A catheter includes an elongated body having a longitudinal axis, a distal assembly distal the elongated body, the distal assembly having a tapered helical form comprising a larger, electrode-carrying proximal loop and a smaller, softer distal loop, and a shape-memory support member extending through at least the proximal loop. For example, the helical loop subtends at least about 720 radial degrees, with the proximal loop subtending about 360 radial degrees, and the distal loop subtending about 360 radial degrees. The softer distal loop with a straight distal end atraumatically guides the distal assembly into a tubular region so that the larger proximal loop can sit on the ostium of the tubular region with improved electrode and tissue contact.

Some embodiments of the invention may be related to an apparatus for non-invasive directional tissue treatment. The apparatus includes a radiofrequency (RF) generator and an array of RF energy delivery elements in monopolar configuration, in active communication with the RF generator, at least one of: a return electrode and a return pad, and a power source and a controller. In some embodiments, each of the RF energy delivery elements comprises a monopolar electrode such that each monopolar electrode has a first dimension and a second dimension, the first dimension perpendicular to the second dimension. In some embodiments, the first dimension of each monopolar electrode and the distance between the monopolar electrodes in each pair are configured to create an elongated heated volume of tissue when the RF generator is activated and at least one of the RF delivery elements is in contact with the tissue.

An intra-cardiac mapping system is based on locating the ports through which blood flows in or out the heart chambers. For many procedures, such as ablation to cure atrial fibrillation, locating the pulmonary veins and the mitral valve accurately allows to perform a Maze procedure. The location of the ports and valves is based on using the convective cooling effect of the blood flow. The mapping can be performed by a catheter-deployed expandable net or a scanning catheter. The same net or catheter can also perform the ablation procedure.

A system includes a catheter, a switching assembly, and a processor. The catheter including an expandable frame, which is coupled to a distal end of the catheter, and multiple electrodes, which are disposed on the expandable frame in a radial geometry. The switching assembly is electrically connected to the catheter, and is configured to electrically short between selected ones of the electrodes. The processor is configured, for first and second disjoint groups of the electrodes, to control the switching assembly to electrically short the electrodes within each of the first and second groups, for applying one or more bipolar ablation energy between the first and second groups when the electrodes are placed in contact with a target tissue of the organ.

In some embodiments, a plurality of transducers of a transducer-based device may be selected for activation. A first pair of subsets of the selected transducers may be identified for initial activation, each subset of the first pair being activated with a different phase angle range than the other. No transducer in one subset is sufficiently close to a transducer in the other subset to cause a confluence of ablated tissue regions therebetween. The first pair of subsets may be activated simultaneously or concurrently. Upon activation or a conclusion thereof of the pair of subsets of the selected transducers, one or more subsequent pairs of subsets of the selected transducers may be activated iteratively on a pair-by-pair basis, until all of the selected transducers have achieved desired activation results, according to some embodiments. Each subsequent pair may include the same or similar characteristics as the first pair.

Methods, systems, and devices for providing treatment to a tissue in body lumens are described. The system may include a catheter, an expansion member coupled with a distal portion of the catheter, an ablation structure including one or more longitudinal electrode segments, and an ablation structure support coupled to the ablation structure configured to at least partially unfurl as the expansion member expands and furl as the expansion member contracts. The ablation structure may include multiple separately wired and/or separately controlled longitudinal electrodes, longitudinal electrode zones, or both, such that each longitudinal electrode or longitudinal electrode zone may be selectively enabled or selectively disabled. In some instances, one or more springs are coupled to the ablation structure configured to promote unfurl or furl around the expansion member. In some instances, one or more protection elements are be positioned along the catheter.

In general, surgical devices switchable between monopolar functionality and bipolar functionality are provided. In an exemplary embodiment, a surgical device is configured to selectively apply each of bipolar energy and monopolar energy.

A multi-pole synchronous pulmonary artery radiofrequency ablation catheter may comprise a control handle, a catheter body and an annular ring. One end of the catheter body may be flexible, and the flexible end of the catheter body may be connected to the annular ring. The other end of the catheter body may be connected to the control handle. A shape memory wire may be arranged in the annular ring. One end of the shape memory wire may extend to an end of the annular ring and the other end of the shape memory wire may pass through a root of the annular ring and be fixed on the flexible end of the catheter body. The annular ring may be provided with an electrode group. The device possesses advantages of simple operation, short operation time and controllable precise ablation. The device can be used to treat pulmonary hypertension with pulmonary denervation.

Various embodiments are directed to electrosurgical systems for providing an electrosurgical signal to a patient. A control circuit may, for a first application period, apply the electrosurgical signal to first and second electrodes according to a first mode. In the first mode, the control circuit may limit the electrosurgical signal to a first maximum power when the impedance between the first and second electrodes exceeds a first mode threshold. The control circuit may also, for a second application period after the first application period, apply the electrosurgical signal according to a second mode. In the second mode, the control circuit may limit the electrosurgical signal to a second mode maximum power when the impedance between the first and second electrodes exceeds a second mode threshold. The second maximum power may be greater than the first maximum power.

In some embodiments, a plurality of transducers of a transducer-based device may be selected for activation. A first pair of subsets of the selected transducers may be identified for initial activation, each subset of the first pair being activated with a different phase angle range than the other. No transducer in one subset is sufficiently close to a transducer in the other subset to cause a confluence of ablated tissue regions therebetween. The first pair of subsets may be activated simultaneously or concurrently. Upon activation or a conclusion thereof of the pair of subsets of the selected transducers, one or more subsequent pairs of subsets of the selected transducers may be activated iteratively on a pair-by-pair basis, until all of the selected transducers have achieved desired activation results, according to some embodiments. Each subsequent pair may include the same or similar characteristics as the first pair.