Embodiments of pumps are described herein that may be used as peristaltic pumps. The pumps may include features that provide for quiet operation as well as automatically loading of tubing. Embodiments may be implemented in blood separation systems.

A piezoelectric actuator includes a first piezoelectric element that outputs a first signal when being driven, a second piezoelectric element that outputs a second signal when being driven, a signal combining part that delays phase of the second signal and outputs a composite signal by combination of the second signal and the first signal, and a drive state determination part that determines respective drive states of the first piezoelectric element and the second piezoelectric element based on the composite signal.

Features relating to a pumping mechanism of a peristaltic infusion pump are provided. Stabilizing protrusions are provided for one or more pumping fingers of the pumping mechanism, where the one or more pumping fingers move in a coordinated and synchronized fashion with respect to one another to provide a controlled peristaltic action against a flexible tube for delivery of a fluid to a patient. The protrusions extend outward from one or more side regions of the pumping fingers to create points of contact on a side-wall of a recess in a chassis in which the pumping mechanism is positioned. The points of contact serve to stabilize the fingers to prevent vibration and/or movement of the fingers against the sidewall.

A peristaltic pump includes a conduit having a first end tor receiving a fluid from a reservoir and a second end for delivering the fluid. A plurality of fingers are disposed at respective locations along a segment of the conduit and are configured to alternately compress and release the conduit at the locations. A cyclical pump mechanism is coupled to move the fingers between respective compressed and released positions in a spatio-temporal pattern so as to drive a predetermined quantity of the fluid through the segment of the conduit in each pump cycle. A motor is coupled to drive the pump mechanism. A controller is coupled to activate and deactivate the motor in alternation during each pump cycle with a duty cycle that varies within the pump cycle.

The present invention provides such pumping apparatuses that have very little deviation and high stability in pumping flow. A pumping apparatus comprises two members that are set along a longitudinal direction of a tube made of an elastic material with a relation that the space formed by grooves made in the two members holds the tube. The two members have reciprocal motion such that at least one of the two opposing members shuttles in parallel with the other opposing member and has a move-in motion such that at least one of the two opposing members vertically moves to the opposing surfaces of the other opposing member so that surrounding part of the groove thereof moves into an inner space of the groove of the other opposing member, by which motion the liquid in the tube is discharged from the tube by the deformation of tube cross sectional shape.

A piezoelectric actuator includes a plurality of piezoelectric elements that generate a driving force to be transmitted to a driven portion; and a power supply portion that supplies power to the plurality of piezoelectric elements. The plurality of piezoelectric elements are electrically connected to the power supply portion in parallel.

A sterile liquid pump, having replaceable single use components, with a first and second chamber, and a gas valve assembly to selectively communicate gas pressure and vacuum with the chambers, and a resilient tubing liquid manifold loop with a sequence of four ports located within a manifold receiver that supports four pinch actuators aligned to engage and selectively pinch-off flow through the manifold between adjacent pairs ports, and, a controller that operates the valve assembly to alternatingly couple pressure and vacuum to the pump chambers, and that also operates to alternatingly actuate pairs of the pinch actuators to sequentially pump fluid from pump chambers under gas pressure, and through an opposing pair of ports in the resilient tubing manifold.

A piezoelectric driving device includes: a piezoelectric vibrating body which includes a plurality of piezoelectric elements each formed of a first electrode, a second electrode, and a piezoelectric body positioned between the first electrode and the second electrode, and is disposed at least one surface of the first surface and the second surface of the vibrating plate, wherein the plurality of piezoelectric elements are connected in series.

A peristaltic pump is disclosed that includes a plunger, a spring, an actuator, a position sensor, and a processor. The plunger actuates toward and away from a tube. The spring biases the plunger toward the tube. The actuator actuates the plunger away from the tube and mechanically engages and disengages from the plunger. The position sensor senses a position of the plunger. The processor receives the sensed position of the plunger and estimates fluid flow within the tube using a first position of the plunger when the actuator is engaged with the plunger and a second position of the plunger when the actuator is disengaged from the plunger.

A method of testing the rotor engagement of a peristaltic pump rotor. The method comprising steps of providing a pump system comprising a peristaltic pump rotor; a tube; a valve; a pressure sensor; a comparator; and a processor. The pressure sensor is configured to monitor the pressure in a fluid in the tube downstream of the peristaltic pump rotor and upstream of the valve. The comparator is configured to continuously monitor the pressure sensor and compare the measured fluid pressure data with a predetermined parameter. The processor is configured to receive a signal from the comparator and generate an alert signal when the measured pressure data falls outside the predetermined parameters.