| 摘要 |
The invention relates to a patient-controlled drug delivery device. The delivery device comprises a reservoir (2) for the drug (6) and a pump (4) having a predetermined delivery dose, which is capable of sucking the drug from the reservoir (2) delivering it to the patient. The pump (4) comprises a pumping means (14), a finely gauged tube (10) capable of controlling the flow rate, which is chosen in conjunction with the delivery dose of the pumping means (14) in order to set a predetermined maximum dosing rate, said tube (10) connecting the reservoir (2) to a pumping means (14). A one-way valve (18) in fluid communication with the finely gauged tube (10) and the pumping means (14) permits the drug flow into the pumping means (14) but prevents the reverse flow, and a controlling means (32) and a second conduit (28) extending from the pumping means and having a distal end (30) through which the drug may be released, wherein the controlling means (32) is in fluid communication with the pumping means (14) and with the second conduit (28), the one-way valve (18) opening when the pressure inside the dosing chamber (12) exceeds a minimum pressure predetermined for the controlling means (32), being adapted to prevent the reverse flow of the drug and the air penetration into the pumping means. |
