Fluid pumping systems, devices and methods
First Claim
1. An actuation system for a reciprocating membrane-based pump having a pumping chamber separated from an actuation chamber by a flexible membrane, a delivery stroke resulting from the application of positive pressure in the actuation chamber, and a fill stroke resulting from the application of negative pressure in the actuation chamber, the actuation system comprising:
- at least one valve fluidly connecting the actuation chamber with a reservoir arranged to supply positive pressure to the actuation chamber and fluidly connecting the actuation chamber with a reservoir arranged to supply negative pressure to the actuation chamber;
a controller configured to signal the at least one valve to operate in a plurality of pulses during a delivery stroke or a fill stroke, each pulse comprising an opening period and a closing period of the valve;
whereinthe controller is configured to command the at least one valve to pulse with an opening period during an initial phase of a delivery or fill stroke that is longer than an opening period during a later phase of the delivery or fill stroke.
1 Assignment
0 Petitions
Accused Products
Abstract
Reciprocating positive-displacement membrane pumps (which may be referred to hereinafter as “pods,” “pump pods,” or “pod pumps”) used to pump fluids, such as a biological fluid (e.g., blood or peritoneal fluid), a therapeutic fluid (e.g., a medication solution), or a surfactant fluid are disclosed. The speed of a pump stroke can be adjusted by altering a frequency of pressure pulses delivered to the pump membrane during a fill stroke or a delivery stroke of the pump. A pumping algorithm may divide a pump stroke into an initial pumping period and a end-of-stroke pumping period, with the pressure pulse duration being longer during the initial pumping period. This arrangement may allow for a minimum pump flow rate while also providing a pressure ripple that can be used to detect the end of a pump stroke.
539 Citations
16 Claims
-
1. An actuation system for a reciprocating membrane-based pump having a pumping chamber separated from an actuation chamber by a flexible membrane, a delivery stroke resulting from the application of positive pressure in the actuation chamber, and a fill stroke resulting from the application of negative pressure in the actuation chamber, the actuation system comprising:
-
at least one valve fluidly connecting the actuation chamber with a reservoir arranged to supply positive pressure to the actuation chamber and fluidly connecting the actuation chamber with a reservoir arranged to supply negative pressure to the actuation chamber; a controller configured to signal the at least one valve to operate in a plurality of pulses during a delivery stroke or a fill stroke, each pulse comprising an opening period and a closing period of the valve;
whereinthe controller is configured to command the at least one valve to pulse with an opening period during an initial phase of a delivery or fill stroke that is longer than an opening period during a later phase of the delivery or fill stroke. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A method of operating a reciprocating membrane-based pump having a pumping chamber separated from an actuation chamber by a flexible membrane, a delivery stroke resulting from the application of positive pressure in the actuation chamber, and a fill stroke resulting from the application of negative pressure in the actuation chamber, the method comprising:
-
pulsing at least one valve connecting the actuation chamber with a first reservoir arranged to supply positive pressure to the actuation chamber and connecting the actuation chamber with a second reservoir arranged to supply negative pressure to the actuation chamber by switching from an opening period in which the valve is opened or partially opened to a closing period in which the valve is closed or open to a lesser degree than during the opening period a plurality of times during a delivery or fill stroke; and operating the pulsing so that the opening period of the valve is longer in duration in an initial phase of the delivery or fill stroke than in a later phase of the delivery or fill stroke. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
-
Specification