Abstract: A method, including selecting a first maximum radiofrequency (RF) power to be delivered by an electrode within a range of 70W-100W, and selecting a second maximum RF power to be delivered by the electrode within a range of 20W-60W. The method also includes selecting an allowable force on the electrode within a range of 5 g-50 g, selecting a maximum allowable temperature, of tissue to be ablated, within a range of 55° C.-65° C., and selecting an irrigation rate for providing irrigation fluid to the electrode within a range of 8-45 ml/min. The method further includes performing an ablation of tissue using the selected values by initially using the first power, switching to the second power after a predefined time between 3 s and 6 s, and terminating the ablation after a total time for the ablation between 10 s and 20 s.

Abstract: An electromagnetic navigation system having a wireless, battery-powered medical tool is provided. The system charges the medical tool using energy from the same magnetic fields used to locate the tool in 3-D space. The system includes one or more wireless transmission devices which generate the magnetic fields. The medical tool includes a receiving coil which generates electrical signals indicative of a location of the tool in response to receiving the magnetic fields. The tool also includes a wireless interface which provides electrical signals for processing to determine the location of the tool in 3-D space and a battery which supplies power to the tool. The tool also includes one or more charging coils, electrically connected to the battery. Each charging coil receives energy from the magnetic fields passing through a charging coil surface and supplies the energy to the battery to charge the battery.

Abstract: Apparatus, including a multiplexer, having a first output and multiple first inputs receiving analog input signals and an analog feedback signal and cycling through and selecting the signals for transfer in sequential signal groupings to the first output. The apparatus also includes an amplification circuit, having a second output and a second input connected to the multiplexer first output, that amplifies signals corresponding to the analog input signals with a selected gain so as to generate respective amplified analog signals at the second output. Circuitry selects a characteristic of the respective amplified analog signals from an initial signal grouping, feeds the characteristic back for input to the multiplexer as the analog feedback signal, selects a subsequent characteristic of the respective amplified analog signals from a subsequent signal grouping, and adjusts the amplification circuit gain so that the analog feedback signal and the subsequent characteristic have the same amplitude.

Abstract: A method, including selecting a first maximum radiofrequency (RF) power to be delivered by an electrode within a range of 70 W-100 W, and selecting a second maximum RF power to be delivered by the electrode within a range of 20 W-60 W. The method also includes selecting an allowable force on the electrode within a range of 5 g-50 g, selecting a maximum allowable temperature, of tissue to be ablated, within a range of 55° C.-65° C., and selecting an irrigation rate for providing irrigation fluid to the electrode within a range of 8-45 ml/min. The method further includes performing an ablation of tissue using the selected values by initially using the first power, switching to the second power after a predefined time between 3 s and 6 s, and terminating the ablation after a total time for the ablation between 10 s and 20 s.

Abstract: Medical catheterization is carried out by receiving a plurality of analog bioelectric signals in respective channels and multiplexing the bioelectric signals in respective selection events. The selection events consist of making a first connection with a reference voltage, thereafter breaking the first connection and making a second connection with one of the bioelectric signals. The method is further carried out by outputting the multiplexed bioelectric signals to an analog-to-digital converter.

Abstract: Wall thickness of a cavity is determined by inserting a catheter into contact with a wall of a cavity in a body of a subject. The distal segment of the catheter is provided with a contact force sensor and an ultrasound transducer. The transducer is actuated to acquire ultrasound reflection data from the wall of the cavity, and while the transducer is actuated, the catheter is reciprocated against the wall of the cavity and the contact force measured between the catheter and the wall of the cavity. The reflection data is correlated with the contact force. A set of the correlated reflection data having the highest correlation with the contact force is identified. The tissue thickness between the inner surface and the identified set of the reflection data is calculated according to the time-of-flight therebetween.

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 system and method of filtering input data to remove power line interference is disclosed. The system and method estimates the statistics of the input signal and include determining a value (R) from the ratio of a peak amplitude (Apeak) and a root-mean-square of the amplitudes of the interference harmonics (Arms), calculate a running histogram of the determined value (R) to determine a threshold value (THR), comparing the determined value (R) to the determined threshold value (THR) to make a decision about feature existence, and outputting a feature decision. The system and method include estimating the interference level to determine if interference is low level or high level. The system and method include estimating interference using the feature detection, amplitude and phase; and removing the estimated interference from the signal to result in a signal substantially free of power line interference.

Abstract: Body tissue ablation is carried out by inserting a probe into a body of a living subject, urging the probe into contact with a tissue in the body, generating energy at a power output level, and transmitting the generated energy into the tissue via the probe. While transmitting the generated energy the ablation is further carried out by determining a measured temperature of the tissue and a measured power level of the transmitted energy, and controlling the power output level responsively to a function of the measured temperature and the measured power level. Related apparatus for carrying out the ablation is also described.

Abstract: Medical catheterization is carried out by receiving a plurality of analog bioelectric signals in respective channels and multiplexing the bioelectric signals in respective selection events. The selection events comprise making a first connection with a reference voltage, thereafter breaking the first connection and making a second connection with one of the bioelectric signals. The method is further carried out by outputting the multiplexed bioelectric signals to an analog-to-digital converter.

Abstract: A method for use with an intra-body probe, a distal end of which includes an ablation electrode and a temperature sensor, is described. While (i) the ablation electrode is driving an ablating current into tissue of a subject, and (ii) fluid is passed from the distal end of the intra-body probe at a fluid-flow rate, a processor receives a temperature sensed by the temperature sensor. The processor estimates a temperature of the tissue, based at least on the sensed temperature and at least one parameter selected from the group consisting of: the fluid-flow rate, and a parameter of the ablating current. The processor generates an output in response to the estimated temperature. Other embodiments are also described.

Abstract: A method, including selecting a first maximum radiofrequency (RF) power to be delivered by an electrode within a range of 70 W-100 W, and selecting a second maximum RF power to be delivered by the electrode within a range of 20 W-60 W. The method also includes selecting an allowable force on the electrode within a range of 5 g-50 g, selecting a maximum allowable temperature, of tissue to be ablated, within a range of 55° C.-65° C., and selecting an irrigation rate for providing irrigation fluid to the electrode within a range of 8-45 ml/min. The method further includes performing an ablation of tissue using the selected values by initially using the first power, switching to the second power after a predefined time between 3 s and 6 s, and terminating the ablation after a total time for the ablation between 10 s and 20 s.

Abstract: A method, including selecting a first maximum radiofrequency (RF) power to be delivered by an electrode within a range of 70 W-100 W, and selecting a second maximum RF power to be delivered by the electrode within a range of 20 W-60 W. The method also includes selecting an allowable force on the electrode within a range of 5 g-50 g, selecting a maximum allowable temperature, of tissue to be ablated, within a range of 55° C.-65° C., and selecting an irrigation rate for providing irrigation fluid to the electrode within a range of 8-45 ml/min. The method further includes performing an ablation of tissue using the selected values by initially using the first power, switching to the second power after a predefined time between 3 s and 6 s, and terminating the ablation after a total time for the ablation between 10 s and 20 s.

Abstract: Apparatus, including a tube having a proximal end, and a distal end for insertion into a body cavity including anatomical structures, and a blade mounted at the distal end. The apparatus also includes a handle at the proximal end and including a device which generates sensible outputs upon receiving activation signals, and a position sensor fixed in a predefined disposition relative to the tube. The apparatus additionally includes a processor configured to acquire an image of the cavity, to determine, in the image, locations for each of the structures, to receive, from the sensor, a position signal indicative of a blade location of the blade within the cavity, to determine, based on the blade location and the respective structure locations, a proximity of the blade to a given structure, and to convey, to the warning device, a given activation signal in response to the proximity to the given structure.

Abstract: A power management method and system for switching on a wireless tool when location frequencies are detected, and subsequently invoking a low-powered hibernation mode when location frequencies are not detected. The method and system include a wireless tool configured to emit a mixed electromagnetic frequency signal, and a processor configured to acquire a mixed signal and determine a voltage, set the wireless tool to a hibernation mode when the voltage is below a predetermined amount, and set the wireless tool to an active mode and apply an algorithm to calculate the location and orientation of the wireless tool when the voltage is above the predetermined amount. The system and method thus allow for conservation of battery power of the wireless tool, improving the battery life of the wireless tool and increasing procedural efficiency.

Abstract: An apparatus includes at least one electrode configured to contact a body tissue of a living subject, and an electrosurgical generator, which is configured to drive radio-frequency electrical currents through the at least one electrode and to measure the electrical currents passing through the at least one electrode. The apparatus includes a neutral electrode configured for attachment to a body surface of the living subject. The apparatus also includes a switch connected between the neutral electrode and the generator, and a controller coupled to open and close the switch and to assess, based on a response of the measured electrical currents to opening and closing of the switch, whether the neutral electrode is attached to the body surface of the subject.

Abstract: Apparatus, including a multiplexer, having a first output and multiple first inputs receiving analog input signals and an analog feedback signal and cycling through and selecting the signals for transfer in sequential signal groupings to the first output. The apparatus also includes an amplification circuit, having a second output and a second input connected to the multiplexer first output, that amplifies signals corresponding to the analog input signals with a selected gain so as to generate respective amplified analog signals at the second output. Circuitry selects a characteristic of the respective amplified analog signals from an initial signal grouping, feeds the characteristic back for input to the multiplexer as the analog feedback signal, selects a subsequent characteristic of the respective amplified analog signals from a subsequent signal grouping, and adjusts the amplification circuit gain so that the analog feedback signal and the subsequent characteristic have the same amplitude.

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 method for use with an intra-body probe, a distal end of which includes an ablation electrode and a temperature sensor, is described. While (i) the ablation electrode is driving an ablating current into tissue of a subject, and (ii) fluid is passed from the distal end of the intra-body probe at a fluid-flow rate, a processor receives a temperature sensed by the temperature sensor. The processor estimates a temperature of the tissue, based at least on the sensed temperature and at least one parameter selected from the group consisting of: the fluid-flow rate, and a parameter of the ablating current. The processor generates an output in response to the estimated temperature. Other embodiments are also described.

Abstract: Body tissue ablation is carried out by inserting a probe into a body of a living subject, urging the probe into contact with a tissue in the body, generating energy at a power output level, and transmitting the generated energy into the tissue via the probe. While transmitting the generated energy the ablation is further carried out by determining a measured temperature of the tissue and a measured power level of the transmitted energy, and controlling the power output level responsively to a function of the measured temperature and the measured power level. Related apparatus for carrying out the ablation is also described.