Abstract: A system and method are provided for assessing the compliance of internal patient tissue for purposes of catheter guidance and/or ablation procedures. Specifically, the system/method provides for probing internal patient tissue in order to obtain force and/or tissue displacement measurements. These measurements are utilized to generate an indication of tissue elasticity. In one exemplary embodiment, the indication of elasticity is correlated with an image of the internal tissue area and an output of this image including elasticity indications is displayed for a user.

Abstract: A system for determining a location of an electrode of a medical device (e.g., a catheter) in a body of a patient includes a localization block for producing an uncompensated electrode location, a motion compensation block for producing a compensation signal (i.e., for respiration, cardiac, etc.), and a mechanism for subtracting the compensation signal from the uncompensated electrode location. The result is a corrected electrode location substantially free of respiration and cardiac artifacts. The motion compensation block includes a dynamic adaptation feature which accounts for changes in a patient's respiration patterns as well as intentional movements of the medical device to different locations within the patient's body. The system further includes an automatic compensation gain control which suppresses compensation when certain conditions, such as noise or sudden patch impedance changes, are detected.

Abstract: A system and method is provided that allows for determining the local impedance of one or more electrodes of an electrode catheter. Such local impedance may be utilized to identify the relative position of an electrode catheter to a sheath of a guiding introducer. In another arrangement, local impedance of a catheter electrode can be utilized to calibrate a catheter electrode to provide improved contact sensing.

Abstract: A system for detecting the dimensions and geometry of a native valve annulus for trans-catheter valve implantation includes a compliant balloon and a shaft within the balloon. One or more drive electrodes may be affixed to a surface of the balloon, and one or more sense electrodes may be affixed to the shaft. After insertion of the balloon into the native valve annulus, the drive electrodes may be energized with a predetermined voltage. Using a trained statistical model and the voltages measured at the sense electrodes, initial estimates of the cross-section of the valve annulus may be obtained. The initial estimates may then be provided to an optimization model of the valve annulus to obtain a highly accurate prediction of the cross-section of the valve annulus.

Abstract: A system for mapping a tissue surface includes a probe for mapping a tissue surface, a localization system to measure a location data point indicative of the probe's location, a memory in which to store the location data point, a servo mechanism to move the probe along at least a portion of the tissue surface, a controller to move the probe to a plurality of locations and to record in the memory a plurality of location data points, and a contact-sensing processor to analyze the plurality of location data points and to identify a subset thereof on the tissue surface. A modeling processor generates a model of the tissue surface using the subset of location data points. The contact-sensing processor utilizes probe velocity, or a rate of change in the distance moved by the probe, to determine contact between the probe and the tissue surface.

Abstract: A system and method is provided that allows for determining the local impedance of one or more electrodes of an electrode catheter. Such local impedance may be utilized to identify the relative position of an electrode catheter to a sheath of a guiding introducer. In another arrangement, local impedance of a catheter electrode can be utilized to calibrate a catheter electrode to provide improved contact sensing.

Abstract: Catheter navigation is coupled with ultrasound imaging to yield a context map showing the location on a heart of the ultrasonically imaged frame.

Abstract: A system and method are provided for determining characteristics of a device electrode disposed on a medical device within a body. A plurality of measurement electrodes are coupled to an external surface of the body and establish transmission paths for current through the body. An electronic control unit (ECU) is configured to cause transmission of current between a pair of active electrodes selected from the measurement electrodes and thereby generate a voltage on the device electrode. The ECU receives impedance signals from a plurality of passive electrodes among the measurement electrodes other than the active electrodes. The ECU establishes a virtual reference electrode at a reference position within the body responsive to the impedance signals and computes a position of the device responsive to the voltage on the device electrode and the reference position of the reference electrode. The ECU may also compute impedances at the device and measurement electrodes.

Abstract: A method of generating a diagnosis map of at least a portion of the heart includes inserting an electrode within the portion of a heart, robotically moving the electrode therein, measuring electrophysiology information at a point on the surface of the heart, associating the measured electrophysiology information with position information for the point on the surface of the heart, repeating the measuring and associating steps for a plurality of points on the surface of the heart, thereby generating a plurality of surface diagnostic data points, and generating the diagnosis map therefrom. The electrode may be moved within the heart randomly, pseudo-randomly, or according to one or more predetermined patterns. A three-dimensional model of the portion of the heart may be provided and presented as a graphical representation, either with or without information indicative of the measured electrophysiology information superimposed thereon.

Abstract: An apparatus for determining a length of a portion of a steering wire disposed within a bendable medical device includes an electrical contact slidably coupled with a steering wire, an electrical source configured to transmit an electrical signal through a portion of the steering wire, and a processor configured to monitor a parameter of the electrical signal at or about the electrical contact and configured to determine a length of a portion of the steering wire using the monitored parameter.

Abstract: A system and method for assessing contact between a medical device and tissue may comprise an electronic control unit (ECU) configured to be coupled to a medical device, the medical device comprising a first electrode and a second electrode. The ECU may be further configured to select the first electrode as an electrical source and the second electrode as an electrical sink, to cause an electrical signal to be driven between the source and sink, to detect respective electric potentials on the first electrode and the second electrode while the electrical signal is driven, and to determine an impedance respective of one of the first electrode and the second electrode according to both of the respective electric potentials.

Abstract: Catheter navigation is coupled with ultrasound imaging to yield a context map showing the location on a heart of the ultrasonically imaged frame.

Abstract: A system and method are provided for determining characteristics of a device electrode disposed on a medical device within a body. A plurality of measurement electrodes are coupled to an external surface of the body and establish transmission paths for current through the body. An electronic control unit (ECU) is configured to cause transmission of current between a pair of active electrodes selected from the measurement electrodes and thereby generate a voltage on the device electrode. The ECU receives impedance signals from a plurality of passive electrodes among the measurement electrodes other than the active electrodes. The ECU establishes a virtual reference electrode at a reference position within the body responsive to the impedance signals and computes a position of the device responsive to the voltage on the device electrode and the reference position of the reference electrode. The ECU may also compute impedances at the device and measurement electrodes.

Abstract: A method for scaling the impedance measured during the course of an electrophysiology study accounts for impedance drifts. By scaling the impedance there is greater assurance that previously recorded positional information can be used to accurately relocate an electrode at a prior visited position. The scale factor may be based upon a mean value across several sensing electrodes. Alternatively, the scale factor may be calculated specifically with respect to an orientation of a dipole pair of driven electrodes.

Abstract: A cardiac navigation system including a mapping catheter, a control system coupled to the mapping catheter, an electrode array, and means for driving an electrical current across the electrode array. The mapping catheter includes means for sensing an electrical field. The control system includes means for receiving sensed signals from the mapping catheter. The cardiac navigation system includes at least one electrode array including means for providing an electrical field across three axes. The three axes are approximately orthogonal with respect to one another. The means for driving an electrical current across the three axes includes means for providing a plurality of individual current sources to the electrode array.

Abstract: An input device for a robotic medical system includes a handle configured to be rotatable about a center axis, and to be longitudinally displaceable along the center axis. The input device also includes a deflection control element disposed on the handle and configured to selectively control deflection of the distal end of a flexible medical instrument electrically coupled to the input device. Longitudinal displacement of the handle may cause or result in a corresponding longitudinal motion or deflection of the flexible medical instrument. Rotation of the handle may cause or result in a corresponding rotation of the deflection plane. Longitudinal displacement and rotation of the handle may be detected or sensed electronically.

Abstract: An apparatus for maintaining a robotic catheter system in a responsive state includes a catheter, a plurality of linear translatable control elements, and a controller. In an embodiment, the catheter includes a proximal portion, a distal portion, and at least two steering wires. The steering wires may be configured at one end to control the movement of at least a portion of the distal portion of the catheter and at the other end for connection to a control member. In an embodiment, each control element may be configured to engage or interface with a respective control member, and the controller may be configured to measure a force exerted on at least one control member by a respective control element and further configured to linearly translate the control element to substantially maintain a force within a predetermined range.

Abstract: A method of generating a diagnosis map of at least a portion of the heart includes inserting an electrode within the portion of a heart, robotically moving the electrode therein, measuring electrophysiology information at a point on the surface of the heart, associating the measured electrophysiology information with position information for the point on the surface of the heart, repeating the measuring and associating steps for a plurality of points on the surface of the heart, thereby generating a plurality of surface diagnostic data points, and generating the diagnosis map therefrom. The electrode may be moved within the heart randomly, pseudo-randomly, or according to one or more predetermined patterns. A three-dimensional model of the portion of the heart may be provided and presented as a graphical representation, either with or without information indicative of the measured electrophysiology information superimposed thereon.

Abstract: A system and method are provided for determining characteristics of a device electrode disposed on a medical device within a body. A plurality of measurement electrodes are coupled to an external surface of the body and establish transmission paths for current through the body. An electronic control unit (ECU) is configured to cause transmission of current between a pair of active electrodes selected from the measurement electrodes and thereby generate a voltage on the device electrode. The ECU receives impedance signals from a plurality of passive electrodes among the measurement electrodes other than the active electrodes. The ECU establishes a virtual reference electrode at a reference position within the body responsive to the impedance signals and computes a position of the device responsive to the voltage on the device electrode and the reference position of the reference electrode. The ECU may also compute impedances at the device and measurement electrodes.

Abstract: The present invention provides a differential pressure body suit with external support against body suit migration. In its preferred embodiment, such body suit may comprise a close-fitting, multi-layered suit sealed against a mammal's skin to contain the differential pressure, or a looser-fitting suit that bends at the mammal's joints with minimal force. External support means include either fixed or movable mechanical supports attached to the body suit, extraordinary air pressure levels for making the body suit rigid, or exoskeletons attached to the body suit. A cyclic control system can turn the differential pressure condition within the body suit on and off on a selective basis to accommodate the movement of the legs of the mammal. The pressurization reduces the weight of the body to greater or lesser extents, and offloads the weight to the ground through the external support means.