# US 11,439,310 B2 · Method of estimating blood volume > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,439,310 B2 - Document ID: US11439310B2 - Status: Granted - Kind: B2 - Application number: 16/557,708 - Filed: 2019-08-30 - Published: 2020-03-05 - Granted: 2022-09-13 - Earliest claimed: 2017-01-11 - Assignees: Cypher Medical, LLC - Applicants: Cypher Medical, LLC - Inventors: Christopher A. Carew; Jian Ling - Web page: https://patentgrep.com/patent/US11439310B2 ## CPC - A61B 5/02042: {Determining blood loss or bleeding, e.g. during a surgical procedure} - G01F 22/00: Methods or apparatus for measuring volume of fluids or fluent solid material, not otherwise provided for - G01N 33/49: Blood {(chemical methods for determining blood cell populations G01N33/5094; chemical analysis of blood groups or blood types G01N33/80)} - G01N 33/80: involving blood groups or blood types {or red blood cells (white blood cells G01N33/56972)} - G08G 5/21: located onboard the aircraft - G08G 5/30: Flight plan management - G01F 19/00: Calibrated capacity measures for fluids or fluent solid material, e.g. measuring cups - G01N 2001/4083: {sedimentation} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G08G: TRAFFIC CONTROL SYSTEMS (guiding railway traffic, ensuring the safety of railway traffic B61L; arrangement of road signs or traffic signals E01F9/00; radar or analogous systems, sonar systems, lidar systems specially adapted for traffic control G01S13/91, G01S15/88, G01S17/88; {radar or analogous systems, sonar systems, lidar systems specially adapted for anti-collision purposes G01S13/93, G01S15/93, G01S17/93}) ## Abstract Disclosed are methods, materials and devices for approximation of blood volume in a fluid, such as in a biological fluid collected during a surgical procedure. The method and devices include the use of a RBC flocculant, such as polyDADMAC, and an approximate blood hematocrit for the type of animal, as well as a calculated RBC packing ratio corresponding to the collection device being used. Also provided is a Blood Indicator Panel (BIP), comprising a series of markings calculated from an observed red blood settlement volume, the average animal type hematocrit, and a calculated RBC packing ratio “η” value for the collection device. Pediatric (about 200 ml or 250 ml size container), adult human (about 1,000 ml-1,500 ml) and veterinary (about 500 ml-2,500 ml) collection containers are also disclosed, that include a RBC flocculant, for use in approximating blood volume in a fluid. Methods of detecting blood in a sample, such as a fluid sample, and kits for performing the methods, are also provided. ## Claims ### Claim 1 A method for approximating blood volume in a fluid comprising: receiving an amount of a red blood cell flocculant and a volume of the fluid into a container; determining a volume of sedimented red blood cells from the fluid; and determining a volume of blood in the fluid, wherein the volume of sedimented red blood cells is correlated with the approximate blood volume in the fluid; and wherein the amount of the red blood cell flocculant is about 320 mg. ### Claim 2 (depends on 1) The method of claim 1 wherein the red blood cells are human red blood cells. ### Claim 3 (depends on 1) The method of claim 1 wherein the fluid comprises saline. ### Claim 4 (depends on 1) The method of claim 1 wherein the red blood cell flocculant is provided in a solid form, an aqueous solution, a water-in-oil emulsion, or as a dispersion in water. ### Claim 5 (depends on 1) The method of claim 1 wherein the red blood cell flocculant comprises polyDADMAC, PEI, or PAM. ### Claim 6 (depends on 1) The method of claim 1 wherein the red blood cell flocculant comprises polyDADMAC. ### Claim 7 (depends on 6) The method of claim 6 wherein the polyDADMAC comprises a high-molecular weight polyDADMAC having a molecular weight of 100, 200, 300, or 400 kDA. ### Claim 8 (depends on 6) The method of claim 6 wherein the polyDADMAC has a molecular weight of 200-350 kDa. ### Claim 9 (depends on 1) The method of claim 1 wherein the fluid comprises about 20% blood, 30% blood, 40% blood, 50% blood, or about 65% blood by volume. ### Claim 10 (depends on 1) The method of claim 1 wherein a volume of saline is added to the volume of fluid and red blood cell flocculant. ### Claim 11 (depends on 1) The method of claim 1 wherein the container is a canister having a volume capacity of 1.2 liters. ### Claim 12 (depends on 1) The method of claim 1 wherein the volume of blood in the fluid is determined according to a formula: Vb=Vm/(Hct×η) wherein Vb is the blood volume, Vm is the volume of settled red blood cells, Hct is an average hematocrit, and η is the red blood cell packing ratio. ### Claim 13 (depends on 1) The method of claim 1 wherein the fluid is at room temperature. ### Claim 14 (depends on 1) The method of claim 1 wherein the fluid comprises about 40% blood by volume of the fluid. ### Claim 15 (depends on 1) The method of claim 1 wherein the fluid is a fluid from a horse, a human or a cow. ### Claim 16 (depends on 1) The method of claim 1 wherein the fluid comprises a fluid from a human. ### Claim 17 (depends on 1) The method of claim 1 wherein the fluid comprises urine, bile, saliva, lymph, amniotic fluid, peritoneal fluid, or any combination thereof. ### Claim 18 A method for approximating blood volume in a fluid comprising: receiving into a container a volume of the fluid and an amount of a red blood cell flocculant sufficient to permit stable sedimentation of red blood cells from the fluid; determining a volume of stable sedimented red blood cells in the container; and approximating blood volume in the fluid, wherein the volume of sedimented red blood cells is used to provide the approximate blood volume in the fluid, and the amount of red blood cell flocculant is about 320 mg. ### Claim 19 (depends on 18) The method of claim 18 wherein the fluid comprises adult human blood. ### Claim 20 (depends on 18) The method of claim 18 wherein the approximate blood volume in the fluid is provided by dividing the volume of sedimented red blood cells by an average blood hematocrit multiplied by a red blood cell packing ratio in the container to provide the approximate blood volume. ### Claim 21 (depends on 18) The method of claim 18 wherein the red blood cell flocculant comprises polyDADMAC. ### Claim 22 (depends on 18) The method of claim 18 wherein the approximate blood volume (Vb) in the fluid is calculated according to a formula: Vb=Vm/(Hct×η) wherein Vm is the volume of settled red blood cells, Hct is an average hematocrit, and η is the red blood cell packing ratio.