Infusion pump system with disposable cartridge having pressure venting and pressure feedback
View Patent ↗Embodiments are directed to portable infusion devices, systems, and methods of using the same for dispensing materials. In some cases, the devices, systems and methods may be used for infusing a material such as medicament, e.g., insulin, into a body in need thereof.
1. A portable infusion pump system, comprising:
(a) a pump device configured to accept a disposable fluid cartridge and including a housing, a drive mechanism with a motor, and a controller operatively coupled to the drive mechanism;
(b) a disposable fluid cartridge configured to be operatively coupled to the housing, the cartridge including:
(i) a collapsible reservoir having an interior volume surrounded by a flexible fluid tight membrane, the interior volume being in fluid communication with a reservoir inlet port,
(ii) a substantially rigid shell disposed over the collapsible reservoir and forming a second interior volume between an outside surface of the collapsible reservoir and an inside surface of the substantially rigid shell with a vent inlet port in communication with the second interior volume, and
(iii) a delivery mechanism including a bore within a pump body of the delivery mechanism, a spool slidingly disposed in the bore forming a collapsible first volume which is configured to communicate with the reservoir inlet port and a dispense port of the bore independent of reservoir inlet port; and
(c) a pressure sensor in communication with the second interior volume between the inside surface of the rigid shell and the outside surface of the collapsible reservoir.
2. The system of claim 1 wherein the spool further comprises at least one seal, and the at least one seal of the spool is always disposed between the reservoir inlet port and dispense port so as to prevent a free flow condition to the dispense port from the collapsible reservoir.
3. The system of claim 1 wherein the collapsible first volume is formed between two seals disposed on the spool, an inside surface of the bore and an outside surface of the spool body disposed between the two seals; and wherein the seals are axially displaceable relative to each other to form a collapsible volume between the two seals.
4. The system of claim 3 wherein at least one of the seals disposed on the spool comprises a sliding seal which is axially displaceable relative to a slide portion of the spool, which forms a fluid tight seal between an outside surface of the seal and an inside surface of the bore and which forms a fluid tight seal between an outside surface of the slide portion of the spool and an aperture of the seal.
5. The system of claim 4 wherein friction between the inside surface of bore and the sliding seal is greater than friction between the outside surface of the slide portion of the spool and aperture of the sliding seal.
6. The system of claim 4 wherein the sliding seal comprises an o-ring.
7. The system of claim 4 wherein the spool comprises an elongate cylindrical member having a transverse dimension of about 0.5 mm to about 10 mm.
8. The system of claim 1 wherein the pressure sensor is configured to measure small changes in pressure at low pressures.
9. The system of claim 8 wherein the pressure sensor is configured to measure pressures up to about 30 psi gauge.
10. The system of claim 9 wherein the pressure sensor is configured to measure pressures up to about 5 psi gauge.
11. The system of claim 1 wherein the collapsible first volume comprises a first seal disposed on a distal section of the spool and a second seal disposed on a main section of the spool, the distal section of the spool being axially displaceable relative to the main section of the spool to allow the seals of the collapsible first volume to axially converge and reduce the volume of the collapsible first volume.