Abstract: For example, one or more non-transitory computer-readable media includes executable instructions to perform a method. The method includes defining a plurality of spatial regions distributed across a geometric surface. At least one wave front that propagates across the geometric surface is detected based on electrical data representing electrophysiological signals for each of a plurality of nodes distributed on the geometric surface over at least one time interval. An indication of conduction velocity of the wave front is determined for at least one spatial region of the plurality of spatial regions during the time interval based on a duration that the wave front resides within the at least one spatial region. Slow conduction activity is identified for the at least one spatial region based on comparing the indication of conduction velocity relative to a threshold. Conduction data is stored in memory to represent each slow conduction event.

Abstract: For example, one or more non-transitory computer-readable media includes executable instructions to perform a method. The method includes defining a plurality of spatial regions distributed across a geometric surface. At least one wave front that propagates across the geometric surface is detected based on electrical data representing electrophysiological signals for each of a plurality of nodes distributed on the geometric surface over at least one time interval. An indication of conduction velocity of the wave front is determined for at least one spatial region of the plurality of spatial regions during the time interval based on a duration that the wave front resides within the at least one spatial region. Slow conduction activity is identified for the at least one spatial region based on comparing the indication of conduction velocity relative to a threshold. Conduction data is stored in memory to represent each slow conduction event.

Abstract: Methods for determining a surface geometry of an object, including determining a first projection matrix based on a first imaging device, determining a second projection matrix based on a second imaging device, obtaining at least one first two-dimensional (2D) image of the object using the first imaging device, obtaining at least one second 2D image of the object using the second imaging device, determining a contour of the object in the first 2D image and the second 2D image, and, based on the at least two contours, the first projection matrix, and the second projection matrix, reconstructing 3D data associated with the surface of the object. In one embodiment, the object can be a heart.

Abstract: A method of detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes forming a first sensing vector and a second sensing vector, and determining first heart rate estimates associated with cardiac signals sensed from the first sensing vector and cardiac signals sensed from the second sensing vector in response to a metric of heart rate associated with the sensed cardiac signals. Second heart rate estimates associated with the first sensing vector and with the second sensing vector are generated in response to the determined first heart rate estimates, and a determination is made as to whether both of the second heart rate estimates are greater than a predetermined heart rate threshold.

Abstract: A method of detecting a cardiac event in a medical device that includes sensing a cardiac signal from a plurality of electrodes, determining amplitudes of the sensed cardiac signal during a predetermined sensing window, determining a noise to signal ratio corresponding to the determined amplitudes, and determining the sensed cardiac signal during the predetermined sensing window is corrupted by noise in response to the determined noise to signal ratio being greater than a noise to signal ratio threshold.

Abstract: A method of detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes forming a first sensing vector and a second sensing vector, determining inflections of the sensed cardiac signals, generating a pulse amplitude threshold in response to the determined inflections, determining whether the sensed cardiac signals are corrupted by noise in response to the determined inflections and the generated pulse amplitude threshold, and determining, in response to the sensed cardiac signals being corrupted by noise, whether the sensed cardiac signals are both corrupted by noise and shockable.

Abstract: A method of detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes forming a first sensing vector and a second sensing vector, determining whether a signal energy content metric of the sensed cardiac signals is within predetermined limits, determining whether a noise to signal ratio of the sensed cardiac signals is less than a signal to noise threshold, determining whether the sensed cardiac signals are associated with muscle noise, and determining whether a mean frequency corresponding to the sensed cardiac signals is less than a mean frequency threshold.

Abstract: A method of detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes forming a first sensing vector and a second sensing vector, determining whether the first sensing vector and the second sensing vector is corrupted by noise, and determining, in response to one of the first sensing vector and the second sensing vector being corrupted by noise, whether the other of the first sensing vector and the second sensing vector is one of a first cardiac event and a second cardiac event different from the first cardiac event.

Abstract: A method of detecting a cardiac event in a medical device that includes determining a first characteristic in response to cardiac signals sensed along a first sensing vector over a predetermined sensing window and in response to cardiac signals sensed along a second sensing vector over the predetermined sensing window, determining a second characteristic in response to cardiac signals sensed along the first sensing vector over the predetermined sensing window and in response to cardiac signals sensed along the second sensing vector over the predetermined sensing window, and determining a third characteristic in response to cardiac signals sensed along the first sensing vector over the predetermined sensing window and in response to cardiac signals sensed along the second sensing vector over the predetermined sensing window.

Abstract: A method of detecting a cardiac event that includes sensing cardiac signals from a plurality of electrodes, determining rates of change of the sensed cardiac signals, and determining a range of the sensed cardiac signals. The sensed cardiac signals are detected as being associated with the cardiac event in response to the determined rates of change and the determined range.

Abstract: A method of detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes forming a first sensing vector and a second sensing vector, determining inflections of the sensed cardiac signals, generating a pulse amplitude threshold in response to the determined inflections, and determining whether the inflections are indicative of noise in response to the determined inflections and the generated pulse amplitude threshold.

Abstract: A method of detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes forming a first sensing vector and a second sensing vector, and determining whether the sensing of cardiac signals along the first sensing vector and along the second sensing vector is corrupted by noise. If the cardiac signals sensed along both the first sensing vector and the second sensing vector are not corrupted by noise, a determination is made as to whether the cardiac signals sensed along the first sensing vector and along the second sensing vector are one of a first cardiac event and a second cardiac event. The determination of whether the cardiac signals sensed along the first sensing vector and along the second sensing vector are one of a first cardiac event and a second cardiac event is then confirmed.

Abstract: A SubQ ICD that is entirely implantable subcutaneously with minimal surgical intrusion into the body of the patient and associated with subcutaneous leads provides distributed cardioversion-defibrillation sense and stimulation electrodes for delivery of cardioversion-defibrillation shock and pacing therapies across the heart when necessary. A level crossing detection system and process is implemented to detect noise, sinus rhythm and ventricular fibrillation in subcutaneous or body surface signals to deliver therapies as needed.

Abstract: A cardiac pacemaker and method of its use. The pacemaker is provided with a pacing electrode array configured for location at a left anterior portion of a patient's thorax between the patients third and sixth ribs, outside the patient's thoracic cavity. The pacing electrode array includes multiple pacing electrodes and preferably includes one or more steering electrodes for configuring the electrical field produced by delivery of pacing pulses to avoid unwanted nerve and muscle stimulation while allowing cardiac stimulation. The electrode array may be located subcutaneously, submuscularly or on the patient's skin.

Abstract: Methods and systems for computing epicardial surface electric potentials based on measured body surface electric potentials, where the methods and systems include representing at least one geometric relationship between at least one body surface electric potential measuring system and the epicardial surface as a multidimensional matrix, estimating an inverse of the multidimensional matrix based on a Generalized Minimum Residual (GMRes) method, and, based on the inverse matrix and the measured body surface potentials, determining the epicardial surface electric potentials.

Abstract: Methods and systems for determining a surface geometry of an object, including determining a first projection matrix based on a first imaging device, determining a second projection matrix based on a second imaging device, obtaining at least one first two-dimensional (2D) image of the object using the first imaging device, obtaining at least one second 2D image of the object using the second imaging device, determining a contour of the object in the first 2D image and the second 2D image, and, based on the at least two contours, the first projection matrix, and the second projection matrix, reconstructing 3D data associated with the surface of the object. In one embodiment, the object can be a heart.

Abstract: Methods for determining a surface geometry of an object, including determining a first projection matrix based on a first imaging device, determining a second projection matrix based on a second imaging device, obtaining at least one first two-dimensional (2D) image of the object using the first imaging device, obtaining at least one second 2D image of the object using the second imaging device, determining a contour of the object in the first 2D image and the second 2D image, and, based on the at least two contours, the first projection matrix, and the second projection matrix, reconstructing 3D data associated with the surface of the object. In one embodiment, the object can be a heart.

Abstract: Methods and systems for determining a surface geometry of an object, including determining a first projection matrix based on a first imaging device, determining a second projection matrix based on a second imaging device, obtaining at least one first two-dimensional (2D) image of the object using the first imaging device, obtaining at least one second 2D image of the object using the second imaging device, determining a contour of the object in the first 2D image and the second 2D image, and, based on the at least two contours, the first projection matrix, and the second projection matrix, reconstructing 3D data associated with the surface of the object. In one embodiment, the object can be a heart.

Abstract: Methods and systems for computing epicardial surface electric potentials based on measured body surface electric potentials, where the methods and systems include representing at least one geometric relationship between at least one body surface electric potential measuring system and the epicardial surface as a multidimensional matrix, estimating an inverse of the multidimensional matrix based on a Generalized Minimum Residual (GMRes) method, and, based on the inverse matrix and the measured body surface potentials, determining the epicardial surface electric potentials.