# US 9,872,756 B2 · Removable embolus blood clot filter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,872,756 B2 - Document ID: US9872756B2 - Status: Granted - Kind: B2 - Application number: 15/291,000 - Filed: 2016-10-11 - Published: 2017-02-02 - Granted: 2018-01-23 - Earliest claimed: 2005-05-12 - Assignees: C. R. Bard, Inc. - Applicants: C. R. Bard, Inc. - Inventors: Robert M. Carr, Jr.; Andrzej J. Chanduszko; John D. McDermott; John A. Kaufman - Web page: https://patentgrep.com/patent/US9872756B2 ## CPC - A61F 2/0105: {Open ended, i.e. legs gathered only at one side} - A61B 90/39: {Markers, e.g. radio-opaque or breast lesions markers} - A61F 2/0103: {With centering means} - A61F 2002/016: {made from wire-like elements} - A61F 2220/0016: with sharp anchoring protrusions, e.g. barbs, pins, spikes - A61F 2230/005: Rosette-shaped, e.g. star-shaped - A61F 2230/0067: conical - A61F 2230/008: paraboloidal - A61F 2250/0037: differing in height or in length - A61F 2250/0039: differing in diameter - A61F 2250/0067: Means for introducing or releasing pharmaceutical products into the body - A61F 2250/0098: radio-opaque, e.g. radio-opaque markers - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A removable blood clot filter includes a number of locator members and anchor members disposed radially and extending angularly downward from a hub. The locator members include a number of linear portions having distinct axes configured to place a tip portion approximately parallel to the walls of a blood vessel when implanted to apply sufficient force to the vessel walls to position the filter near the vessel centerline. The anchor members each include a hook configured to penetrate the vessel wall to prevent longitudinal movement due to blood flow. The hooks may have a cross section sized to allow for a larger radius of curvature under strain so that the filter can be removed without damaging the vessel wall. ## Claims ### Claim 1 A filter comprising: a hub disposed along a longitudinal axis; at least one anchor member projecting from the hub, the at least one anchor member including a hook adapted to penetrate a blood vessel wall, the hook spaced along the longitudinal axis from the hub and spaced a first radial distance from the longitudinal axis; and at least one locator member projecting from the hub, the at least one locator member having a tip segment spaced along the longitudinal axis from the hub and spaced a second radial distance from the longitudinal axis, the second radial distance being less than the first radial distance, the at least one locator member having at least four segments including the tip segment, each disposed on respective distinct axes, the four segments comprising: a proximal segment proximate the hub; a first segment that extends along a first angle; a second segment that extends along a second angle; and the tip segment that extends along a third angle. ### Claim 2 (depends on 1) The filter according to claim 1 wherein the proximal segment proximate the hub comprises a curved portion that extends along the longitudinal axis on a radius of curvature. ### Claim 3 (depends on 2) The filter according to claim 2 wherein the curved portion comprises a radius of curvature of about 0.1 inches about an axis generally orthogonal to the longitudinal axis. ### Claim 4 (depends on 3) The filter according to claim 3 wherein the hook is offset in alignment with respect to the axis on which at least one segment of the anchor member is aligned. ### Claim 5 (depends on 4) The filter according to claim 4 wherein each of the at least one anchor member comprises: a first anchor segment that extends away from the longitudinal axis at a fourth angle; a second anchor segment that extends away from the longitudinal axis at a fifth angle; and a retention portion. ### Claim 6 (depends on 5) The filter according to claim 5 wherein at least two locator members define a first virtual circle having a first diameter extending through the longitudinal axis. ### Claim 7 (depends on 6) The filter according to claim 6 wherein the at least two locator members include a hook to engage with the wall of the blood vessel. ### Claim 8 (depends on 7) The filter according to claim 7, wherein at least two anchor members define a second virtual circle having a second diameter extending through the longitudinal axis, the second diameter being about 1.2 times the first diameter. ### Claim 9 (depends on 5) The filter according to claim 5 wherein the retention portion comprises a hook. ### Claim 10 (depends on 9) The filter according to claim 9 wherein the hook comprises a curved configuration in an operative condition and a generally linear configuration in a constrained condition. ### Claim 11 A blood vessel filter, comprising: a hub disposed along a longitudinal axis; a plurality of locator members projecting from the hub, a proximal end of each of the locator members attached to the hub, the locator members bounded by a first compound surface of revolution about the longitudinal axis, the first compound surface of revolution including a first frustum distal of the hub having a first volume, and a second frustum distal of the first frustum having a second volume greater than the first volume; and a plurality of anchor members projecting from the hub, a proximal end of each of the anchor members attached to the hub, the anchor members bounded by a second compound surface of revolution about the longitudinal axis, the second compound surface of revolution including a third frustum and a fourth frustum distal of the third frustum, wherein at least one of the plurality of locator members has a proximal segment, a first segment, a second segment that extends along a second angle, and a tip segment that extends along an angle. ### Claim 12 (depends on 11) The blood vessel filter according to claim 11 wherein the first surface of revolution further includes a cylinder distal of the second frustum. ### Claim 13 (depends on 12) The blood vessel filter according to claim 12 wherein the ratio of a volume defined by the first surface of revolution to a volume defined by the second surface of revolution is in the range from about 0.92 to about 1.0. ### Claim 14 (depends on 13) The blood vessel filter according to claim 13 wherein about 15% or more of the volume defined by the second surface of revolution is surrounded by the volume defined by the first surface of revolution. ### Claim 15 (depends on 14) The blood vessel filter according to claim 14 wherein about 25% or more of the volume defined by the second surface of revolution is surrounded by the volume defined by the first surface of revolution. ### Claim 16 (depends on 15) The blood vessel filter according to claim 15 wherein about 35% or more of the volume defined by the second surface of revolution is surrounded by the volume defined by the first surface of revolution. ### Claim 17 (depends on 16) The blood vessel filter according to claim 16 wherein: each of the anchor members includes a hook spaced a first radial distance from the longitudinal axis; and each of the locator members includes a tip segment spaced a second radial distance from the longitudinal axis, wherein the second radial distance is less than the first radial distance. ### Claim 18 (depends on 17) The blood vessel filter according to claim 17 wherein each of the locator members has at least four segments including the tip segment, each disposed on respective distinct axes, the four segments comprising: a proximal segment proximate the hub; a first segment extending from the proximal segment along a first angle with respect to the longitudinal axis; a second segment extending from the first segment along a second angle with respect to the longitudinal axis less than the first angle; and the tip segment extending from the second segment along a third angle with respect to the longitudinal axis less than the second angle. ### Claim 19 (depends on 18) The blood vessel filter according to claim 18 wherein the first and second segments are linear.