Transducer-based systems and methods may be configured to display a graphical representation of a transducer-based device, the graphical representation including graphical elements corresponding to transducers of the transducer-based device, and also including between graphical elements respectively associated with a set of the transducers and respectively associated with a region of space between the transducers of the transducer-based device. Selection of graphical elements and/or between graphical elements can cause activation of the set of transducers associated with the selected elements. Transducer activation characteristics, such as initiation time, activation duration, activation sequence, and energy delivery characteristics, can vary based on numerous factors. Visual characteristics of graphical elements and between graphical elements can change based on an activation-status of the corresponding transducers. Activation requests for a set of transducers can be denied if it is determined that a transducer in the set of transducers is unacceptable for activation.

A catheter configured to deliver therapeutic energy to a tissue can include can include an elongate shaft extending along a shaft longitudinal axis and comprising a shaft proximal end and a shaft distal end. The catheter can include a flexible tip assembly comprising a tip assembly outer surface, wherein the flexible tip assembly is connected to the shaft distal end and is configured to deliver therapeutic energy to the tissue, and wherein the flexible tip assembly further includes. The flexible tip assembly can include an insulative layer comprising an insulative layer outer surface, wherein the insulative layer is disposed on the tip assembly outer surface and a mapping electrode disposed on the insulative layer outer surface.

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 catheter has a cooling distal section for freezing tissue to sub-zero temperatures with one or more miniature reverse thermoelectric or Peltier elements, also referred to herein as micro-Peltier cooling (MPC) units or electrodes. The MPC units may be on outer surface of an inflatable or balloon member or a tip electrode shell wall that has a fluid-containing interior cavity acting as a heat sink. Each MPC unit has a hot junction and a cold junction whose temperatures are regulated by the heat sink, and a voltage/current applied to the MPC units. A temperature differential of about 70 degrees Celsius may be achieved between the hot and cold junctions for extreme cooling, especially where the MPC units include semiconductor materials with high Peltier co-efficients. An outer coating of thermally-conductive but electrically-insulative material seals the MPC units to prevent unintended current paths through the MPC units.

Embodiments described herein include apparatus that includes an electrical interface and a processor. The processor is configured to receive, via the electrical interface, a first signal that indicates a time-varying force that was applied to a portion of tissue, and one or more second signals that are derived from ultrasound reflections received from the portion of tissue. The processor is further configured to learn, from the first signal and the second signals, a dependency of a thickness of the portion of tissue on the force applied to the portion of tissue. Other embodiments are also described.

A method includes, using a probe, applying irreversible electroporation (IRE) pulses to tissue over a time period to form a lesion in the tissue. A contact force applied to the tissue by the probe is measured over the time period. An IRE index is calculated based on the measured contact force and on a power level of the IRE pulses. Application of the IRE pulses to the tissue is ceased in response to the calculated IRE index reaching a prespecified target IRE index value.

A catheter includes an insertion tube, a flexible substrate and one or more electrical devices. The insertion tube is configured for insertion into a patient body. The flexible substrate is configured to wrap around a distal end of the insertion tube and includes electrical interconnections. The electrical devices are coupled to the flexible substrate and are connected to the electrical interconnections.

Ablation electrode assemblies include an inner core member and an outer shell surrounding the inner core member. The inner core member and the outer shell define a space or separation region therebetween. The inner core member is constructed from a thermally insulative material having a reduced thermal conductivity. In an embodiment, the space is a sealed or evacuated region. In other embodiments, irrigation fluid flows within the space. The ablation electrode assembly further includes at least one thermal sensor in some embodiments. Methods for providing irrigation fluid during cardiac ablation of targeted tissue are disclosed that include calculating the energy delivered to irrigation fluid as it flows within the ablation electrode assembly through temperature measurement of the irrigation fluid. Pulsatile flow of irrigation fluid can be utilized in some embodiments of the disclosure.

Aspects of the present disclosure are directed to flexible high-density mapping catheters with a high-density array of mapping electrodes. These mapping catheters may be used to detect electrophysiological characteristics of tissue in contact with the electrodes, and may be used to diagnose cardiac conditions, such as cardiac arrhythmias for example.

The present disclosure provides embodiments of devices that are useful in the structural remodeling of various parts of the cardiovascular system, most notably the heart. Certain of the disclosed devices relate to RAMIN procedures (“remodeling and ablation using myocardial interstitial navigation”). RAMIN procedures, as described herein, represent a new family of non-surgical catheter-based procedures in order to accomplish ablation, drug delivery, re-shaping, pacing, and related structural heart interventional procedures, as desired.