초록 ▼

Metering systems and methods are disclosed. A metering system is part of a larger fluidics sub-system that includes a flexible reservoir for storing insulin and a cannula assembly for delivering the insulin into sub-cutaneous tissue. The metering system draws a small dose of fluid from the reservoir

Metering systems and methods are disclosed. A metering system is part of a larger fluidics sub-system that includes a flexible reservoir for storing insulin and a cannula assembly for delivering the insulin into sub-cutaneous tissue. The metering system draws a small dose of fluid from the reservoir and then pushes it down the cannula line and into the patient. The fluid dose is small relative to the reservoir volume, such that many pump strokes are required to completely empty the reservoir.

대표청구항 ▼

1. A rotational metering pump comprising: a manifold comprising a reservoir port in fluid communication with a fluid reservoir and a cannula port in fluid communication with a cannula;a sleeve comprising a side hole, the sleeve adapted to rotate axially within the manifold between a first orientatio

1. A rotational metering pump comprising: a manifold comprising a reservoir port in fluid communication with a fluid reservoir and a cannula port in fluid communication with a cannula;a sleeve comprising a side hole, the sleeve adapted to rotate axially within the manifold between a first orientation with said side hole aligned with the reservoir port and a second orientation with said side hole aligned with the cannula port, the sleeve further comprising a helical groove having a first end and a second end;a plunger adapted to rotate and translate axially within the sleeve, wherein axial translation of the plunger within the sleeve changes a pump volume, the pump volume being in fluid communication with the side hole of the sleeve, the plunger further comprising a coupling member adapted to move within the helical groove and between the first end and the second end of the helical groove to cause the plunger to translate axially within the sleeve as the plunger is rotated;a motor adapted to rotate the plunger in a first direction causing the pump volume to increase when the sleeve is in the first orientation, and to rotate the sleeve and plunger together when the coupling member reaches the first end of the helical groove, such that the sleeve moves into the second orientation. 2. The rotational metering pump of claim 1, wherein the plunger further comprises a tab and the manifold comprises a window, and the tab moves within the window to prevent the sleeve from translating axially relative to the manifold as the sleeve rotates within the manifold. 3. The rotational metering pump of claim 1, further comprising a rotational limit switch, the rotational limit switch causing the motor to reverse direction after the sleeve rotates to orient the side hole with the cannula port. 4. The rotational metering pump of claim 3, wherein a feature on the sleeve engages the rotational limit switch. 5. The rotational metering pump of claim 1, further comprising a plug inserted into the sleeve to form a surface of the pump volume opposing the plunger. 6. The rotational metering pump of claim 1, wherein the sleeve comprises a face stop that forms a surface of the pump volume opposing the plunger. 7. The rotational metering pump of claim 1, further comprising seals on said plunger and a plug to form a liquid tight seal between the plunger and the sleeve, and between the plug and the sleeve. 8. The rotational metering pump of claim 1, wherein a plug is fixed within the sleeve, and wherein the plug comprises a cam surface that operates a sleeve switch when the sleeve rotates between the first and second orientation. 9. The rotational metering pump of claim 1, wherein the motor comprises an output gear having a slot to receive a tab of the plunger, the slot permitting the plunger to move axially relative to the motor while the motor rotates the plunger. 10. The rotational metering pump of claim 1, wherein the sleeve further comprises first and second conductive pads and a metering system further comprises first, second and third electrical contacts, wherein the first conductive pad electrically connects the first and second electrical contacts when the sleeve is in the first orientation, and the second conductive pad electrically connects the second and third electrical contacts when the sleeve is in the second orientation. 11. The rotational metering pump of claim 10, wherein the first, second and third electrical contacts are electrically isolated from each other as the sleeve rotates between the first orientation and the second orientation. 12. The rotational metering pump of claim 3, wherein the rotational limit switch comprises two normally open flexible conductive members that are forced into electrical contact when engaged by a feature on the sleeve. 13. The rotational metering pump of claim 12, wherein the rotational limit switch comprises a third normally open flexible conductive member, and wherein when the sleeve rotates in a first direction, the first, second and third conductive members are forced into electrical contact in a first order, and when the sleeve rotates in a second direction, the first, second and third conductive members are forced into electrical contact in a second order. 14. The rotational metering pump of claim 1, further comprising an interlock that prevents rotation of the sleeve when a torque applied to the sleeve is below a predetermined threshold, and wherein the interlock permits the sleeve to rotate when the torque exceeds the predetermined threshold. 15. The rotational metering pump of claim 14, wherein the sleeve comprises a detent that engages a bump on the interlock to prevent rotation of the sleeve, and wherein the interlock flexes to permit the detent to move past the bump on the interlock when a torque applied to the sleeve exceeds the predetermined limit. 16. The rotational metering pump of claim 1, further comprising at least one port seal forming a liquid tight seal between the sleeve and the reservoir port. 17. The rotational metering pump of claim 1, further comprising at least one port seal forming a liquid tight seal between the sleeve and the cannula port. 18. The rotational metering pump of claim 1, wherein a port seal is a unitary elastomeric part.