US 12,357,736 B2
Flow balancing devices, methods, and systems
David Desouza, Essex, MA (US); Daniel Joseph Rubery, Jr., Nashua, NH (US); Dennis M. Treu, Castle Rock, CO (US); Mark T. Wyeth, Andover, MA (US); Jerome James, Vestavia, AL (US); Garrett D. Casey, Methuen, MA (US); James M. Brugger, Newburyport, MA (US); William J. Schnell, Libertyville, IL (US); Jeffrey H. Burbank, Manchester, MA (US); and Goetz Friederichs, Beverly, MA (US)
Assigned to NxStage Medical, Inc., Lawrence, MA (US)
Filed by NxStage Medical, Inc., Lawrence, MA (US)
Filed on Feb. 8, 2023, as Appl. No. 18/107,136.
Application 18/107,136 is a continuation of application No. 17/122,772, filed on Dec. 15, 2020, granted, now 11,607,482.
Application 17/122,772 is a continuation of application No. 16/317,903, granted, now 10,898,635, issued on Jan. 26, 2021, previously published as PCT/US2017/042683, filed on Jul. 18, 2017.
Claims priority of provisional application 62/524,518, filed on Jun. 24, 2017.
Claims priority of provisional application 62/363,394, filed on Jul. 18, 2016.
Prior Publication US 2023/0191015 A1, Jun. 22, 2023
Int. Cl. A61M 1/36 (2006.01); A61M 1/16 (2006.01)
CPC A61M 1/1647 (2014.02) [A61M 1/1601 (2014.02); A61M 1/3607 (2014.02); A61M 1/3663 (2013.01); A61M 2205/3334 (2013.01); A61M 2205/3393 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method for controlling flow in a fluid circuit, comprising:
in a blood treatment system that regulates net ultrafiltration of a patient by balancing a fluid withdrawn from a blood treatment device against the fluid pumped into the blood treatment device by controlling a relative volume displaced during a treatment by an inflow pump and an outflow pump, wherein the inflow pump and the outflow pump are regulated independently of each other;
using a controller, during a testing mode, detecting a difference between a flow rate of the inflow pump and a flow rate of the outflow pump continuously over a test interval while storing difference data representing said difference over time;
using the controller, while detecting said difference and generating said difference data, controlling a pumping rate of at least one of the inflow and outflow pumps to minimize said difference in flow rate without establishing a minimum of said difference;
calculating, from the difference data and the pumping rate of the at least one of the inflow and outflow pumps, a control parameter for regulating said at least one of the inflow and outflow pumps by extrapolating from a trend in said difference data an equilibrium rate of the at least one of the inflow and outflow pumps that corresponds to the minimum of said difference; and
performing the treatment including controlling a net flow of the fluid to or from a patient by controlling the inflow and outflow pumps responsively to said control parameter.