Device and method for measuring the flow of a fluid in a tube moved by a peristaltic pump

Patent metadata

Field	Value
Publication number	US-12196193-B2
Application number	US-202418584642-A
Country	US
Kind code	B2
Filing date	Feb 22, 2024
Priority date	Nov 9, 2020
Publication date	Jan 14, 2025
Grant date	Jan 14, 2025

Abstract

Various embodiments provide a device for measuring the flow of fluid inside a tube moved by a peristaltic pump is provided with: a detection electrode arrangement coupled to the tube to detect an electrostatic charge variation originated by the mechanical action of the peristaltic pump on the tube; a signal processing stage, electrically coupled to the detection electrode arrangement to generate an electrical charge variation signal; and a processing unit, coupled to the signal processing stage to receive and process in the frequency domain the electrical charge variation signal to obtain information on the flow of a fluid that flows through the tube based on the analysis of frequency characteristics of the electrical charge variation signal.

First claim

The invention claimed is:

1. A device, comprising:
receiving electrodes on a tube in which a pump causes a fluid to flow inside of the tube, the receiving electrodes configured to receive a change in electrostatic charge in a surrounding environment;
signal processing circuitry coupled to the receiving electrodes, the signal processing circuitry configured to generate an electrostatic charge variation signal that indicates the change in electrostatic charge; and
a processor coupled to the signal processing circuitry, the processor configured to determine frequency characteristics of the electrostatic charge variation signal, and determine flow information for the fluid based on the frequency characteristics.

2. The device of claim 1 , wherein the processor is configured to:
determine frequency values of harmonics of the electrostatic charge variation signal;
obtain, from the frequency values, a rotation speed of the pump; and
determine the flow information based on the rotation speed and dimensional characteristics of the tube.

3. The device of claim 2 , wherein
the processor is configured to obtain the rotation speed of the pump from the frequency values based on calibration data, and
the calibration data includes calibration curves associating corresponding rotation speed values of the pump with the frequency values of the harmonics of the electrostatic charge variation signal.

4. The device of claim 3 , wherein the processor is configured to:
associate corresponding rotation speed values of the pump with the frequency values of the harmonics of the electrostatic charge variation signal based on the calibration curves; and
determine the rotation speed of the pump as an average of the corresponding rotation speed values.

5. The device of claim 3 , wherein
the calibration curves are a linear regression of calibration frequencies of respective harmonics of the electrostatic charge variation signal acquired at different calibration values of rotation speed of the pump, and
the calibration curves are indicative of a linear trend of frequencies of the harmonics with respect to the rotation speed of the pump.

6. The device of claim 2 , wherein the processor is configured to determine the flow information based on the rotation speed, a dimension of the tube, and design characteristics of the pump.

7. The device of claim 1 , wherein
the pump includes roller elements that contact the tube in a contact area, and
the receiving electrodes are arranged downstream of the contact area.

8. The device of claim 7 , wherein the receiving electrodes include:
a first receiving electrode having a ring shape and surrounding the tube;
a dielectric layer having a ring shape and surrounding the first receiving electrode; and
a second receiving electrode on the dielectric layer.

9. The device of claim 1 , wherein the signal processing circuitry includes:
an instrumentation amplifier having a differential input coupled to the receiving electrodes; and
an analog-to-digital converter coupled at an output of the instrumentation amplifier to provide the electrostatic charge variation signal.

10. A system, comprising:
a tube;
a pump coupled to the tube, the pump configured to cause a fluid to flow inside of the tube;
a measuring device coupled to the tube, the measuring device including:
receiving electrodes on the tube, the receiving electrodes configured to receive a change in electrostatic charge in a surrounding environment; signal processing circuitry coupled to the receiving electrodes, the signal processing circuitry configured to generate an electrostatic charge variation signal that indicates the change in electrostatic charge; and
a processor coupled to the signal processing circuitry, the processor configured to determine frequency characteristics of the electrostatic charge variation signal, and determine flow information for the fluid based on the frequency characteristics; and

a controller configured to control operation of the system based on the flow information.

11. The system of claim 10 , wherein the processor is configured to:
determine frequency values of harmonics of the electrostatic charge variation signal;
obtain, from the frequency values, a rotation speed of the pump; and
determine the flow information based on the rotation speed and dimensional characteristics of the tube.

12. The system of claim 11 , wherein the processor is configured to determine the flow information based on the rotation speed, a dimension of the tube, and design characteristics of the pump.

13. The system of claim 10 , wherein
the pump includes roller elements that contact the tube in a contact area, and
the receiving electrodes are arranged downstream of the contact area.

14. The system of claim 10 , wherein
the receiving electrodes includes a first receiving electrode having a ring shape and surrounding the tube, and a second receiving electrode, and
the measuring device includes a dielectric layer having a ring shape and surrounding the first receiving electrode, the dielectric layer separating the first receiving electrode and the second receiving electrode from each other.

15. A method, comprising:
receiving, by receiving electrodes, a change in electrostatic charge in a surrounding environment, the receiving electrodes being on a tube in which a pump causes a fluid to flow inside of the tube;
generating, by signal processing circuitry, an electrostatic charge variation signal that indicates the change in electrostatic charge;
determining, by a processor, frequency characteristics of the electrostatic charge variation signal; and
determining, by the processor, flow information for the fluid based on the frequency characteristics.

16. The method of claim 15 , further comprising:
determining, by the processor, frequency values of harmonics of the electrostatic charge variation signal;
obtaining, by the processor and from the frequency values, a rotation speed of the pump; and
determining, by the processor, the flow information based on the rotation speed and dimensional characteristics of the tube.

17. The method according to claim 16 , further comprising:
obtaining, by the processor, the rotation speed of the pump from the frequency values based on calibration data, the calibration data including calibration curves associating corresponding rotation speed values of the pump with the frequency values of the harmonics of the electrostatic charge variation signal.

18. The method of claim 16 , further comprising:
determining, by the processor, the flow information based on the rotation speed, a dimension of the tube, and design characteristics of the pump.

19. The method of claim 15 , wherein
the pump includes roller elements that contact the tube in a contact area, and
the receiving electrodes are arranged downstream of the contact area.

20. The method of claim 15 , wherein the receiving electrodes include:
a first receiving electrode having a ring shape and surrounding the tube;
a dielectric layer having a ring shape and surrounding the first receiving electrode; and
a second receiving electrode on the dielectric layer.

Assignees

• St Microelectronics Srl

Inventors

• Dellutri Michele Alessio
• Passaniti Fabio
• Alessi Enrico Rosario

Classifications

• F04B49/06

  Control using electricity (regulating by means of floats actuating electric switches F04B49/04) · CPC title

• G01F1/7048

  the concentration of electrical loaded particles giving an indication of the flow · CPC title

• G01F1/7046

  using electrical loaded particles as tracer, e.g. ions or electrons · CPC title

• F04B43/12 Primary

  having peristaltic action · CPC title

• G01F1/64 Primary

  by measuring electrical currents passing through the fluid flow; measuring electrical potential generated by the fluid flow, e.g. by electrochemical, contact or friction effects (G01F1/58 takes precedence) · CPC title