Abstract: An N-M tomography system comprising: a carrier for the subject of an examination procedure; a plurality of detector heads; a carrier for the detector heads; and a detector positioning arrangement operable to position the detector heads during performance of a scan without interference or collision between adjacent detector heads to establish a variable bore size and configuration for the examination. Additionally, collimated detectors providing variable spatial resolution for SPECT imaging and which can also be used for PET imaging, whereby one set of detectors can be selectably used for either modality, or for both simultaneously.

Abstract: Methods for estimating of the effectiveness of catheter ablation procedures to form lesions. Lesion effectiveness parameters are received, and effectiveness of a corresponding ablation (optionally planned, current, and/or already performed) is estimated. The estimating is based on use by computer circuitry of an estimator constructed based on observed associations between previously analyzed lesion effectiveness parameters, and observed lesion effectiveness. The estimator is used by application to the received lesion effectiveness parameters.

Abstract: Systems and method for remote field measurement-based mapping of anatomical structures (e.g., using impedance image of electrical fields) are described. In some embodiments, an image of features within a target region is produced by analysis of a spatial pattern of field measurements made in a measurement region remote from the target region features; for example, but not exclusively, by treating the spatial arrangement of field measurements in some portion of the measurement region as indicating the spatial (e.g., angular and/or distance) arrangement of features (e.g., anatomical structure of topography and/or tissue type) in the target region.

Abstract: A conformational state of a medical device operated within a body lumen is determined by measuring, using the medical device as an electrode, an electrical parameter which varies in a correspondence with a conformational state (e.g., deployment state) of the portion of the medical device used as the electrode. The conformational state of the medical device is determined, based on the electrical parameter; and an image is presented indicating the determined conformational state. In some embodiments, the electrical parameter is a self-impedance of the portion of the medical device used as the electrode. In some embodiments, current positioning of the medical device is used as part of calibrating a parametric relationship between the electrical parameter and conformational states of the medical device.

Abstract: Electrical field-guided positioning of a second device within a body cavity, using electrical field mapping information generated from electrical field measurements by electrodes of a first device. The first device, in some embodiments, is a catheter electrode probe, and the second device is an internally implantable and/or operated medical device. An exposed, electrically conductive portion of the second device is optionally configured to be used as an electrical field measuring electrode. A rule is applied to measurements made by this electrode to estimate its position within a body cavity. The rule is generated, in some embodiments, using measurements made by the first device. In some embodiments, electrical measurements are used to guide implantation verification. In some embodiments, electrical measurements are used to guide navigation at and through a septal wall between body cavities.

Abstract: Degree of occlusion is monitored for an occlusive device configured to occlude passage of fluid between two compartments in a lumenal space of a body of a patient. In some embodiments, changes in an electrical signal measured from the body of the patient are induced by perturbing the fluid; for example, by “tagging” a portion of fluid with a perturbation of temperature and/or composition. The degree of occlusion is estimated based on the measured changes. The electrical signal changes may be indicative of fluid movements redistributing the perturbed fluid among the two compartments; for example, by diffusion, mixing, and/or jetting of fluid.

Abstract: Methods and devices using measurements of heart electrophysiological activity to guide structural heart disease interventions. In some embodiments, measurements of heart electrophysiological activity are mapped into locations of a heart model defined by one or more additional measurement modalities. In some embodiments, the additional measurement modalities comprise impedance measurements. Locations to map electrophysiological data to, in some embodiments, are determined by non-electrophysiological measurements simultaneous with the electrophysiological data measurement which locate a probe—for example, measurements made by the probe itself, and/or measurements which themselves indicate positioning of the probe.

Abstract: An N-M tomography system comprising: a carrier for the subject of an examination procedure; a plurality of detector heads; a carrier for the detector heads; and a detector positioning arrangement operable to position the detector heads during performance of a scan without interference or collision between adjacent detector heads to establish a variable bore size and configuration for the examination. Additionally, collimated detectors providing variable spatial resolution for SPECT imaging and which can also be used for PET imaging, whereby one set of detectors can be selectably used for either modality, or for both simultaneously.

Abstract: There is provided a computerized method of tracking a position of an intra-body catheter, comprising: physically tracking coordinates of the position of a distal portion of a physical catheter within the physical body portion of the patient according to physically applied plurality of electrical fields within the body portion and measurements of the plurality of electrical fields performed by a plurality of physical electrodes at a distal portion of the physical catheter; registering the physically tracked coordinates with simulated coordinates generated according to a simulation of a simulated catheter within a simulation of the body of the patient, to identify differences between physically tracked location coordinates and the simulation coordinates; correcting the physically tracked location coordinates according to the registered simulation coordinates; and providing the corrected physically tracked location coordinates for presentation.

Abstract: Heart tissue electrical activity mapping used to guide the placement of devices to intervene in (treat) structural heart disease. In some embodiments, the intervention comprises placement of an implantable device, and/or positioning of a therapeutic device used to remove and/or remodel tissue. In some embodiments, electrical activity mapping is performed along with spatial mapping of a body cavity. In some embodiments, the intervention device position is compared to the measured positions of anatomical structures critical to heart electrical function to assess and/or prevent complications due to the device damaging heart electrical function.

Abstract: Methods and systems for position determination are described for using an intrabody probe having a plurality of electrodes to generate a plurality of different electrical fields, and to also measure, using the plurality of electrodes, a measurement set (a Ve-e measurement set) comprising a plurality of measurements of the plurality of different electrical fields while the probe remains in one position. From the Ve-e measurement set, spatial position coordinates for the intrabody probe are estimated within an intrabody coordinate system, using an established mapping between previously observed Ve-e measurement sets and positions in the intrabody coordinate system. Systems and methods for generating and selecting such mappings are also described.

Abstract: Methods and systems of computing parameter values of one or more model parameters are described. The model models structural and dielectric properties of a structure in a human or an animal body. An exemplary method includes: accessing voltage measurements made at different places in the vicinity of the structure by one or more in-body field sensing electrodes in response to currents applied to one or more field supplying electrodes; and computing the parameter values by adjusting the parameter values to fit predicted voltage values to the accessed voltage measurements, wherein the predicted voltage values are predicted from the model for the currents applied to the field supplying in-body electrodes.

Abstract: Electrical field-guided positioning of a second device within a body cavity, using electrical field mapping information generated from electrical field measurements by electrodes of a first device. The first device, in some embodiments, is a catheter electrode probe, and the second device is an internally implantable and/or operated medical device. An exposed, electrically conductive portion of the second device is optionally configured to be used as an electrical field measuring electrode. A rule is applied to measurements made by this electrode to estimate its position within a body cavity. The rule is generated, in some embodiments, using measurements made by the first device.

Abstract: In some embodiments, a body cavity shape of a subject is reconstructed based on intrabody measurements of at least one property of an electromagnetic field by an intrabody probe (for example, a catheter probe) moving within a plurality of electrical fields intersecting the body cavity. In some embodiments, the electrical fields are generated at least in part from electrodes positioned in close proximity, for example, within 1 cm, of the body cavity. In some embodiments, the body cavity is a chamber of a heart (for example, a left atrium or left ventricle), and the electrodes used to generate the electrical field are positioned in the coronary sinus, a large vein occupying the groove between the left atrium and left ventricle. In some embodiments, known distances between measuring electrodes are used in guiding reconstruction, potentially overcoming difficulties of reconstruction from measurements of non-linear electrical fields.

Abstract: A method of computing a dielectric map is disclosed comprising exciting at least one pair of electrodes according to an excitation scheme, the at least one pair of electrodes comprising at least one pair of in-body electrodes (also referred herein below intra-body electrode) located inside of the examined living body, measuring and recording voltages developing on the in-body electrodes during the excitation according to the excitation scheme, solving an inverse problem to derive a 3D dielectric map from the recorded voltages and optionally providing a 3D image of the body tissues based on the 3D dielectric map. Methods are also disclosed that combine intrabody electrodes and surface electrodes secured to the body or use only surface electrodes. Embodiments encompass the use of constraints in deriving the 3D dielectric map and combining measurements made at different locations inside the body with moving intrabody electrodes.

Abstract: A method of modifying cardiac tissue behavior, comprising applying a therapeutically effective electric field having an effect of modifying protein activation levels of at least one protein, and repeatedly applying the field at time intervals timed to increase the activation levels of the at least one protein beyond an activation level achieved by natural and/or paced excitation of the muscle without the application, to an extent about at least as high as a decay of the activation between applications of the field.

Abstract: A method of generating a combined image of a body part from a sequence of partially overlapping source images of the body part, each of the partially overlapping source images showing the body part at one of a plurality of different times, the source images being ordered in the sequence according to the different times, the method including defining a temporally coherent sequence of transformations, for registering the partially overlapping source images in the sequence with each other, registering the source images to each other using the defined temporally coherent sequence of transformations, to obtain co-registered images, and combining at least some of the co-registered images into a combined image. Related apparatus and methods are also described.

Abstract: A method of estimating a spatial relationship between at least a part of a patient esophagus and a heart chamber, including: measuring at least one electric parameter at one or more positions within the heart chamber to obtain measured values; and estimating the spatial relationship based on the measured values.

Abstract: In some embodiments, a body cavity shape of a subject is reconstructed based on intrabody measurements of voltages by an intrabody probe (for example, a catheter probe) moving within a plurality of differently-oriented electromagnetic fields crossing the body cavity. In some embodiments, the method uses distances between electrodes as a spatially calibrated ruler. Positions of measurements made with the intrabody probe in different positions are optionally related by using spatial coherence of the measured electromagnetic fields as a constraint. Optionally, reconstruction is performed without using a detailed reference (image or simulation) describing the body cavity shape. Optionally, reconstruction uses further information to refine and/or constrain the reconstruction; for example: images, simulations, additional electromagnetic fields, and/or measurements characteristic of body cavity landmarks. Optionally, reconstruction accounts for time-dependent cavity shape changes, for example, phasic changes (e.g.