Drug delivery device and method
First Claim
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1. A drug delivery device for metered delivery of a liquid medicament to an outlet, the device comprising:
- (a) a pressurized reservoir configured for storing and supplying the liquid medicament at a pressure above atmospheric pressure;
(b) a flow path in fluid communication with said pressurized reservoir and the outlet, said flow path including;
(i) a first valve assuming a normally-closed flow-blocking state and selectively actuatable to an open state which permits fluid flow through said first valve, (ii) a flow restriction configured to limit fluid flow along said flow path, and (iii) a second valve assuming a normally-closed flow-blocking state and selectively actuatable to an open state which permits fluid flow through said second valve, such that, when both said first valve and second valve are in said open state, the liquid medicament flows from the pressurized reservoir along said flow path to the outlet at a rate limited primarily by said flow restriction;
(c) a pressure measurement arrangement deployed in pressure-sensing engagement with a first point and a second point along said flow path, at least part of said flow restriction being between said first and second points, one of said first and second points being intermediate to said first and second valves; and
(d) a controller electronically associated with said pressure measurement arrangement and said first and second valves, and configured to selectively open said first and second valves to deliver a defined quantity of the liquid medicament to the outlet.
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Abstract
A drug delivery device includes a pressurized reservoir in communication with a flow path to an outlet. The flow path includes two normally-closed valves and a flow restriction. A pressure measurement arrangement measures a differential fluid pressure between two points along the flow path which span at least part of the flow restriction, one of the points being between the valves. A controller selectively opens the valves to deliver a defined quantity of the liquid medicament to the outlet.
345 Citations
21 Claims
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1. A drug delivery device for metered delivery of a liquid medicament to an outlet, the device comprising:
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(a) a pressurized reservoir configured for storing and supplying the liquid medicament at a pressure above atmospheric pressure;
(b) a flow path in fluid communication with said pressurized reservoir and the outlet, said flow path including;
(i) a first valve assuming a normally-closed flow-blocking state and selectively actuatable to an open state which permits fluid flow through said first valve, (ii) a flow restriction configured to limit fluid flow along said flow path, and (iii) a second valve assuming a normally-closed flow-blocking state and selectively actuatable to an open state which permits fluid flow through said second valve, such that, when both said first valve and second valve are in said open state, the liquid medicament flows from the pressurized reservoir along said flow path to the outlet at a rate limited primarily by said flow restriction;
(c) a pressure measurement arrangement deployed in pressure-sensing engagement with a first point and a second point along said flow path, at least part of said flow restriction being between said first and second points, one of said first and second points being intermediate to said first and second valves; and
(d) a controller electronically associated with said pressure measurement arrangement and said first and second valves, and configured to selectively open said first and second valves to deliver a defined quantity of the liquid medicament to the outlet. - View Dependent Claims (2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15)
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8. The drug delivery device of claim I,. wherein said pressurized reservoir includes an elastic pressurizing member such that a fluid pressure within said reservoir varies as a function of a volume of the liquid medicament currently stored, and wherein said controller is configured to:
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(a) estimate a remaining volume of the liquid medicament in said reservoir based upon at least one measurement from said pressure measurement arrangement obtained under zero flow conditions; and
(b) if said remaining volume is less than a minimum volume value, generate a low-remaining-volume indication.
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16. A drug delivery device for metered delivery of a liquid medicament to an outlet, the device comprising:
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(a) a pressurized reservoir configured for storing and supplying the liquid medicament at a pressure above atmospheric pressure;
(b) a flow path in fluid communication with said pressurized reservoir and the outlet, said flow path including;
(i) a first valve assuming a normally-closed flow-blocking state and selectively adjustable to provide a flow restriction configured to limit fluid flow along said flow path, and (ii) a second valve assuming a normally-closed flow-blocking state and selectively actuatable to an open state which permits fluid flow through said second valve, such that, when both said first valve and second valve are both opened, the liquid medicament flows from the pressurized reservoir along said flow path to the outlet at a rate limited primarily by said flow restriction of said first valve;
(c) a pressure measurement arrangement deployed in pressure-sensing engagement with a first point and a second point along said flow path, said first valve being between said first and second points, said second point being intermediate to said first and second valves; and
(d) a controller electronically associated with said pressure measurement arrangement and said first and second valves, and configured to selectively actuate said first and second valves to deliver a defined quantity of the liquid medicament to the outlet.
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17. In a drug delivery device having a pressurized source of a liquid medicament supplying a flow path including two valves and a flow restriction, a method for identifying malfunction of at least one of the valves, the method comprising:
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(a) closing both valves in such a manner as to ensure a pressure differential across at least one of the valves; and
(b) monitoring for a change in liquid pressure between the valves. - View Dependent Claims (18, 19)
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20. A method for delivery of a liquid medicament to an outlet, the method comprising:
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(a) providing a drug delivery device including;
(i) a pressurized reservoir storing and supplying the liquid medicament at a pressure above atmospheric pressure;
(ii) a flow path in fluid communication with said pressurized reservoir and the outlet, said flow path including two valves and a flow restriction;
(b) opening the two valves to allow flow from the reservoir through the flow restriction to the outlet;
(c) while the drug is flowing, measuring a fluid pressure differential across at least part of the flow restriction and deriving from the pressure differential a rate of fluid flow;
(d) closing at least one of the valves; and
(e) monitoring a differential fluid pressure between two points in the flow path while at least one of the valves is closed so as to identify at least one state of malfunction. - View Dependent Claims (21)
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Specification