Provided is a tube pump system which includes: a pair of roller units which are rotated around an axis line from a closing position to a releasing position; a pair of drive units which are configured to respectively rotate the pair of roller units; a control unit which is configured to control each of the pair of drive units; and a pressure sensor which is configured to detect a pressure of a liquid in a pipe connected to the other end of the tube, wherein the control unit controls a first rotation angle when the first roller unit passes through the closing position and a second rotation angle when the second roller unit passes through the releasing position such that fluctuation of the pressure of the liquid when the pair of roller units are rotated through at least one revolution falls within a predetermined value.

Apparatus are provided for infusion devices and related systems and operating methods. An exemplary system includes a motor, a sensing arrangement coupled to the motor to provide output indicative of a detected characteristic of the motor when the sensing arrangement is enabled, and a module coupled to the sensing arrangement to periodically enable the sensing arrangement while the motor is idle and detect potential unintended motion of the motor based on the output from the sensing arrangement while periodically enabling the sensing arrangement. In some embodiments, the motor includes a rotor configured such that its rotation provides translational displacement of a plunger in a fluid reservoir, and the sensing arrangement includes one or more sensors configured to provide output indicative of a detected magnetic field of the rotor magnet.

A rotary sub-assembly for pumping of fluid is provided. The sub-assembly includes a hollow body defining a cavity having a longitudinal axis, the body comprising a cavity wall with at least two ports passing therethrough. At least a portion of the cavity has a non-circular cross-section such that a first constant or varying radial distance from the longitudinal axis to inwardly-offset segments of the cavity wall surrounding the two ports is less than a second constant or varying radial distance from the longitudinal axis to second segments of the cavity wall spaced apart from the two ports. A rotatable plunger is housed in the cavity. The plunger is sized and shaped such that a side wall of the plunger can establish a liquid-tight seal against the inwardly-offset segments of the cavity wall, but does not establish a liquid-tight seal with the second segments of the cavity wall spaced apart from the two ports.

A rotary sub-assembly for pumping of fluid is provided. The sub-assembly includes a hollow body defining a cavity having a longitudinal axis, the body comprising a cavity wall with at least two ports passing therethrough. At least a portion of the cavity has a non-circular cross-section such that a first constant or varying radial distance from the longitudinal axis to inwardly-offset segments of the cavity wall surrounding the two ports is less than a second constant or varying radial distance from the longitudinal axis to second segments of the cavity wall spaced apart from the two ports. A rotatable plunger is housed in the cavity. The plunger is sized and shaped such that a side wall of the plunger can establish a liquid-tight seal against the inwardly-offset segments of the cavity wall, but does not establish a liquid-tight seal with the second segments of the cavity wall spaced apart from the two ports.

Provided is a tube pump system which includes: a pair of roller units which are rotated around an axis line from a closing position to a releasing position; a pair of drive units which are configured to respectively rotate the pair of roller units; a control unit which is configured to control each of the pair of drive units; and a pressure sensor which is configured to detect a pressure of a liquid in a pipe connected to the other end of the tube, wherein the control unit controls a first rotation angle when the first roller unit passes through the closing position and a second rotation angle when the second roller unit passes through the releasing position such that fluctuation of the pressure of the liquid when the pair of roller units are rotated through at least one revolution falls within a predetermined value.

A fluid infusion device includes a pump having a rotor and a stator. A rotor cam element rises from a reference surface of the rotor. The stator includes a cam element having a stator cam surface. The cam elements axially displace the rotor as the rotor revolves. Inlet and outlet valves open and close as a function of angular and axial position of the rotor. A motor actuates the rotor to pump fluid to a body, via a subcutaneous conduit. First and second contact elements are located on the rotor. A sensing element on the stator cooperates with a detection circuit to detect when the sensing element makes contact with the first sensor contact element and the second sensor contact element. The detection circuit monitors a detection signal obtained from the sensing element to determine an operating condition of the fluid pump mechanism.