A self-contained peristaltic pump includes a flexible flow conduit with a plurality of circumferential and/or longitudinal shapechange elements distributed longitudinally and/or transversely along the longitudinal axis of the flow conduit. The activations of the shapechange elements result in the positive displacement of fluid in the anterograde direction (i.e. from the anterior end of the pump to the posterior end).

An example medical device is disclosed. The example medical device includes a tubular scaffold having an inner surface and an outer surface. The medical device also includes a flexible inner member extending along at least a portion of the inner surface of the scaffold. Further, the medical device includes an activation assembly positioned along a portion of the inner member, the activation assembly including a conductive member having a first end region and a second end region, wherein a portion of the first end region is coupled to an activation element, and wherein the second end region is coupled to a power source. Additionally, the power source is configured to deliver an electrical stimulus to the activation element which shifts the inner member between a first configuration and a second expanded configuration.

A pumping system (200) for controlling the flow of interatrial blood comprises, housed inside a container (201), a control element (30, 30′, 30″) of the interatrial blood flow. The control element comprises: at least one worm screw (31), the rotation of which creates a two-way flow of interatrial blood; or a pair of counter-rotating propellers (31′); or a pair of membranes (31″) whose deformation creates a two-way flow of interatrial blood; or a flexible structure (31″) whose change in volume within the container (201) creates a two-way flow of interatrial blood.

Ventricular assist devices configured to be placed in a ventricle of a heart are described. In one embodiment, a ventricular assist device may include a pumping pouch. The pumping pouch may have an opening. The pumping pouch may be flexible, and may define an internal volume configured to fill with blood in through the opening. The ventricular assist device may also include a contraction element coupled to the contraction pouch. The contraction element may be capable of squeezing at least a portion of the pumping pouch to force at least a portion of the blood out through the opening. The ventricular assist device may also include a frame coupled to the pumping pouch. The frame may be configured to be coupled to a wall of the heart.

An example pump for driving a biological fluid is described herein. The pump can include an inner tubular structure and an outer tubular structure arranged around the inner tubular structure. The outer tubular structure can be configured as an artificial muscle. The pump can also include a gel layer disposed between the inner and outer tubular structures.

Tubular propulsion devices and systems and methods for using such devices and systems to restore, replace, or augment or otherwise modulate active transport of fluids through a diseased or damaged tubular organ or organ segment are described. The devices have a hollow center surrounded by a peripheral wall. The devices can be multilayer devices. The devices may be single tube devices or multi-section devices. Typically, elements for altering the structure of the device, such as via compression, expansion, twisting, and/or contraction of one or more sections of the peripheral wall, are included in the walls or are outside or inside, of the walls of the device. The devices undergo intermittent change of the contained volume (luminal volume) in a sequential manner to direct fluid flow. In use, the devices are able to serve as local mini- or regional-pumps.

An implantable blood flow control system has an open passageway defined inside a radially inner wall, behind which is a closed passageway. The radially inner wall includes electroactive polymer actuator members for providing a variable flow restriction. The flow restriction has an undulating shape so that the volume of the closed passageway may remain constant during actuation of the electroactive polymer actuator members. In this way, the chamber behind the actuator members does not impede free movement of the actuator members. The undulating pattern presents no sharp edges, where blood coagulation could otherwise occur.

An implantable device includes an EAP actuator and a sensor. The sensor is configured to monitor a force external to the implantable device acting in a direction either with or counter to a direction of actuation of the actuator, and a controller is adapted to control the actuator to actuate at a moment when force counter to the direction of actuation is sensed to be at its lowest within a given time window or force with the direction of actuation is sensed to be at its highest within a given time window. In this way, actuation is effected at a moment of least resistance force, reducing the power needed for deployment of the actuator, and permitting actuation to occur even in conditions experiencing large variable forces.

An actuation system includes a virtual or computer-modeled portion that is coupled to a physical portion. The virtual portion is a computer model that models or otherwise simulates a function or action, such as a physiological function or action, including for example an action potential, a calcium transient, and/or a chemical reaction. The computer model may model or simulate a chemical action, a mechanical action (such as movement of a wing) or any other action. The virtual portion drives or controls one or more physical actuators, which can be sized on a microscopic scale, such as on a nanometer scale. The actuation system can be used as or part of an artificial anatomical structure or organ, such as an artificial heart.

Ventricular assist devices configured to be placed in a ventricle of a heart are described. In one embodiment, a ventricular assist device may include a pumping pouch. The pumping pouch may have an opening. The pumping pouch may be flexible, and may define an internal volume configured to fill with blood in through the opening. The ventricular assist device may also include a contraction element coupled to the contraction pouch. The contraction element may be capable of squeezing at least a portion of the pumping pouch to force at least a portion of the blood out through the opening. The ventricular assist device may also include a frame coupled to the pumping pouch. The frame may be configured to be coupled to a wall of the heart.