Liquid Dosing Arrangement
OwnerBruno Slettenmarkinventor
Life of this patent
Estimating the term…
Abstract
A liquid dosing arrangement has a liquid supply system with a first pressure sensor for measuring a first pressure p1; a liquid delivery system, with a second pressure sensor for measuring a second pressure p2; and an injection valve, which is arranged so that the liquid is supplied through a restricting member in the injection valve and let through the restricting member by a pulsed opening and closing valve mechanism. The pressure drop, and the dimensions of the restricting member in the injection valve, are selected to make the velocity ν of the liquid flowing through the restricting member is high enough to make the flow of liquid through the liquid delivery system independent of the viscosity of the liquid.
Claims18
A liquid dosing arrangement, comprising:
- a liquid supply system comprising a first pressure sensor that measures a first pressure p1;
- a liquid delivery system comprising a second pressure sensor that measures a second pressure p2;
- and
- an injection valve between the liquid supply system and the liquid delivery system comprising a restricting member through which said liquid flows, and a pulsed opening and closing valve mechanism that operates said restricting member with opening pulses having frequency fo and width to, wherein the pressure drop Δp over the injection valve (2) is Δp=p1−p2;
- with the pressure drop Δp, and the dimensions (b, d1) of the restricting member in the injection valve making the velocity ν of the liquid flowing through the restricting member sufficiently high to make the flow Φ of liquid through the liquid delivery system essentially independent of the viscosity of the liquid.
(canceled)
A method of dosing liquid in a liquid dosing arrangement comprising a liquid supply system, a liquid delivery system, and an injection valve between the liquid supply system and the liquid delivery system, the method comprising the steps of:
- measuring a first pressure p1 in the liquid supply system with a first pressure sensor;
- measuring a second pressure p2 in the liquid delivery system with a second pressure sensor;
- and
- supplying liquid through a restricting member in the injection valve by a pulsed opening and closing valve mechanism with opening pulses having frequency fo and width to, the pressure drop Δp over the injection valve being Δp=p1−P2;
- and
- selecting the pressure drop Δp=p1−p2 over the injection valve, and the dimensions (b, d1) of the restricting member in the injection valve, so that the velocity ν of the liquid flowing through the restricting member insufficiently high to make the flow Φ of liquid through the liquid delivery system essentially independent of the viscosity of the liquid.
An apparatus for intravenous infusion comprising
- a liquid dosing arrangement comprising a liquid supply system comprising a first pressure sensor that measures a first pressure p1, a liquid delivery system comprising a second pressure sensor that measures a second pressure p2, and an injection valve between the liquid supply system and the liquid delivery system comprising a restricting member through which said liquid flows, and a pulsed opening and closing valve mechanism that operates said restricting member with opening pulses having frequency fo and width to, wherein the pressure drop Δp over the injection valve (2) is Δp=p1−p2;
- and
- a liquid delivery interface connected to said liquid delivery system and configured to interact with a patient to deliver said liquid to the patient.
Dependencies are inferred from the claim text.