# US 7,611,478 B2 · Continuous volume detection for a reservoir in a fluid circuit of a medical system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,611,478 B2 - Document ID: US7611478B2 - Status: Granted - Kind: B2 - Application number: 12/100,876 - Filed: 2008-04-10 - Published: 2008-08-14 - Granted: 2009-11-03 - Earliest claimed: 2003-10-02 - Assignees: Minnetronix, Inc. - Inventors: Lori E. Lucke; Matthew J. Cunningham; Richard A. Nazarian - Web page: https://patentgrep.com/patent/US7611478B2 ## CPC - A61M 1/3627: {Degassing devices; Buffer reservoirs; Drip chambers; Blood filters} - A61M 1/3666: {Cardiac or cardiopulmonary bypass, e.g. heart-lung machines} - G09B 23/303: {specially adapted to simulate circulation of bodily fluids} - A61M 1/3639: {Blood pressure control, pressure transducers specially adapted therefor} - A61M 2205/3389: Continuous level detection (A61M2205/3393 takes precedence) - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} - G09B: EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS (devices for psychotechnics or for testing reaction times A61B5/16; games, sports, amusements A63; projectors, projector screens G03B) ## Abstract Continuous volume detection for a reservoir in a fluid circuit of a medical system is described. Volume detection is based on a pressure measurement that is manipulated via application of fluid mechanics. Next-generation medical system controllers may use this data to control the volume contained in the reservoir. ## Claims ### Claim 1 A medical system comprising: a fluid circuit having a reservoir; a pressure sensor coupled within the fluid circuit near an outlet of the reservoir, wherein the pressure sensor generates a pressure signal representative of a sensed pressure of the fluid circuit; a flow sensor coupled within the fluid circuit that generates a flow signal representative of a fluid velocity of the fluid exiting the reservoir; a controller that computes a volume of fluid within the reservoir as a function of the pressure signal and the flow signal , the controller configured to output an indicator based on the computed volume; and a memory programmed to store a set of container profiles, wherein the controller selects one of the container profiles for the reservoir and computes the volume based an the selected profile, and further wherein the container profiles comprise one or more coefficients that are applied by the controller to compute the volume. ### Claim 2 (depends on 1) The medical system of claim 1, wherein the fluid circuit is a cardiopulmonary bypass circuit, and wherein the flexible reservoir is a venous reservoir of the cardiopulmonary bypass circuit. ### Claim 3 (depends on 1) The system of claim 1, wherein the controller applies a polynomial to map pressure to volume. ### Claim 4 (depends on 3) The system of claim 3, wherein the one or more coefficients of each container profile are associated with a respective type of container, and the controller applies the coefficients of the selected container profile to evaluate the polynomial. ### Claim 5 (depends on 1) The system of claim 1, wherein at least one of the container profiles corresponds to a flexible container. ### Claim 6 (depends on 1) The system of claim 1, wherein at least one of the container profiles corresponds to a hard container. ### Claim 7 (depends on 1) The system of claim 1, wherein the controller comprises an input device to receive input from a user for selecting the container profile. ### Claim 8 (depends on 1) The system of claim 1, wherein the controller comprises an input device to receive patient-specific parameters from a user, and wherein the controller computes the volume as a function of the patient-specific parameters. ### Claim 9 (depends on 1) The system of claim 1, wherein the reservoir is a reservoir within a fluid circuit of an IV pump. ### Claim 10 (depends on 1) The system of claim 1, wherein the reservoir is a reservoir within a fluid circuit of a dialysis machine. ### Claim 11 (depends on 1) The system of claim 1, wherein the reservoir is flexible reservoir within a fluid circuit of a cardiac assist system. ### Claim 12 (depends on 1) The medical system of claim 1, wherein the reservoir is reservoir within a fluid circuit of an arthroscopy system. ### Claim 13 A method comprising: generating a set of container profiles, wherein each container profile is associated with a particular type of container that can be used as a reservoir within a medical system, and further wherein the container profiles comprise one or more coefficients; storing the set of container profiles within a memory; generating a pressure signal representative of a pressure in a fluid circuit of the medical system at a location near an outlet of a reservoir; selecting one of the container profiles for the reservoir; computing a volume of fluid within the reservoir as a function of the pressure signal based on the selected container profile, wherein the coefficients of the selected container profile are applied to compute the volume; and outputting an indicator based on the computed volume. ### Claim 14 (depends on 13) The method of claim 13, further comprising generating a flow signal representative of a fluid velocity of the fluid exiting the reservoir, wherein computing a volume comprises computing the volume as a function of the flow signal and the pressure signal. ### Claim 15 (depends on 13) The method of claim 13, wherein the fluid circuit is a cardiopulmonary bypass circuit, and wherein the flexible reservoir is a venous reservoir of the cardiopulmonary bypass circuit. ### Claim 16 (depends on 13) The method of claim 13, wherein computing the volume comprises evaluating a polynomial that maps pressure to volume in accordance with the selected container profile. ### Claim 17 (depends on 16) The method of claim 16, wherein the coefficients of each of the container profiles are associated with a respective type of container, and wherein evaluating a polynomial comprises applying the coefficients defined by the selected container profile to evaluate the polynomial. ### Claim 18 (depends on 13) The method of claim 13, wherein at least one of the container profiles corresponds to a flexible container. ### Claim 19 (depends on 13) The method of claim 13, wherein at least one of the container profiles corresponds to a hard container. ### Claim 20 (depends on 13) The method of claim 13, further comprising: receiving input from a user indicating a type of container; and selecting the container profile based on the input. ### Claim 21 (depends on 13) The method of claim 13, further comprising: receiving patient-specific parameters from a user; and computing the volume as a function of the patient-specific parameters. ### Claim 22 (depends on 13) The method of claim 13, wherein the reservoir is a reservoir within a fluid circuit of an IV pump. ### Claim 23 (depends on 13) The method of claim 13, wherein the reservoir is a reservoir within a fluid circuit of a dialysis machine. ### Claim 24 (depends on 13) The method of claim 13, wherein the reservoir is flexible reservoir within a fluid circuit of a cardiac assist system. ### Claim 25 (depends on 13) The method of claim 13, wherein the reservoir is reservoir within a fluid circuit of an arthroscopy system. ### Claim 26 A method comprising: storing the set of container profiles within a memory, wherein each container profile is associated with a particular type of container that can be used as a reservoir within a fluid circuit of a medical system, and further wherein the container profiles comprise one or more coefficients; selecting one of the container profiles for the reservoir; receiving a pressure signal representative of a pressure in the fluid circuit at a location near an outlet of the reservoir; computing a volume of fluid within the reservoir as a function of the pressure signal based on the selected container profile, wherein the coefficients of the selected container profile are applied to compute the volume; and automatically generating a pump control signal based on the computed volume to control the volume of fluid within the reservoir.