Method and device for monitoring the flow speed of an infusion solution

• US 20040025597A1
• Filed: 12/17/2002
• Published: 02/12/2004
• Est. Priority Date: 04/19/2000
• Status: Active Grant

• Current Assignee: Gambro Lundia AB (Baxter International Inc.)
• Original Assignee: Gambro Lundia AB (Baxter International Inc.)
• Inventors: Neckling, Ola, Ericson, Bjorn
• Granted Patent: US 7,044,002 B2
• Time in Patent Office: Days
• US Class Current: 73/861.52
• CPC Class Codes: A61M 1/3441 Substitution rate control as a function of the ultrafiltration rate
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 5/16804 Flow controllers
• CPC Class Codes: A61M 5/16854 by monitoring line pressure
• CPC Class Codes: A61M 5/16881 Regulating valves on-off valves, e.g. clamps A61M39/28
• CPC Class Codes: G01F 1/363 with electrical or electro-mechanical indication G01F1/37 and G01F1/38 take precedence
• CPC Class Codes: G01F 1/42 Orifices or nozzles

Abstract

Method and device for monitoring the flow speed of an infusion solution, such as with hemofiltration or hemodiafiltration. The device has a tube for conducting an infusion solution from a source of infusion solution to a pump device in the form of a metering pump, such as a peristaltic pump or a ceramic pump, and on to an infusion device, such as a drip chamber. The flow speed is determined by the metering pump. The flow speed is monitored separately in that the pressure across a restriction device in the tube is measured. The restriction device can be a separately arranged restriction valve. Alternatively the restriction device is arranged by the tube having a small internal diameter of the order of 0.5 mm in size. The pressure measuring device only needs to measure the absolute pressure with respect to the atmosphere. The hydrostatic pressure due to the infusion bag being hung above the pump and the pressure meter is subtracted in a calculation device.

Claims

1. Method for monitoring the flow speed of an infusion solution, such as with hemofiltration or hemodiafiltration, comprising:

conducting an infusion solution from a source of infusion solution, via a tube to a pump device,

pumping the infusion solution to an infusion device, such as a drip chamber,

characterized by

measuring the flow speed by measuring the pressure drop across a restriction device arranged in said tube.

2. Method according to claim 1, characterized by metering the infusion solution via said pump, which is constituted by a metering pump, such as a peristaltic pump or a ceramic pump.

3. Method according to claim 1 or 2, characterized in that said source of infusion solution is constituted by one or more bags with sterile infusion solution, such as hemofiltration solution.

4. Method according to claim 3, characterized in that said bags are hung on a hanging device at a particular height with respect to a pressure measuring device, and in that

the pressure measuring device measures the pressure with respect to the surrounding atmosphere;

and

in that the pressure drop is calculated as the measured pressure corrected for the hydrostatic pressure on the basis of said height.

5. Method according to claim 4, characterized in that the hydrostatic pressure is measured at zero flow of the infusion solution.

6. Device for monitoring the flow speed of an infusion solution, such as with hemofiltration or hemodiafiltration, comprising

a tube for conducting the infusion solution from a source of infusion solution to a pump device,

a pump device for pumping the infusion solution to an infusion device, such as a drip chamber,

characterized by

a pressure measuring device for measuring the flow speed by measuring the pressure drop across a restriction device arranged in said tube.

7. Device according to claim 6, characterized in that said pump is constituted by a metering pump for metering the infusion solution, whereby the metering pump is preferably a peristaltic pump or a ceramic pump.

8. Device according to claim 6 or 7, characterized in that said source of infusion fluid is constituted by one or more bags with sterile infusion solution, such as hemofiltration solution.

9. Device according to claim 8, characterized by a hanging device for arranging said bag at a particular height in respect to the pressure measurement device, and in that

the pressure measuring device is arranged to measure the pressure with respect to the surrounding atmosphere;

and by

a calculation device for calculating the pressure drop as the measured pressure corrected for the hydrostatic pressure due to said height.

10. Device according to claim 9, characterized in that the hydrostatic pressure is measured at zero flow of the infusion solution.