Flow rate sensor

Patent metadata

Field	Value
Publication number	US-10436619-B2
Application number	US-201615543452-A
Country	US
Kind code	B2
Filing date	Jan 14, 2016
Priority date	Jan 16, 2015
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

The disclosure relates to a flow rate sensor for determining a flow rate of a liquid within a tube, the flow rate sensor comprising at least one coil arranged in the vicinity of the tube in such a manner that an eddy current in the liquid due to the liquid's flowing affects an impedance of the coil.

First claim

The invention claimed is:

1. A flow rate sensor for determining a flow rate of a liquid within a tube, the flow rate sensor comprising:
at least one coil arranged in the vicinity of the tube in such a manner that an eddy current in the liquid due to the liquid's flowing affects an impedance of the coil;
wherein the at least one coil comprises a first coil and a second coil, the first coil arranged in the vicinity of a first section of the tube, the first section having a first diameter, the second coil arranged in the vicinity of a second section of the tube, the second section having a second diameter, and the first diameter being different from the second diameter.

2. The flow rate sensor according to claim 1 , wherein the at least one coil is arranged around the tube.

3. The flow rate sensor according to claim 1 , wherein the at least one coil is connected to a measuring unit adapted to determine the impedance of the at least one coil.

4. The flow rate sensor according to claim 3 , wherein the measuring unit is adapted to determine a relation between a real part and an imaginary part of the impedance.

5. The flow rate sensor according to claim 1 , wherein the at least one coil is arranged around a respective magnetic guide having one or two air gaps in which the tube is received.

6. The flow rate sensor according to claim 5 , wherein the magnetic guide is arranged as a cup-core ferrite arranged about the tube, wherein the at least one coil is arranged within the magnetic guide.

7. The flow rate sensor according to claim 6 , wherein the magnetic guide comprises an arcuate base member with a semicircular or crescent cross section and a plurality of, inwardly directed protrusions having tips, between which respective air gaps are provided, wherein at least one coil is arranged on at least one of the protrusions, wherein a tube is arranged in the air gaps between the inward tips of the protrusions such that the tube is contacted by the tips of the protrusions at angular offsets.

8. The flow rate sensor according to claim 7 , wherein the protrusions are arranged as spikes originating from the base member.

9. The flow rate sensor according to claim 7 , wherein the tips of the protrusions are angularly offset by substantially 90°.

10. The flow rate sensor according to claim 1 , wherein the at least one coil is arranged at a predetermined distance from the tube, wherein at least in the vicinity of the coil, the tube is flexible to such an extent that the tube can expand depending on a pressure of the liquid by an amount sufficient to change the predetermined distance from the tube.

11. The flow rate sensor according to claim 10 , wherein a thickness of a wall of the tube is taken into account in the predetermined distance such that the predetermined distance is between a surface of the liquid flowing through the tube and the at least one coil.

12. The flow rate sensor according to claim 1 , wherein the at least one coil consists of a number of cascaded coils, electrically connected in series.

13. A drug delivery device, comprising:
a tube; and
a flow rate sensor for determining a flow rate of a liquid within the tube, the flow rate sensor comprising at least one coil arranged in the vicinity of the tube in such a manner that an eddy current in the liquid due to the liquid's flowing affects an impedance of the coil;
wherein the at least one coil comprises a first coil and a second coil, the first coil arranged in the vicinity of a first section of the tube, the first section having a first diameter, the second coil arranged in the vicinity of a second section of the tube, the second section having a second diameter, and the first diameter being different from the second diameter.

14. The device according to claim 13 , wherein the at least one coil is arranged around the tube.

15. The device according to claim 13 , wherein the at least one coil is connected to a measuring unit adapted to determine the impedance of the at least one coil.

16. The device according to claim 15 , wherein the measuring unit is adapted to determine a relation between a real part and an imaginary part of the impedance.

17. The device according to claim 13 , further comprising the liquid within the tube, wherein the liquid comprises a drug.

18. The device according to claim 17 , wherein the drug comprises a pharmaceutically active compound.

Assignees

• Sanofi Aventis Deutschland

Inventors

• Nessel Christian

Classifications

• A61M5/16886

  for measuring fluid flow rate, i.e. flowmeters · CPC title

• G01F1/582 Primary

  without electrodes · CPC title

• G01F1/56 Primary

  by using electric or magnetic effects (G01F1/66 takes precedence) · CPC title

• A61M5/142

  Pressure infusion, e.g. using pumps · CPC title

• G01F1/60

  Circuits therefor · CPC title