# US 2008/0188759 A1 · Flow reduction hood systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0188759 A1 - Document ID: US20080188759A1 - Status: Published application - Kind: A1 - Application number: 12/026,455 - Filed: 2008-02-05 - Published: 2008-08-07 - Earliest claimed: 2007-02-05 - Assignees: Voyage Medical, Inc. - Inventors: Vahid SAADAT; Edmund TAM; Chris A. ROTHE; David MILLER; Ruey-Feng PEH - Web page: https://patentgrep.com/patent/US20080188759A1 ## CPC - A61B 1/00089: {Hoods} - A61B 1/0008: {characterised by distal tip features} - A61B 1/00148: {using anchoring means} - A61B 1/00165: {with light-conductive means, e.g. fibre optics (A61B1/07 takes precedence)} - A61B 1/015: Control of fluid supply or evacuation - A61B 1/018: for receiving instruments - A61B 1/05: characterised by the image sensor, e.g. camera, being in the distal end portion - A61B 1/051: {Details of CCD assembly} - A61B 1/12: with cooling or rinsing arrangements - A61B 1/3137: {for examination of the interior of blood vessels} - A61B 1/32: Devices for opening or enlarging the visual field, e.g. of a tube of the body - A61B 5/6851: {Guide wires} - A61B 17/29: Forceps for use in minimally invasive surgery - A61B 18/00: Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body (eye surgery A61F9/007; ear surgery A61F11/00) - A61B 18/18: by applying electromagnetic radiation, e.g. microwaves - A61B 6/503: {for diagnosis of the heart} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract Flow reduction hood systems are described which facilitate the visualization of tissue regions through a clear fluid. Such a system may include an imaging hood having one or more layers covering the distal opening and defines one or more apertures which control the infusion and controlled retention of the clearing fluid into the hood. In this manner, the amount of clearing fluid may be limited and the clarity of the imaging of the underlying tissue through the fluid within the hood may be maintained for relatively longer periods of time by inhibiting, delaying, or preventing the infusion of surrounding blood into the viewing field. The aperture size may be controlled to decrease or increase through selective inflation of the membrane or other mechanisms. ## Claims ### Claim 1 An apparatus configured to control fluid flow for visualization, 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; and an imaging element positioned to image the open area through the clearing fluid. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein the membrane comprises an inflatable dual-membrane. ### Claim 3 (depends on 1) The apparatus of claim 1 wherein the aperture is controllable to variably alter its diameter. ### Claim 4 (depends on 1) The apparatus of claim 1 wherein the membrane is distensible such that proximal tensioning or releasing of the barrier correspondingly controls a diameter of the aperture. ### Claim 5 (depends on 1) The apparatus of claim 1 wherein the aperture is slotted transversely relative to the catheter. ### Claim 6 (depends on 1) The apparatus of claim 1 wherein the aperture comprises at least one slotted opening which extends in an arcuate or curved manner over the membrane. ### Claim 7 (depends on 1) The apparatus of claim 1 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. ### Claim 8 (depends on 1) The apparatus of claim 1 wherein the at least one membrane comprises a plurality of movable segments which are rotatable relative to one or more stationary segments which are non-moving relative to the barrier, wherein rotation of the movable segments transition a plurality of apertures between an open and closed configuration. ### Claim 9 (depends on 1) The apparatus of claim 1 wherein the at least one membrane defines a meshed membrane. ### Claim 10 (depends on 1) The apparatus of claim 1 further comprising a dilator which is translatable relative to the barrier, wherein distal translation of the dilator engages the aperture and transitions the barrier to a low-profile configuration. ### Claim 11 (depends on 1) The apparatus of claim 1 wherein the aperture has a diameter of 1 to 4 mm. ### Claim 12 (depends on 1) The apparatus of claim 1 wherein the imaging element comprises a CCD, CMOS, or optical fiber imager. ### Claim 13 A method for controlling fluid flow for visualization, comprising: positioning a barrier projecting distally from a deployment catheter and defining an open area therein proximate or adjacent to a tissue region of interest; infusing a clearing fluid into the open area while visualizing within the open area such that an opaque fluid is purged at least partially therefrom; and controlling the flow of the clearing fluid from the open area through at least one aperture defined along at least one membrane covering the open area. ### Claim 14 (depends on 13) The method of claim 13 wherein visualizing within the open area comprises imaging the open area via a CCD, CMOS, or optical fiber imager. ### Claim 15 (depends on 13) The method of claim 13 further comprising adjusting a size of the at least one aperture. ### Claim 16 (depends on 15) The method of claim 15 wherein adjusting comprises inflating or deflating the at least one membrane such that the aperture size is correspondingly adjusted. ### Claim 17 (depends on 13) The method of claim 13 further comprising tensioning or releasing the barrier such that a diameter of the at least one aperture is correspondingly sized. ### Claim 18 (depends on 13) The method of claim 13 further comprising rotating a plurality of movable segments relative to a plurality of stationary segments which are non-moving relative to the barrier such that relative rotation transitions a plurality of apertures between an open and closed configuration. ### Claim 19 (depends on 13) The method of claim 13 further comprising advancing a dilator into the open area such that the dilator engages the aperture. ### Claim 20 (depends on 19) The method of claim 19 further advancing the dilator relative to the barrier such that the barrier collapses into a low-profile configuration against the dilator. ### Claim 21 (depends on 13) The method of claim 13 further comprising advancing an instrument into the open area to treat tissue underlying the barrier. ### Claim 22 (depends on 21) The method of claim 21 further comprising ablating the tissue while visualizing through the open area. ### Claim 23 (depends on 22) The method of claim 22 wherein ablating the tissue comprises ablating the tissue defined by the at least one aperture.