Fluid flow device

• US 10,384,001 B2
• Filed: 01/17/2017
• Issued: 08/20/2019
• Est. Priority Date: 01/17/2017
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Nackaerts, Axel, Disselkoen, Micha Benjamin
• Primary Examiner(s): Schmidt, Emily L
• Assistant Examiner(s): Chidiac, Nicholas J
• Application Number:
  US15/408,105
• Publication Number:
  US 20180200431A1
• Time in Patent Office: 945 Days
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/3576 with non implanted data transmission devices, e.g. using external transmitter or receiver
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 5/1411 Drip chambers A61M5/162, A61M5/1689, A61M5/40 take precedence
• CPC Class Codes: A61M 5/1414 Hanging-up devices
• CPC Class Codes: A61M 5/16804 Flow controllers
• CPC Class Codes: A61M 5/1684 by detecting the amount of infusate remaining, e.g. signalling end of infusion
• CPC Class Codes: A61M 5/16881 Regulating valves on-off valves, e.g. clamps A61M39/28
• CPC Class Codes: A61M 5/1689 Drip counters
• CPC Class Codes: G01F 13/006 measuring volume in function of time
• CPC Class Codes: G01F 15/0755 involving digital counting
• CPC Class Codes: G01F 22/02 involving measurement of pressure
• CPC Class Codes: G01F 3/00 Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow measuring a proportion of the volume flow G01F5/00

Abstract

One example discloses a fluid flow device, including: a drop chamber, having an interior, a fluid input, and a fluid output; a drop detector coupled to the drop chamber and configured to detect a fluid drop at the fluid input; a pressure sensor configured to monitor a pressure in the interior of the drop chamber; and a flow rate device configured to determine a fluid flow rate based on a number of fluid drops detected over a time period, and the pressure in the interior of the drop chamber.

Claims

1. A fluid flow device, comprising:

a drop chamber, having an interior, a fluid input, and a fluid output;

a drop detector coupled to the drop chamber and configured to detect a fluid drop at the fluid input and to count the number of detected fluid drops in a counting time window;

a pressure sensor configured to monitor a pressure in the interior of the drop chamber; and

a flow rate device configured to determine a fluid flow rate based on a number of fluid drops detected over a time period, and the pressure in the interior of the drop chamber, wherein the fluid flow rate is calculated as ((drop volume)*drops counted)/(counting time window), where drop volume is a function of the monitored pressure and the drops counted and is calculated as drop volume=(volume of fluid measured by pressure differential)/(total drops counted between pressure measurements).

2. The device of claim 1:

wherein the drop detector is a capacitive sensor.

3. The device of claim 1:

further comprising a fluid reservoir coupled and configured to supply a fluid to the fluid input of the drop chamber; and

wherein the fluid flow rate is a function of a hydrostatic pressure generated by a fluid in the fluid reservoir.

4. The device of claim 1:

wherein the flow rate device includes a computing unit configured to track or control the fluid flow rate over time.

5. The device of claim 1:

wherein the computing unit is configured to generate an alarm in response to at least one of;

a fault condition, a minimum fluid supply, a fluid reservoir empty, a minimum fluid flow rate, or a maximum fluid flow rate.

6. The device of claim 1:

wherein the flow rate device includes a communications unit configured to control the flow control device in response to wireless signals.

7. The device of claim 1:

wherein the fluid flow device is configured as an intravenous therapy device.

8. The device of claim 1, further comprising:

a flow control device coupled to the drop chamber and configured to increase or decrease the number of fluid drops detected over a time period in response to a signal from the flow rate device.

9. The device of claim 8:

wherein the flow control device is positioned at either the fluid input or the fluid output.

10. The device of claim 8:

wherein the number of fluid drops detected over the time period is increased or decreased by opening or closing a valve.

11. The device of claim 10:

wherein the valve is configured to move between a closed position and an open position in response to a magnetic field.

12. The device of claim 11:

wherein the valve is within the interior of the drop chamber.

13. The device of claim 12:

wherein the valve includes a first set of magnets;

further comprising a second set of magnets outside of the drop chamber;

wherein the valve is configured to move between a closed and an open positions based on a position of the second set of magnets and the first set of magnets.

14. The device of claim 13:

wherein the second set of magnets surround an exterior surface of the drop chamber.

15. The device of claim 14:

wherein the second set of magnets are moved with a servo motor or a linear motor.

16. An article of manufacture including at least one non-transitory, tangible machine readable storage medium containing executable machine instructions for fluid flow, comprising:

a drop chamber, having an interior, a fluid input, and a fluid output;

a drop detector coupled to the drop chamber and configured to detect a fluid drop at the fluid input and to count the number of detected fluid drops in a counting time window;

a pressure sensor configured to monitor a pressure in the interior of the drop chamber; and

a flow rate device configured to determine a fluid flow rate based on a number of fluid drops detected over a time period, and the pressure in the interior of the drop chamber, wherein the fluid flow rate is calculated as ((drop volume)*drops counted)/(counting time window), where drop volume is a function of the monitored pressure and the drops counted and is calculated as drop volume=(volume of fluid measured by pressure differential)/(total drops counted between pressure measurements); and

a flow control device coupled to the drop chamber and configured to increase or decrease the number of fluid drops detected over a time period in response to a signal from the flow rate device; and

a fluid reservoir coupled and configured to supply a fluid to the fluid input of the drop chamber; and

wherein the instructions include;

calculate a fluid fill level of the fluid reservoir;

set the flow control device to an initial opening state;

count a current number of fluid drops entering the drop chamber using the drop detector;

convert the current number of fluid drops into a current flow rate based on the pressure monitored by the pressure sensor, wherein the current flow rate is calculated as ((drop volume)*drops counted)/(counting time window), where drop volume is a function of the monitored pressure and the drops counted and is calculated as drop volume=(volume of fluid measured by pressure differential)/(total drops counted between pressure measurements);

if the current flow rate is different from a desired flow rate, then adjust the flow control device to a next opening state.

17. The article of claim 16, wherein the instructions further comprise:

generating an alarm in response to at least one of;

a fault condition, a minimum fluid level in the fluid reservoir, an empty fluid reservoir, a minimum fluid flow rate, or a maximum fluid flow rate.

18. The article of claim 16, wherein the instruction for calculating the fluid fill level further comprises:

setting the flow control device to a closed state; and

measuring the drop chamber pressure with the pressure sensor to recheck the fluid fill level of the fluid reservoir.