Infusion device and driving mechanism for same
First Claim
1. A drive mechanism for delivery of infusion medium comprising:
- an inlet for receiving infusion medium;
an outlet for discharging infusion medium;
a piston channel having a generally annular wall with an axial length defined between an open inlet end on a same side of the drive mechanism as the inlet and an open outlet end on a same side of the drive mechanism as the outlet;
a piston within an interior of the generally annular wall along the axial length of the piston channel and moveable axially between a retracted position and a forward position to drive infusion medium toward the outlet;
a clearance between the interior of the generally annular wall and the piston along the axial length of the piston channel;
an armature located proximate to the open inlet end of the piston channel and moveable between a retracted position and a forward position;
a spring around and coaxial with the piston and between the armature and a shoulder within the interior of the generally annular wall of the piston channel to exert a spring force to urge the armature toward its retracted position;
a coil located coaxial with the piston and in a position relative to the armature to generate an electromagnetic field upon energization sufficient to overcome the spring force and cause the armature and piston to move from their retracted positions to their forward positions; and
a valve assembly having a valve cap and a valve member, the valve member being supported on the valve cap for movement relative to the valve cap and being moveable between open and closed positions to selectively open and close the open outlet end of the piston channel to an outlet chamber, the valve member being moveable in response to axial movement of the piston within the piston channel, the valve cap being free of any fluid flow opening therethrough; and
the inlet, piston channel, outlet chamber and outlet defining a fluid flow direction from the inlet, then through the clearance along the axial length of the piston channel from the open inlet end to the open outlet end, and then through the outlet chamber and the outlet, for communication of infusion medium during operation of the drive mechanism.
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Accused Products
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.
41 Citations
27 Claims
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1. A drive mechanism for delivery of infusion medium comprising:
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an inlet for receiving infusion medium; an outlet for discharging infusion medium; a piston channel having a generally annular wall with an axial length defined between an open inlet end on a same side of the drive mechanism as the inlet and an open outlet end on a same side of the drive mechanism as the outlet; a piston within an interior of the generally annular wall along the axial length of the piston channel and moveable axially between a retracted position and a forward position to drive infusion medium toward the outlet; a clearance between the interior of the generally annular wall and the piston along the axial length of the piston channel; an armature located proximate to the open inlet end of the piston channel and moveable between a retracted position and a forward position; a spring around and coaxial with the piston and between the armature and a shoulder within the interior of the generally annular wall of the piston channel to exert a spring force to urge the armature toward its retracted position; a coil located coaxial with the piston and in a position relative to the armature to generate an electromagnetic field upon energization sufficient to overcome the spring force and cause the armature and piston to move from their retracted positions to their forward positions; and a valve assembly having a valve cap and a valve member, the valve member being supported on the valve cap for movement relative to the valve cap and being moveable between open and closed positions to selectively open and close the open outlet end of the piston channel to an outlet chamber, the valve member being moveable in response to axial movement of the piston within the piston channel, the valve cap being free of any fluid flow opening therethrough; and the inlet, piston channel, outlet chamber and outlet defining a fluid flow direction from the inlet, then through the clearance along the axial length of the piston channel from the open inlet end to the open outlet end, and then through the outlet chamber and the outlet, for communication of infusion medium during operation of the drive mechanism. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A drive mechanism for delivery of infusion medium comprising:
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an inlet for receiving infusion medium into an inlet chamber; an outlet for discharging infusion medium from an outlet chamber; a piston channel having a generally annular wall with an axial length defined between an open inlet end on a same side of the drive mechanism as the inlet and an open outlet end on a same side of the drive mechanism as the outlet; a piston within an interior of the generally annular wall along the axial length of the piston channel and moveable axially between a retracted position and a forward position to drive infusion medium toward the outlet; a clearance between the interior of the generally annular wall and the piston along the axial length of the piston channel, the clearance forming a fluid path through which infusion medium is communicated between the inlet chamber and the outlet chamber through the piston channel, wherein the drive mechanism is free of further fluid flow paths between the inlet chamber and the outlet chamber other than the piston channel; an armature located proximate to the open inlet end of the piston channel and moveable between a retracted position and a forward position; a coil located coaxial with the piston and in a position relative to the armature to generate an electromagnetic field upon energization sufficient to overcome a spring force and cause the armature and piston to move from their retracted positions to their forward positions; and the inlet, inlet chamber, piston channel, outlet chamber and outlet defining a fluid flow direction from the inlet, through the inlet chamber, through the clearance along the axial length of the piston channel from the open inlet end to the open outlet end, and through the outlet chamber and the outlet, for communication of infusion medium during operation of the drive mechanism. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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19. A method for delivery of infusion medium comprising:
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providing a drive mechanism including a housing and cover structure having an inlet for receiving infusion medium into an inlet chamber, an outlet for discharging infusion medium from an outlet chamber and a piston channel having a generally annular wall with an axial length defined between an open inlet end on a same side of the drive mechanism as the inlet and an open outlet end on a same side of the drive mechanism as the outlet through which infusion medium is communicated between the inlet chamber and the outlet chamber, wherein the inlet, inlet chamber, piston channel, outlet chamber and outlet define a fluid flow direction in a fluid flow path from the inlet, then through the inlet chamber, then along the axial length through the piston channel, then through the outlet chamber and then through the outlet, for fluid to flow during delivery of infusion medium, and wherein the drive mechanism is free of further fluid flow paths between the inlet chamber and the outlet chamber other than through the piston channel; energizing a coil to generate an electromagnetic field in the area of a piston and an armature; moving the piston axially within an interior of the generally annular wall along the axial length of the piston channel between a retracted position and a forward position to drive infusion medium toward the outlet in response to the generation of the electromagnetic field by energizing the coil, providing a valve assembly having a valve cap and a moveable valve member in a unitary valve structure form for coupling to the housing as a unitary preassembled structure, the moveable valve member being supported on the valve cap for movement relative to the valve cap, the valve cap being free of any fluid flow opening therethrough; coupling the valve assembly as the unitary preassembled structure to the housing and cover structure and in the fluid flow path, upstream in the fluid flow direction from the outlet of the housing and cover structure, the moveable valve member moveable between a closed position in which the valve member closes one end of the piston channel and an open position in which the valve member opens the one end of the piston channel upon the valve assembly being coupled to the housing and cover structure; moving the valve member in the valve assembly between open and closed positions to selectively open and close the open outlet end of the piston channel, in response to axial movement of the piston within the piston channel toward the forward position. - View Dependent Claims (20, 21, 22, 23, 24, 25)
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26. A method for delivery of infusion medium comprising:
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providing a drive mechanism including a housing and cover structure having an inlet for receiving infusion medium into an inlet chamber, an outlet for discharging infusion medium from an outlet chamber and a piston channel having a generally annular wall with an axial length defined between an open inlet end on a same side of the drive mechanism as the inlet and an open outlet end on a same side of the drive mechanism as the outlet through which infusion medium is communicated between the inlet chamber and the outlet chamber, wherein the inlet, inlet chamber, piston channel, outlet chamber and outlet define a fluid flow direction in a fluid flow path from the inlet, then through the inlet chamber, then along the axial length through the piston channel, then through the outlet chamber and then through the outlet for fluid to flow during delivery of infusion medium, and wherein the drive mechanism is free of further fluid flow paths between the inlet chamber and the outlet chamber other than through the piston channel; energizing a coil to generate an electromagnetic field in the area of a piston and an armature; moving the piston axially within an interior of the generally annular wall along the axial length of the piston channel between a retracted position and a forward position to drive infusion medium toward the outlet in response to the generation of the electromagnetic field by energizing the coil, coupling a valve assembly to the housing and cover structure, the valve assembly having a moveable valve member moveably supported by a valve cap for movement relative to the valve cap, the valve member being moveable between a closed position in which the valve member closes one end of the piston channel and an open position in which the valve member opens the one end of the piston channel when the valve assembly is coupled to the housing and cover structure, wherein coupling a valve assembly to the housing comprises disposing the valve assembly within a threaded aperture in the housing and engaging a threaded surface on the valve cap with matching threads on the housing aperture to threadingly connect the valve assembly to the threaded aperture of the housing, the valve cap being free of any fluid flow opening there-through; moving the valve member in the valve assembly between open and closed positions to selectively open and close the open outlet end of the piston channel, in response to axial movement of the piston within the piston channel toward the forward position; abutting the valve member against a valve seat with a force; and adjusting the force of the valve member against the valve seat by adjusting an amount that the valve assembly to the threaded into the aperture of the housing. - View Dependent Claims (27)
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Specification