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 through which infusion medium is communicated between the inlet and the outlet;
a piston located within the piston channel to define a fluid flow path between the inlet and outlet, the piston being moveable axially within the piston channel between a retracted position and a forward position to drive infusion medium toward the outlet, the piston comprising a magnetically permeable material,an armature located on one side of the piston channel and moveable between a retracted position and a forward position;
a coil located in a position relative to the armature to generate an electromagnetic field upon energization sufficient to cause the armature and piston to move from their retracted positions to their forward positions; and
a magnet arranged relative to at least one of the armature and the piston to impart a force on the piston sufficient to move the piston from the forward position to the retracted position upon deenergization of the coil;
wherein the armature is arranged between the magnet and the piston and includes a first section free of magnetically permeable material through which magnetic flux from the magnet passes to the piston in a path that is free of magnetically permeable material from the magnet to the piston.
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Accused Products
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.
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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 through which infusion medium is communicated between the inlet and the outlet; a piston located within the piston channel to define a fluid flow path between the inlet and outlet, the piston being moveable axially within the piston channel between a retracted position and a forward position to drive infusion medium toward the outlet, the piston comprising a magnetically permeable material, an armature located on one side of the piston channel and moveable between a retracted position and a forward position; a coil located in a position relative to the armature to generate an electromagnetic field upon energization sufficient to cause the armature and piston to move from their retracted positions to their forward positions; and a magnet arranged relative to at least one of the armature and the piston to impart a force on the piston sufficient to move the piston from the forward position to the retracted position upon deenergization of the coil; wherein the armature is arranged between the magnet and the piston and includes a first section free of magnetically permeable material through which magnetic flux from the magnet passes to the piston in a path that is free of magnetically permeable material from the magnet to the piston. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. 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 through which infusion medium is communicated between the inlet and the outlet; a piston located within the piston channel to define a fluid flow path between the inlet and outlet, the piston being moveable axially within the piston channel between a retracted position and a forward position to drive infusion medium toward the outlet, an armature located on one side of the piston channel and moveable between a retracted position and a forward position; a coil located in a position relative to the armature to generate an electromagnetic field upon energization sufficient to cause the armature and piston to move from their retracted positions to their forward positions; and a magnet arranged relative to at least one of the armature and the piston to impart a force on at least one of the armature and the piston sufficient to move at least one of the armature and the piston from the forward position to the retracted position upon deenergization of the coil; wherein the armature is arranged between the magnet and the piston and includes a first section formed of a non-magnetic material to allow magnetic flux from the magnet to effect the piston, through the first section of the armature, and the first section of the armature comprises at least one of stainless steel, plastic, ceramic and glass.
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18. A method for delivery of infusion medium comprising:
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providing a housing and cover structure having an inlet for receiving infusion medium, an outlet for discharging infusion medium and a piston channel through which infusion medium is communicated between the inlet and the outlet; energizing a coil located in a position relative to an armature and a piston to generate an electromagnetic field in the area of the armature and piston upon energization moving the piston axially within the piston channel between a retracted position and a forward position to drive infusion medium in the piston channel toward the outlet in response to the generation of an electromagnetic field by energization of the coil, moving an armature between a retracted position and a forward position in response to the generation of an electromagnetic field by energization of the coil; and moving the piston from the forward position to the retracted position using, at least in part, the force imparted on the piston by a magnet, upon de-energization of the coil; wherein the piston comprises a magnetically permeable material and the armature includes a first section that is free of magnetically permeable material and wherein the force imparted by the magnet on the piston is provided by passing magnetic flux from the magnet through the first section of the armature and to the piston in a path that is free of magnetically permeable material from the magnet to the piston. - View Dependent Claims (19, 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 housing and cover structure having an inlet for receiving infusion medium, an outlet for discharging infusion medium and a piston channel through which infusion medium is communicated between the inlet and the outlet; energizing a coil located in a position relative to an armature and a piston to generate an electromagnetic field in the area of the armature and piston upon energization moving the piston axially within the piston channel between a retracted position and a forward position to drive infusion medium in the piston channel toward the outlet in response to the generation of an electromagnetic field by energization of the coil, moving an armature between a retracted position and a forward position in response to the generation of an electromagnetic field by energization of the coil; moving at least one of the armature and the piston from the forward position to the retracted position using, at least in part, the force imparted on at least one of the armature and the piston by a magnet, upon de-energization of the coil; and passing magnetic flux from the magnet through a first section of the armature, the first section of the armature formed of a non-magnetic material; wherein the first section of the armature comprises at least one of stainless steel, plastic, ceramic and glass. - View Dependent Claims (27)
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Specification