Flow reduction hood systems

A method for controlling fluid flow, comprising:

• positioning a barrier in an expanded configuration projecting distally from a deployment catheter and defining an open area therein proximate or adjacent to a tissue region of interest, wherein at least one membrane extends over a distal opening defined by the barrier such that the membrane partially covers the open area;
• infusing a clearing fluid into the open area while visualizing through the open area such that an opaque fluid is purged at least partially from the open area and to an environment external to the barrier through at least one aperture defined along the membrane;
• and
• inhibiting the flow of the clearing fluid from the open area through the at least one aperture.

An apparatus configured to control fluid flow, comprising:

• a barrier projecting distally from a deployment catheter and defining an open area therein, wherein the open area is in fluid communication with at least one lumen;
• at least one membrane covering the open area and defining at least one aperture which is sized to control a flow of a clearing fluid infused within the open area via the at least one lumen, wherein the at least one membrane comprises a plurality of inflatable strips or barriers extending over the open area such that inflation of the strips or barriers controls a size of a plurality of elongate slots;
• and
• an imaging element positioned to image the open area through the clearing fluid.

An apparatus configured to control fluid flow, comprising:

• a non-inflatable fluid barrier projecting distally from a deployment catheter and defining an open area therein;
• a membrane extending over a distal opening defined by the barrier such that the membrane partially encloses the open area and further defines at least one aperture along the membrane, wherein the aperture is sized to inhibit a flow of a clearing fluid infused within the open area via at least one lumen defined through the catheter, and wherein the open area is in fluid communication through the aperture with an environment external to the barrier;
• and
• an imaging element positioned to image the open area through the clearing fluid.

A method for controlling fluid flow, comprising:

• reconfiguring a barrier projecting distally from a deployment catheter to self-expand from a low-profile configuration to an expanded configuration which defines an open area and where a membrane extends over a distal opening defined by the barrier and partially encloses the open area;
• positioning the membrane in proximity or adjacent to a tissue region of interest;
• and,
• infusing a clearing fluid into the open area while visualizing through the open area via an imaging element such that the fluid is purged at least partially through at least one aperture defined along the membrane from the open area to an environment external to the barrier, wherein flow of the fluid from the open area to the environment is inhibited by the aperture.