Abstract: A drive mechanism for delivery of infusion medium has a coil and an armature movable toward a forward position, in response to the electromagnetic field produced by activation of the coil. A piston is movable axially within a piston channel to a forward position, in response to movement of the armature to its forward position. The armature and piston are moved toward a retracted position, when the coil is not energized. In the retracted position of the piston, a piston chamber is formed between the piston and a valve member and is filled with infusion medium. As the piston is moved to its forward position, the piston chamber volume is reduced and pressure within the piston chamber increases to a point where the pressure moves the valve member into an open position through an outlet.

Abstract: A drive mechanism for delivery of infusion medium has a coil and an armature moveable toward a forward position, in response to the electromagnetic field produced by activation of the coil. A piston is moveable axially within a piston channel to a forward position, in response to movement of the armature to its forward position. The armature and piston are moved toward a retracted position, when the coil is not energized. In the retracted position of the piston, a piston chamber is formed between the piston and a valve member and is filled with infusion medium. As the piston is moved to its forward position, the piston chamber volume is reduced and pressure within the piston chamber increases to a point where the pressure moves the valve member into an open position through an outlet.

Abstract: A drive mechanism for delivery of infusion medium a coil capable of being electrically activated to provide an electromagnetic field. The coil surrounds a piston channel extending in an axial direction. An armature is located adjacent the coil, on one side of the axial channel. The armature is moveable toward a forward position, in response to the electromagnetic field produced by activation of the coil. A piston is located within the piston channel and is moveable axially within the channel to a forward position, in response to movement of the armature to its forward position. The armature and piston are moved toward a retracted position, when the coil is not energized. The armature may be configured with a reduced diameter by including a coil cup for supporting the coil including a shelf portion defining at least a portion of a pole surface of the coil cup.

Abstract: A piston-type drive mechanism in combination with a positive pressure reservoir for delivery of infusion medium. A coil capable of being electrically activated to provide an electromagnetic field. The coil surrounds a piston channel extending in an axial direction. The piston channel provides a passage for communication of infusion medium from the positive pressure reservoir to an outlet chamber. A piston is located within the piston channel and is moveable axially within the channel to a forward position. The piston is moved toward a retracted position, when the coil is not energized. As the piston is moved to its forward position, pressure moves a valve member into an open position. When the valve member is in the open position, medium from the piston chamber is discharged into the outlet chamber. An outlet is provided in flow communication with the outlet chamber, for discharging infusion medium from the outlet chamber.

Abstract: A drive mechanism for delivery of infusion medium. A coil surrounds a piston channel. An armature is located adjacent the coil. The armature is moveable toward a forward position in response to the electromagnetic field produced by activation of the coil. A piston located within the piston channel is moveable within the channel to a forward position in response to movement of the armature. The armature and piston are moved toward a retracted position when the coil is not energized. In the retracted position, a piston chamber formed between the piston and a valve member is filled with infusion medium. As the piston is moved to its forward position, piston chamber volume is reduced and pressure within the piston chamber increases and moves the valve member into an open position. Medium from the piston chamber is then discharged into an outlet chamber.

Abstract: A drive mechanism for delivery of infusion medium has a coil and an armature moveable toward a forward position, in response to the electromagnetic field produced by activation of the coil. A piston is moveable axially within a piston channel to a forward position, in response to movement of the armature to its forward position. The armature and piston are moved toward a retracted position, when the coil is not energized. In the retracted position of the piston, a piston chamber is formed between the piston and a valve member and is filled with infusion medium. As the piston is moved to its forward position, the piston chamber volume is reduced and pressure within the piston chamber increases to a point where the pressure moves the valve member into an open position through an outlet.

Abstract: A drive mechanism for delivery of infusion medium a coil capable of being electrically activated to provide an electromagnetic field. The coil surrounds a piston channel extending in an axial direction. An armature is located adjacent the coil, on one side of the axial channel. The armature is moveable toward a forward position, in response to the electromagnetic field produced by activation of the coil. A piston is located within the piston channel and is moveable axially within the channel to a forward position, in response to movement of the armature to its forward position. The armature and piston are moved toward a retracted position, when the coil is not energized. The armature may be configured with a reduced diameter by including a coil cup for supporting the coil including a shelf portion defining at least a portion of a pole surface of the coil cup.

Abstract: A drive mechanism for delivery of infusion medium a coil capable of being electrically activated to provide an electromagnetic field. The coil surrounds a piston channel extending in an axial direction. An armature is located adjacent the coil, on one side of the axial channel. The armature is moveable toward a forward position, in response to the electromagnetic field produced by activation of the coil. A piston is located within the piston channel and is moveable axially within the channel to a forward position, in response to movement of the armature to its forward position. The armature and piston are moved toward a retracted position, when the coil is not energized. The armature may be configured with a reduced diameter by including a coil cup for supporting the coil including a shelf portion defining at least a portion of a pole surface of the coil cup.

Abstract: A drive mechanism for delivery of infusion medium. A coil surrounds a piston channel. An armature is located adjacent the coil. The armature is moveable toward a forward position in response to the electromagnetic field produced by activation of the coil. A piston located within the piston channel is moveable within the channel to a forward position in response to movement of the armature. The armature and piston are moved toward a retracted position when the coil is not energized. In the retracted position, a piston chamber formed between the piston and a valve member is filled with infusion medium. As the piston is moved to its forward position, piston chamber volume is reduced and pressure within the piston chamber increases and moves the valve member into an open position. Medium from the piston chamber is then discharged into an outlet chamber.

Abstract: A drive mechanism for delivery of infusion medium. A coil surrounds a piston channel. An armature is located adjacent the coil. The armature is moveable toward a forward position in response to the electromagnetic field produced by activation of the coil. A piston located within the piston channel is moveable within the channel to a forward position in response to movement of the armature. The armature and piston are moved toward a retracted position when the coil is not energized. In the retracted position, a piston chamber formed between the piston and a valve member filled with infusion medium. As the piston is moved to its forward position, piston chamber volume is reduced and pressure within the piston chamber increases and moves the valve member into an open position. Medium from the piston chamber is then discharged into an outlet chamber.

Abstract: A drive mechanism for delivery of infusion medium a coil capable of being electrically activated to provide an electromagnetic field. The coil surrounds a piston channel extending in an axial direction. An armature is located adjacent the coil, on one side of the axial channel. The armature is moveable toward a forward position, in response to the electromagnetic field produced by activation of the coil. A piston is located within the piston channel and is moveable axially within the channel to a forward position, in response to movement of the armature to its forward position. The armature and piston are moved toward a retracted position, when the coil is not energized. The armature may be configured with a reduced diameter by including a coil cup for supporting the coil including a shelf portion defining at least a portion of a pole surface of the coil cup.

Abstract: A piston-type drive mechanism in combination with a positive pressure reservoir for delivery of infusion medium. A coil capable of being electrically activated to provide an electromagnetic field. The coil surrounds a piston channel extending in an axial direction. The piston channel provides a passage for communication of infusion medium from the positive pressure reservoir to an outlet chamber. A piston is located within the piston channel and is moveable axially within the channel to a forward position. The piston is moved toward a retracted position, when the coil is not energized. As the piston is moved to its forward position, pressure moves a valve member into an open position. When the valve member is in the open position, medium from the piston chamber is discharged into the outlet chamber. An outlet is provided in flow communication with the outlet chamber, for discharging infusion medium from the outlet chamber.

Abstract: A rotary machine includes a helical flow compressor/turbine and a permanent magnet motor/generator including a housing with a stator positioned therein. A shaft is rotatably supported within the housing. A permanent magnet rotor is mounted on a shaft and operatively associated with the stator. An impeller is mounted on the shaft and includes an impeller disk with a plurality of impeller blades extending therefrom. The housing includes a generally horseshoe-shaped fluid flow stator channel with an inlet at a first end and an outlet at a second end. The fluid in the generally horseshoe-shaped fluid flow stator channel proceeds from the inlet to the outlet while following a generally helical flow path with multiple passes through the impeller blades. The impeller disk has a plurality of axially-oriented vent holes formed therethrough to minimize a pressure differential across the impeller, thereby minimizing thrust loads applied to the impeller.

Abstract: An electronic control systems and process for infusion devices and pump configurations can provide highly efficient use of electrical power. The system may include a capacitor which is controlled to partially, but not fully discharge, to provide a power pulse to a pump coil. In this manner, the capacitor remains partially charged and need not be re-charged from a fully discharged state. In addition, the power applied to the coil in a given discharge pulse signal may be controlled to correspond to the power needs of the pump, by controlling the degree to which the capacitor is discharged to produce the pulse signal. A power cut-off switch may be provided to control the discharge of the capacitor such that the capacitor is stopped from discharging prior to the actual end of the armature stroke. The time at which the capacitor discharge is stopped may be selected such that energy remaining in the coil after the capacitor stops discharging is sufficient to continue the pump stroke to the actual end of the stroke.

Abstract: A drive mechanism for delivery of infusion medium a coil capable of being electrically activated to provide an electromagnetic field. The coil surrounds a piston channel extending in an axial direction. The piston channel provides a passage for communication of infusion medium to an outlet chamber located at one end of the piston channel. An armature is located adjacent the coil, on one side of the axial channel. The armature is moveable toward a forward position, in response to the electromagnetic field produced by activation of the coil. A piston is located within the piston channel and is moveable axially within the channel to a forward position, in response to movement of the armature to its forward position. The armature and piston are moved toward a retracted position, when the coil is not energized. In the retracted position of the piston, a piston chamber is formed between the piston and a valve member and is filled with infusion medium.

Abstract: A drive mechanism for delivery of infusion medium a coil capable of being electrically activated to provide an electromagnetic field. The coil surrounds a piston channel extending in an axial direction. The piston channel provides a passage for communication of infusion medium to an outlet chamber located at one end of the piston channel. An armature is located adjacent the coil, on one side of the axial channel. The armature is moveable toward a forward position, in response to the electromagnetic field produced by activation of the coil. A piston is located within the piston channel and is moveable axially within the channel to a forward position, in response to movement of the armature to its forward position. The armature and piston are moved toward a retracted position, when the coil is not energized. In the retracted position of the piston, a piston chamber is formed between the piston and a valve member and is filled with infusion medium.

Abstract: Embodiments of medical infusion pumps are provided that include structural elements for providing sources of compliance within a fluid path within the pump. Some preferred embodiments provide implantable infusion pumps with compliance positioned between an exit port of a pumping mechanism and an outlet (e.g. an opening in a catheter) of the infusion pump. Other embodiments provide compliance in fluid path in proximity to entrance port of the pumping mechanism. Insertion of compliance in a flow path that is down stream of the pumping mechanism may aid in minimizing negative effects associated with attempting to force fluid through a restricted flow path that is further down-stream, such as that offered by a catheter or other outlet component. Insertion of compliance before the pumping mechanism may aid in reducing negative effects associated with an up stream restricted flow path, such as that which might be offered by a rigid filter located between the reservoir and the pumping mechanism.

Abstract: A drive mechanism for delivery of infusion medium a coil capable of being electrically activated to provide an electromagnetic field. The coil surrounds a piston channel extending in an axial direction. The piston channel provides a passage for communication of infusion medium to an outlet chamber located at one end of the piston channel. An armature is located adjacent the coil, on one side of the axial channel. The armature is moveable toward a forward position, in response to the electromagnetic field produced by activation of the coil. A piston is located within the piston channel and is moveable axially within the channel to a forward position, in response to movement of the armature to its forward position. The armature and piston are moved toward a retracted position, when the coil is not energized. In the retracted position of the piston, a piston chamber is formed between the piston and a valve member and is filled with infusion medium.

Abstract: A drive mechanism for delivery of infusion medium a coil capable of being electrically activated to provide an electromagnetic field. The coil surrounds a piston channel extending in an axial direction. The piston channel provides a passage for communication of infusion medium to an outlet chamber located at one end of the piston channel. An armature is located adjacent the coil, on one side of the axial channel. The armature is moveable toward a forward position, in response to the electromagnetic field produced by activation of the coil. A piston is located within the piston channel and is moveable axially within the channel to a forward position, in response to movement of the armature to its forward position. The armature and piston are moved toward a retracted position, when the coil is not energized. In the retracted position of the piston, a piston chamber is formed between the piston and a valve member and is filled with infusion medium.

Abstract: A compliant foil fluid film thrust bearing including a thrust disk rotor, fluid foils, spring foils, a thrust plate, and a housing thrust surface The non-rotating but compliant fluid foils, mounted on the thrust plate and/or housing thrust surface and positioned adjacent to the thrust disk, have open faced channels that induce regenerative vortex flow patterns in the process fluid. The multiple spring foils together provide a tilting pad support for the fluid foils but allow them to follow the axial and overturning motion of the thrust disk. The interaction of the tilting pad underspring supports and the circumferential fluid pressure gradients in the process fluid between the fluid foils and the thrust disk rotor assure that the fluid foils will assume hydrodynamically efficient convex shapes on the surfaces adjacent to the rotor regardless of the load applied to the thrust bearing.