Abstract: A method, including, while imaging a patient using an initial magnetic resonance imaging (MRI) sequence, generating an initial MRI reference signal in response to the initial MRI sequence using a reference sensor placed in proximity to the patient. The method further includes identifying, by locking on to the initial MRI reference signal, noise that will be generated in electrocardiograph (ECG) signals received from the patient, and computing a programmable correction to be applied to the ECG signals to reduce the noise. The method also includes applying the programmable correction to reduce the noise in the ECG signals, received from the patient, while imaging the patient using a subsequent MRI sequence and while locking on to a subsequent MRI reference signal generated in response to the subsequent MRI sequence using the reference sensor.

Abstract: A method, consisting of, while imaging a patient using an initial magnetic resonance imaging (MRI) sequence, receiving an initial set of electrocardiograph (ECG) signals from the patient. The method includes identifying initial noise in the initial set of ECG signals arising from the initial MRI sequence, and characterizing the initial noise in terms of frequency components thereof. The method further includes generating a relation between parameters defining the initial MRI sequence and the frequency components, computing a filter by applying the relation to the parameters of a subsequent MRI sequence, and applying the computed filter to reduce noise in a further set of ECG signals, received from the patient, while imaging the patient using the subsequent MRI sequence.

Abstract: An electrophysiologic catheter with an improved control handle is provided. The catheter includes a heat transfer assembly to better dissipate heat in the control handle. The heat transfer assembly includes a pump, a reservoir containing a coolant, a heat transfer member, and a coolant transport network transporting coolant between at least the reservoir and the heat transfer member. In one embodiment, the heat transfer member is located within the control handle as a heat exchanger on the circuit board to receive the coolant for transferring heat from the integrated circuits to the coolant. In another embodiment, the heat transfer member is located on the circuit board directly surrounding the integrated circuits to internally cool the integrated circuit within the control handle. A second heat transfer member is located outside of the control handle as a heat exchanger.

Abstract: A location pad includes a housing having a flat surface and multiple field generators. The multiple field generators are fixed to the housing and are configured to generate respective magnetic fields having respective axes that are perpendicular to the flat surface.

Abstract: An apparatus, including a bus having electrical power and data lines, and a plurality of location pads, which are positionable at different, respective locations with respect to a body cavity in which the object is located, and which are connected to the bus in series so as to receive electrical power and exchange data signals over the bus. Each location pad includes multiple radiator coils and driving circuitry configured to select, responsively to the data signals, different respective driving frequencies for the coils and to generate, using the electrical power from the bus, driving signals to drive the coils to produce magnetic fields at the respective driving frequencies. The apparatus also includes a console, which is configured to receive and process sensor signals from a magnetic sensor fixed to the object, in response to the magnetic fields in the body cavity, in order to compute position coordinates of the object.

Abstract: Apparatus for controlling a steerable invasive probe having a handle. The apparatus includes a platform and a jig, which is mounted on the platform and is configured to receive the handle. The jig includes at least a first gear that is positioned and shaped to rotate the handle about an axis of the probe and a second gear that is positioned and shaped to operate a control on the handle for deflecting a tip of the probe. A drive module includes one or more motors. A transmission is coupled to the drive module and to the jig so as to controllably rotate at least the first and second gears and to translate the platform along a direction parallel to the axis in order to advance and retract the probe.

Abstract: Apparatus, including an energy generator, configured to supply first ablation power modulated at a first frequency and second ablation power modulated at a second frequency different from the first frequency. The apparatus also includes a probe, having at least one electrode coupled to receive the first and second ablation powers simultaneously and to dissipate the first and second ablation powers in body tissue in contact with the at least one electrode.

Abstract: Apparatus, including a current source which has a transformer having a primary winding coupled to receive input power. The transformer has a secondary winding having a first plurality of secondary taps configured to supply electrical power at an ablation frequency to an electrode in contact with body tissue. The tissue has an impedance, and is ablated by the electrical power. The current source has a second plurality of capacitors. The apparatus also includes a controller which is configured to select one of the secondary taps and at least one of the capacitors in response to the impedance and the ablation frequency, and to connect the selected secondary tap to the selected at least one of the capacitors.

Abstract: A calibration apparatus includes a fixture, which is coupled to accept a probe so that a distal tip of the probe presses against a point in the fixture and produces first measurements indicative of a deformation of the distal tip relative to a distal end of the probe, in response to pressure exerted on the distal tip. A sensing device is coupled to the fixture and is configured to produce second measurements of a mechanical force exerted by the distal tip against the point. A calibration processor is configured to receive the first measurements from the probe, to receive the second measurements from the sensing device and to compute, based on the first and second measurements, one or more calibration coefficients for assessing the pressure as a function of the first measurements.

Abstract: An electrophysiologic catheter with an improved control handle is provided. The catheter includes a heat transfer assembly to better dissipate heat in the control handle. The heat transfer assembly includes a pump, a reservoir containing a coolant, a heat transfer member, and a coolant transport network transporting coolant between at least the reservoir and the heat transfer member. In one embodiment, the heat transfer member is located within the control handle as a heat exchanger on the circuit board to receive the coolant for transferring heat from the integrated circuits to the coolant. In another embodiment, the heat transfer member is located on the circuit board directly surrounding the integrated circuits to internally cool the integrated circuit within the control handle. A second heat transfer member is located outside of the control handle as a heat exchanger.

Abstract: Methods and systems facilitate catheterization of a living subject by passing a fluid through an irrigation conduit. Heat energy is delivered to the conduit to create a heated pod of irrigation fluid that propagates downstream from the heat source. A departure time of the pod from a first location in the conduit is recorded, and an arrival time of the pod is detected at a second location that is downstream from the first location. A transit time of the pod from the first location to the second location is determined, and the flow of the fluid is adjusted responsively to the transit time.

Abstract: Tissue ablation systems and methods are provided, wherein a cardiac catheter incorporates a pressure detector for sensing a mechanical force against the distal tip when engaging an ablation site. Responsively to the pressure detector, a controller computes an ablation volume according to relationships between the contact pressure against the site, the power output of an ablator, and the energy application time. A monitor displays a map of the heart which includes a visual indication of the computed ablation volume. The monitor may dynamically display the progress of the ablation by varying the visual indication.

Abstract: A medical probe includes an insertion tube, having a longitudinal axis and having a distal end. A distal tip is disposed at the distal end of the insertion tube and is configured to be brought into contact with a body tissue. A joint couples the distal tip to the distal end of the insertion tube. A joint sensor, contained within the probe, senses a position of the distal tip relative to the distal end of the insertion tube. The joint sensor includes first and second subassemblies, which are disposed within the probe on opposite, respective sides of the joint and each include one or more magnetic transducers.

Abstract: A magnetic field generator includes a substrate, a main generator coil, at least one field sensor, at least one shim coil, a driver circuit and a correction circuit. The main generator coil, the field sensor, and the shim coil are all disposed on the substrate. The driver circuit is coupled to drive the main generator coil with a driving current at a selected frequency. The correction circuit is coupled to receive a signal at the selected frequency from the at least one field sensor and, in response to deviations in the signal from a predefined baseline, to drive the at least one shim coil with a driving current having an amplitude configured to return the signal to the baseline.

Abstract: An apparatus includes detection circuitry and gating circuitry. The detection circuitry is configured to sense a radio frequency (RF) ablation signal that is applied to a heart by an intra-body probe, and to identify time intervals during which an amplitude of an ablation signal is within a predefined window. The gating circuitry is configured to gate an electrocardiogram (ECG) signal acquired in the heart, such that the ECG signal is sampled only within the identified time intervals.

Abstract: Electrical apparatus includes a probe, having a proximal end and a distal end. The probe includes a sensor, which outputs a sensor signal, and a first connector at the proximal end of the probe, electrically coupled at least to the sensor. A probe adapter includes a second connector, which is arranged to mate with the first connector, and a third connector, for coupling to a console. A shield includes a material of high magnetic permeability, which is configured to enclose an internal volume containing the first and second connectors when the probe is connected to the probe adapter.

Abstract: A calibration apparatus includes a fixture, which is coupled to hold a distal end of a medical probe. A plurality of weights, which have respective masses and respective bottom surfaces that are oriented at respective angles with respect to the distal end of the probe, are coupled to rest on a distal tip of the probe so as to apply to the distal tip respective force vectors that cause a deformation of the distal tip relative to the distal end. A calibration processor is configured to receive from the probe measurements indicative of the deformation of the distal tip in response to the force vectors, and to compute, based on the measurements, the masses and the angles, calibration coefficients for assessing the force vectors as a function of the measurements.

Abstract: A medical probe includes a flexible insertion tube, having a distal end for insertion into a body cavity of a patient, and a distal tip, which is disposed at the distal end of the insertion tube and is configured to be brought into contact with tissue in the body cavity. A resilient member couples the distal tip to the distal end of the insertion tube and is configured to deform in response to pressure exerted on the distal tip when the distal tip engages the tissue. A position sensor within the probe senses a position of the distal tip relative to the distal end of the insertion tube, which changes in response to deformation of the resilient member.

Abstract: Apparatus for tracking an object includes a position transducer, which is adapted to be fixed to the object. The position transducer includes a digital microcontroller, which includes a plurality of output pins, and which is operative to generate an alternating digital output at a selected frequency on at least one of the output pins. At least one transmit antenna is coupled directly to the at least one of the output pins, so that the at least one antenna transmits a magnetic field at the selected frequency responsively to the alternating digital output. A field sensor senses the magnetic field and generates a signal responsively thereto. A processor receives and processes the signal in order to determine coordinates of the position transducer.

Abstract: A method includes disposing multiple medical probes to acquire physiological data concurrently from a living body. The data is sent from the multiple medical probes by transmitting over wireless channels respective sequences of data packets that are marked with respective packet numbers. A synchronization signal that is broadcast to the multiple probes is received in the probes. In response to receiving the synchronization signal, the packet numbers that are to be assigned in the probes to subsequent data packets in the respective sequences are reset.