulating devices, drug pumps, or other therapies. Embodiments of the present invention relate generally to implantable medical devices employing automated cardiac activation sequence monitoring and / or tracking for arrhythmia discrimination. Embodiments of the invention are directed to devices and methods involving sensing a plurality of composite cardiac signals using a plurality of implantable electrodes. A source separation is performed using the sensed plurality of composite cardiac signals and the separation produces one or more cardiac signal vectors associated with one or more cardiac activation sequences that is indicative of ischemia. A change of the one or more cardiac signal vectors is detected using the one or more cardiac signal vectors. Cardiac arrhythmias are discriminated using the one or more cardiac signal vectors.

The implantable medical device (IMD) system disclosed here utilizes one or more cardiac sensors that measure mechanical characteristics of the heart, such as left ventricular acceleration or right ventricular pressure. The raw sensor data is collected and processed by the IMD, which derives one or more mechanical event marker signals from features, traits, and characteristics of the sensor data waveforms. The mechanical event marker signals are wirelessly transmitted to an external monitor device for display.

A cardiac monitoring system and, more particularly, a wireless electrocardiograph (ECG) system. The present invention detects electrical signals from a patient's heart and transmits the signals digitally to a remote base station via telemetry. The base station converts the digital signals back to an analog electrical signals that can be read by an ECG monitor.

A heart monitor for use as a non-invasive screening tool for identifying potential atrial fibrillation in patients comprises a sensor for producing an output waveform of the patient's actual sinus rhythm, a processing unit arranged to store the normalised waveform of an ideal sinus rhythm and to compare the actual and ideal sinus rhythm waveforms and to produce an output dependant on the difference on a display. The value of the output is indicative of whether the patient is atrial fibrillation or other cardiac arrhythmia.

Battery and solar cell powered health glasses monitor the condition of a heart's vital signs. Light emitting diodes (LED's) emit light into human temples. Photodiodes capture light reflected back from the pulsing blood. The amount of reflected light corresponds to the pulse rate. Embedded circuitry cleans and amplifies the signals, which are transmitted to light emitters located in the glasses. The same signals may be transmitted to a remote receiver to be processed and / or stored. Rhythm and shape of the pulse rate, processed on a home computer and available to doctors via the Internet, indicates heart condition. The circuits provide signal triangulation verification and warning lights. The sensors may be located any place on the body, i.e. wrist bands, chest, head, etc. A transmitter sends signals to the circuitry on the glasses to display reading information and lights about heart condition, pulse rate and blood pressure. Circuits on the glasses process and display electrical signals, pressure signals, pulse rate signals and combinations thereof.

Implantable cardiac monitoring and stimulation methods and devices with epicardial leads having sensor feedback. A fixed or extendable / retractable sensor may be displaceable within the lead's lumen and configured to sense the presence of an anatomical feature or physiological parameter of cardiac tissue in proximity with the lead body's distal end. The sensor may include an ultrasonic sensing element, a perfusion sensor, a photoplethysmographic sensor, or a blood oximetry sensor. Methods of determining suitability for implanting a lead involve the steps of accessing an epicardial surface of the heart, and moving the cardiac lead to an implant site at the epicardial surface. A transmitted signal is directed at the implant site. A reflected signal is received, indicative of the presence of a blood vessel at the implant site. A determination may be made to determine whether the implant site is suitable or unsuitable based on the reflected signal.

A cardiac monitoring and / or stimulation method and systems provide monitoring, defibrillation and / or pacing therapies, including systems detecting and / or treating cardiac arrhythmia. A system includes a housing coupled to a plurality of electrodes configured for subcutaneous non-intrathoracic sensing. A signal processor receives a plurality of composite signals associated with a plurality of sources, separates a signal from the plurality of composite signals using blind source separation, and identifies a cardiac signal. The signal processor may iteratively separate signals from the plurality of composite signals until the cardiac signal is identified. A method of signal separation includes detecting a plurality of composite signals at a plurality of locations, separating a signal using blind source separation, and identifying a cardiac signal. The separation may include a principal component analysis and / or an independent component analysis. The composite signals may be filtered before separation using band-pass filtering, adaptive, or other filters.

Systems and techniques for monitoring cardiac activity. In one aspect, a method includes collecting information describing the variability in heart rate over a series of beats, designating variability at a lower end of physiological values as being largely irrelevant to atrial fibrillation, designating variability in a midrange of physiological values as being indicative of atrial fibrillation, designating variability in an upper range of physiological values as being negatively indicative of atrial fibrillation, and determining a relevance of the variability described in the collection to atrial fibrillation.

A medical device system that includes a brain stimulating element, cardiac monitoring element and a processor. The processor is configured to receive a brain stimulation signal from the brain stimulating element and a cardiac signal from the cardiac monitoring element. The processor is further configured to determine at least one reference point for a stimulation event time period by evaluation of the brain stimulation signal. The processor further identifies a first portion of the cardiac signal based on the at least one reference point of the stimulation event time period.

Methods and systems for implantable cardiac monitors reconfigurable to cardiac therapy devices. A device includes a housing with electrodes configured for cardiac activity sensing when the device is operated in monitoring mode, and sensing and energy delivery when operated in an energy delivery mode. A header may be configured to receive a cardiac lead, and may be associated with a switch to switch the device between monitoring and therapy modes in response to connecting one or more leads to the header. The device may include a transceiver that transmits the contents of the memory to a patient-external device. A method involves providing an implantable cardiac device configured to operate in a first mode as a loop recorder for monitoring cardiac activity and storing selected cardiac events, and operating in the second mode to monitor cardiac activity and provide cardiac stimulation therapy when the second mode is enabled.

A cardiac monitoring and / or stimulation system includes a housing coupled to a plurality of electrodes configured for subcutaneous non-intrathoracic sensing. A signal processor receives a plurality of composite signals associated with a plurality of sources, separates a signal from the plurality of composite signals, and identifies the separated signal as a cardiac signal using information derived from a non-electrophysiologic sensor, such as an accelerometer or acoustic transducer. The signal processor may iteratively correlate separated signals from the plurality of composite signals with a non-electrophysiologic sensor signal until the cardiac signal is identified.

The implantable medical device (IMD) system disclosed here utilizes one or more cardiac sensors that measure mechanical characteristics of the heart, such as left ventricular acceleration or right ventricular pressure. The raw sensor data is collected and processed by the IMD, which derives one or more mechanical event marker signals from features, traits, and characteristics of the sensor data waveforms. The mechanical event marker signals are wirelessly transmitted to an external monitor device for display.

Cardiac monitoring and / or stimulation methods and systems that provide one or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac signal separation is employed to detect, monitor, track and / or trend closed-loop cardiac resynchronization therapy using cardiac activation sequence information. Devices and methods involve sensing a plurality of composite cardiac signals using a plurality of electrodes, the electrodes configured for implantation in a patient. A source separation is performed using the sensed plurality of composite cardiac signals, producing one or more cardiac signal vectors associated with all or a portion of one or more cardiac activation sequences. A cardiac resynchronization therapy is adjusted using one or both of the one or more cardiac signal vectors and the signals associated with the one or more cardiac signal vectors. In further embodiments, the cardiac resynchronization therapy may be initiated, terminated, or one or more parameters of the resynchronization therapy may be altered.

A sympatholytic cardiovascular agent delivered by a drug delivery pump to a central nervous system site to alleviate symptoms of acute or chronic cardiac insult or impaired cardiac performance. The drug delivery pump can be external or implantable infusion pump (IIP) coupled with a drug infusion catheter extending to the site. A patient activator can command delivery of a dosage and / or an implantable heart monitor (IHM) coupled with a sensor can detect physiologic parameters associated with cardiac insult or impaired cardiac performance and trigger dosage delivery. The IIP and IHM can be combined into a single implantable medical device (IMD) or can constitute separate IMDs that communicate by any of known communication mechanisms. The sympatholytic cardiovascular agent is one of the group consisting of an alpha-adrenergic agonist and an alpha2-adrenergic agonist (e.g., clonidine, p-aminoclonidine, guanabenz, lidamidine, tizanidine, moxonidine, methyldopa, xylazine, guanfacine, detomidine, medetomidine, and dexmedetomidine).

Cardiac monitoring and / or stimulation methods and systems that provide one or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac signal separation is employed for automatic capture verification using cardiac activation sequence information. Devices and methods sense composite cardiac signals using implantable electrodes. A source separation is performed using the composite signals. One or more signal vectors are produced that are associated with all or a portion of one or more cardiac activation sequences based on the source separation. A cardiac response to the pacing pulses is classified using characteristics associated with cardiac signal vectors and the signals associated with the vectors. Further embodiments may involve classifying the cardiac response as capture or non-capture, fusion or intrinsic cardiac activity. The characteristics may include an angle or an angle change of the cardiac signal vectors, such as a predetermined range of angles of the one or more cardiac signal vectors.

Cardiac monitoring and / or stimulation methods and systems that provide one or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac signal separation is employed to detect, monitor, track and / or trend a patient's posture using cardiac activation sequence information. Devices and methods in accordance with the present invention involve sensing a plurality of composite cardiac signals using a plurality of implantable electrodes. A source separation is performed using the composite cardiac signals, which produces one or more cardiac signal vectors associated with all or a portion of one or more cardiac activation sequences. A change in a patient's posture is detected using the cardiac signal vectors. Further embodiments involve sensing the plurality of composite cardiac signals during the patient's predominant cardiac rhythm before detecting the change in the patient's posture. Other embodiments involve discriminating between one of a postural related change and a cardiac rhythm related change using the cardiac signal vectors.

A sympatholytic cardiovascular agent delivered by a drug delivery pump to a central nervous system site to alleviate symptoms and otherwise treat heart failure (HF) and pathologies associated with HF. The drug delivery pump can be external or implantable infusion pump (IIP) coupled with a drug infusion catheter extending to the site. A patient activator can command delivery of a dosage and / or an implantable heart monitor (IHM) coupled with a sensor can detect physiologic parameters associated with HF (or pathologies associated with HF) and trigger dosage delivery. The IIP and IHM can be combined into a single implantable medical device (IMD) or can constitute separate IMDs that communicate by any of known communication mechanisms. The sympatholytic cardiovascular agent is one of the group consisting of an alpha-adrenergic agonist and an alpha2-adrenergic agonist, e.g., clonidine, p-aminoclonidine, guanabenz, lidamidine, tizanidine, moxonidine, methyldopa, xylazine, guanfacine, detomidine, medetomidine, and dexmedetomidine.