Abstract: A plurality of control-signal generators are configured to generate respective control signals having respective control-signal amplitudes and different respective control-signal frequencies, and a plurality of signal adders are configured to produce respective composite signals for application to a subject, by adding the control signals to respective ablation signals having respective ablation-signal amplitudes. The control-signal generators are configured to generate the control signals such that respective ratios between the control-signal amplitudes and the ablation-signal amplitudes are constant during the application of the composite signals to the subject.

Abstract: An ablation system includes multiple electrodes configured to contact body tissue of a patient, including two or more ablation electrodes for contacting respective locations in a target organ and a return electrode. A signal-generating unit includes multiple signal generators, which are configured to apply respective composite signals to respective ones of the ablation electrodes. The composite signals include multiple, respective signal components, including respective ablation signals, having different, respective ablation-signal amplitudes and phases at a common ablation-signal frequency, and respective probe signals having respective probe-signal amplitudes and different respective probe-signal frequencies. A processor is coupled to measure the probe signals received by each of the multiple electrodes, and responsively to the measured probe signals, to control the ablation-signal amplitudes and phases.

Abstract: A system includes a signal generator, configured to pass a generated signal, which has two different generated frequencies, through a circuit including an intrabody electrode. The system further includes a processor, configured to identify, while the generated signal is passed through the circuit, a derived frequency, which is derived from the generated frequencies, on the circuit, and to generate, in response to identifying the derived frequency, an output indicating a flaw in the electrode. Other embodiments are also described.

Abstract: A plurality of control-signal generators are configured to generate respective control signals having respective control-signal amplitudes and different respective control-signal frequencies, and a plurality of signal adders are configured to produce respective composite signals for application to a subject, by adding the control signals to respective ablation signals having respective ablation-signal amplitudes. The control-signal generators are configured to generate the control signals such that respective ratios between the control-signal amplitudes and the ablation-signal amplitudes are constant during the application of the composite signals to the subject.

Abstract: A system includes a signal generator, configured to pass a generated signal, which has two different generated frequencies, through a circuit including a bidirectional semiconductor device. The system further includes a processor, configured to identify, while the generated signal is passed through the circuit, a derived frequency, which derives from the generated frequencies, on the circuit, and to generate, in response to identifying the derived frequency, an output indicating that a property of the bidirectional semiconductor device is asymmetric. Other embodiments are also described.

Abstract: A system includes a signal generator, configured to pass a generated signal, which has two different generated frequencies, through a circuit including an intrabody electrode. The system further includes a processor, configured to identify, while the generated signal is passed through the circuit, a derived frequency, which is derived from the generated frequencies, on the circuit, and to generate, in response to identifying the derived frequency, an output indicating a flaw in the electrode. Other embodiments are also described.

Abstract: A signal return-path symmetry measurement apparatus includes a transformer and monitoring circuitry. The transformer is coupled to first and second return-path electrodes that are attached to a body of a patient and serve as a return path for an electrical signal applied to the patient. The transformer is configured to generate a return-path-difference electrical signal responsive to a difference between electrical signals returning from the first and second return-path electrodes. The monitoring circuitry is configured to generate an electrode symmetry measure responsive to the return-path-difference electrical signal.

Abstract: A plurality of control-signal generators are configured to generate respective control signals having respective control-signal amplitudes and different respective control-signal frequencies, and a plurality of signal adders are configured to produce respective composite signals for application to a subject, by adding the control signals to respective ablation signals having respective ablation-signal amplitudes. The control-signal generators are configured to generate the control signals such that respective ratios between the control-signal amplitudes and the ablation-signal amplitudes are constant during the application of the composite signals to the subject.

Abstract: A system includes a display, an input device, and a processor. The processor is configured to present to a user, on the display, a GUI that illustrates multiple electrodes disposed on an expandable frame of a multi-electrode catheter, and indicates which of the electrodes is active and which of the electrodes is inactive. The processor is further configured to (a) receive, via the input device first user input that chooses between a single-electrode-selection mode and a fan-selection mode, (b) when in the single-electrode-selection mode, receive via the input device second user input that specifies for activation or deactivation individual ones of the electrodes, and (c) when in the fan-selection mode, receive via the input device third user input that specifies for activation or deactivation an angular sector including two or more of the electrodes, and activate and deactivate the electrodes responsively to the first, second and third user inputs.

Abstract: A cable, an associated monitoring system and methods are provided which monitor the continuity of current of electrical components such as sensor signals from sensors used in connection with a medical apparatus. The cable includes a proximal end for coupling with a processing unit and a distal end with or for coupling to sensors. The processing unit generates a continuity signal that travels through the cable via an inductor coil conductor to a distal end inductor coil which imparts the signal to sensor signal conductors of the cable. The continuity signal is carried back to the processing unit with signals from the sensors. Circuitry of the processing unit can detect the returning continuity signals to indicate proper connectivity of the sensor signals. The connection status information of the sensors can be displayed to inform a doctor or other operator of the medical apparatus of sensor signal continuity.

Abstract: A wiring assembly includes a differential input port, a differential output port, and first and second pairs of electrical conductors. The differential input port is configured to receive a differential signal from a sensor at a first end of the wiring assembly. The differential output port is configured to output the differential signal at a second end of the wiring assembly. The first and second pairs of electrical conductors are laid out in a three-dimensional (3D) crossover configuration relative to one another and configured to conduct the differential signal from the first end to the second end, and to cancel pickup of a magnetic field by the wiring assembly. The electrical conductors of each pair are connected to one another at the first end and at the second end.

Abstract: A cable, an associated monitoring system and methods are provided which monitor the continuity of current of electrical components such as sensor signals from sensors used in connection with a medical apparatus. The cable includes a proximal end for coupling with a processing unit and a distal end with or for coupling to sensors. The processing unit generates a continuity signal that travels through the cable via an inductor coil conductor to a distal end inductor coil which imparts the signal to sensor signal conductors of the cable. The continuity signal is carried back to the processing unit with signals from the sensors. Circuitry of the processing unit can detect the returning continuity signals to indicate proper connectivity of the sensor signals. The connection status information of the sensors can be displayed to inform a doctor or other operator of the medical apparatus of sensor signal continuity.

Abstract: An ablation system includes multiple electrodes configured to contact body tissue of a patient, including two or more ablation electrodes for contacting respective locations in a target organ and a return electrode. A signal-generating unit includes multiple signal generators, which are configured to apply respective composite signals to respective ones of the ablation electrodes. The composite signals include multiple, respective signal components, including respective ablation signals, having different, respective ablation-signal amplitudes and phases at a common ablation-signal frequency, and respective probe signals having respective probe-signal amplitudes and different respective probe-signal frequencies. A processor is coupled to measure the probe signals received by each of the multiple electrodes, and responsively to the measured probe signals, to control the ablation-signal amplitudes and phases.

Abstract: A cable, an associated monitoring system and methods are provided which monitor the continuity of current of electrical components such as sensor signals from sensors used in connection with a medical apparatus. The cable includes a proximal end for coupling with a processing unit and a distal end with or for coupling to sensors. The processing unit generates a continuity signal that travels through the cable via an inductor coil conductor to a distal end inductor coil which imparts the signal to sensor signal conductors of the cable. The continuity signal is carried back to the processing unit with signals from the sensors. Circuitry of the processing unit can detect the returning continuity signals to indicate proper connectivity of the sensor signals. The connection status information of the sensors can be displayed to inform a doctor or other operator of the medical apparatus of sensor signal continuity.

Abstract: An apparatus includes a controllable signal source and a processor. The controllable signal source is configured to apply an Alternating Current (AC) signal to multiple electrodes of a multi-electrode catheter immersed in an aquatic solution. The processor is configured to, responsively to the applied AC signal, estimate a respective surface impedance or a respective electrical noise level of each of the electrodes. The processor is further configured to disconnect each electrode, independently of other electrodes, when the estimated surface impedance or electrical noise level of the electrode drops below a preset value.

Abstract: An apparatus includes a controllable signal source and a processor. The controllable signal source is configured to apply an Alternating Current (AC) signal to multiple electrodes of a multi-electrode catheter immersed in an aquatic solution. The processor is configured to, responsively to the applied AC signal, estimate a respective surface impedance or a respective electrical noise level of each of the electrodes. The processor is further configured to disconnect each electrode, independently of other electrodes, when the estimated surface impedance or electrical noise level of the electrode drops below a preset value.

Abstract: A cable, an associated monitoring system and methods are provided which monitor the continuity of current of electrical components such as sensor signals from sensors used in connection with a medical apparatus. The cable includes a proximal end for coupling with a processing unit and a distal end with or for coupling to sensors. The processing unit generates a continuity signal that travels through the cable via an inductor coil conductor to a distal end inductor coil which imparts the signal to sensor signal conductors of the cable. The continuity signal is carried back to the processing unit with signals from the sensors. Circuitry of the processing unit can detect the returning continuity signals to indicate proper connectivity of the sensor signals. The connection status information of the sensors can be displayed to inform a doctor or other operator of the medical apparatus of sensor signal continuity.

Abstract: A plurality of control-signal generators are configured to generate respective control signals having respective control-signal amplitudes and different respective control-signal frequencies, and a plurality of signal adders are configured to produce respective composite signals for application to a subject, by adding the control signals to respective ablation signals having respective ablation-signal amplitudes. The control-signal generators are configured to generate the control signals such that respective ratios between the control-signal amplitudes and the ablation-signal amplitudes are constant during the application of the composite signals to the subject.

Abstract: A cable, an associated monitoring system and methods are provided which monitor the continuity of current of electrical components such as sensor signals from sensors used in connection with a medical apparatus. The cable includes a proximal end for coupling with a processing unit and a distal end with or for coupling to sensors. The processing unit generates a continuity signal that travels through the cable via an inductor coil conductor to a distal end inductor coil which imparts the signal to sensor signal conductors of the cable. The continuity signal is carried back to the processing unit with signals from the sensors. Circuitry of the processing unit can detect the returning continuity signals to indicate proper connectivity of the sensor signals. The connection status information of the sensors can be displayed to inform a doctor or other operator of the medical apparatus of sensor signal continuity.