47 results about "Cardiac pressures" patented technology

An anchoring device and a delivery method thereof can effectively provide a means for securing an implant to a wall of an internal organ within a patient in a variety of clinical applications. In one embodiment, an anchoring device used to retain a cardiac pressure measurement device is provided. The device is implanted in the body by deforming it to a small cross section profile, sliding it through a low profile delivery device and ejecting from the delivery device at a targeted site. The anchoring mechanism, when ejected from the delivery device, reverts back to pre-formed configuration and engages opposite sides of an organ wall, thereby anchoring the implant in the organ wall.

The present disclosure relates to delivery devices and interventional devices configured to enable monitoring of pressure and other hemodynamic properties before, during, and / or after a cardiac procedure. A guide catheter includes a routing lumen or a routing groove for routing a sensor wire to a desired location during a cardiac procedure. A guide catheter includes one or more pressure sensors positioned to provide desired pressure measurements when the guide catheter is deploying an interventional device. An interventional device may also include one or more associated sensors for providing hemodynamic information before, during, and / or after deployment.

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.

The present disclosure relates to devices and methods for implanting a prosthesis into a heart of a mammal, such as a person. The disclosure includes a prosthesis that acts as a pressure vent between the left and right atria of the heart. The intracardiac pressure vents disclosed allow sufficient flow from the left atrium to the right atrium to relieve elevated left atrial pressure and resulting patient symptoms. The devices also limit the amount of flow from the right atrium to the left atrium to minimize the potential for thrombi or other embolic material from entering arterial circulation.

Various techniques are provided for calibrating and estimating left atrial pressure (LAP) using an implantable medical device, based on impedance, admittance or conductance parameters measured within a patient. In one example, default conversion factors are exploited for converting the measured parameters to estimates of LAP. The default conversion factors are derived from populations of patients. In another example, a correlation between individual conversion factors is exploited to allow for more efficient calibration. In yet another example, differences in thoracic fluid states are exploited during calibration. In still yet another example, a multiple stage calibration procedure is described, wherein both invasive and noninvasive calibration techniques are exploited. In a still further example, a therapy control procedure is provided, which exploits day time and night time impedance / admittance measurements.

Techniques are provided for estimating left atrial pressure (LAP) or other cardiac pressure parameters based on various parameters derived from impedance signals. In particular, effective LAP is estimated based on one or more of: electrical conductance values, cardiogenic pulse amplitudes, circadian rhythm pulse amplitudes, or signal morphology fractionation values, each derived from the impedance signals detected by the implantable device. Predetermined conversion factors stored within the device are used to convert the various parameters derived from the electrical impedance signal into LAP values or other appropriate cardiac pressure values. The conversion factors may be, for example, slope and baseline values derived during an initial calibration procedure performed by an external system, such as an external programmer. In some examples, the slope and baseline values may be periodically re-calibrated by the implantable device itself.

In a method of noninvasive measurement of parameters of diastolic function of left ventricle and automated evaluation of the measured profile at rest and with exercise, a patient performs an isometric exercise. An external pressure sensor and heart sounds microphone are applied in a non-invasive manner on the thoracic wall to obtain a left ventricular pressure mirroring curve (pressocardiogram) and simultaneously the heart sounds (phonocardiogram). An external unit determines and calculates characteristic diastolic parameters derived from the pressocardiographic curve and phonocardiogram at rest, during and after exercise, converts each said pressocardiogram into a digital waveform in the time domain, and automatically categorizes the mentioned characteristic parameters based on exact categorization criteria for defining several differentialforms of diastolic dysfunction of left ventricle in human beings.

The invention is directed to techniques for monitoring the condition of a patient, such as a patient having congestive heart failure, and appropriately modifying the patient's drug therapy as a function of a pressure in the patient's heart, such as the estimated pulmonary artery diastolic pressure. The drugs may be administered by an implanted drug delivery device. The drug selection, the drug dosage or both may be controlled as a function of the pressure and / or the activity level of the patient.

The present invention identifies genes whose gene products are differentially expressed pressure overload of the heart. The invention provides methods for diagnosing or assessing an individual's susceptibility to heart failure from many etiologies, as well as the presence and severity of hypertrophy, chamber enlargement, or systolic heat failure. Also provided are therapeutic methods for treating a heart patient or methods for prophylactically treating an individual susceptible to heart failure. Additionally, the invention describes screening methods for identifying agents that can be administered to treat individuals that have suffered a heart attack or are at risk of heart failure.

Techniques are provided for estimating electrical conduction delays with the heart of a patient based on measured immittance values. In one example, impedance or admittance values are measured within the heart of a patient by a pacemaker or other implantable medical device, then used by the device to estimate cardiac electrical conduction delays. A first set of predetermined conversion factors may be used to convert the measured immittance values into conduction delay values. In some examples, the device then uses the estimated conduction delay values to estimate LAP or other cardiac pressure values. A second set of predetermined conversion factors may be used to convert the estimated conduction delays into pressure values. Techniques are also described for adaptively adjusting pacing parameters based on estimated LAP.

The invention is directed to techniques for monitoring the condition of a patient, such as a patient having congestive heart failure, and appropriately modifying the patient's drug therapy as a function of a pressure in the patient's heart, such as the estimated pulmonary artery diastolic pressure. The drugs may be administered by an implanted drug delivery device. The drug selection, the drug dosage or both may be controlled as a function of the pressure and / or the activity level of the patient.

Techniques are provided for estimating left atrial pressure (LAP) or other cardiac performance parameters based on measured conduction delays. In particular, LAP is estimated based interventricular conduction delays. Predetermined conversion factors stored within the device are used to convert the various the conduction delays into LAP values or other appropriate cardiac performance parameters. The conversion factors may be, for example, slope and baseline values derived during an initial calibration procedure performed by an external system, such as an external programmer. In some examples, the slope and baseline values may be periodically re-calibrated by the implantable device itself. Techniques are also described for adaptively adjusting pacing parameters based on estimated LAP or other cardiac performance parameters. Still further, techniques are described for estimating conduction delays based on impedance or admittance values and for tracking heart failure therefrom.

Techniques are provided for use by an implantable medical device or diagnostic sensor for detecting and discriminating euvolemia, hypervolemia and hypovolemia. In one example, the device detects a pressure signal within the patient representative of changes in cardiac pressure overall several cardiac cycles. The device generates separate time-domain and frequency-domain representations of the pressure signal and then discriminates among euvolemia, hypervolemia and hypovolemia within the patient based on an analysis of the time-domain and the frequency-domain representations of the signal. Depending upon the capabilities of the device, suitable warnings may be generated to alert the patient or caregiver. Diuretics or other medications can be titrated to address abnormal fluid conditions such as a fluid overload during hypervolemia. Techniques for detecting a pressure alternans pattern indicative of imminent decompensation are also described.

A pressure sensor is deployed in the right atrium and is in contact with the tissue of the fossa ovalis. The fossa ovalis acts as a membrane and the pressure sensor determines the relative and / or absolute pressure within the left atrium while remaining within the right atrium. A variety of embodiment are provided to deploy and anchor the sensor into the proper position.

An apparatus for and method of measuring pressure through a septum in a patient's heart. A lead inserted into the right side of a heart is routed through the septum to gain access to the left side of the heart. The lead includes a mounting mechanism that secures the lead to one or both sides of the septal walls. The lead also includes one or more sensors for measuring cardiac pressure on the left side of the heart and, as necessary, the right side of the heart.

An implantable cardioverter defibrillator evaluates the hemodynamic stability of an arrhythmia to determine whether or not to defibrillate. The device obtains cardiac pressure and cardiac impedance data and evaluates a phase relationship between these parameters. Hemodynamically stable rhythms will result in an out of phase relationship.

Various techniques are provided for use with an implantable medical device for estimating cardiac pressure within a patient based on admittance (or related electrical values such as impedance or conductance) that takes into account the presence of acute MR within the patient. Briefly, the device detects an indication of acute MR, if occurring within the patient. The device also applies electrical fields to tissues of the patient and measures electrical parameters influenced by the electrical field, such as admittance, impedance or conductance. The device then estimates cardiac pressure within the patient based on the measured electrical parameter and the indication of acute MR. In one example, different linear correlation functions are used to convert admittance values to left atrial pressure (LAP) values depending upon the presence or absence of acute MR within the patient.

An implantable medical device includes a pressure input, an excitation source, a detector module, and a processor. The pressure input is configured to be joined to a pressure sensor located proximate to a cardiac chamber of the heart. The pressure input receives pressure measurements representative of a pressure in the cardiac chamber. The excitation source is configured to deliver stimulation pulses to the heart. The detector module communicates with the pressure sensor to receive and compare the pressure measurements to a pressure threshold. The processor instructs the excitation source to deliver the stimulation pulses at a pressure-based rate based on the comparison of the pressure measurements to the pressure threshold.

An implantable cardioverter defibrillator evaluates the hemodynamic stability of an arrhythmia to determine whether or not to defibrillate. The device obtains cardiac pressure and cardiac impedance data and evaluates a phase relationship between these parameters. Hemodynamically stable rhythms will result in an out of phase relationship.

The invention relates to a breathing machine man-machine asynchronous classification method and system, a terminal and a storage medium. The method comprises the steps: collecting the multi-channel breathing data of a simulated flow channel, a tidal volume channel, airway pressure, alveolar pressure, pleural cavity internal pressure, cardiac pressure, a corrugated pipe position channel and the like under a man-machine asynchronous event simulated by a simulated lung and a breathing machine; carrying out replacement deviation index (PDI) feature extraction on the respiration data, and labeling the respiration data according to the extracted PDI features; inputting the labeled respiration data into a network model for training to obtain a trained man-machine asynchronous classification model; and classifying the breathing machine man-machine asynchronous events through the trained man-machine asynchronous classification model. According to the embodiment of the invention, the acquired respiration data is small in interference and convenient to acquire, difference analysis of the respiration data of the adjacent channels is carried out by using the PDI features, and the accuracy of man-machine asynchronous classification is improved.