A catheter includes an elongated body, a distal assembly with a shape-memory member defining a generally circular form, and a control handle adapted to actuate a deflection puller wire for deflecting a portion of the elongated body, and a contraction wire for contracting the generally circular form. The generally circular form which carries at least one ring electrode has an off-edge configuration relative to the elongated body such that a longitudinal axis of the elongated body does not intersect the circumference of the circular form and the generally circular form spirals about the longitudinal axis of the elongated body. Moreover, the circular form can have an on-axis configuration such that the longitudinal axis of the elongated body is axially aligned with a central longitudinal axis of the circular form, or an off-axis configuration such that these axes are axially offset from each other. In a more detailed embodiment, the catheter has a distal assembly with a helical form or a crescent form carrying a plurality of irrigated ablation ring electrodes and a plurality of smaller ring electrodes adapted for impedance recording or PV potential recording. A support member with shape memory extends through the distal assembly to provide the helical or crescent form. The support member has a varying stiffness along its length, for example, a decreasing stiffness toward a distal end of the support member. The support member can also be hollow so that it can receive a mandrel whose stiffness is greater than that of the support member.

Cardiac ablation catheters and methods of use. Catheters that include an expandable membrane, an imaging member disposed within the expandable membrane, the imaging member having a field of view, a light source disposed within the expandable member adapted to deliver light towards the field of view of the imaging member, and an electrode comprising an outer conductive layer and inner light absorbing layer disposed between the electrode and the expandable membrane, the inner light absorbing layer adapted to absorb light from the light source and thereby reduce reflection of the light from the outer conductive electrode.

Pulsed field ablation systems are disclosed, some of which may include an output pulse generation circuit and a high voltage pulse generation circuit electrically connected to the output pulse generation circuit. The high voltage pulse generation circuit may be configured to deliver a high voltage pulse set to the output pulse generation circuit. The output pulse generation circuit may be configured to generate an output pulse set at least in response to the high voltage pulse set. The output pulse set may be deliverable to a set of selectable electrodes and may be configured to cause pulsed field ablation of tissue. Each pulse in the output pulse set may have a rise time that is shorter than a rise time of at least one high voltage pulse in the high voltage pulse set.

A plurality of catheter-based ablation apparatus embodiments are provided that address several areas of atrial target tissue and which feature firm and consistent ablation element to tissue contact enabling the creation of effective continuous lesions.

Apparatus and methods for ablation efficacy are described herein where a hood having a deployable elongated feature can extend beyond a distal face of the hood. The elongated feature can channel the energy to the deeper regions within the tissue (such as trabeculated regions or other tissue structures) such that the energy can be delivered to the target tissue despite small or large irregularities in the target tissue surface (or region) and/or changes in the relative distances between the hood and the target tissue.

A system for ablating internal heart tissue in an ablation pattern on a surface of the tissue within the heart. The system includes an ablation catheter with a distal end having an ablating tip portion operative to allow selective ablation of tissue. A guiding device is engageable with the ablation catheter and includes a tissue anchoring portion operable to engage with tissue proximate to the tissue to be ablated so as to temporarily anchor the guiding device relative to the tissue. Engagement of the guiding device with the ablation catheter operates to assist with guiding the ablating tip portion in moving along the pattern. Various devices and methods of use are further disclosed.

Surgical systems and methods for administering an ablation treatment and other therapeutic or diagnostic protocols to a patient tissue involve a flexible stabilizer mechanism having an inner recess and an ablation mechanism coupled with the stabilizer mechanism.

An apparatus for medical diagnosis and/or treatment is provides. The apparatus includes a flexible substrate forming an inflatable body and a plurality of force sensing elements disposed on the flexible substrate. The plurality of force sensing elements are disposed about the inflatable body such that the force sensing elements are disposed at areas of minimal curvature of the inflatable body in a deflated state.

Provided is an ablation device including a narrow insertion section insertable into a body, a distal end section provided at a distal end of the insertion section and having a narrow cauterizing surface that is formed in a longitudinal direction in one area in a circumferential direction and that releases energy to biological tissue, and a radiopaque marking section provided at the distal end section and substantially parallel to the cauterizing surface. The marking section has a three-dimensional shape such that projection shapes obtained when projected from different sides in a radial direction of the distal end section are different from each other.

The invention relates to an ablation catheter for treatment of a patient's tissue by delivery of high-voltage pulses comprising a catheter shaft and an ablation portion being arranged at a distal end of the catheter shaft with a plurality of electrodes accommodated along the ablation portion, wherein the ablation portion forms a spiral and comprises a first loop section and a neighboring second loop section, wherein an inner diameter of the first loop section increases towards an inner diameter of the second loop section starting from a first end of the first loop section located opposite the second loop section, wherein the first loop section has a greater stiffness than the second loop section.