Infusion device and driving mechanism for same

A drive mechanism for delivery of infusion medium comprising:

• an inlet for receiving infusion medium;
• a piston channel for communication of infusion medium received by the inlet;
• a coil surrounding the piston channel;
• a piston located within the piston channel and moveable axially within the piston channel to drive infusion medium into the piston channel;
• and
• an armature disposed adjacent the coil, on one side of the piston channel,
• wherein a clearance between the piston and the piston channel causes a volume of the infusion medium for refilling the piston channel to be greater than a volume of the infusion medium backflowing through the piston channel;
• wherein the coil is capable of being electrically activated to provide an electromagnetic field;
• wherein the armature is moveable toward the coil, in response to the electromagnetic field produced by an activation of the coil;
• and
• wherein the armature comprises radial struts for conducting electromagnetic flux in a radial direction.

A drive mechanism for delivery of infusion medium comprising:

• an inlet for receiving infusion medium;
• a piston channel for communication of infusion medium received by the inlet;
• a coil surrounding the piston channel;
• a piston located within the piston channel and moveable axially within the piston channel to drive infusion medium into the piston channel;
• and
• an armature disposed adjacent the coil, on one side of the piston channel,
• wherein a clearance between the piston and the piston channel causes a volume of the infusion medium for refilling the piston channel to be greater than a volume of the infusion medium backflowing through the piston channel;
• wherein the armature has an annular inner pole surface and an annular outer pole surface, each made of a magnetizable material, wherein the inner pole surface of the armature faces the inner pole surface of the inner coil cup wall, and outer pole surface of the armature faces the outer pole surface of the outer coil cup wall.

A drive mechanism for delivery of infusion medium comprising:

• an inlet for receiving infusion medium;
• at least one coil capable of being electrically activated to provide an electromagnetic field, the at least one coil surrounding an axial piston channel that provides a passage for communication of infusion medium received by the inlet;
• an armature disposed adjacent the coil, on one side of the axial piston channel and moveable in a first direction relative to the coil, in response to the electromagnetic field produced by an activation of the coil, the armature having a pair of pole surfaces and also having radial struts for conducting electromagnetic flux between the pole surfaces in a radial direction;
• and
• a piston located within the piston channel and moveable axially within the channel in the first direction, in response to movement of the armature,
• wherein a clearance between the piston and the piston channel causes a volume of infusion medium for refilling the piston channel to be greater than a volume of infusion medium backflowing through the piston channel.

An infusion device for delivering infusion medium, the device comprising:

• a housing having an outlet through which infusion medium may be discharged;
• a reservoir disposed within the housing, for containing a volume of infusion medium;
• a control circuit for providing drive control signals;
• a drive mechanism disposed within the housing, for driving infusion medium from the reservoir and out the outlet, in response to drive control signals from the control circuit;
• and
• a power source disposed within the housing, for providing power to the control circuit and drive mechanism;
• wherein the drive mechanism comprises:
• an inlet for receiving infusion medium from the reservoir;
• at least one coil capable of being electrically activated to provide an electromagnetic field in response to a signal from the control circuit, the at least one coil surrounding an axial piston channel that provides a passage for communication of infusion medium received by the inlet;
• an armature disposed adjacent the coil, on one side of the axial channel and moveable in a first direction relative to the coil, in response to the electromagnetic field produced by an activation of the coil, the armature having a pair of pole surfaces and also having radial struts for conducting electromagnetic flux between the pole surfaces in a radial direction;
• and
• a piston located within the piston channel of the coil and moveable axially within the channel in the first direction, in response to movement of the armature,
• wherein a clearance between the piston and the piston channel causes a volume of infusion medium for refilling the piston channel to be greater than a volume of infusion medium backflowing through the piston channel.

A drive mechanism for delivery of infusion medium comprising:

• an inlet for receiving infusion medium;
• a piston channel for communication of infusion medium received by the inlet;
• a coil surrounding the piston channel;
• a piston located within the piston channel and moveable axially within the piston channel to drive infusion medium into the piston channel;
• an armature disposed adjacent the coil, on one side of the piston channel;
• an outlet chamber disposed adjacent the coil, on the opposite side of the piston channel relative to the armature for receiving infusion medium from the channel;
• and
• an outlet in flow communication with the outlet chamber, for discharging infusion medium from the outlet chamber,
• wherein the coil is capable of being electrically activated to provide an electromagnetic field;
• wherein the armature is moveable toward the coil, in response to the electromagnetic field produced by an activation of the coil;
• and
• wherein the armature comprises radial struts for conducting electromagnetic flux in a radial direction.

A drive mechanism for delivery of infusion medium comprising:

• an inlet for receiving infusion medium;
• a piston channel for communication of infusion medium received by the inlet;
• a coil surrounding the piston channel;
• a piston located within the piston channel and moveable axially within the piston channel to drive infusion medium into the piston channel;
• a coil cup containing the coil, the coil cup having an inner pole surface and an outer pole surface;
• an armature disposed adjacent the coil, on one side of the piston channel;
• an outlet chamber disposed adjacent the coil, on the opposite side of the piston channel relative to the armature for receiving infusion medium from the channel;
• and
• an outlet in flow communication with the outlet chamber, for discharging infusion medium from the outlet chamber,
• wherein the armature has an annular inner pole surface and an annular outer pole surface, each made of a magnetizable material, and
• wherein the inner pole surface of the armature faces the inner pole surface of the coil cup, and the outer pole surface of the armature faces the outer pole surface of the coil cup.