A control system is provided to restrict the flow rate of blood in a venous line 12 of a perfusion system 1 comprising a reservoir 10 supplied by the venous line 12 and supplying an outgoing line 22. The control system comprises an outgoing flow sensor 32 configured to determine an outgoing flow value indicative of the outgoing flow rate in the outgoing line 22, and a controller configured to process the outgoing flow value and to determine if the outgoing flow value exceeds a pre-set pairing threshold. The system further comprises an adjustable restriction 28 for restricting the flow rate in the venous line 12 to maintain a venous flow rate that does not exceed a venous restriction threshold, wherein the adjustable restriction 28 is responsive to the controller and wherein the controller comprises a configuration allowing the controller to set the adjustable restriction at the level of the outgoing flow rate, to change the venous restriction threshold with the outgoing flow rate, if the outgoing flow value is above the pre-set pairing threshold.

An artificial heart and lung apparatus includes a roller pump; a blood removal line; a first blood transfer line; a blood removal rate sensor; a control unit that performs the linked control of the roller pump in correspondence with a blood removal rate; and a blood transfer rate adjustment unit that instructs the roller pump to transfer a blood transfer rate. The blood transfer rate adjustment unit includes an operation amount input unit to which an operation amount from an arbitrary circumferential position can be input, and which outputs a pulse signal according to the input operation amount. A counter adds and subtracts pulse signals output from the operation amount input unit, and outputs a resultant as blood transfer rate adjustment data. The counter performs a counting operation with respect to the circumferential position of the operation amount input unit when blood transfer control transitions to the normal control.

A method of estimating an amount of work available to be performed by a blood pump implanted in a patient includes calculating a first coordinate value characterizing a volume of blood impelled in the pump and a second coordinate value characterizing a differential pressure across the pump for each of a plurality of flow rate data points of a given cardiac cycle of the patient, each flow rate data point indicative of a flow rate of blood through the pump. An area enclosed by the first and second coordinate values of the plurality of flow rate data points is determined, the determined area being indicative of an amount of work available to be performed by the blood pump.

A by-pass shunt for use with a bodily fluid pump. The by-pass shunt includes an inflow conduit, an outflow conduit, and an intermediate conduit fluidically coupling the inflow and outflow conduits. A flow restrictor is operably coupled to a portion of the intermediate conduit and is configured to reduce a fluid flow from the outflow conduit, through the intermediate conduit, and into the inflow conduit.

A method of managing a speed of implantable blood pump. The implantable blood pump is in communication with an internal battery and a transcutaneous energy transfer system (TETS). The method includes starting the pump at a programmed set speed. The speed of the pump is decreased from the programmed set speed to a minimum set speed if either a capacity of the internal battery is less than a predetermined reserve level and TETS power is unavailable, or there is insufficient TETS power to maintain the programmed set speed. The speed of the pump is progressively decreased from the programmed set speed if there is insufficient power to maintain the programmed set speed.

A method of managing a speed of implantable blood pump. The implantable blood pump is in communication with an internal battery and a transcutaneous energy transfer system (TETS). The method includes starting the pump at a programmed set speed. The speed of the pump is decreased from the programmed set speed to a minimum set speed if either a capacity of the internal battery is less than a predetermined reserve level and TETS power is unavailable, or there is insufficient TETS power to maintain the programmed set speed. The speed of the pump is progressively decreased from the programmed set speed if there is insufficient power to maintain the programmed set speed.

A system for detecting a suction condition in an implantable blood pump including a controller in communication with the blood pump. The controller includes a control circuit configured to calculate a present value during a time period, the present value corresponding to a pump speed divided by a pump current, determine a plurality of data values during the time period based on the present value, and determine a suction detection threshold value using the plurality of data values. The control circuit is also configured to compare the present value during the time period to the suction detection threshold value and generate an alert when the present value exceeds the suction detection threshold value on a plurality of instances during the time period, the alert corresponding to a suction condition.

An extracorporeal blood circulation system reduces the risk of generation of air bubbles entering the circulation circuit associated with placement of a pressure sensor that detects a patient's blood pressure at a blood removal line. Instead of directly measuring pressure at the blood removal line where suction exists, an intermediate part pressure sensor detects pressure between a centrifugal pump and an oxygenator. A controller identifies a discharge pressure specific to the centrifugal pump based on a rotation speed of the pump and a blood flow rate. The discharge pressure and the intermediate pressure values are combined to estimate the pressure at the blood removal line.

The present specification describes a modular, portable hemofiltration system, for providing improved clearance levels of blood toxins, which includes at least one roller pump that is designed and operated to generate a rapidly varying pressure profile of fluid within at least a blood circuit of the hemofiltration system.

In one general aspect, a method includes measuring blood flow through a right rotary blood pump, measuring blood flow through a left rotary blood pump, and controlling a speed of one of the rotary blood pumps using a controller that calculates the speed of one of the rotary blood pumps based on the measured blood flow through the other rotary blood pump.